Search results for: METAL-ORGANIC FRAMEWORKSOPEN METAL SITESCATALYSISHYDROGENATION4-NITROPHENOL
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Selection of Electrode Material for Inconel 617/P92 Steel SMAW Dissimilar Welds
PublicationThe present work aimed to investigate the microstructure and mechanical properties of the dissimilar shielded metal arc welded (SMAW) joint of Alloy 617 and P92 steel for advanced ultrasupercritical boilers. The SMAW joint was produced using three different types of electrodes, namely, ENiCrFe-3, ENiCrMo-3, and ENiCrCoMo-1. During microstructural observation of the welded joints, no possible cracking was detected in the weldments....
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Superconductivity–Electron Count Relationship in Heusler Phases─the Case of LiPd2Si
PublicationWe report superconductivity in the full Heusler compound LiPd2Si (space group Fm3̅m, No. 225) at a critical temperature of Tc = 1.3 K and a normalized heat capacity jump at Tc, ΔC/γTc = 1.1. The low-temperature isothermal magnetization curves imply type-I superconductivity, as previously observed in LiPd2Ge. We show, based on density functional theory calculations and using the molecular orbital theory approach, that while LiPd2Si...
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Wpływ kształtu elektrody woltamperometrycznej na jej właściwości metrologiczne w dziedzinie czasu
PublicationW artykule omówiono właściwości metrologiczne elektrod woltamperometrycznych. Wykazano, że w przypadku oznaczania małych wartości stężeń jonów metali, elektrody te zachowują się tak jak przetworniki pomiarowe I rzędu. Ich właściwości metrologiczne opisuje czułość i stała czasowa. Wartości tych wielkości są uzależnione od mechanizmu transportu jonów do/od powierzchni elektrod oraz od ich kształtu. Wykonano symulacje wpływu kształtu...
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Characterization of the Co-base layers obtained by laser cladding technique.
PublicationBadano zawory wylotowe pokrywane stopami kobaltu: mikrostrukturę warstw w strefie wierzchniej i przy granicy napoina - metal. Badano rozkład pierwiastków w warstwach. Zarówno mikrostruktura, jak i skład chemiczny warstw były podobne w przypadku dwóch stosowanych stopów kobaltu.
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Sintering Parameter Investigation for Bimetallic Stainless Steel 316L/Inconel 718 Composite Printed by Dual-Nozzle Fused Deposition Modeling
PublicationFused deposition modeling (FDM) nowadays offers promising future applications for fabricating not only thermoplastic-based polymers but also composite PLA/Metal alloy materials, this capability bridges the need for metallic components in complex manufacturing processes. The research is to explore the manufacturability of multi-metal parts by printing green bodies of PLA/multi-metal objects, carrying these objects to the debinding...
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The effect of Ag, Au, Pt, and Pd on the surface properties, photocatalytic activity and toxicity of multicomponent TiO2-based nanomaterials
PublicationMulticomponent TiO2-based nanomaterials (MC-NMs) show better physicochemical properties than their individual components or bulk materials. However, the same unique properties that offer innovative applications might also pose unknown risks to human health and the environment. In this context, TiO2- based nanomaterials with a mixture of noble metal precursors (Ag, Au, Pt, and Pd) for large-scale technological applications in air...
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Arctic catchment as a sensitive indicator of the environmental changes: distribution and migration of metals (Svalbard)
PublicationArctic regions experience metal pollution, despite their remote location, and the distribution and migration of those metals determine their potential impact on the local environment. Here, a High-Arctic catchment (Revelva, Svalbard) located remotely from human-induced pollution sources is studied with respect to the distribution and migration of chosen trace elements (Ag, Al, As, B, Ba, Bi, Ca, Cd, Co, Cr, Cu, Cs, Mo, Ni, Pb,...
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Study on Dry Sliding Wear and Friction Behaviour of Al7068/Si3N4/BN Hybrid Composites
PublicationHybrid aluminium metal matrix composites have the potential to replace single reinforced aluminium metal matrix composites due to improved properties. Moreover, tribological performance is critical for these composites, as they have extensive application areas, such as the automotive, aerospace, marine and defence industries. The present work aims to establish the tribological characteristics of Al7068/Si3N4/BN hybrid metal matrix...
