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Tytuł:
Heavy Metals in Soil and Plants During Revegetation of Coal Mine Spoil Tips and Surrounded Territories
Autorzy:
Kucher, Larisa
Krasnoshtan, Igor
Nedilska, Uliana
Muliarchuk, Oksana
Manzii, Olena
Menderetsky, Vadim
Boroday, Vira
Beregniak, Evgeniy
Voitsekhivskyi, Volodymyr
Myronycheva, Olena
Powiązania:
https://bibliotekanauki.pl/articles/27323823.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
spoil tip
rock waste
heavy metals
threshold limiting value
soil
pH
ordinary chernozem
plant biomass
Opis:
Coal mining in Donbas is a global problem as it causes the destabilization of ecological landscapes. Spoil tips, covering almost 52% of the territory, alter the topography of the land, affect the ecosystem, and decrease soil fertility. The soils become degraded and are unsuitable for agricultural use. The occupation of the Donetsk region by the Russian Federation has suspended the observation and research of man-made influence on this territory, which is a major concern for the scientific community. To reduce the negative impact of spoil tips, it is necessary to slow down the process of pyrite oxidation and the formation of toxic substances, as well as the migration of heavy metals due to erosion. Biological reclamation with grass and woody plants can help in achieving this goal. Another urgent issue is the constant supervision and assessment of the suitability of the bedrock of coal mines for agricultural use. The study investigated the total and mobile content of heavy metals in the rock samples from the “South Donbaska-1” mine, ordinary chernozem (background soil), and vegetation growing on the spoil tip. The results showed that the content of Co, Cr, Cu, and Fe in the rock of the spoil tip is higher than in the background soils. The content of heavy metals gradually decreases as the distance from the spoil tip increases. The content of Pb in ordinary chernozem and rock is practically the same, indicating its active migration. An analysis of the biomass of plant samples growing on the spoil tip showed that the content of Co, Cu, and Zn was within the limits of the threshold limiting values. However, the content of other studied elements exceeded the permissible norms. The research results provide information on the ecological state of the spoil tip and can be used for recreational as well as reclamation works in these areas.
Źródło:
Journal of Ecological Engineering; 2023, 24, 7; 234--245
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on Changes in Microstructures and Mechanical Properties of Welding Caps as a Result of their Usage During Resistance Spot Welding Process
Autorzy:
Rdzawski, Zbigniew
Kwaśniewski, Paweł
Głuchowski, Wojciech
Łagoda, Marek
Maleta, Marcin
Boczkal, Sonia
Franczak, Krystian
Powiązania:
https://bibliotekanauki.pl/articles/2203749.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
CuCrZr alloy
resistance spot welding
mechanical properties
microanalysis
tip electrodes
Opis:
Mating electrodes made of copper alloys are commonly used for welding galvanized steel sheets used in the production of car bodies. These alloys are characterized by high mechanical properties, a high level of electrical and thermal conductivity as well as the stability of these properties under changing conditions of current, thermal and mechanical load. Much careful attention was paid to the essence of the ongoing structural changes as well as to the mechanical properties in the welding process (RSW - Resistant Spot Welding) of steel sheets, including high-strength ones. There is a lack of research on structural changes and the related mechanical properties occurring in welding electrodes made of copper alloys caused by the welding process. This study is devoted to these issues and contains a critical review of the research results enabling a better understanding of the relationships between the structure and properties of welding electrodes caused by the cyclic welding process. In order to illustrate the phenomena occurring during the welding process, both in the material to be welded and in the tip electrodes, hardness and structural tests were carried out on electrode samples before and after their exploitation. The data collected in the article supplements a certain lack of information in the literature regarding the microstructural aspects of the welding process of galvanized steel sheets for the production of car bodies. The conducted research may be the starting point for the search for more effective materials for the tip electrodes.
