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Search results for: WALERY STARCZEWSKI
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Biosilica from sea water diatoms algae—electrochemical impedance spectroscopy study
PublicationHere, we report on an electrochemical impedance study of silica of organic origin as an active electrode material. The electrode material obtained from carbonized marine biomass containing nanoporous diatoms has been characterised by means of XRD, IR, SEM and EIS. Dif- ferent kinds of crystallographic phases of silica as a result of thermal treatment have been found. The electrode is electrochemically stable during subsequent cyclic...
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Experimental and Computational Analysis of the Ship Propeller in Open Water Conditions for Inclined Flow
PublicationThe paper presents the results of computational analyses simulating the open water tests of ship propeller in inclined flow. The results of computations are compared with the results of corresponding experimental analyses carried out in the towing tank of Ship Design and Research Centre (CTO S.A.). The object of the research was the model propeller identified as CP469. The aim of the study was to validate the results of numerical...
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Influence of water and mineral oil on the leaks in satellite motor commutation unit clearances
PublicationThe article describes the flow rates of mineral oil and water flowing, as working media, through the commutation unit of a hydraulic satellite motor. It is demonstrated that geometrical dimensions of commutation unit clearances change as a function of the machine shaft rotation angle. Methods for measuring the rate of this flow and the pressure in the working chamber are presented. The results of pressure measurements in the working...
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Examination of fresh water chemistry in maritime Antarctica during austral summer 2017
PublicationDue to the fact that Antarctica is one of the least polluted places on Earth, it is a perfect place to observe the spread of global pollution. Therefore, research conducted on this continent is important due to the possibility of investigating the type of pollution and their way of transport. This work considers presence of organic contaminants in Maritime Antarctica in unexplored until now, Lions Rump headland. Qualitative and...
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Design and Application of Magnetic Photocatalysts for Water Treatment. The Effect of Particle Charge on Surface
PublicationCore-interlayer-shell Fe3O4/SiO2/TiO2, CoFe2O4/SiO2/TiO2 and BaFe12O19/SiO2/TiO2 magnetic photocatalysts were obtained. A water-in-oil microemulsion system with suitable surfactants was used for functionalization of the magnetic core with silica interlayer and TiO2-based photocatalyst. Uncoated and coated particles were characterized by electrophoretic meaurements, X-ray diffractometry (XRD), scanning electron microscopy (SEM),...
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The impact of the Tri-City Ring Road on surface water of small endorheic wetlands
PublicationThe paper presents the results of the impact of the Tri-City Ring Road on small endorheic catchment basins. Particular attention was paid to pollution discharged from the road to the surface water, as well as changes in hydrological conditions in the vicinity of the road. In the study, surface water samples were analysed in terms of their electrolytic conductivity, pH and content of major minerals. GIS was also used to study transformation...
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A Comparison of Simplified Two-dimensional Flow Models Exemplified by Water Flow in a Cavern
PublicationThe paper shows the results of a comparison of simplified models describing a two-dimensional water flow in the example of a water flow through a straight channel sector with a cavern. The following models were tested: the two-dimensional potential flow model, the Stokes model and the Navier-Stokes model. In order to solve the first two, the boundary element method was employed, whereas to solve the Navier-Stokes equations, the...
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Unusual structural properties of water within the hydration shell of hyperactive antifreeze protein
PublicationMany hypotheses can be encountered explaining the mechanism of action of antifreeze proteins. One widespread theory postulates that the similarity of structural properties of solvation water of antifreeze proteins to ice is crucial to the antifreeze activity of these agents. In order to investigate this problem, the structural properties of solvation water of the hyperactive antifreeze protein from Choristoneura fumiferana were...
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Role of the Solvation Water in Remote Interactions of Hyperactive Antifreeze Proteins with the Surface of Ice
PublicationMost protein molecules do not adsorb onto ice, one of the exceptions being so-called antifreeze proteins. In this paper, we describe that there is a force pushing an antifreeze protein molecule away from the ice surface when it is not oriented with its ice-binding plane toward the ice and that this pushing force may be also present even when the protein is oriented with its ice-binding plane toward the ice. This force is absent...
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Experimental investigation of forced convection of water/EGAl2O3 nanofluids inside horizontal tube
PublicationIn this paper, forced convection of water/EG-Al2O3 nanofluids inside horizontal stainless steel tube is studied experimentally. As base fluid served water/EG mixture of two ratios (60:50 and 50:50). Nanoparticle mass concentrations was 0.1% or and 1%. Transition and turbulent flow regimes were tested. Average heat transfer coefficient and pressure drop values were determined for nanofluids and compared to base fluids. Deterioration...
