Wyniki wyszukiwania - BazTech

1

Odra - funkcjonowanie w czasach konfliktów społecznych i gospodarczych na tle kryzysu klimatycznego

Czerniawski Robert, Horska-Schwarz Sylwia, Grygoruk Mateusz, Sługocki Łukasz, Szklarek Sebastian, Kobos Justyna, Maciej Humiczewski

Gospodarka Wodna

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2024

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Nr 2

18--27

PL

Odra, będąca z jednej strony rzeką wykorzystywaną do celów gospodarczych, jest jednym z najważniejszych ekosystemów wodnych Polski. Dotychczasowe publikacje branżowe poświęcone katastrofie odrzańskiej (zdarzeniu z lipca i sierpnia 2022 r., w którym w warunkach wysokiego zasolenia wód rzeki towarzyszącemu głębokiej niżówce doszło do intensywnego rozwoju glonów Prymnesium parvum oraz do śmierci ryb i makrobezkręgowców wodnych) dotyczyły hipotetycznych przyczyn tego zdarzenia, pomijając podmiotowość Odry jako złożonego ekosystemu wodnego, którego odporność na niekorzystne zdarzenia ekohydrologiczne została znacząco zmniejszona w wyniku destrukcyjnej dla tego ekosystemu, wieloletniej działalności człowieka. W niniejszej pracy dokonano szerokiego opisu elementów środowiska ekosystemu wodnego Odry. Uwzględniono jej stan hydromorfologiczny, sytuację hydrologiczną oraz wybrane wyniki pomiarów jakości wody ocenione w czasie trwania katastrofy odrzańskiej. Przeanalizowano typową dynamikę gęstości populacji, składników odżywczych i aktywności toksycznej podczas zakwitów Prymnesium parvum w okresach występowania śnięć ryb. W podsumowaniu wskazano elementy struktur abiotycznych i biotycznych Odry, które - jako jedne z najważniejszych wskaźników zmian i prognoz jej stanu - powinny być brane pod uwagę w dyskusjach o możliwościach dalszego korzystania z Odry jako jednej z najbardziej zmienionych, a przede wszystkim najbardziej przez ścieki zdegradowanych dużych rzek Europy.

EN

The Oder River, largely used for economic purposes, is also one of the most important aquatic ecosystems in Poland. The hitherto published studies devoted to the Oder environmental disaster (which happened in July and August 2022 in conditions of high salinity of the river waters accompanying a very low water level that led to an intensive growth of the Prymnesium parvum algae and death of fish and aquatic macroinvertebrates) focused on hypothetical reasons of this catastrophe, forgetting to see the Oder River as a complex water ecosystem whose resistance to adverse ecohydrological incidents has been significantly reduced by the long-term destructive human activity. This article contains a detailed description of the Oder River aquatic ecosystem environment. It includes its hydromorphological status, hydrological situation and selected results of water quality measurements assessed during the Oder disaster. The authors analyse the typical dynamics of the population density, nutrients and toxic activity during the Prymnesium parvum algae bloom in the periods of fish die-offs. In the summary, the authors indicate the abiotic and biotic structure components of the Oder River - being one of the most important indicators of change and a forecast of the river status - that should be taken into account in discussions on the possibility to continue the exploitation Oder as one of the most transformed and, in particular, one of the most sewage-degraded large European rivers.

2

Chezy’s Resistance Coefficient in a Round-cornered Rectangle Channel

Loukam Imed, Achour Bachir

Archives of Hydro-Engineering and Environmental Mechanics

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2024

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Vol. 71, nr 1

89--103

EN

The determination of resistance coefficients, such as Chezy’s or Manning’s coefficients, requires a great deal of sensible thought in order to express these coefficients better and more extensively in free-surface channels and aqueducts. This can be achieved if the expression of the resistance coefficient is well stated and takes into account the maximum number of parameters for governing flows in channels. However, in most practical cases, if these coefficients are not expressed by implicit models, they are generally taken as constant and arbitrary. To this end and in a rational manner, the dimensioning and design of channels requires the expression of the resistance coefficient in an easily and explicit form by adopting numerous flow parameters, namely the roughness of the walls, the aspect ratio, the slope of the channels and essentially the viscosity of the liquid. To achieve this aim, the Chezy’s resistance coefficient C is identified using the rough model method (RMM), which gives the discharge under uniform flow conditions appropriate to a round-cornered rectangle channel.