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Novel decahedral TiO2 photocatalysts modified with Ru or Rh NPs: Insight into the mechanism
PublicationNovel decahedral TiO2 modified with Ru or Rh NPs were successfully synthesized by hydrothermal method. The effect of metal type as well as amount of noble metal precursor (0.05, 0.1, 0.2, 0.3 and 0.5 wt.%) on the photocatalytic activity were investigated. Decahedral TiO2 decorated by Ru and Rh nanoparticles was prepared by photodeposition method, whereas Rh doped TiO2 was obtained by onestep hydrothermal method with introduction...
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M-BDC (M = Co and/ or Fe) MOFs as effective catalysts for hydrogen generation via hydrolysis of sodium borohydride
PublicationMono- (Co-BDC, Fe-BDC) and bimetallic FeCo-BDC Metal-Organic Frameworks are successfully synthesized by the solvothermal method in DMF at 150 °C within 15 h and tested as catalysts for sodium borohydride hydrolysis. The materials are characterized by FTIR, PXRD, TGA, ICP-OES, H2-TPR, BET model, and SEM-EDS. The catalytic activity of these materials is studied for dehydrogenation of sodium borohydride in water at various temperatures...
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Defective TiO2 Core-Shell Magnetic Photocatalyst Modified with Plasmonic Nanoparticles for Visible Light-Induced Photocatalytic Activity
PublicationIn the presented work, for the first time, the metal-modified defective titanium(IV) oxide nanoparticles with well-defined titanium vacancies, was successfully obtained. Introducing platinum and copper nanoparticles (NPs) as surface modifiers of defective d-TiO2 significantly increased the photocatalytic activity in both UV-Vis and Vis light ranges. Moreover, metal NPs deposition on the magnetic core allowed for the effective separation...
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Corrosion behavior of hydrogen charged super duplex stainless steel welded joints
PublicationThe electrochemical behavior of the weld metal, heat-affected zone (HAZ), and base material of super duplex stainless steel (SDSS) welded joints, made with the application of flux-cored arc welding (FCAW) and submerged arc welding (SAW), were investigated with the use of metallographic examinations (optical microscopy and scanning electron microscopy), potentiodynamic polarization measurements and total hydrogen content determination...
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Superconductivity in a new intermetallic structure type based on endohedral Ta@Ir7Ge4 clusters
PublicationWe report the observation of superconductivity at a temperature near 3.5 K for the previously unreported compound TaIr2Ge2. In addition to being a superconductor, this material displays a new crystal structure type that contains endohedral clusters, as determined by single-crystal x-ray diffraction structure refinement; the structure is more complex than those of the commonly observed tetragonal 122 intermetallic phases. Despite...
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Photophysics of Ru(II) Dyads Derived from Pyrenyl-Substitued Imidazo[4,5-f][1,10]phenanthroline Ligands.
PublicationThe photophysics of a series of Ru(II) dyads based on the 2-(1-pyrenyl)-1H-imidazo[4,5-f][1,10]-phenanthroline ligand was investigated. The ability of these metal complexes to intercalate DNA and induce cell death upon photoactivation makes them attractive photosensitizers for a range of photobiological applications, including photodynamic therapy. In the present study, time-resolved transient absorption and emission spectroscopy...
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Effects of Storing Flux-Cored Wires under Various Conditions
PublicationWelding processes involving the use of flux-cored wires are becoming increasingly popular, particularly in shipbuilding as well as in off-shore and civil engineering. The article presents characteristics of the welding process, its areas of application as well as advantages and disadvantages (e.g. necessity of ensuring appropriate conditions for the storage of filler metal wires). The satisfaction of quality-related requirements...
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Synergistic effects of nitrogen-doped carbon and praseodymium oxide in electrochemical water splitting
PublicationHybrid materials featuring perovskite-type metal oxide in conjunction with heteroatom-doped graphene hold immense promise as alternatives to costly noble metal catalysts for electrochemical water splitting, facilitating the generation of environmentally friendly hydrogen. In this study, perovskite-type oxide containing praseodymium, barium, strontium, cobalt, and iron atoms dispersed in a carbon matrix as a catalyst is synthesized...
