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Wyniki wyszukiwania dla: micro-arc oxidation
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The Effect of Sodium Tetrafluoroborate on the Properties of Conversion Coatings Formed on the AZ91D Magnesium Alloy by Plasma Electrolytic Oxidation
PublikacjaMagnesium and its alloys are widely used in many areas because of their light weight, excellent dimensional stability, and high strength-to-weight ratio. However, the material exhibits poor wear and corrosion resistance, which limits its use. Plasma electrolytic oxidation (PEO) is an effective surface modification method for producing ceramic oxide layers on Mg and their alloys. The influence of the additions of sodium tetrafluoroborate...
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Spatial aspects of urban air quality management: Estimating the impact of micro-scale urban form on pollution dispersion
PublikacjaUrban planning and design solutions affect urban ventilation conditions, thus mitigating the effects of atmospheric pollution. However, these findings are not being implemented in the planning practice to a sufficient extent, partly due to the lack of specific guidelines. Moreover, many urban air quality monitoring (AQM) sites have low represnentativeness and thus do not provide comprehensive data for effective urban air pollution control...
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The Impact of Ground Tire Rubber Oxidation with H2O2 and KMnO4 on the Structure and Performance of Flexible Polyurethane/Ground Tire Rubber Composite Foams
PublikacjaThe use of waste tires is a very critical issue, considering their environmental and economic implications. One of the simplest and the least harmful methods is conversion of tires into ground tire rubber (GTR), which can be introduced into different polymer matrices as a filler. However, these applications often require proper modifications to provide compatibility with the polymer matrix. In this study, we examined the impact...
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Mechanical and fracture properties of concrete reinforced with recycled and industrial steel fibers using Digital Image Correlation technique and X-ray micro computed tomography
PublikacjaPaper presents investigation of fracture phenomenon in plain concrete and in concrete reinforced with both recycled steel fibers (RSF) and industrial steel fibers (ISF). The wedge splitting test (WST), which enables stable crack propagation for quasi-brittle materials, was carried out on 75 75 75 mm cube samples. Initially, fracture process zone development was investigated only on the surface of samples using Digital Image Correlation...
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Pilot scale degradation study of 16 selected volatile organic compounds by hydroxyl and sulfate radical based advanced oxidation processes
PublikacjaThe studies of effective technologies for complete degradation of the volatile organic compounds (VOCs), are very important due to the high biotoxicity of the VOCs which makes the biological technologies ineffective. It also increases the risk of VOCs emission instead of their treatment when using open air biological technologies. In the present study, different types of Advanced Oxidation Processes (AOPs) were investigated for...
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Micro solid oxide fuel cells and their fabrication methods
PublikacjaW pracy przedstawiono obecny stan badań związany z tlenkowymi microogniwami paliwowymi oraz metodami ich wytwarzania.
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Micro solid oxide fuel cells and their fabrication methods
PublikacjaW pracy przedstawiono obecny stan badań i tendencje w rozwoju tlenkowych ogniw paliwowych.
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Aging and rejuvenation effects in bismuth ferrite micro-cubes
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Multiphase separated polyurethanes studied by micro Raman spectroscopy.
PublikacjaPrzedmiotem badań były poliuretany o zawartości 30% segmentów sztywnych,charakteryzujące się obecnością globul i sferolitów. Badania za pomocą mikro Ramana wykazały różny skład chemiczny w wymienionych mikroobszarach. W globulach stwierdzono zanik obecności segmentów giętkich lub ich bardzo znikomą ilość w porównaniu z matrycą i sferolitami.
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Shear localization in granular bodies with micro-polar hypoplasticity.
PublikacjaW książce przedstawiono wyniki numerycznej analizy lokalizacji odkształceń stycznych w materiałach granulowanych dla różnych problemów brzegowych quasi-statycznych. Obliczenia wykonano przy zastosowaniu metody elementów skończonych i mikropolarnego modelu hipoplastycznego.
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Micro-polar effects under monotonic and cyclic shearing.