Źródło:
Archives of Metallurgy and Materials; 2023, 68, 1; 295--306
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Uyghurs of Syria: Significance for the Syrian Conflict and International Implications
Ujgurzy w Syrii – znaczenie dla konfliktu syryjskiego i implikacje międzynarodowe
Autorzy:
Mazur, Przemysław
Powiązania:
https://bibliotekanauki.pl/articles/22435850.pdf
Data publikacji:
2023-09-30
Wydawca:
Wydawnictwo Adam Marszałek
Tematy:
Uyghurs
Syria
terrorism
Turkey
China
ISIS
Turkistan Islamic Party (TIP)
Ujgurzy
TIP
terroryzm
Turcja
Chiny
Opis:
The main objective of the article was to determine whether the Uyghurs were a relevant group in the Syrian conflict, i.e., whether they were numerous, well-organized and determined enough to take the fight to the Syrian army or other non-state actors or cooperate with them. Several levels of analysis were carried out in this article. Firstly, article aimed to show where the Uyghurs in Syria came from. Secondly, the following section assessed their importance to the Syrian conflict, as well as who they worked with and fought against. Thirdly, it analysed whether their military and political involvement could have an impact on the international situation. Last but not least, the fate of Uyghurs, especially those who left for Syria, was discussed. The latter issue is also a question about Syria, its fate and place in the politics of other countries.
Głównym celem artykułu było ustalenie, czy Ujgurzy byli istotną grupą w konflikcie syryjskim, innymi słowy – czy byli na tyle liczni, dobrze zorganizowani i zdeterminowani, by podjąć walkę z wojskami syryjskimi czy innymi aktorami niepaństwowymi lub z nimi współpracować. W artykule przeprowadzono analizę na kilku poziomach. Po pierwsze, artykuł miał na celu ustalenie, z jakich przyczyn Ujgurzy wyemigrowali do Syrii. Po drugie, oceniono ich znaczenie dla konfliktu syryjskiego, a także to, z kim współpracowali i z kim walczyli. Po trzecie, przeanalizowano, czy ich militarne i polityczne zaangażowanie może mieć wpływ na sytuację międzynarodową. Na koniec omówiono losy Ujgurów, zwłaszcza tych, którzy wyjechali do Syrii. To ostatnie zagadnienie stanowi też pytanie o Syrię, jej dalsze losy i miejsce w polityce innych państw.
Źródło:
Athenaeum. Polskie Studia Politologiczne; 2023, 79; 194-214
1505-2192
Pojawia się w:
Athenaeum. Polskie Studia Politologiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bandwidth and power enhancement in the MEMS-based piezoelectric energy harvester using magnetic tip mass
Autorzy:
Anand, Ashutosh
Pal, Srikanta
Kundu, Sudip
Powiązania:
https://bibliotekanauki.pl/articles/2173519.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
vibration
piezoelectric energy harvester
magnetic tip mass
bandwidth
stress
wibracja
zbieracz energii piezoelektryczny
magnetyczna masa końcówki
przepustowość łącza
stres
Opis:
In this paper, the performance and frequency bandwidth of the piezoelectric energy harvester (PZEH) is improved by introducing two permanent magnets attached to the proof mass of a dual beam structure. Both magnets are in the vicinity of each other and attached in such a way to proof mass of a dual beam so that they create a magnetic field around each other. The generated magnetic field develops a repulsive force between the magnets, which improves electrical output and enhances the bandwidth of the harvester. The simple rectangular cantilever structure with and without magnetic tip mass has a frequency bandwidth of 4 Hz and 4.5 Hz, respectively. The proposed structure generates a peak voltage of 20 V at a frequency of 114.51 Hz at an excitation acceleration of 1 g (g= 9.8 m/s2 ). The peak output power of a proposed structure is 25.5 µW. The operational frequency range of a proposed dual beam cantilever with a magnetic tip mass of 30 mT is from 102.51 Hz to 120.51 Hz, i.e., 18 Hz. The operational frequency range of a dual beam cantilever without magnetic tip mass is from 104.18 Hz to 118.18 Hz, i.e., 14 Hz. There is an improvement of 22.22% in the frequency bandwidth of the proposed dual beam cantilever with a magnetic tip mass of 30 mT than the dual beam without magnetic tip mass.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2022, 70, 1; e137509, 1--10
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Monitoring of helicopter swash-plate wear using the FAM-C diagnosis method
Autorzy:
Gębura, Andrzej
Kowalczyk, Henryk
Tokarski, Tomasz
Handzel, Kacper
Klimaszewski, Sławomir Jerzy
Zgrzywa, Franciszek
Powiązania:
https://bibliotekanauki.pl/articles/2096175.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:
frequency analysis
blade tip timing
bearing wear
gear wear
alternator
frequency modulation
power transmission
characteristic pattern
helicopter swash-plate
analiza częstotliwości
metoda wirującego obserwatora
zużycie łożyska tocznego
zużycie przekładni
modulacja częstotliwości
transmisja mocy
śmigłowiec
Opis:
