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Wyniki wyszukiwania dla: unsteady surface flow
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A solid phase extraction–ion chromatography with conductivity detection procedure for determining cationic surfactants in surface water samples
PublikacjaA new analytical procedure for the simultaneous determination of individual cationic surfactants (alkyl benzyl dimethyl ammonium chlorides) in surface water samples has been developed. We describe this methodology for the first time: it involves the application of solid phase extraction (SPE – for sample preparation) coupled with ion chromatography–conductivity detection (IC-CD – for the final determination). Mean recoveries of...
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The correlation of fractal dimension to fracture surface slope for fatigue crack initiation analysis under bending-torsion loading in high-strength steels
PublikacjaIn this study, the fractal dimension of fatigue fracture surfaces is investigated in order to find an alternative failure loading indicator. Some of many metrological factors are generalized by reducing the fracture surface structure to one factor and develop an entire fracture surface procedure by analyzing the impact of surface slope and calculation resolution. Three notched geometries are studied under cyclic bending-torsion:...
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Bacteriological and physicochemical monitoring of inland surface waters within the administrative boundaries of Gdańsk city in 2010
Dane BadawczeThe dataset containst the results of a bacteriological and physico-chemical study of inland surface waters within the administrative boundaries of Gdańsk city in 2010.The examined material consisted of water samples collected from four lakes located within the administrative boundaries of Gdańsk, Poland.
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Bacteriological and physicochemical monitoring of inland surface waters within the administrative boundaries of Gdańsk City in 2008
Dane BadawczeThe dataset containst the results of a bacteriological and physico-chemical study of inland surface waters within the administrative boundaries of Gdańsk city in 2008. The examined material consisted of water samples collected from four lakes located within the administrative boundaries of Gdańsk, Poland.
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Bacteriological and physicochemical monitoring of inland surface waters within the administrative boundaries of Gdańsk City in 2009
Dane BadawczeThe dataset containst the results of a bacteriological and physico-chemical study of inland surface waters within the administrative boundaries of Gdańsk city in 2009. The examined material consisted of water samples collected from four lakes located within the administrative boundaries of Gdańsk, Poland.
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Bacteriological and physicochemical monitoring of inland surface waters within the administrative boundaries of Gdańsk City in 2011
Dane BadawczeThe dataset containst the results of a bacteriological and physico-chemical study of inland surface waters within the administrative boundaries of Gdańsk city in 2011. The examined material consisted of water samples collected from four lakes located within the administrative boundaries of Gdańsk, Poland.
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Bacteriological and physicochemical monitoring of inland surface waters within the administrative boundaries of Gdańsk city in 2006
Dane BadawczeThe dataset containst the results of a bacteriological and physico-chemical study of inland surface waters within the administrative boundaries of Gdańsk city in 2006.
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The efficiency and technological reliability of biogenic compounds removal during long-term operation of a one-stage subsurface horizontal flow constructed wetland
PublikacjaThe paper presents the results of a study of the efficiency and technological reliability of total nitrogen and total phosphorus removal during long term operation of a one-stage constructed wetland system with subsurface horizontal wastewater flow. The flow rate of the wastewater treatment plant was 1.2m3/d during the research period. Physical and chemical analyses of raw wastewater and treated effluent were carried out in the...
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Trace elements content of surface peat deposits in the Solovetsky Islands (White Sea)
PublikacjaPeatlands form environmental archives of trace element deposition. In this regard they are particularly valuable for areas such as the Arctic, where regular pollution monitoring is either impossible or extremely costly. The aim of this study was to assess pollution in the Solovetsky Islands (65° 05' N, 35° 53' E) by examining the spatial variability in trace element content of the uppermost layer of peat, immediately below the...
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Determination of selected chemical parameters in surface water samples collected from the Revelva catchment (Hornsund fjord, Svalbard)
PublikacjaSurface water samples (river and lake) were collected from the Revelva catchment every summer from 2010 to 2013. This study concerns importance of the use of some analytical techniques for pollutants and parameters deter- mination in Arctic environmental samples based on the example of total organic carbon, phenols, and formaldehyde determination and measurement of pH and electrical conductivity parameters. Significant...
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Morphology, surface properties and photocatalytic activity of the bismuth oxyhalides semiconductors prepared by ionic liquid assisted solvothermal method
PublikacjaThis is the first report of the effect of the ILs cation type (imidazolium, pyridinium and pyrrolidinium) on the morphology, surface properties and photoactivity of BiOX semiconductors type obtained by solvothermal method in glycerol. The various ionic liquids (IL) cation type as a halogen source and templating agent for the synthesis of the bismuth oxyhalides nanoparticles has been systematically investigated. The role of ILs...