PublikacjaW artykule przedstawiono wyniki obliczeń lokalizacji odkształceń podczas ścinania monotonicznego i cyklicznego w materiałach granulowanych. Obliczenia wykonano przy zastosowaniu mikropolarnego hipoplastycznego modelu konstytutywnego.
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Hierarchical MnO2 nanoflowers blooming on 3D nickel foam: A novel micro-macro catalyst for peroxymonosulfate activation
PublikacjaIn this work, birnessite-type δ-MnO2 nanoflowers were uniformly deposited on 3D nickel foam (NF) by one-step hydrothermal route for high-efficient activation of peroxymonosulfate (PMS) towards degradation of acid orange 7 (AO7). High specific surface area, large pore volume and 3D hierarchical structure promotes the mass and electron transfer for great catalytic activity. Low reaction energy barrier (Ea=27.5 kJ/mol) and outstanding...
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Physicochemical properties of Mn1.45Co1.45Cu0.1O4 spinel coating deposited on the Crofer 22 H ferritic steel and exposed to high-temperature oxidation under thermal cycling conditions
PublikacjaThe Crofer 22 H ferritic steel substrate was coated with an Mn1.45Co1.45Cu0.1O4 spinel by means of electrophoresis. After high-temperature oxidation under thermal cycling conditions, the physicochemical properties of the obtained system were evaluated. During 48-h cycles that involved heating the samples up to temperatures of either 750 or 800 °C, the oxidation kinetics of both coated and unmodified steel approximately obeyed...
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The effect of lyophilization on selected biologically active components (vitamin c, catalase, lysozyme), total antioxidant capacity and lipid oxidation in human milk
PublikacjaHuman milk is rich in polyunsaturated fatty acids, as well as lysozyme, vitamin C and other bioactive compounds. The effect of lyophilization on the content of antioxidants (vitamin C and catalase CAT), bactericidal compounds (lysozyme), total antioxidant capacity (TAC) and lipid peroxidation in human milk was investigated in this study. Samples of mature human milk were collected from five healthy women who gave birth on the scheduled...
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Electrochemical oxidation of landfill leachate using boron-doped diamond anodes: pollution degradation rate, energy efficiency and toxicity assessment
PublikacjaElectrochemical oxidation (EO), due to high efficiency and small carbon footprint, is regarded as an attractive option for on-site treatment of highly contaminated wastewater. This work shows the effectiveness of EO using three boron-doped diamond electrodes (BDDs) in sustainable management of landfill leachate (LL). The effect of the applied current density (25–100 mA cm−2) and boron doping concentration (B/C ratio: 500 ppm, 10,000...
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The impedance of hydrogen oxidation reaction in a proton exchange membrane fuel cell in the presence of carbon monoxide in hydrogen stream
PublikacjaEvaluation of performance of a proton exchange membrane fuel cell, which is affected by carbon monoxide that pollutes the hydrogen stream, was presented. This influence was studied for carbon monoxide concentration of 125–325 ppb, which are close to values specified in ISO 14687:2019 standard. Performed studies provided crucial information for further development of fuel cell as an energy source for automotive application. Impedance...
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Influence of C60and Fullerene Soot on the Oxidation Resistance of Vegetable Oils
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Influence of the type of photocatalyst on photocatalytic oxidation of triclosan in the aquatic environment
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Montmorillonite as the catalyst in oxidation of limonene with hydrogen peroxide and in isomerization of limonene
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The studies on the limonene oxidation over the microporous TS-1 catalyst
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Heterogeneous Oxidation of Phenolic Compounds with Photosensitizing Catalysts Incorporated into Chitosan
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The Role of pH in the Mechanism of .OH Radical Induced Oxidation of Nicotine
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Controlling the europium oxidation state in diopside through flux concentration
PublikacjaThis paper explores the connection between the H3BO3 flux concentration and the co-existence of Eu2+ and Eu3+ dopants within CaMgSi2O6 crystals (diopside). The samples were synthesised using a solid-state synthesis method under varying atmospheric conditions, including oxidative (air), neutral (N2), and reductive (H2/N2 mixture) environments. Additionally, some materials underwent chemical modification by partially substituting...