3

Mechanizm adaptacyjnego zarządzania czasami życia przepływów w sieciach SDN

Radamski Krystian, Wójcik Robert

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

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2023

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nr 4

411--414

PL

Sieci sterowane programowo pozwalają na dynamiczne sterowanie ruchem w sieci. Do sprawnego działania konieczne jest odpowiednie zarządzanie tablicami przepływów w węzłach. W artykule proponujemy mechanizm zarządzania czasami życia przepływów, który wykorzystuje ustawienia parametrów idle timeout oraz hard timeout. W celu wyliczenia odpowiednich wartości parametrów mechanizm analizuje czas przybycia kolejnych pakietów przepływu. Dodatkowo, działanie algorytmu uwzględnia aktualny poziom wypełnienia tablicy wpisów.

EN

Software-Defined Networking allows dynamic control of network traffic. For efficient operation, proper flow table management is necessary. In this paper, we propose a mechanism to manage flow timeout values, which uses idle timeout and hard timeout parameters. To calculate the appropriate values of the parameters, the mechanism analyses the packet interarrival times. The algorithm also takes into account the current occupancy of the flow table.

4

Effect of soil consolidation on the fractality of the filtration law

Panahov Geylani, Museibli Parviz, Sultanov Babek

International Journal of Applied Mechanics and Engineering

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2023

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Vol. 28, no. 1

84--94

EN

In this paper, the effect of consolidation of the soil structure on the fractality of the fluid flow was evaluated. The equation of fractal law of flow in the porous medium under consolidation of two-phase, fully fluid-saturated soil was determined. Given all the simplifications, as well as the undoubted importance of the nature of the porous medium, which primarily determine the possible processes of both consolidation and fractal flow based on the results of the studies, we can conclude that a homogeneous porous reservoir at given parameters under the effect of groundwater pressure will expand its fractal structure.

5

Characterization of Climatic Drought Sequences in the Upper Moulouya Watershed, Morocco

Hachem Abdelaaziz, Mili El-Mostafa, Benbella Bouchra, El Ouardi Hmidou, Mehdaoui Radouan

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 2

162--179

EN

Like most of the countries of the African continent and the MENA, Morocco has experienced alternating wet and dry periods for several decades and is still confronted with the effects of unstable climate change due to the specificities conferred by its geographical position and the diversity of its ecosystems. It is one of the countries most affected by desertification, with an arid and semi-arid climate covering more than 93% of its territory. Indeed, the Upper Moulouya watershed has been exposed to severe droughts several times in recent decades. The spatial and temporal distribution of drought episodes in this watershed is studied over a 91-year period between 1931 and 2022. In order to characterize and evaluate the severity and sustainability of drought in this watershed, four indices were used and applied in this study, as they have advantages in terms of statistical consistency and have the capacity to describe, through different time scales (short, medium and long) the impacts of the climatic drought in question. These are the Standardized Precipitation Index SPI, RDI, RI and DI. The annual rainfall series at the eight meteorological stations of the said watershed show irregularities and very marked spatial and temporal variability with a generally decreasing trend. The SPI calculation results obtained show a heterogeneous distribution of SPI values throughout the watershed area. The analysis of the graphical illustrations of this index allowed to highlight an important fluctuation of the dry and wet periods with a strong dominance and tendency to drought with the order of 51% in the stations of Midelt, and Ansegmir, 52% in the station of Zaida, 59% in the stations of Tabouazant, Barrage (Dam) Enjil and El Aouia, 58% in the station of Louggagh, 47% in the station of Anzar Oufounes. The analysis of the results of the of the drought indices RDI, RI and DI at the level of this watershed also made it possible to highlight the existence of numerous drought sequences alternating with other wet sequences and indicates a dominance of dry years, perfectly remarkable during the period 1976-93. The most important dry episode, in number of successive years, was recorded at the Ansegmir station from 1976-89 and the most important rainy episode was recorded at the Midelt station from 1966-76. The years of the 2015-2022 series show an overall persistent decrease in rainfall, thus allowing the installation of a severe drought episode. The trend in the entire watershed is a decrease in rainfall and the installation of mild, moderate and severe drought episodes of varying length and duration.