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Small-scale passive emission chamber for screening studies on monoterpene emission flux from the surface of wood-based indoor elements
PublikacjaAnalysis of literature data published in the last fewyears leads to the conclusion that in the process of assessment of emission flux of organic compounds emitted from different types of equipment and finishing materials, new types of devices, among which small-scale passive emission chambers for the performance of in-situ research are designed and applied on a larger scale. These devices can be successfully used for the assessment...
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Applying response surface method to optimize the performance of a divergent-chimney solar power plant
PublikacjaOne of the effective tools to generate electricity from solar energy is Divergent-chimney solar power plant (DSPP). Divergent and cylindrical chimneys of solar power plants have different performances considering turbine pressure drop ratio (ft). For the first time, the divergent angle (DA) and solar radiation (SR) interaction effects on 〖ft〗_opt are discussed through applying the Computational Fluid Dynamics (CFD) and Response...
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The effect of imidazolium ionic liquid on the morphology of Pt nanoparticles deposited on the surface of SrTiO3 and photoactivity of Pt–SrTiO3 composite in the H2 generation reaction
PublikacjaPhotocatalytic water splitting has great potential in solar-hydrogen production as a low-cost and environmentally friendly method. Different unique techniques used to obtain photocatalysts with various modifications to improve H2 generation have been introduced. In the present work, SrTiO3 was successfully synthesized via the solvothermal method in the presence of ionic liquid (IL) - 1-butyl-3-methylimidazolium bromide ([BMIM][Br])...
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Dielectric Barrier Discharge Systems with HV Generators and Discharge Chambers for Surface Treatment and Decontamination of Organic Products
PublikacjaThe article presents applications of systems with power electronic converters, high voltage transformers, and discharge chambers used for nonthermal, dielectric barrier discharge plasma treatment of a plastic surface and decontamination of organic loose products. In these installations, the inductance of the high voltage transformers and the capacitances of the electrode sets form resonant circuits that are excited by inverters....
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Application of subsurface vertical flow constructed wetlands to reject water treatment in dairy wastewater treatment plant
PublikacjaThe paper presents the effects of applying subsurface vertical flow constructed wetlands (SS VF) for the treatment of reject water generated in the process of aerobic sewage sludge stabilization in the biggest dairy wastewater treatment plant (WWTP) in Poland. Two SS VF beds were built: bed (A) with 0.65 m depth and bed (B) with 1.0 m depth, planted with reeds. Beds were fed with reject water with hydraulic load of 0.1 m d-1 in...
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Synergistic effects in micellization and surface tension reduction in nonionic gemini S-10 and cationic RTAB surfactants mixtures
PublikacjaMixtures of nonionic gemini surfactant S-10 (α,α′-[2,4,7,9-tetrametyl-5-decyne-4,7-diyl]bis[ω-hydroxy -polioxyetylene] with cationic alkyltrimethylammonium bromides of different alkyl chain length (RTAB) were investigated. Basing on surface tension measurements the cmc values and other adsorption parameters were found. The Clint, Rubing’s and Rosen theories were applied for evaluation of the synergistic effects in mixed films and...
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Shore Construction Detection by Automotive Radar for the Needs of Autonomous Surface Vehicle Navigation
PublikacjaAutonomous surface vehicles (ASVs) are becoming more and more popular for performing hydrographic and navigational tasks. One of the key aspects of autonomous navigation is the need to avoid collisions with other objects, including shore structures. During a mission, an ASV should be able to automatically detect obstacles and perform suitable maneuvers. This situation also arises in near-coastal areas, where shore structures like...
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Spatial Differences in the Chemical Composition of Surface Water in the Hornsund Fjord Area: A Statistical Analysis with A Focus on Local Pollution Sources
PublikacjaSurface catchments in Svalbard are sensitive to external pollution, and yet what is frequently considered external contamination may originate from local sources and natural processes. In this work, we analyze the chemical composition of surface waters in the catchments surrounding the Polish Polar Station in Svalbard, Hornsund fjord area. We have pooled unpublished and already published data describing surface water composition...
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Processing of LiDAR and Multibeam Sonar Point Cloud Data for 3D Surface and Object Shape Reconstruction
PublikacjaUnorganised point cloud dataset, as a transitional data model in several applications, usually contains a considerable amount of undesirable irregularities, such as strong variability of local point density, missing data, overlapping points and noise caused by scattering characteristics of the environment. For these reasons, further processing of such data, e.g. for construction of higher order geometric models of the topography...
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Determination of selected parameters/ analytes in surface water samples collected in the surroundings of the capital of Spitsbergen (Longyearbyen)
PublikacjaPolar regions are extremely sensitive to pollution such as harmful gases, particles or toxic substances which affect the Arctic climate and ecosystems. Spitsbergen, as well as all Arctic region, because of its geographically distant location and lack of industry sector, should be free of chemical pollution. Despite this, many pollutants could be found in the Polar environment, for example in freshwaters. Their occurrence is related...