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Sodium nitrite as a corrosion inhibitor of copper in simulated cooling water
PublicationThe corrosion inhibition behavior of sodium nitrite (NaNO2) towards pure copper (99.95%) in simulated cooling water (SCW) was investigated by means of electrochemical impedance spectroscopy (EIS) and dynamic electrochemical impedance spectroscopy (DEIS). NaNO2 interferes with metal dissolution and reduce the corrosion rate through the formation or maintenance of inhibitive film on the metal surface. Surface morphologies illustrated...
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On electrochemical noise analysis for monitoring of uniform corrosion rate
PublicationSzybkość korozji jest określona przez rezystancję polaryzacyjną warstwy metal-elektrolit. Jej wartość może być wyznaczona za pomocą pomiarów szumów elektrochemicznych. Przedstawiono szczegółowo algorytm wyznaczania wartości rezystancji polaryzacyjnej na podstawie rejestrowanych sygnałów losowych dla przykładowych wyników badań eksperymentalnych. Oszacowano dokładność wyznaczanej wartości.
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Metals in the environment as risk factors for infectious diseases: gaps and opportunities
PublicationThis chapter aims to provide insights into current knowledge and gaps in our understanding of the influence that trace metals in the environment have on the pathogenesis of infectious diseases. By reducing immune function, trace metal deficiencies may substantially contribute to the global burden of diarhea, pneumonia, and malaria. Improved methods and biomarkers for assessing the risk of trace metals deficiencies and toxicities...
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P92 steel and inconel 617 alloy welds joint produced using ERNiCr-3 filler with GTAW process: Solidification mechanism, microstructure, mechanical properties and residual stresses
PublicationThe objective of the current study was to analyse the microstructure, mechanical characteristics, and residual stresses of a dissimilar welded joint (DWJ) made of P92 steel and the Inconel alloy 617 (IN617) using the gas tungsten arc welding (GTAW) method. The ERNiCr-3 filler was selected to produce the conventional V groove (VG) and narrow V groove (NVG) butt joint. The filler deficient zones in the weldments, such as the filler...
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An approach for estimation of water wall degradation within pulverized-coal boilers
PublicationThe main aim of this paper is to estimate the lifetime of water walls of pulverized-coal boilers at nominal conditions as well as after degradation of water tubes. An approach for a pulverized-coal chamber degradation process has been formulated based on operational and experimental data. This model was formulated using on-line state monitoring of a pulverized coal burner with aim of preventing the fireplace screens from high degradation...
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The influence of the size of a one-faced metallic head in Janus nanoparticles as a co-catalyst on the photocatalytic efficiency of hydrogen evolution under vis light irradiation
PublicationJanus nanoparticles (NPs) consisting of MoOxSy nanospheres and silver (Ag) head, successfully developed by a simple, controlled method were in the first time they were applied as a co-catalysts in photocatalytic hydrogen generation reaction under vis light irradiation (λ > 420 nm). The MoOxSy-Ag as a co-catalysts were deposited on the obtained ZnIn2S4 microspheres (ZIS) using physical absorption method. The influence of the size...
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APPLICATION POSSIBILITIES OF THE S960 STEEL IN UNDERWATER WELDED STRUCTURES
PublicationIn this paper, the application possibilities of the ultra-high strength (UHSS). Domex 960 steel in the underwater welded structures are analyzed. In the research, the investigated material has been tested in bead-on-plate wet welding conditions with the usage of different heat input values, namely 0.63 kJ/mm, 0.72 kJ/mm and 0.93 kJ/mm. Specimens were performed by the manual metal arc (MMA) welding method with the usage of rutile...
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A novel hierarchically-porous diamondized polyacrylonitrile sponge-like electrodes for acetaminophen electrochemical detection
PublicationA novel composite electrode material consisting of tangled fibrous polyacrylonitrile-based hierarchically-struc- tured nanocomposites has been produced by wet-spinning, carbonized and decorated with a carbon nano- architecture by microwave plasma-enhanced chemical vapor deposition and investigated as a metal-free electrode for the enhanced electrochemical detection of acetaminophen. Surprisingly, the hierarchical fiber ar- chitecture...