6

Influence of the disturbance created in the measuring channel on the readings of the hot-wire anemometric sensor

Nitkiewicz Szymon, Al-Jumaily Ahmed

Diagnostyka

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2023

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Vol. 24, No. 3

art. no. 2023315

EN

The research presents issues related to fluid mechanics, thermodynamics, and statistics. In the first sections, the authors review methods and parameters of fluid measurements. The work mainly emphasizes measurements concerning the parameters of air flows during human breathing. In the following section, the test bench for the analysis is described, and the methodology of data acquisition is described. Finally, the authors present a numerical model of the measurement channel and its calculations compared to measurements from an actual test stand. The data acquirement was performed with LabVIEW, modeling with COMSOL Multiphysics®, and calculations with MATLAB software.

7

3D simulation of incompressible flow around a rotating turbulator: Effect of rotational and direction speed

Zoubai Elhadi, Laidoudi Houssem, Tlanbout Ismail, Makinde Oluwole Daniel

Archives of Thermodynamics

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2023

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Vol. 44, no 2

139--157

EN

This paper presents new results for the dynamic behaviour of fluid around a rotating turbulator in a channel. The turbulator has a propeller form which is placed inside a flat channel. The research was carried out using 3D numerical simulation. The rationale of the experiment was as follows: we put a propeller-turbulator inside a flat channel, and then we insert a water flow inside the channel. The turbulator rotates at a constant and uniform speed. The main points studied here are the effect of the presence of turbulator and its rotational direction on the flow behaviour behind the turbulator. The results showed that the behaviour of flow behind the turbulator is mainly related to the direction of turbulator rotating. Also, the studied parameters affect coefficients of drag force and power number. For example, when the turbulator rotates in the positive direction, the drag coefficient decreases in terms of rotational speed of the turbulator, while the drag coefficient increases in terms of rotational speed when the turbulator rotates in the negative direction.

8

Numerical modelling of SS316L powder flowability for laser powder-bed fusion

Bouabbou A., Vaudreuil S.

Archives of Materials Science and Engineering

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2023

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Vol. 120, nr 1

22--29

EN

Purpose: This work aims to improve the powder-bed spreading process for laser powder bed fusion additive manufacturing by gaining a greater understanding of metal powder flowability through numerical modelling and in-situ experimentation. Design/methodology/approach: Using the Discrete Element Method (DEM) to study the flowability of the powder and its intrinsic properties. A high-fidelity particle-scale model was developed to capture the dynamics of metal particle interactions in a virtual Hall flow meter based on a modified Beverloo law. The results are validated experimentally using the Hall flow static powder characterisation technique. Findings: For SS316L powder alloy with the hall-value of 29s/50g and with an angle of repose (AOR) of 32°, the modelled powder that exhibited the same flow behaviour was found using 0.5 for both rolling and sliding coefficients resulting in simulated Hall value of 28.55s/50g with a simulated flow rate of 0.571 g/s, which is validated by AOR of the simulated powder [31.2°- 32.6°]. However, rolling friction had minimal effect on the mass flow rate but increased the angle of repose. Sliding friction significantly decreased the mass flow rate and increased AOR. Research limitations/implications: DEM is an ideal method to study flowability. However, there are certain constraints imposed on the computational power by a number of simulated particles and simulation time-step. Future research may involve investigating other dynamic flowability characterisation techniques. Practical implications: Enabling a better understanding of powder particle flow at a micro-scale by modelling powder flowability. This leads to simulating a more realistic powder bed and improving the powder spreading process, leading to better AM parts quality. Originality/value: This paper provides a unique approach for modelling the flowability of SS316L powder using a Beverloo law-based design of the Hall flow meter. This will improve the modelling of the spreading process needed for metal 3D printing.