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The Influence of Sulfate on Anaerobic Ammonium Oxidation in a Sequencing Batch Reactor
PublikacjaAnaerobic ammonia-oxidizing bacteria have a more comprehensive metabolism than expected - there may be other electron acceptors that oxidize ammonium nitrogen under anaerobic conditions, in addition to the well-known nitrite nitrogen, one of which is sulfate in the sulfammox process. Sulfate-containing compounds are part of the medium for the anammox process, but their concentrations are not particularly high (0.2 g MgSO4 ∙ 7H2O/dm3...
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Advanced oxidation technologies for preventing the formation of detrimental disinfection by-products
PublikacjaDezynfekcja jest jednym z najważniejszych etapów uzdatniania wody. Konwencjonalnie stosowane środki dezynfekujące to chlor, dwutlenku chloru, a także chloraminy. Powszechnie wiadomo, że DBPs mogą powodować choroby oczu i układu oddechowego, astmę, jak również choroby skóry. Jednakże stwierdzono, że DBPs są genotoksyczne i rakotwórcze. Zaawansowane metody utleniania stanowią obiecującą technologię, która może w znacznym stopniu...
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Influence of stress on oxidation behaviour of carbon steel studded coil.
PublikacjaAnalizowano awarię wężownicy kołkowej ze stali węglowej pracującej przez 10 lat w środowisku przegrzanej pary w temperaturze 290ºC i ciśnieniu 0,67 MPa. Obserwacje mikroskopowe powierzchni i przekroju rury ukazały drobne pęknięcia w ściance wynikające z procesu selektywnego utleniania. Zastosowano metodę elementów skończonych w celu ustalenia zależności postępu korozji od ciśnienia i obciążenia cieplnego.
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Micro-cracking pattern recognition of hybrid CNTs/GNPs cement pastes under three-point bending loading using acoustic emission technique
PublikacjaThe generation of microcracks has an important influence on the behaviour of concrete structures. In this study, the acoustic emission (AE) technique was used to investigate the fracture phenomena and micro-cracking behavior of hybrid carbon nanotubes (CNTs, the 1-D allotrope of carbon atoms) and graphene nanoplatelets (GNPs, 2D monolayer of sp2-hybridized carbon atoms), cement composites under three-point bending loading. In...
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New heterometallic Co/Zn, Ag/Co, and Ag/Zn imidazolates: structural characterization and catalytic activity in the oxidation of organic compounds
PublikacjaNanocrystalline powders of monometallic and bimetallic imidazolates of Co, Zn, and Ag were produced by a reaction carried out in water. The powders were characterized by powder X-ray diffraction and the crystal structures of new compounds Ag2ZnIm4 and Ag2CoIm4 (Im = imidazolate) were solved. Heterometallic Co/Zn imidazolates showed the standard ZIF-8 crystal structure while Ag/Zn and Ag/Co systems were isostructural with the copper...
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Exploring multi-step glucose oxidation kinetics at GOx-functionalized nanotextured gold surfaces with differential impedimetric technique
PublikacjaFor a few past years, we can observe the enormous growth of investigations related to ultrasensitive electrochemical sensors capable of reliable determination of important body parameters and analytes. Utilized procedures rely on standard electrochemical methods, demanding electrode polarization, and information about the initial characteristics of the working electrode. More and more complex electrode materials are characterized...
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Electrophoretic co-deposition of Fe2O3 and Mn1,5Co1,5O4: Processing and oxidation performance of Fe-doped Mn-Co coatings for solid oxide cell interconnects
PublikacjaThe “in-situ” Fe-doping of the manganese cobalt spinel was achieved by electrophoretic co-deposition of Mn1,5Co1,5O4 and Fe2O3 powders followed by a two-step reactive sintering treatment. The effects on the coating properties of two different Fe-doping levels (5 and 10 wt.% respectively) and two different temperatures of the reducing treatment (900 and 1000 °C) are discussed. Samples with Fe-doped coatings demonstrated a lower...