Helicopter rotor dynamics (blade vibrations, ground resonance, influence of forward speed, etc.) play an important role in the wear and tear of the transmission system and power unit. Particularly fast wear of these components is to be expected in military helicopters in combat conditions, where the flight dynamics parameters are often exceeded. The FAM-C method developed at the Air Force Institute of Technology in Poland has been used to assess and monitor this wear. This method can be used to monitor damage to helicopter propulsion and transmission, where other "classical" methods are less effective due to a very complicated system of forces, variable as to the direction of amplitude and frequency, causing vibrations in closely spaced kinematic pairs. For this reason, vibroacoustic and thermal effects are created around these kinematic pairs, which interfere with each other. In a helicopter, the propulsion unit, including the power transmission unit, is at the same time the carrier unit. This has forced designers to construct a propulsion system with a much greater number of joints and bearing supports. This article presents the possibilities of the FAM-C method for monitoring of swash-plate main bearing wear. The swash-plates are not formally part of the helicopter's propulsion unit but are used to direct the thrust vector of the blades i.e., they direct the helicopter's power vector. Since during this process their components are observable by the FAM-C method, the authors found it necessary to include issues related to their diagnosis in this study. In the FAM-C method, the signal from the AC generator during the normal operation of the helicopter is processed. Analysis of this signal allows simultaneous monitoring of multiple engine and transmission components simultaneously. It does not require any separate sensors for this purpose - one "full-time" alternator or tachometer generator is - with proper collection and processing of the output voltage signal - the source of a whole range of diagnostic information. Thus, one generator is an observer of the technical condition of many elements of the power unit simultaneously. What's more, the signal can be collected from any place in the electrical network, which makes it possible to install the measuring system in safe locations, even while the power train is running. Some examples of diagnostic symptoms leading to wear detection are described. Research based on analysis of these findings with the use of the FAM-C method is described in the paper. In the FAM-C method, signal from the AC generator used in routine operation of the helicopter is processed. Signal analysis enables simultaneous monitoring of several engine and transmission elements. Some examples of diagnostic symptoms used to detect wear are described in the paper.
Źródło:
Diagnostyka; 2022, 23, 1; 1--12
1641-6414
2449-5220
Pojawia się w:
Diagnostyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multiscale water drop contact angles at selected silica surfaces
Autorzy:
Zhang, Chen
Wang, Xuming
Li, Lixia
Jin, Jiaqi
Polson, Randy
Miller, Jan D.
Powiązania:
https://bibliotekanauki.pl/articles/2146924.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
contact angle
atomic force microscopy
hollow tip
submicron-drop
wettability
MD simulation
Opis:
In this study, multiscale advancing contact angles for glycerol/water drops at silica surfaces are reported for millidrops, submicron-drops, and nanodrops. Selected silica surfaces were muscovite, silicon, and talc. The contact angles for millidrops (1–2 mm) were determined by the traditional sessile drop technique. For submicron-drops (0.1–1.0 μm), a hollow tip Atomic Force Microscope (AFM) procedure was used. The contact angles for nanodrops (~7 nm) were examined from Molecular Dynamics (MD) simulation. The results were compared to evaluate the effect of drop size on the contact angle. In the case of the hydrophobic talc surface, the 75° advancing contact angle did not vary significantly with drop size. For the hydrophilic muscovite surface, the water drop wet the surface and an advancing contact angle of about 10° was found for the millidrops and submicron-drops. However, for the MD simulated nanodrops, attachment and spreading of the ~7 nm drop created a 2D film of molecular dimensions, the contact angle of which was difficult to define and varied from 0° to 17°. Perhaps of equal interest from the MD simulation results was that the spreading of the glycerol/water nanodrop at the muscovite surface resulted in crystallographic directional transport of water molecules to the extremities of the 2D film. Such separation and segregation left the center of the film with an increased concentration of glycerol. Based on these results, the line tension, which has been found in other investigations to account for contact angle decrease with a decrease in drop size, does not seem to be a significant factor in this study.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 5; art. no. 152154