9

Osuwiska spływowe w Paśmie Bukowicy (Beskid Niski)

Walicka Anna

Przegląd Geologiczny

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2022

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Vol. 70, nr 9

651--660

EN

The study area is located in the tectonized area - the Dukla Nappe thrust zone. Rocks in this region are highly fractured and disintegrated, which predisposes it to the development of landslides. The movement occurs as a combination of slide (mainly rotational) and flow (mainly debris flow). Landslide initiation takes place in the upper part of the slope, in the spring area, as a slide. Flow is mobilized within the landslide body as a result of high precipitation and intensive water infiltration. Flow-like landslides often “use” existing channel of the catchment to transport material downslope. To show differentiation of flow-like landslides, the author selected six forms observed in the Bukowica Range. The character of flow depends mainly on liquefaction and volume of transported material, as well as on land relief. Keywords: flow, slide, complex landslides, Bukowica Range, flow-like landslides.

10

Curve Flow-duration-Frequency. The flood modelling regime of the Wadi Mazafran catchment in the north of Algeria

Kourat Sofiane, Touaibia Bénina, Yahiaoui Abdelhalim

Journal of Water and Land Development

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2022

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no. 54

121--130

EN

Synthetic modelling of the flood regime is based on the overall knowledge of the hydrological regime in a catchment. The Flow-duration-Frequency (QdF) modelling is used to combine three parameters characterising flood with its mean or exceeded flow, its characteristic duration, and occurrence frequency. Which of these can be established locally at the extreme mean volume flow rates of a catchment reference hydrometric station? The determination of the reference QdF model in mean (volume) and exceeded flows requires two characteristics reflecting the flood regime in a catchment. The first is the characteristic flood duration and the second is the 10-year quantile of the annual maximum instantaneous flow. The comparison of the local situation to the reference QdF models enables to develop the final QdF model of the catchment and therefore the baseline QdF for exceeded and synthetic mono-frequency hydrographs. These are essential components in the study of flood risk mapping and the estimation of the instantaneous peak distribution from mean daily streamflow series.

11

Monitoring of Water Flow in the Springs of the Golesh Massif, Kosovo

Çadraku Hazir S.

Ecological Engineering & Environmental Technology

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2022

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Vol. 23, iss. 5

109--123

EN

Water spring are vital to all human activities. The integration of hydrological, geological, hydrogeological and ecological characteristics of resource ecosystems provides a much needed tool for recognizing the characteristics and their distribution. The objective of this study was to identify springs in the study area, in order to evaluate their hydrogeological characteristics and parameters. Eight springs have been identified in the Golesh Massif area. They are mainly of lithological contact. Water flow ranging from 0.03 to 5 l/s, the temperature, pH and total hardness in the water of spring Curreli range within 11.1 to 15.7 °C, 5.51 to 8.03 °C and 18.8 to 21.67 °dH, respectively. Their recharge mainly depends on the amount of precipitations that falls in the area.

12

Novel model for emptying of a self-pressurised nitrous oxide tank

Szymborski Jakub, Kardaś Dariusz

Archives of Thermodynamics

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2022

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Vol. 43, no 3

141--173

EN

Nitrous oxide is often used in the space industry, as an oxidiser or monopropellant, mostly in self-pressurised configurations. It has potential for growth in use due to the recent rising interest in green propellants. At the same time, modelling the behaviour of a self-pressurising nitrous oxide tank is a challenging task, and few accurate numerical models are currently available. Two-phase flow, heat transfer and rapid changes of mass and temperature in the investigated system all increase the difficulty of accurately predicting this process. To get a get better understanding of the emptying of a self-pressurised nitrous oxide tank, two models were developed: a phase equilibrium model (single node equilibrium), treating the control volume as a single node in equilibrium state, and a phase interface model, featuring a moving interface between parts of the investigated medium. The single node equilibrium model is a variation of equilibrium model previously described in the literature, while the phase interface model involves a novel approach. The results show that the models are able to capture general trends in the main parameters, such as pressure or temperature. The phase interface model predicts nitrous oxide as a liquid, a two-phase mixture, and vapour in the lower part of the tank, which is reflected in the dynamics of changes in pressure and mass flow rate. The models developed for self-pressurisation, while created for predicting nitrous oxide behaviour, could be adapted for other media in conditions near vapour– liquid equilibrium by adding appropriate state equations.