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Direct algorithm for optimizing robust MPC of drinking water distribution systems hydraulics
PublicationModel-based predictive control is an effective method for control the large scale systems [1]–[6], [8], [16], [17]. Method is based on on-line solution of the control task over the control horizon using current and past measurements, as well as the system model. Only a first element of calculated control sequence is applied to the plant. At the next sampling instant, based on new process output measurements, control procedure is...
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FEM Calculations in Analysis of Steel Subsea Water Injection Flowlines Designing Process
PublicationPaper describes the result of theoretical research aimed at assessing the loads and operating conditions of a Coiled Tubing pipeline injecting water, suspended to the mining platform of Lotos Petrobaltic. For this purpose, appropriate calculation models have been developed using the Finite Element Method (FEM), taking into account the nature of the analyzed object and its loads. The analyzes were carried out for two pipes (previously...
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Study of the Flow Dynamics of Surface Water Masses in the Area of the Coastal Gulf of Gdansk
PublicationThe paper describes two methods of predicting the movement of small objects with surface water masses. One of the methods uses graph theory to describe the motion of water masses in port docks. The results of this study were compared to a simulation using the hydrodynamic numerical model M3D. The results obtained in a virtual environment were related to the experiments in the real world. In the coastal area of the Gulf of Gdansk,...
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Ecological bearing systems for water turbines – research and development at Gdansk University of Technology
PublicationIncreasing requirements for environmental protection make it necessary to introduce new materials and designs. Hydroelectric power plants operating in direct contact with water reservoirs and rivers are potentially endangering water cleanliness, hence they should also be modernized in the way minimizing the environmental hazards. A lot of progress in this field has been achieved in last decades, but still there is much work to...
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COMPARATIVE ANALYSIS OF TRANSPORT ORGANIZATION AND FUNCTIONING OF WATER TRAMS IN GDAŃSK, BYDGOSZCZ AND KRAKÓW
PublicationThe subject of this work is to identify and juxtapose solutions implemented in transport provided by water trams for the following cities: Gdańsk, Bydgoszcz and Kraków. As a result of the conducted analysis of transport factors, the degree of conformity of project objectives to the actual role of the water tram has been determined. It was found that the Kraków Water Tram (also known as Cracow Water Tram) is characterized by the...
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Experimental investigation of forced convection of water-Al2O3 nanofluids inside horizontal tubes,
PublicationIn this paper, forced convection of water–Al2O3 nanofluids inside horizontal copper tube is studied experimentally. Experiments were conducted for three, i.e. 0.1%, 1% and 5% nanoparticle mass concentrations under transition and turbulent flow regimes. Average heat transfer coefficients and pressure drop values were determined and compared to distilled water. Enhancement of heat transfer for lower nanoparticle concentration and...
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Magnetic semiconductor photocatalysts for the degradation of recalcitrant chemicals from flow back water
PublicationIn the present study treatability of persistent organic compounds from the flow back water after hydrauling fracturing was investigated. The combination of TiO2 photocatalyst and magnetic oxide nanoparticles enhance the separation and recoverable property of nanosized TiO2 photocatalyst. Fe3O4/ TiO2 and Fe3O4@SiO2/TiO2 nanocomposites were prepared by heteroagglomeration. The photocatalysts’ characteristics by X-ray diffractometry...
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Improvement of S355G10+N steel weldability in water environment by Temper Bead Welding
PublicationThe normalized S355G10 + N steel was chosen for testing, it is used in a variety of applications including the building of offshore structures, which may require repairs in water environment. The main aim of the work was to check susceptibility to cold cracking for fillet welds – Controlled Thermal Severity (CTS) tests and butt welds – Tekken tests and in the next step evaluation of effectiveness of Temper Bead Welding (TBW) application...
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Water uptake in protective organic coatings and its reflection in measured coating impedance
PublicationWater uptake in commercially available epoxy coating on mild steel using impedance spectroscopy and gravimetry was studied. The water content in the coating was determined using the Brasher-Kingsbury equation and various methods of coating capacitance calculation used in the literature. The obtained results were compared with reference gravimetric data. An overestimation of values obtained from impedance data in relation to gravimetric...