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Determinants of the surface quality, density and dimensional correctness in selective laser melting of the Ti-13Zr-13Nb alloy
PublikacjaSelective laser melting is widely used for custom-designed elements. Successful manufacturing depends on laser treatment parameters and material features. This research aimed to determine the effects of laser power, scan time and hatch distance on surface quality, relative density and dimensional precision for cuboids made of the Ti-13Zr-13Nb alloy. The influence of energy density, energy flux and pre-heating was seen to be decisive...
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The accretion of the new ice layer on the surface of hexagonal ice crystal and the influence of the local electric field on this process
PublikacjaThe process of creation of a new layer of ice on the basal plane and on the prism plane of a hexagonal ice crystal is analyzed. It is demonstrated that the ordering of water molecules in the already existing crystal affects the freezing. On the basal plane, when the orientations of water molecules in the ice block are random, the arrangement of the new layer in a cubic manner is observed more frequently — approximately 1.7 times...
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NP-hardness of compact scheduling in simplified open and flow shops
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Power flow in typical series-parallel hybrid filters topologies
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Numerical Analysis of Flow in Building Arrangement: Computational Domain Discretization
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Laboratorial studies on the seepage impact in open-channel flow turbulence
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Analysis of Turbulent Flow Measurements in a Flume with Induced Upward Seepage
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Flow cytometry as an estimation tool for honey bee sperm viability
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Design and evaluation of a flow-to-frequency converter circuit with thermal feedback
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Comparative study of flow condensation in conventional and small diameter tubes
PublikacjaIn the paper a method developed earlier by the first author is applied to calculations of heat transfer coefficient for inside tube condensation. The method has been verified using experimental data from literature on several fluids in different microchannels and compared to three well established correlations.
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Numerical Simulation of Open Channel Flow between Bridge Piers
PublikacjaPrzedstawiono dwuwymiarowy model przepływu wody płytkiej, który wykorzystano do symulacji przepływu wody w kanale otwartym w rejonie przekroju mostowego. Równania przepływu rozwiązano metodą objętości skończonych. Wyniki symulacji ruchu wody pomiędzy filarami mostowymi porównano z pomiarami laboratoryjnymi przeprowadzonymi w Laboratorium Hydrauliki i Inżynierii Środowiska politechniki Gdańskiej. Zgodność uzyskanych wyników obliczeń...
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Liveness measurements using optical flow for biometric person authentication
PublikacjaAutomatyczne rozpoznawanie twarzy jest jedną z najpopularniejszych technik biometrycznych, jednak nawet najdokładniejsze algorytmy identyfikacji okażą się bezużyteczne, jeśli będzie można je oszukać, np. używając zdjęcia zamiast rzeczywistej osoby. Dlatego też odpowiedni pomiar żywotności jest niezwykle istotny. W pracy zaprezentowano metodę, która jest w stanie rozróżnić pomiędzy sekwencjami wideo pokazującymi żywe osoby oraz...
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Efficiency of acoustic heating produced in the thermoviscous flow of a fluid with relaxation
PublikacjaInstantaneous acoustic heating of a fluid with thermodynamic relaxation is the subject of investigation. Among others, viscoelastic biological media described by the Maxwell model of the viscous stress tensor, belong to this type of fluid. The governing equation of acoustic heating is derived by means of the special linear combination of conservation equations in differential form, allowing the reduction of all acoustic terms in...
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Modelling of energy flow in mechatronic systems. A bond graph approach
PublikacjaW referacie przedstawiono w sposób jednoliy modelowanie systemów mechatroniki metodą grafów wiązań (GW) w aspekcie symulacji przepływu energii. Omówiono ogólne założenia modelowania w ujęciu GW. Modelowanie przepływu energii rozważano na przykładzie napędu pojazdu hybrydowego PH-MAK.
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Determination of selected parameters in a 1D open channel flow model
PublikacjaOkreślenie parametrów jest ważnym etapem tworzenia modelu matematycznego. W przypadku jednowymiarowego modelu przepływu ze swobodną powierzchnią opisanego układem równań de Saint-Venanta, jedną z grup parametrów wymagających identyfikacji są parametry związane z tarciem. Mogą one być określone w różny sposób, ale w większości przypadków problem ten stanowi zagadnienie żle postawione. W takich przypadkach najczęściej stosowaną...
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Monitoring of solid behaviour during gravitational flow in rectangular silo
PublikacjaW pracy przedstawiono wyniki pomiarów zmian koncentracji w protokątnym modelu silosu. Omówiono przyczyny błędów pomiarowych w modelu protkątnym, zarówno dla danych surowych, jak rózniez danych zrekonstruowanych.