13

Impact of flow and damming on water quality of the mountain Raba River (southern Poland) : long-term studies

Szarek-Gwiazda Ewa, Gwiazda Robert

Archives of Environmental Protection

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2022

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Vol. 48, no. 1

31--40

EN

Climate change, manifested by long term periods of drought to heavy rainfall, may remarkably modify river flow regimes. We hypothesize that flow prevailing in a given year determines water chemistry of the Carpathian Raba River above and below Dobczyce Reservoir (southern Poland), used for drinking purposes. Based on the mean annual river flow for years 1991-2017, hydrologically dry (HD), hydrologically average (HA) and hydrologically wet (HW) years were distinguished. We found significant differences in the values of most studied physicochemical parameters of river water above and below the reservoir between studied hydrological years (for a period of April‒November). In HD years, the water above the dam had significantly higher temperature and values of conductivity (point pollution source, groundwater inflow), while lower ones of nutrients NO3- and P-tot (diffuse pollution) compared to those in HA and/or HW years. The best GLM models for mean monthly flows above and below the dam include 3-5 factors among which conductivity and NO3 concentration were always present. The reservoir in different ways influences the water chemistry below the dam in HD, HA and HW years. The impact of flow on the water quality in hydrologically varied years is discussed. The obtained results are important for appropriate management in catchment basins of mountain rivers and the protection of dam reservoirs against the eutrophication processes in changing climate and flow regime.

PL

Zmiany klimatu, przejawiające się długotrwałymi okresami suszy lub obfitych opadów, mogą znacząco zmienić roczny reżim przepływów. Stawiamy hipotezę, że przepływ dominujący w danym roku determinuje chemizm wody rzeki górskiej. Celem pracy było określenie (1) różnic w chemizmie wody górskiej rzeki pomiędzy latami hydrologicznie suchymi (HD), przeciętnymi (HA) i mokrymi (HW), (2) wpływu zbiornika zaporowego na chemię wody odpływającej rzeki w różnych latach hydrologicznych, (3) parametrów fizyczno-chemicznych związanych ze średnim miesięcznym przepływem wody w latach HD, HA i HW. Badania prowadzono w karpackiej rzece Rabie powyżej i poniżej Zbiornika Dobczyckiego w południowej Polsce. W oparciu o średni roczny przepływ rzeki z wielolecia 1991–2017 wyróżniono lata HD, HA i HW. Przeanalizowano zmiany parametrów fizyczno- chemicznych wody (temperatura, przewodność elektrolityczna, pH, tlen rozpuszczony, nasycenie tlenem, BZT5, biogeny: NO3-, NH4+, P-tot) pobieranych co miesiąc w okresie kwiecień–listopad. Stwierdziliśmy istotne różnice w chemizmie wody rzeki między badanymi latami hydrologicznymi. W latach HD wody powyżej zbiornika miały istotnie wyższą temperaturę i wartości przewodności elektrolitycznej, natomiast niższe wartości biogenów NO3- i P-tot (zanieczyszczenie obszarowe) w porównaniu do lat HA i/lub HW. Zbiornik w różny sposób kształtował skład chemiczny wody rzeki poniżej zapory w latach HD, HA i HW. Najlepsze modele GLM dla średnich miesięcznych przepływów obejmowały 3–5 czynników, wśród których zawsze występowały przewodność elektrolityczna i stężenia NO3-. Uzyskane wyniki mają istotne znaczenie dla właściwego gospodarowania w zlewniach rzek górskich i ochrony zbiorników zaporowych przed procesami eutrofizacji.