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Effects of preheating on laser beam–welded NSSC 2120 lean duplex steel
PublicationDuplex stainless steels show sustainable alternative for the conventional austenitic grades, with higher strength, higher resistance against stress corrosion cracking, and lower purchase cost. Thus, duplex stainless steel gains more attention in construction, oil and gas, and chemical industries. Among duplex stainless steels, low nickel and low molybdenum alloyed lean duplex stainless steel are a cost-efective substitution of...
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On the effective properties of foams in the framework of the couple stress theory
PublicationIn the framework of the couple stress theory, we discuss the effective elastic properties of a metal open-cell foam. In this theory, we have the couple stress tensor, but the microrotations are fully described by displacements. To this end, we performed calculations for a representative volume element which give the matrices of elastic moduli relating stress and stress tensors with strain and microcurvature tensors.
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RESEARCH ON ORGANIC COATINGS DESIGNED FOR UNDERWATER APPLICATIONS
PublicationUnderwater steel structures require periodic maintenance. In the case of vessels, anti-corrosion works are carried out in the shipyard, where very good conditions for applying organic protective coatings can be provided. Very good surface preparation can be obtained by the use of abrasive blasting. The well-prepared metal surface is free from impurities (particularly inorganic salts). Suitable conditions for the application and...
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Zeolitic imidazolate framework (ZIF-8) modified cellulose acetate NF membranes for potential water treatment application
PublicationIn this study, cellulose acetate (CA)-based nanofiltration membranes, modified with zeolitic imidazole framework-8 (ZIF-8) particles, were prepared with various ZIF-8 contents (0, 0.1, 0.25, 0.5, 1 and 2 wt%), to obtain membranes with improved flux and filtration performance by combining advantages of CA polymer and ZIF-8 metal-organic frameworks. Removal efficiency studies were carried out with bovine serum albumin and two different...
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Cu-Doped Layered Double Hydroxide Constructs the Performance-Enhanced Supercapacitor Via Band Gap Reduction and Defect Triggering
PublicationLayered double hydroxides (LDHs) are regarded as the excellent electrode materials for supercapacitors because of their high theoretical capacitance and abundance. However, the poor conductivity and limited reaction kinetics of LDHs restrict their practical application severely. Herein, Cu is chosen from groups VIII/IB/IIB as dopants for Co-based LDH (CuCo-LDH). The designed metal–organic framework-derived hierarchical CuCo-LDH...
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Sea spray as a secondary source of chlorinated persistent organic pollutants? - Conclusions from a comparison of seven fresh snowfall events in 2019 and 2021
PublicationSecondary sources of persistent organic pollutants (POPs) gain in importance worldwide as primary sources decline. In this work, we aim to determine whether sea spray may be a secondary source of chlorinated POPs to the terrestrial Arctic, since a similar mechanism was proposed there only for the more water-soluble POPs. To this end, we have determined polychlorinated biphenyls and organochlorine pesticides concentrations in fresh...
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Effect of copper and silver modification of NH2-MIL-125(Ti) on the photoreduction of carbon dioxide to formic acid over this framework under visible-light irradiation
PublicationCu and Ag enhance the photocatalytic activities of metal–organic frameworks (MOFs) toward CO2 conversion because of their CO2 adsorption capacities and effects on the lowest unoccupied molecular orbital (LUMO) overpotentials of MOFs. However, to date, targeted introduction of metals into MOFs to achieve visible (Vis)- light-active photocatalysts for CO2 photoconversion has not been realized. Herein, a series of aminefunctionalized...
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Magnetic photocatalysts for water treatment
PublicationThe concept of magnetic photocatalysts with separation function requires ferromagnetic material with high magnetic susceptibility to an external magnetic field to enable recycling of composite nanoparticles. Currently, much attention is devoted to functionalization of photocatalyst using MFe2O3, where M =Fe, Zn, Co, Mn. However direct contact between photocatalyst and magnetic iron oxide particles leads to photodissolution of iron...