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Fuzzy Multi-Regional Fractional PID controller for Pressurized Water nuclear Reactor
PublicationThe paper presents the methodology for the synthesis of a Fuzzy Multi-Regional Fractional Order PID controller (FMR-FOPID) used to control the average thermal power of a PWR nuclear reactor in the load following mode. The controller utilizes a set of FOPID controllers and the fuzzy logic Takagi-Sugeno reasoning system. The proposed methodology is based on two optimization parts. The first part is devoted to finding the optimal...
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Ultrasound-assisted heterogeneous activation of persulfate and peroxymonosulfate by asphaltenes for the degradation of BTEX in water
PublicationThis study investigated – for the first time - the simultaneous degradation of benzene, toluene, ethylbenzene and o-xylene (BTEX) by persulfate (PS) and peroxymonosulfate (PMS) activated by asphaltenes (Asph) under ultrasound (US) irradiation. Advantageous properties such as high thermal stability, low production cost and extensive availability make asphaltenes as an appealing carbonaceous material for heterogeneous catalysis....
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Properties of the Langmuir and Langmuir–Blodgett monolayers of cholesterol-cyclosporine A on water and polymer support
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Legislative and criminal law aspects of water protection and prevention of pharmaceuticals accumulation in nature
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Zeta potential, effective diameter and multimodal size distribution in oil/water emulsion
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Ni-MOF-based electrodes: A promising strategy for efficient overall water splitting
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Environmentally friedly propeller shaft support with the use of water lubricated foil bearings
PublicationW pracy przedstawiono podsumowanie prowadzonych badań w celu opracowania oryginalnej metodyki projektowania oraz technologii wykonania pierwszego w świecie łożyska foliowego smarowanego wodą. Zaprezentowano koncepcje nowego łożyska foliowego poprzecznego oraz opisano opracowany algorytm obliczeniowy wykorzystany do predykcji jego charakterystyk. W rezultacie prowadzonych prac opracowano i przebadano doświadczalnie na stanowisku...
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Removal of organic compounds from water by solvent sublation. Criteria for solvent selection.
PublicationProces flotoekstrakcji zastosowano do usuwania z wody następujących związków organicznych: tetrachlorku węgla, chloroformu, 1,3,5-trimetylobenzenu (mezytylenu), fenolu i 2,4,5-trichlorofenolu. Jako odbierające fazy organiczne użyto: olej mineralny, 1-dekanol, 1-oktanol, octan amylu, dodekan i tetradekan. Mechanizmem decydującym o usuwaniu lotnych związków organicznych (VOC) było odparowanie do wnętrza pęcherzyków gazu, podczas...
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The calculation long-term physical field created by water flow around the ship
PublicationThe paper presents a description of the problems with fluid flow around a ship. Using the described solution of the problem were performed numerical calculations using the boundary element method. Were also presented preliminary results of the calculation of pressure fields at the bottom of the ship, taking into account the impact of the bottom.
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Multistatic sonar for man-made lakes and water-power plants antiterrroristic protection
PublicationArtykuł opisuje nową koncepcję dopplerowskiego sonaru multistatycznego opracowanego w Katedrze Systemów Elektroniki Morskiej Politechniki Gdańskiej. System składa się z sieci hydrofonów rozmieszczonych równomiernie w obserwowanym akwenie oraz ze źródła dźwięku w postaci fali ciągłej o stałej częstotliwości i bardzo niskim natężeniu. Dzięki zastosowaniu specjalnie opracowanych algorytmów przetwarzania sygnałów uzyskuje się poprawną...
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Space-Time Conservation Method applied to numerical solution of water hammer equations
PublicationArtykuł poświęcony jest metodzie czasoprzestrzennych objętości skończonych (STC) zastosowanej do przypadku uderzenia hydraulicznego w stalowym przewodzie pracującym pod ciśnieniem. Metoda STC ze względu na swoje własności numeryczne - m.in. wysoką dokładność - może być interesującą alternatywą dla tradycyjnych metod numerycznych, szczególnie w przypadku, gdy efekty numeryczne mają bardzo silny wpływ na rozwiązanie, tym samym utrudniając...
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Operating and economical conditions of cooling water control for marine steam turbines condensers
PublicationW pracy dokonano analizy ekonomicznej i eksploatacyjnej sterowania pracą pomp wody chłodzącej skraplacze turbin okrętowych. Wzięto pod uwagę cechy konstrukcyjne pomp wody chłodzącej skraplacze główne i najnowsze wyniki badań dla takich pomp w zastosowaniach lądowych. Uwagę skupiono przede wszystkim na turbinowych parowych siłowniach okrętowych.