14

Research on sand resistance performance of comprehensive protection facilities for desert hinterland highways under strong wind environment

Yin Wenhua, Wang Xu, Wu Yongxiang, Wang Fang

Archives of Civil Engineering

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2022

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Vol. 68, nr 4

683--698

EN

Based on the test and observation of the desert hinterland wind field, combined with the numerical simulation of Fluent wind-sand two-phase flow, the sand resistance performances of comprehensive protection in the desert hinterland under strong wind environment are researched. The transient wind speed and wind direction around the comprehensive protection facility are measured by two 3D ultrasonic anemometers on the highway in the desert hinterland, and the initial wind speed of the sand flow is provided for the numerical simulation boundary. The sedimentary sand particles around the comprehensive protection facility are collected for particle size analysis, and the particle size distributions of sedimentary sand particles at different locations are obtained. Numerical models of high vertical sand barriers, grass checkered sand barriers and roadbeds are established by Fluent, the wind-sand flow structures around the comprehensive protection facilities and desert hinterland highway under the strong wind environment are obtained, and the influence laws of the comprehensive protection facilities on the movement of wind-sand flow and sand deposition characteristics are obtained. The study found that the comprehensive protection facilities disturbed the wind and sand flow, and there are significant airflow partitions around the comprehensive protection facilities. The wind speed decreases rapidly after the wind-sand flows through the high vertical sand barrier; the wind-sand flow rises at the end of the high vertical sand barrier. When the wind-sand flow moves around the grass checkered sand barrier, the wind speed has dropped to the range of 0-3 m/s, and the wind speed near the ground by the grass checkered sand barrier is further reduced. Due to the existence of the concave surface of the grass grid, there are small vortices inside the grass grid sand barrier. Large sand particles are mainly deposited on the windward side and inside of high vertical sand barriers. The grass checkered sand barrier forms a stable concave surface to generate backflow, which can ensure that the sand surface does not sand itself in a strong wind environment, and can also make a small amount of sand carried in the airflow accumulate around the groove of the grass checkered sand barrier. The numerical simulation results are consistent with the measured results, and the comprehensive protection measures have achieved good sand control effects.

15

Simulation of a downhole jet-vortex pump’s working process

Panevnyk Denis

Nafta-Gaz

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2021

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R. 77, nr 9

579--586

EN

The article is devoted to the theoretical study of the operation process of the borehole ejection system as part of the tubing string, jet pump and packer installed below; the system implements the hydrojet method of oil well operation. The improved design of the jet pump contains inclined guiding elements placed in its receiving chamber for swirling the injected flow, which results in an increase in the efficiency of the borehole ejection system. Based on the law of conservation of liquid momentum in the mixing chamber of the jet pump and taking into account the inertial pressure component caused by the swirling of the injected flow, there is obtained the relative form of the equation of the ejection system pressure characteristic, the structure of which contains a component that determines the value of the additional dynamic head. According to the results obtained, the additional dynamic head caused by swirling of the injected flow is determined by the ratio of the geometric dimensions of the flow path of the jet pump, the angle of inclination of the elements for creating vortex flows, and the ratio of the power and reservoir fluids. In the case of asymmetric swirling of the injected flow, an increase in the value of the relative displacement of the jet pump decreases the value of the additional dynamic pressure. In order to study the effect of flow swirling on the energy characteristic of the ejection system, the pressure characteristic of the jet pump was transformed into the dependence of its efficiency on the injection coefficient. Jet pump models with the ratio of the cross-sectional areas of the mixing chamber and the nozzle of 5.012 and 6.464, respectively, were used to check the adequacy of the theoretical pressure and energy characteristics obtained during the simulation of the performance process of the concentric ejection system. The average error in the theoretical determination of the pressure and efficiency of the vortex jet does not exceed 8.65% and 6.48%, respectively.