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Insight Into Vibration Sources in Turbines
Autorzy:
Moneta, Grzegorz
Jachimowicz, Jerzy
Pietrzakowski, Marek
Doligalski, Adam
Szwedowicz, Jarosław
Powiązania:
https://bibliotekanauki.pl/articles/2105187.pdf
Data publikacji:
2021
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
Tematy:
vibrations
blade
gas turbine
turbine engine
strain gauge
tip timing
Additive Manufacturing
Opis:
Despite of nearly 100 years of turbine engine development and design, blade vibrations remain a great engineering challenge. The rotating turbine blades’ vibrations lead to cyclic oscillations, which result in alternating stress and strain in harsh environments of high temperature and pressure. In modern aeroengines, high hot flow velocities might generate erosion and corrosion pitting on the metal surfaces, that leverage remarkably mean stresses. The combination of both mean and alternating stresses can lead to unexpected engine failures, especially under resonance conditions. Then, alternating stress amplitudes can exceed the safety endurance limit, what accelerates the high cyclic fatigue leading quickly to catastrophic failure of the blade. Concerning the existing state-of-the-art and new market demands, this paper revises forced vibrations with respect to excitation mechanisms related to three design levels: (i) a component like the blade design, (ii) turbine stage design consisting of vanes and blades and (iii) a system design of a combustor and turbine. This work reviews the best practices for preventing the crotating turbine and compressor blades from High Cyclic Fatigue in the design process. Finally, an engine commissioning is briefly weighed up all the pros and cons to the experimental validations and needed measuring equipment.
Źródło:
Fatigue of Aircraft Structures; 2021, 13; 40--53
2081-7738
2300-7591
Pojawia się w:
Fatigue of Aircraft Structures
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Verification of strength resistance of sandy soil using small scale penetrometer tests
Autorzy:
Saleem, Hiba D.
Aldefae, Asad H.
Humaish, Wissam H.
Powiązania:
https://bibliotekanauki.pl/articles/35538646.pdf
Data publikacji:
2021
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
cone penetration
tip resistance
sleeve resistance
relative density
angle of internal friction
Opis:
This study focuses on utilizing cone penetrometer models to determine strength (resistance) of sandy soil and also assessment how the relative density and the angle of friction effects on the measured cone penetration resistance in sandy soil. Simple empirical equations are used also to determine the cone penetration resistance components such as the sleeve resistance and the tip resistance. Simple comparison is performed between the measured and calculated soil strength and well agreement is noticed between them.
Źródło:
Scientific Review Engineering and Environmental Sciences; 2021, 30, 2; 304-314
1732-9353
Pojawia się w:
Scientific Review Engineering and Environmental Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design and evaluation of a needle tip measurement system based on binocular vision
Autorzy:
Lin, Yuyang
Shi, Yunlai
Zhang, Jun
Wang, Fugang
Sun, Haichao
Powiązania:
https://bibliotekanauki.pl/articles/220501.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
needle tip measurement
binocular vision system
measurement capability analysis
non-contact optical positioning
Opis:
The precise location of the needle tip is critical in robot-assisted needle-based percutaneous interventions. An automatic needle tip measuring system based on binocular vision technology with the advantages of non-contact, excellent accuracy and high stability is designed and evaluated. First the measurement requirements of the prostate intervention robot are introduced. A laser interferometer is used as the reference for measuring the position of the needle tip whose relative position variation is described as the needle tip distance in the time domain. The parameters of the binocular cameras are obtained by Zhang’s calibration method. Then a robust needle tip extraction algorithm is specially designed to detect the pixel coordinates of the needle tip without installing the marked points. Once the binocular cameras have completed the stereo matching, the 3D coordinates of the needle tip are estimated. The measurement capability analysis (MCA) is used to evaluate the performance of the proposed system. The accuracy of the system can be controlled within 0.3621 mm. The agreement analysis is conducted by the Bland-Altman analysis, and the Pearson correlation coefficient is 0.999847. The P/T ratio value is 16.42% in the repeatability analysis. The results indicate that the accuracy and stability of the binocular vision needle tip measuring system are adequate to meet the requirement for the needle tip measurement in percutaneous interventions.