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Water Solubilization Using Nonionic Surfactants from Renewable Sources in Microemulsion Systems
PublicationIn this study the effect of temperature, NaCl andoils (hydrocarbons: C8-C16) on the formation and solubilizationcapacity of the systems of oil/monoacylglycerols(MAG):ethoxylated fatty alcohols (CEO20)/propylene glycol(PG)/water was investigated. The effects of the surfactantmixture on the phase behavior and the concentration ofwater or oil in the systems were studied at three temperatures(50, 55, 60 C) and with varied NaCl solutions...
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Experimental research on effectiveness of the magnetic fluid seals for rotary shafts working in water
PublicationUszczelnianie wałów obrotowych, łożysk i innych zespołów mechanicznych, za pomocą cieczy magnetycznej, tworzącej przegrodę uszczelniającą utrzymywaną siłami pola magnetycznego jest techniką uszczelniania, stosowaną z powodzeniem w urządzeniach pracujących w środowisku gazowym przy ciśnieniu do około 1,0 MPa. Uszczelnienia te umożliwiają również skuteczne rozwiązywanie problemu szczelności przepustów stałych i ruchowych w urządzeniach...
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Chemometric estimation of natural water and sediment using toxicity tests and physicochemical parameters
PublicationOceny jakości wód dokonano na podstawie analizy chemometrycznej bazy danych monitoringowych, składającej się z wyników testów toksyczności i wyników badań parametrów fizykochemicznych. Badaniom poddano próbki wód powierzchniowych pobrane z Jeziora Turawskiego oraz próbki wód podziemnych pobranych z otworów badawczych wykonanych w jego dnie, jak i wokół niego. Zastosowano następujące metody chemometryczne: analizę wiązkową i analizę...
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Complexation of amino acids derivatives in water by calix[4]arene phosphonic acids
PublicationSeries of the calix[4]arene phosphonic acids with various substituents at the lower rim was synthesized. Complexing properties of these receptors towards methyl esters of six amino acids strongly depended on the calix[4]arene conformation flexibility. The complex formation processes were monitored using 1H NMR spectroscopy (deuterated phosphate buffer at pD 7.3, 22 oC) and association constant values were evaluated. Inherently...
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Monitoring of Chlorine Concentration in Drinking Water Distribution Systems Using an Interval Estimator
PublicationThis paper describes the design of an interval observer for the estimation of unmeasured quality state variables in drinking water distribution systems. The estimator utilizes a set bounded model of uncertainty to produce robust interval bounds on the estimated state variables of the water quality. The bounds are generated by solving two differential equations. Hence the numerical efficiency is sufficient for on-line monitoring...
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Problems of inland navigation in Poland in view of integrated water resources management (IWRM)
PublicationW artykule przedstawiono zasady zintegrowane zarządzania gospodarką wodna. Przedstawiono rolę żeglugi środlądowej w gospodarce wodnej Polski i krajów czlonkowskich Unii Europejskiej. Przedstawiono aktualny stan dróg wodnych w Polsce, ograniczenia rozwoju i perspektywy na przyszłośc z punktu widzenia ZZGW.
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Properties of water in the region between a tubulin dimer and a single motor head of kinesin
PublicationA kinesin is a molecular motor that can perform movement on a microtubule track in a stepping-like manner. This motion is connected with processes of association and dissociation of kinesin and tubulin. Water is an important participant in these kinds of molecular interactions. This is why we have decided to investigate the dynamical and structural properties of water in the region between the kinesin catalytic domain and the tubulin...
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Assessment of the water quality of Kłodnica River catchment using self-organizing maps
PublicationRisk assessment of industrial areas heavily polluted due to anthropogenic actions is of increasing concern worldwide. So is the case of Polish Silesia region where mostly heavy industry like smelters, mining, chemical industries as well as heat and electricity production facilities are being located. Such situation raises numerous questions about environmental state of local water bodies with special attention paid to the Kłodnica...
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Preparation of platinum modified titanium dioxide nanoparticles with the use of laser ablation in water
PublicationWe report on the preparation method of nanocrystalline titanium dioxide modified with platinum by using nanosecond laser ablation in liquid (LAL). Titania in the form of anatase crystals has been prepared in a two-stage process. Initially, irradiation by laser beam of a titanium metal plate fixed in a glass container filled with deionized water was conducted. After that, the ablation process was continued, with the use of a platinum...
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Influence of water salinity on corrosion risk - the case of the southern Baltic Sea coast.