PL

Artykuł poświęcony jest teoretycznemu studium opisującemu proces pracy wgłębnego systemu wydobycia z odwiertu złożonego z kolumny rur wydobywczych, pompy strumieniowej i zainstalowanego poniżej pakera; przy użyciu tego systemu prowadzona jest eksploatacja odwiertów naftowych metodą hydrojet. Udoskonalona konstrukcja pompy strumieniowej zawiera skośne elementy prowadzące umieszczone w jej komorze zasilającej do zawirowania przepływu tłoczonego płynu, co skutkuje zwiększeniem wydajności systemu wydobycia z odwiertu. Na podstawie zasady zachowania pędu cieczy w komorze mieszania pompy strumieniowej oraz po uwzględnieniu bezwładnościowej składowej ciśnienia wywołanej zawirowaniem przepływu tłoczonego płynu otrzymuje się względną postać równania charakteryzującego ciśnienia w układzie ejekcyjnym, którego struktura zawiera składnik określający wartość dodatkowej wysokości podnoszenia. Zgodnie z uzyskanymi wynikami dodatkowa wysokość podnoszenia spowodowana zawirowaniem przepływu tłoczonego płynu jest określona przez: stosunek wymiarów geometrycznych toru przepływu pompy strumieniowej, kąt nachylenia elementów tworzących przepływ wirowy oraz stosunek płynów zasilających i złożowych. W przypadku asymetrycznego zawirowania przepływu tłoczonego płynu wzrost wartości względnej wyporności pompy strumieniowej powoduje zmniejszenie wartości dodatkowego ciśnienia dynamicznego. W celu zbadania wpływu zawirowania przepływu na charakterystykę energetyczną układu ejekcyjnego – charakterystykę ciśnieniową pompy strumieniowej przekształcono na zależność jej sprawności od współczynnika tłoczenia. Do sprawdzenia prawidłowości teoretycznych charakterystyk ciśnienia i energii uzyskanych podczas symulacji procesu pracy koncentrycznego układu ejekcyjnego wykorzystano modele pomp strumieniowych o stosunku powierzchni przekroju komory mieszania do dyszy odpowiednio 5,012 i 6,464. Średni błąd ciśnienia i wydajności strumienia wirowego wyznaczonych w sposób teoretyczny nie przekraczał odpowiednio 8,65% i 6,48%.

16

Dilemmas of Management Psychology in Building a Social Group in Military Institutions

Wasilewski Paweł

Logistics and Transport

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2021

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Vol. 49-50, No. 1-2

93--102

EN

Technological progress on the battlefield and the evaluation of the tactics of soldiers' actions entail a change in the philosophy of human resource management in military institutions, and thus a reorientation in the preparation of commanders-leaders to perform this mission. The modern soldier represents a different level of psychophysical resources. The new, more precise and at the same time more complicated to use equipment forces a change in the concept of preparing a soldier to perform tasks. Directing the development of the contemporary battlefield forces the continuous expansion of the cognitive level, both in the general and specialist area. This new approach to soldier formation shifts the centre of gravity in leadership formation to the area of cognitive resource development. This changes the emphasis of training and education towards the theory of social communication underlying the creation of psychophysical resources and issues related to the contemporary psychology of management in the military environment.

17

Optimization of Balance Components of Fuel and Energy Resources for Organizational and Economic Support of Energy Efficiency in Ukraine

Andrusiv Uliana, Zelinska Haluna, Kupalova Halyna, Galtsova Olga, Marynchak Liliya, Dovgal Olena

Ecological Engineering & Environmental Technology

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2021

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Vol. 22, iss. 6

27--35

EN

In this paper the general fundamentals of the formation of the balance of fuel and energy resources were determined and the main components of the general energy balance were substantiated. It was formed according to the indicators from the state energy statistics of Ukraine, and on the basis of the obtained data the analysis of energy flows was carried out. Mathematical substantiation of its support on the traffic of energy flows from their extraction (production), transformation and final consumption was offered. The algorithm for compiling the overall energy balance was detailed to eliminate possible discrepancies between the indicators during the final operations of the balance sections. In order to ensure timely response to unsolved problems in the energy sector of Ukraine, it is proposed to implement a constant monitoring of the energy balance as a whole and by partial indicators. The use of a new algorithm for optimizing the balance of fuel and energy resources (FER) for individual balance sheet items was proposed. A model of organizational and economic mechanism was developed to study the functional interactions of international organizations in the field of energy independence, administrative and financial institutions, fuel and energy entities and the national economy, which are subjects of all hierarchical levels of energy security. It reflects the equivalence of two main aspects of energy security of the national economy: ensuring the stability and efficiency of the fuel and energy complex on one hand, and the formation of energy efficient consumers through the introduction of innovations and energy saving technologies, on the other.