Źródło:
Metrology and Measurement Systems; 2020, 27, 3; 495-512
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental study on dynamic structure of propeller tip vortex
Autorzy:
Li, Guangnian
Chen, Qingren
Liu, Yue
Powiązania:
https://bibliotekanauki.pl/articles/260305.pdf
Data publikacji:
2020
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
propeller
blade tip
tip vortex
PIV
Opis:
Propeller cavitation is a main source of fluctuating pressure and noise induced by propellers, and the tip vortex cavitation is the principal source. The present study measures the flow fields near the blade tip using the 2D-PIV technique. The experimental setup and scheme are introduced. We monitor the process of generation and shedding of the propeller tip vortex in real time and analyse the dynamic structure of the tip vortex by testing the propeller wake field under different phases of the axial plane. The distribution characteristics of radial and axial velocity are also analysed. The influence range and the vorticity of the tip vortex and trailing vortex are obtained. All of the measured quantitative data are useful for future propeller design.
Źródło:
Polish Maritime Research; 2020, 2; 11-18
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental Study on the Half Flat Tip Serrated Trailing Edge for Stand Fan
Autorzy:
Lee, Hsiao Mun
Lim, Kian Meng
Xie, Jinlong
Lee, Heow Pueh
Powiązania:
https://bibliotekanauki.pl/articles/177337.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
trailing edge noise
half flat tip
serration
stand fan
Opis:
The effectiveness of half flat tip serrations on reducing fan blade trailing edge noise was investigated using experimental methods. The experiments were conducted at an anechoic chamber under different rotating fan speeds. Numerical simulations were performed to investigate the mass flow rate generated by the serrated fan and compared with that by the baseline fan. The experimental results showed that the overall amount of noise reduction decreased with the increasing of the distance away from the fan. It was found that the effectiveness of the serrations was not proportional with the rotating speed of the fan where it was most effective at 263 rpm and 2041 rpm with noise reductions about 3.1 dBA and 3.5 dBA, respectively. This phenomenon might be depended on how trailing edge vortex would interact with the serrations at different speeds of the fan. The reduction of mass flow rate reduced with the increasing of the rotating speed and the highest reduction was found at 263 rpm which was about 18% and this reduction was accompanied by overall noise reduction of 3.1 dBA.
Źródło:
Archives of Acoustics; 2020, 45, 2; 359-365
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of Effect of Linear Tip Relief Modification in Power Transmission Efficiency of Spur Gears
Autorzy:
Thamba, Narendiranath Babu
Tambare, Abhijeet Mukund
Ananthanarayanan, Krishna Caitanya
Duraiswamy, Rama Prabha
Thangavelu, Shankar
Easwara Pillai, Raj Kumar
Mangalaraja, Ramalinga Viswanathan
Powiązania:
https://bibliotekanauki.pl/articles/176575.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
linear gear tip relief profile modification
tooth profile deformation
transmission efficiency
TE
transmission error
Opis:
This paper explores the influence of linear gear tip relief modification on power transmission efficiency. In real time applications gears experience transmission error (TE) during operation which increases noise and vibration and also results in increased tooth profile deformation during operation of the gear. By providing tip relief profile modification this TE can be decreased. Using MATLAB for computation and ANSYS for the simulation of deformation, stress, strain, life, and factor of safety results for the gear assemblies are obtained. Deformation results are used for the computation change in power transmission efficiency followed by the modal and harmonic analysis of the gears and gear assemblies to determine change in the first mode of natural frequency.
Źródło:
Archives of Acoustics; 2020, 45, 2; 271-282
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the macrostructure of the fuel spray atomized with marine engine injector
Autorzy:
Grochowalska, Joanna
Powiązania:
https://bibliotekanauki.pl/articles/133817.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
marine diesel engine
marine fuel injector
spray tip penetration
spray cone angle
opening pressure
back pressure
okrętowy silnik tłokowy
wtryskiwacz silnika okrętowego
penetracja strugi paliwa
kąt stożka strugi
ciśnienie otwarcia
ciśnienie wsteczne
Opis:
One of the main problem influencing the combustion process in the cylinder of the marine engine is an fuel spray phenomena. The parameters describing the shape of the fuel spray are named macro parameters. This article presents the research results of the macrostructure parameters of the fuel spray atomized with the marine engine injector. The research were carried out by optical visualization measurement method of Mie scattering. The diameter of nozzle injector was 0.375 mm and L/D coefficient 8.3. In these research were considered different parameters of injection opening pressures and backpressures in the constant volume chamber. Generally conlusions are: the opening pressure influence on maximum spray tip penetration, spray cone angle and influence on speed of the injected fuel. The increase of backpressure into the constant volume chamber causes the reduction of spray tip penetration and the increase of the spray cone angle.