PublicationWater corrosivity in Gdansk Bay, Poland, the southern part of the Baltic Sea, was investigated. The analysed region is heavily industrialized, and the coastline is very diverse. Twenty-seven test points along the coastline were selected. Water parameters such as salinity, total dissolved solids content, resistivity, conductivity, oxygenation, pH and corrosion rate were determined. The results of the investigation are presented....
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Determination of causes of accelerated local corrosion of austenitic steels in water supply systems
PublicationThis paper concerns an inspection of a water supply system, made of AISI 304 steel, which showed signs of local corrosion at the weld. Such corrosion caused material perforation after very short periods of operation. It was revealed that steel was sensitised during the welding process. It was also proven that chromium micro-segregation occurred in the alloy leading to galvanic cell formation which initialised the process of pitting...
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Water related esthetics - the phenomenon of new structure in the post industrial shipyard areas
PublicationDirection of the main movements that are made in the European cities determines not only structural but also an esthetic changes. Paper follows the topic of visual diversity of post industrial waterfront cities and it’s relation to the local identity and cultural changes that are provided. Reshaping of the cities continuously proceed. Are those changes related with industrial shipyard districts only economical and spatial or also...
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Water-mediated long-range interactions between the internal vibrations of remote proteins
PublicationIt is generally acknowledged that the mobility of protein atoms and the mobility of water molecules in the solvation layer are connected. In this article, we answer the question whether a similar interdependence exists between the motions of atoms of proteins separated by the hydration layers of variable thickness. The system consisted of a kinesin catalytic domain and a tubulin dimer. It was studied using molecular dynamics simulations....
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Determination of metals in water samples by atomic absorption spectrometry and flame emission spectrometry
PublicationMetal species in environmental waters are relevant to characterize the metal toxicity, the mobility between different environmental compartments, and for remediation purposes in case of contamination. The concentration of many trace metals in natural water samples are generally at µg/l level. The paper describes determination of metals in water samples based on flame atomic emission and flame atomic absorption spectrometry.
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Investigation of the distribution of imidazolium ionic liquids in the environment - aggregation in water and sorption on minerals
PublicationWpływ cieczy jonowych na środowisko, a w szczególności: migracja do wód powierzchniowych i gruntowych, jak również transport/retencja w gruntach jest determinowany przede wszystkim przez właściwości fizykochemiczne cieczy jonowej jak i właściwości matrycy środowiskowej. Znajomość zjawisk zachodzących w wyniku kontaktu cieczy jonowych z wodą oraz glebą jest jednym z podstawowych warunków oceny ryzyka chemicznego. W pracy wykazano,...
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Determination of Selected Organic Acids in Animal Farm Water Samples by Ion Chromatography
PublicationLow molecular mass carboxylic acids (LCAs) occur in many environmental compartments due to natural processes and human activity. They are an important group of organic pollutants of waste water that mainly includes, volatile fatty acids, and also dicarboxylic, aromatic, hydroxy- and ketoacids. LCAs are present in the environment at concentrations between 1 to 5000 ppm and different methods have been reported for their determination...
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Possible application of new class of solvents in the purification of water used in hydraulic fracturing
PublicationNowym źródłem energii niekonwencjonalnej w Polsce może być gaz, który jest uwięziony w łupkach. Podczas poszukiwań gazu łupkowego, duże ilości wody wykorzystywanej w procesie szczelinowania hydraulicznego powracają na powierzchnię zanieczyszczone. Istnieje wiele metod usuwania śladowych ilości węglowodorów tj. fizyczne czyli filtracja czy chemiczne czyli zakwaszanie, ale mogą one być nieskuteczne. Pożądana metoda to monitorowanie...
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Hydrogen assisted cracking of 2205 duplex stainless steel in synthetic sea water
PublicationThe cracking behavior of 2205 duplex stainless steels (DSSs) in synthetic sea water under cathodic polarization condition was investigated. (SSRT) method was employed in aim to evaluate the susceptibility to hydrogen assisted cracking. The results showed that the reduction in the uniform elongation (UEL) and the reduction of area (RA) varied with the applied cathodic current density. Significant reductions in ductility were found,...
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Characterization of PVDF/Graphene Nanocomposite Membranes for Water Desalination with Enhanced Antifungal Activity
PublicationSeawater desalination is a worldwide concern for the sustainable production of drinking water. In this regard, membrane distillation (MD) has shown the potential for effective brine treatment. However, the lack of appropriate MD membranes limits its industrial expansion since they experience fouling and wetting issues. Therefore, hydrophobic membranes are promising candidates to successfully deal with such phenomena that are typical...