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Modeling of textural anisotropy in granular materials with micro-polar hypoplasticity
PublikacjaW artykule przedstawiono wyniki numerycznej wpływu anizotropii strukturalnej w materiałach granulowanych na powstawanie lokalizacji odkształceń. Obliczenia wykonano dla ściskania w płaskim stanie odkształcenia stosując metodę elementów skończonych na bazie mikropolarnego prawa hipoplastycznego. Wpływ anizotropii modelowano stosując skorelowane pola początkowego wskaźnika porowatości.
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Analysis of selected fluids for use in micro-CHP for domestic applications
PublikacjaW pracy przeanalizowano 4 płyny, etanol, SES36, R141b oraz R134a celem ich zastosowania w domoych mikrosiłowniach. Najlepszym płynem okazuje się być alkohol etylowy oraz SES36.
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Experimental investigation of Organic Rankine Cycles for domestic micro CHP
PublikacjaW artykule przedstawiono wyniki badań eksperymentalnych obiegu ORC wyposażonego w ekspander typu scroll (I etap badań) oraz ekspander utworzony na bazie turbinki pneumatycznej (II etap badań). Raportowane badania przeprowadzono na laboratoryjnym stanowisku realizującym obieg ''domowej'' mikrosiłowni parowej.
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A Method and Device for 3D Recognition of Cutting Edge Micro Geometry
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Micro and Macroelements in Honey and Atmospheric Pollution (NW and Central Poland)
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Electrospinning: An Efficient Biopolymer-Based Micro- and Nanofibers Fabrication Technique
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A study of a reduction of a micro- and nanometric bismuth oxide in hydrogen atmosphere
PublikacjaA reduction of bismuth oxide in hydrogen atmosphere was investigated. The reaction was performed with a material in various structural forms: powder: with micrometric grains, powder with nanometric grains and powder pressed into pellets. The process was performed in both isothermal and non-isothermal conditions. An activation energy of the reaction calculated with Friedman method was found to be about 85 kJ/mol for the reduction...
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Discrete analysis of micro-structural events in granular shear zones
PublikacjaW artykule pokazano rozwój różnych zjawisk mikrostrukturalnych na poziomie ziarna podczas parcia pasywnego piasku na sztywną ściankę przemieszczającą się poziomo. Obliczenia wykonano stosując metodę DEM. Wyniki na poziomie globalnym porównano z wynikami MES. Szczególna uwagę zwrócono na rozwój łańcuchów sił miedzy ziarnami.
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Study of some micro-structural phenomena in granular shear zones
PublikacjaW artykule pokazano wyniki dyskretne zachowania się ziaren materiałów granulowanych w strefie ścinania uzyskane metodą DEM. Wyniki porównano z wynikami MES na bazie mikropolarnego hipoplastycznego prawa konstytutywnego. Szczególną uwagę zwrócono w obliczeniach na zjawiska mikrostrukturalne w strefie ścinania takie jak: wiry, łańcuchy sił, lokalne zmiany porowatości.
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Efficient removal of 2,4,6-trinitrotoluene (TNT) from industrial/military wastewater using anodic oxidation on boron-doped diamond electrodes
PublikacjaWith growing public concern about water quality particular focus should be placed on organic micropollutants, which are harmful to the environment and people. Hence, the objective of this research is to enhance the security and resilience of water resources by developing an efficient system for reclaiming industrial/military wastewater and protecting recipients from the toxic and cancerogenic explosive compound – 2,4,6-trinitrotoluene...
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Modification of structured bio‑carbon derived from spongin-based scaffolds with nickel compounds to produce a functional catalyst for reduction and oxidation reactions: Potential for use in environmental protection
PublikacjaThree different 3D fibrous-like NiO/Ni(OH)2/Ni‑carbonized spongin-based materials were prepared via a simple sorption–reduction method. Depending on the support used, the catalysts were composed of carbon, nickel oxide, nickel hydroxide and zero-valent nickel, with the surface content of the nickel-containing phase in the range 15.2–26.0 wt%. Catalytic studies showed promising activity in the oxidation of phenolic compounds in water...