Źródło:
Combustion Engines; 2019, 58, 4; 80-85
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Restored External Spoil Tip of a Lignite Mine on the Discharge in a Cross-Border Watercourse (PL−CZ)
Wpływ zrekultowywanego zwałowiska zewnętrznego kopalni węgla brunatnego na wielkości przepływów w cieku transgranicznym (PL−CZ)
Autorzy:
Wojarnik, Krzysztof
Iwaniak, Edward
Wiatkowski, Mirosław
Czamara, Włodzimierz
Powiązania:
https://bibliotekanauki.pl/articles/1811762.pdf
Data publikacji:
2019
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
open-cast mining
borrow pit management
spoil tip management
river network
hydrological calculations
hydraulic calculations
Wołoszyn’s method
Kaczmarek’s method
cross-border catchment
górnictwo odkrywkowe
zagospodarowanie wyrobiska
zagospodarowanie zwałowiska
sieć rzeczna
obliczenia hydrologiczne
obliczenia hydrauliczne
metoda Wołoszyna
metoda Kaczmarka
zlewnia transgraniczna
Opis:
This article presents a novel method for the assessment of the influence of a restored external spoil tip in "Turów" Lignite Mine (Poland) on the discharge in the cross border watercourse called in Poland Bezimienny Potok and in the Czech Republic – Minovickỳ Potok. Moreover, possible flood protection needs of the areas below the spoil tip in the Czech Republic (below the Tank No. 4) are indicated. In the investigated area, after the spoil tip had been formed, restoration work was carried out, i.e. a forest was planted on it. This restoration work, combined with the surface drainage structures, helped to reduce the rate of surface runoff. This, in turn, reduced the flood risk, since the high water culmination and the frequency of flood events were reduced. The hydrological and hydraulic calculations of the watercourse channel and hydro-technical structures' flow capacity indicate that the creation of the external spoil tip followed by the restoration work and the system of hydro-technical devices do not adversely affect the hydrological regime in the Bezimienny Potok catchment area, near the village of Minkovice in the Czech Republic. The forests planted as part of the restoration work play a significant role in reducing the high water culmination and the frequency of flood events. These forests cover the entire surface of the spoil tip and slow down the runoff of water. Moreover, it was confirmed that alternative solutions based on reservoirs – waste ponds located in the Bezimienny Potok catchment area – will improve the flood protection of the areas located in the Czech Republic (thanks to their storage capacity and provided that appropriate water management is ensured). The main stages of the method used for the assessment of the influence of the external spoil tip of "Turów" Lignite Mine on the discharge in the investigated cross-border watercourse are explained by means of the calculation of maximum discharge with a given probability of exceedance by the Wołoszyn's method used in Poland in the Lower Silesia region. This method accounts for the intensity of rainfall. Moreover, in order to determine the retention capacity of the investigated watercourse catchment area, the reduction of high water discharge (Q1% and Q10%) was calculated in the profiles of the sedimentation tanks, based on the reproduced hydrograph of the flood wave and with the assumption that the time required for the flood wave to go down to equals twice the time of concentration tk (to = 2tk). The sedimentation tanks' useful capacities were used to calculate the reduced discharge Q1%reduced and Q10%reduced. These values were added to the design flows for the sedimentation tanks located below, with the assumption that the swell waves coincide (the most unfavourable case). The calculation of probable discharges was carried out using the Kaczmarek's method (adopted in Poland) and using the maximum likelihood method. The methodology presented has been developed for the purpose of operation of the lignite waste external spoil tip in Turów (South-West of Poland, on the border with the Czech Republic). The main assumptions and implementation rules are universal and may be used for other sites of this kind.