18

Experimental Investigation of Self-Compacting Concrete Containing Coir Fibres

Lakhiar Muhammad Tarque, Lakhiar Muhammad Tahir, Abdullah Abd Halid, Mohamad Noridah

Civil and Environmental Engineering Reports

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2021

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Vol. 31, no. 2

163--177

EN

Many researchers have investigated alternative sources to overcome the problem of conventional building material polluting the environment by the development of green self-compacting concrete in the construction industry. The best alternative solution is to utilise non-conventional construction materials like agricultural wastes. Meanwhile, self-compacting concrete (SCC) is considered as high strength as well as high-performance concrete. The demerits, which include tensile and flexural strength, can be improved by incorporating coir fibres. The utilisation of coir fibres also modifies self-compacting concrete performance after cracking and improves the toughness. This study defines an experimental investigation of the mechanical properties of self-compacting concrete containing coir fibres (CF) with different percentages being 0%, 0.2%, 0.5%, 1%, and 1.5% at 7- and 28-days water curing. The mechanical properties include the slump flow and compressive and tensile strength were examined. The outcomes demonstrated that a required slump flow for self-compacting concrete was achieved using coir fibres up to 1%, beyond which it reduced the slump significantly. The length of fibre and proportion of fibres directly affected the workability. The compressive strength was 10% to 15% enhanced with the incorporation of coir fibres up to 0.5%; after that, the strength was slightly reduced, and tensile strength was 30% to 50% improved compared to conventional self-compacting concrete up to 1% of coir fibres incorporation in the SCC mix, after which it rapidly reduced.

19

Assessment of Security of Water Supply for Benissa Municipality, Spain Employing the Shannon-Weaver Model

Miazga Maciej, Królikowska Jadwiga

Rocznik Ochrona Środowiska

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2020

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Tom 22, cz. 2

593--604

EN

This publication is a presentation of the methodology to determine the degree of diversification and allocation of water resources in water supply systems; with a differentiated level of need based on the example of the municipality of Benissa Spain. The article shows a frequency of the changes and factors that affect the functioning of the water supply system. Moreover, its presents the calculation of the diversification indices for the selected water supply system while the methodology offers the possibility of evaluating the diversification of water resources in two parameters according to an adapted form of the Shannon-Weaver index.

PL

Publikacja przedstawia metody wyznaczenia współczynnika dywersyfikacji i alokacji zasobów wodnych dla systemu zbiorowego zapotrzebowania wody cechującego się zróżnicowanym jej zapotrzebowaniem na przykładzie miasta Benissa w Hiszpanii. W pracy przedstawiono obliczenia stopnia dywersyfikacji zasobów wodnych, metodą dwu-parametryczną, wg zaadaptowanego wskaźnika Shannona-Weavera.

20

Impact of the Municipal Solid Waste Typology on Leachate Flow Under Semi-Arid Climate – A Case Study

Arabi Mourad, Sbaa Mohamed, Vanclooster Marnik, Darmous Ahmed

Journal of Ecological Engineering

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2020

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Vol. 21, nr 6

94--101

EN

As recently created, the landfill site of Oujda, Morocco receives an annual flow of municipal solid wastes of 140000 tons. It became clear that the leachate storage ponds were undersized compared to the actually emanating flows. With no adequate treatment, the storage time of leachates in deep and anaerobic ponds increase and produce olfactory nuisances directly affecting the air quality of the nearest agglomerations. The monitoring of leachate flows during a year, showed the daily average production of 126 m3 (annual cumulative leachate is 46800 m3). Thus, highest volumes were recorded during the summer season (4716 m3 in July 4945 m3 in August, and 4927 m3 in September) with a monthly average rate of 3700 m3. In addition, the monitoring of leachate flows exhibits seasonal variations. Simultaneously, the MSW’s typology and moisture content study showed the dominance of organic matter (73%) and high moisture content (63.5%). The results obtained are an essential asset for any decision in order to achieve appropriate leachates treatment with a possibility of recirculation into the landfill cells to enhance removal of their toxic contents.