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Investigations on fracture in reinforced concrete beams in 3-point bending using continuous micro-CT scanning
PublikacjaThis study explores a fracture process in rectangular reinforced concrete (RC) beams subjected to quasi-static three-point bending. RC beams were short and long with included longitudinal reinforcement in the form of a steel or basalt bar. The ratio of the shear span to the effective depth was 1.5 and 0.75. The focus was on the load–deflection diagram and crack formation. Three-dimensional (3D) analyses of the size and distribution...
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In situ spectroelectrochemical and theoretical study on the oxidation of a 4H-imidazole-ruthenium dye adsorbed on nanocrystalline TiO2thin film electrodes
PublikacjaTerpyridine 4H-imidazole-ruthenium(ii) complexes are considered promising candidates for use as sensitizers in dye sensitized solar cells (DSSCs) by displaying broad absorption in the visible range, where the dominant absorption features are due to metal-to-ligand charge transfer (MLCT) transitions. The ruthenium(iii) intermediates resulting from photoinduced MLCT transitions are essential intermediates in the photoredox-cycle...
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Desulfurization of raw naphtha cuts using hybrid systems based on acoustic cavitation and advanced oxidation processes (AOPs)
PublikacjaA combination of dual-frequency acoustic cavitation (acoustic cavitation) and UV assisted advanced oxidation processes (AOPs) reaction system was developed for desulfurization of raw naphtha used to produce aviation fuels. Various types of oxidants in hybrid systems including hydrogen peroxide, acetic acid, acetone, air and ozone were compared. At optimum oxidant to sulfur compounds molar ratio (rox) of 5.0, the hybrid process...
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Efficiency of pollutants removal from landfill leachates using Nb/BDD and Si/BDD anodic oxidation
PublikacjaLandfill leachates (LLs) is a complex, refectory and difficult to depurate liquid generated from sanitary landfills. It contains excessive levels of biodegradable and in particular non-biodegradable products (e.g. heavy metals, phenols, sulphide, plasticisers). LLs are among the effluents that may pose major environmental concerns, they can be a dangerous source of pollution e.g. due to infiltration into soil and underlying water....
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Advanced oxidation processes (AOPs) based wastewater treatment - unexpected nitration side reactions - a serious environmental issue: A review
PublikacjaChemical compounds containing nitro group (nitro-products) are a one of toxic by-products, that can be formed during wastewater treatment processes. In case of presence of nitrite or nitrate ions, the formation of nitro-products during advanced oxidation processes (AOPs) is very common. It is caused by the reactive nitrogen species (RNs) such as nitrate radical (NO3•), nitrite radical (NO2•), nitrogen oxide radical (NO•) and peroxynirite...
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The oxidation of limonene at raised pressure and over the various titanium-silicate catalysts
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Reduced diameter distribution of single-wall carbon nanotubes by selective oxidation
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Selection of the UV irradiation conditions for accelerated edible oil oxidation procedure.
PublikacjaCelem badań było dobranie optymalnych warunków etapu naświetlania olejów roślinnych z zastosowaniem promieniowania ultrafioletowego. Dobrano powierzchnię naświetlania i grubość filmu oleju, a także odległość próbki oleju od źródła światła i moc promieniowania ultrafioletowego.Lotne produkty utleniania izolowano przy pomocy mikroekstrakcji do fazy stacjonarnej i rozdzielano z zastosowaniem chromatografii gazowej z detektorem płomieniowo-jonizacyjnym.
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The Effect Fabrication Method of Cobalt Base Clad Layer On Air Oxidation
PublikacjaNapawane warstwy ze stopu kobaltu zostały wykonane za pomocą napawania plazmowego (PTA) oraz laserowego. Zostały one poddane utlenia niu w temperarurze 1100 stopni celsiusza prze 200 godzin. Przeprowadzono badania mikrostruktury i składu chemicznego warstwy tlenkowej oraz głębszych warstw napoiny. Nie stwierdzono wpływu metody wytwarzania na skutki procesu utleniania.