W pracy zaprezentowano nowatorską metodę oceny wpływu zrekultywowanego zwałowiska zewnętrznego, znajdującego się w Kopalni Węgla Brunatnego „Turów” (Polska) na wielkości przepływów w cieku transgranicznym o nazwie Potok Bezimienny – Minovickỳ Potok (Republika Czeska). Ponadto wskazano na ewentualne potrzeby w zakresie ochrony przeciwpowodziowej terenów położonych poniżej zwałowiska na terenie Republiki Czeskiej (poniżej Zbiornika nr 4). Na omawianym obszarze po zakończeniu formowania zwałowiska prowadzono zabiegi rekultywacyjne, które polegały na zalesianiu. Przeprowadzone prace rekultywacyjne i wykonane urządzenia odwodnienia powierzchniowego przyczyniły się do zmniejszenia natężenia spływu powierzchniowego. To spowodowało zmniejszenie zagrożenia powodziowego poprzez zmniejszenie kulminacji wielkich wód i ograniczenie częstotliwości wezbrań. Wykonane w pracy obliczenia hydrologiczne i hydrauliczne przepustowości koryta cieku i budowli wodnych wskazują na to, że budowa zwałowiska zewnętrznego wraz z wykonaną rekultywacją i systemem urządzeń hydrotechnicznych nie wpływa ujemnie na reżim hydrologiczny w zlewni Potoku Bezimiennego w obrębie miejscowości Minkovice w Republice Czeskiej. Dużą rolę w zmniejszeniu kulminacji wielkich wód i ograniczeniu częstotliwości wezbrań pełnią powstałe w wyniku rekultywacji obszary leśne, obejmujące całą powierzchnię zwałowiska, które opóźniają spływ wody. Wyniki badań potwierdziły, że alternatywne rozwiązania wykorzystujące zastosowanie zbiorników wodnych – osadników zlokalizowanych w zlewni Potoku Bezimiennego, poprzez utworzoną pojemność retencyjną i przy właściwie prowadzonej gospodarce wodnej, wpłyną na poprawę ochrony przed powodzią terenów położonych w Republice Czeskiej. Główne etapy stosowanej metody oceny wpływu zwałowiska zewnętrznego kopalni węgla brunatnego „Turów” na wielkości przepływów w cieku transgranicznym wyjaśnione zostały za pomocą obliczeń przepływów maksymalnych o określonym prawdopodobieństwie przewyższenia metodą Wołoszyna stosowaną w Polsce w regionie Dolnego Śląska, uwzględniającą natężenie deszczu. Ponadto w celu określenia zdolności retencyjnej zlewni rozpatrywanego cieku, w przekrojach zbiorników-osadników przeprowadzono obliczenia redukcji przepływów wielkich wód (Q1% i Q10%), opartej na odwzorowanym hydrogramie fali wezbraniowej, przy założeniu, że czas opadania fali to jest równy 2-krotności czasu koncentracji tk (to = 2tk). Pojemności użytkowe zbiorników-osadników posłużyły do obliczenia zredukowanego przepływu Q1%reduced i Q10%reduced, o które następnie zostały powiększone przepływy miarodajne dla osadników położonych poniżej, przy założeniu, że szczyty fal nakładają się na siebie (wariant niekorzystny). Wykonane w pracy obliczenia przepływów prawdopodobnych wykonano obowiązującą w Polsce metodą Kaczmarka oraz dodatkowo metodą największej wiarygodności. Przedstawiona metodyka została opracowana na potrzeby eksploatacji zwałowiska zewnętrznego kopalni Turów (południowo-zachodnia Polska, przy granicy z Czechami). Główne założenia i zasady realizacji prac mają charakter uniwersalny i mogą być wykorzystywane na innych tego typu obiektach.
Źródło:
Rocznik Ochrona Środowiska; 2019, Tom 21, cz. 1; 343-363
1506-218X
Pojawia się w:
Rocznik Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Innovative system for monitoring the tip over stability of mobile excavating machines on a tracked undercarriage
Autorzy:
Dudziński, Piotr
Kosiara, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/2064380.pdf
Data publikacji:
2019
Wydawca:
STE GROUP
Tematy:
tip over stability
operator assisting system
monitoring system
mobile excavating machines
stabilność przechyłu
system wspomagania operatora
system monitorowania
koparki mobilne
Opis:
The article points out that the operational safety of mobile excavating machines can be significantly improved by equipping them with on-board systems for tip over stability monitoring. Critical analysis has been conducted on tip over stability monitoring systems available on the market. Their capabilities and limitations have been analysed. The second part of the article presents an innovative concept of on-board systems for monitoring tip over stability in tracked excavating machines. This concept was developed to create a device that would allow the vehicle's tip over stability to be monitored with greater accuracy and reliability compared to current systems of this type. The article also presents a demonstrator and a simulation model of the developed device. The final part of the article presents exemplary results obtained in preliminary simulation tests of the developed system.
Źródło:
New Trends in Production Engineering; 2019, 2, 1; 104--111
2545-2843
Pojawia się w:
New Trends in Production Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
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