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Application of vertical flow cw for highly contaminated wastewater treatment
PublikacjaBasing on quantitative and qualitative characteristics of reject waters generated during digested sewage sludge dewatering on centrifuges in conventional WWTP (RWC) and municipal landfill leachate (LL), the pilot constructed wetlands for treatment of both types of highly contaminated wastewater were designed. In the paper the characteristics of the pilot plants and assumed treatment efficiencies are presented. According to the...
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Modelling of energy flow in electrical machines. A bond graph approach
PublikacjaPrzedstawiono w ujęcia grafów wiązań model przepływu energii/mocy w maszynach elektrycznych pracujących w hybrydowych systemach przetwarzania energii. Jako przykład do rozważań przyjęto system napędu trakcyjnego pojazdów hybrydowych.
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Cross-Flow Microfiltration of Glycerol Fermentation Broths with Citrobacter freundii
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Effect of flow-rate on ethanol separation in membrane distillation process
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Examination of the effect of altering model complexity on representing groundwater flow
PublikacjaW artykule przedstawiono wyniki badań na dokładnością modeli numerycznych przepływu wód podziemnych. Analizowano wpływ upraszczania struktury przestrzennej modelu na wyniki obliczeń.
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Electrical capacitance tomography for studying the flow of friable materials in silos.
PublikacjaArtykuł opisuje możliwość aplikacji tomografii do pomiarów przepływu materiałów sypkich w silosach
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Horizontal flow boiling of refrigerants inside porous coated tube.
PublikacjaPrzedstawiono wyniki badań przejmowania ciepła i spadku ciśnienia podczas wrzenia czynników chłodniczych R22, R134a i R407C w poziomej rurce z wewnętrzną powłoką porowatą.
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Application of time-frequency methods for analysis of dynamic silo flow
PublikacjaW artykule przedstawiono możliwość stosowania metod czasowo-częstotliwościowych w analizie dynamicznego przepływu materiału sypkiego w silosie. W pracy omówiono wyniki FT (Fourier Transform), STFT (Short Time Fourier Transform) oraz WT (Wavelet Transform)
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The numerical simulation of two-dimensional vertical incompressible viscous flow
PublikacjaW artykule przedstawiono numeryczne symulacje płaskiego pionowego przepływu nieściśliwej cieczy lepkiej ze swobodną powierzchnią. Zastosowano model bazujący na rozwiązaniu równań Naviera-Stokesa metodą "ciśnień" (SIMPLE). Przy takim podejściu otrzymano dywergencję równań Naviera-Stokesa oraz równanie Poissona na ciśnienie. W rozwiązaniu zastosowano schemat Laxa-Wendroffa z przesuniętą siatką Eulera. Takie podejście zapewnia dokładność...
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The contribution of blood-flow-induced conductivity changes to measured impedance
PublikacjaW pracy rozwazane sa zmiany przewodnosci zachodzace w anizotropowym osrodku i ich wplyw na mierzona rezystancje. Uzyskano to za pomoca rozszerzenia wzoru Geselowizta na przypadki anizotropowe. Wykazano, ze tylko te skladowe zmian przewodnosci wplywaja na mierzona rezystancje, dla ktorych odpowiadajacy im skladnik pola eklektrycznego byl niezerowy.Wyniki te zastosowanu do zmian rezystywnosci wywolanych zmiananmi przewodnosci plynacej...
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Experimental and numerical analysis of streamwise vortex generator for subsonic flow
PublikacjaW pracy przedstawiono porównanie wyników obliczeń numerycznych dwoma kodami (FLUENT i SPARC) na tle badań eksperymentalnych generatora wirów wzdłużnych. Przedstawiono wyniki dla liczb Macha przepływu głównego 0.3 i 0.8. Porównano ciśnienie całkowite w dwóch przekrojach za otworem przez który realizowany jest wydmuch. Przedstawiono strukturę wiru wzdłużnego uzyskaną dla obu programów. Średnica otworu jetu jest równa 1mm, co odpowiada...
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Nonlinear Interaction of Magnetoacoustic Modes in a Quasi-Isentropic Plasma Flow
PublikacjaThe nonlinear interaction of magnetoacoustic waves in a plasma is analytically studied. A plasma is an open system. It is affected by the straight constant equilibrium magnetic flux density forming constant angle with the wave vector which varies from 0 till . The nonlinear instantaneous equation which describes excitation of secondary wave modes in the field of intense magnetoacoustic perturbations is derived by use of projecting....
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Confined granular flow in silos with inserts - full-scale experiments
PublikacjaArtykuł omawia wyniki doświadczalne przepływów silosowych w silosach w naturalnej skali ze wstawkami. Podczas doświadczeń pomierzono przemieszczenia oraz napór na ściany. Zastosowano różne typy wstawek położone na różnej wysokości. Wyniki badań doświadczalnych porównano z przepływami bez wstawek.