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Usefulness of the voltamperometric method for assessment of the purity of soil
PublicationThis paper presents a voltammetric analysis of soil. It shows that the voltammetry is a useful method for the assessment of soil contaminated with heavy metal ions. There are two major problems with voltammetry analysis: the diffusion coefficient and the measurement system. The paper contains a short literature study of mathematical equations and a study of differences between soil and water measurements. Suggestions of the solution...
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Mechanical, Thermal and Rheological Properties of Polyethylene-Based Composites Filled with Micrometric Aluminum Powder
PublicationInvestigations related to polymer/metal composites are often limited to the analysis of the electrical and thermal conductivity of the materials. The presented study aims to analyze the impact of aluminum (Al) filler content (from 1 to 20 wt%) on the rarely investigated properties of composites based on the high-density polyethylene (HDPE) matrix. The crystalline structure, rheological (melt flow index and oscillatory rheometry),...
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Laser Beam as a Precision Tool to Increase Fatigue Resistance in an Eyelet of Undercarriage Drag Strut
PublicationThe article contains the results of tests on a laser-processed eyelet of undercarriage drag strut to increase its fatigue strength. Laser processing concentrated on both sides around the hole of eye for connecting the undercarriage drag strut caused that the material in this area withstood more than twice the number of load cycles established for this material. In order to determine the reasons for the increase in fatigue strength,...
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Influence of operation temperature instability on gas sensor performance
PublicationGas sensors based on the semiconducting metal-oxides, such as SnO2, have been found to be very useful for detecting a wide range of gases. The reversible interactions of the gas with the surface of the sensing layer made of semiconducting metal-oxides are responsible for changes of sensor resistance which is usually used as a measure of sensor response. Semiconductor gas sensors are commercially available and applied in numerous...
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Mono- and bi-metallic plasmonic photocatalysts for degradation of organic compounds under UV and visible light irradiation
PublicationTitania powders were surface modified with gold and/or silver nanoparticles (NPs) by photodeposition method. Gold modified titania exhibited much higher photocatalytic activity during methanol dehydrogenation under UV irradiation than titania modified with monometallic silver and bimetallic Au–Ag NPs. Bimetallic photocatalysts exhibited either enhanced or reduced visible light activity, depending on properties of noble metal NPs,...
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Performance Assessment of Using Docker for Selected MPI Applications in a Parallel Environment Based on Commodity Hardware
PublicationIn the paper, we perform detailed performance analysis of three parallel MPI applications run in a parallel environment based on commodity hardware, using Docker and bare-metal configurations. The testbed applications are representative of the most typical parallel processing paradigms: master–slave, geometric Single Program Multiple Data (SPMD) as well as divide-and-conquer and feature characteristic computational and communication...
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Pasywacja stali nierdzewnych
PublicationOdporność chemiczna stali odpornych na korozję oparta jest calkowicie na pasywnym charakterze warstw powierzchniowych istniejących na tych stalach. Pasywność to stan, w którym metal aktywny wykazuje podwyższoną odporność korozyjną dzięki tworzeniu na powierzchni warstewki, która jest stabilna w danym środowisku, pH i potencjale oraz stanowi produkt korozji.
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Impact of a newly-formed periglacial environment and other factors on fresh water chemistry at the western shore of Admiralty Bay in the summer of 2016 (King George Island, Maritime Antarctica)
PublicationThis study provides a comprehensive analysis of the inorganic chemistry of flowing water at the western shore of Admiralty Bay. In the water samples, ions, and major and trace metals (and B)were detected and quantified. Additionally, the parameters of pH, specific electrolytic conductivity (SEC25) and total organic carbon (TOC) were determined. Moreover, multivariate data set was created and Principal Component Analysis (PCA) was...
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Speciation of heavy metals in bottom sediments of drinking water reservoir for Gdansk, Poland – changes over the 14 years
PublicationThere was conducted a comparative study of the concentrations of heavy metals (Zn, Cu, Pb, and Cd) in the surface layer of sediments collected in two investigation periods: 1999–2000 and 2013. Theresults demonstrated that the degree of metals pollution decreased over time. The contamina-tion factors (Cf) calculated for Zn, Cu, Pb, and Cd were respectively 3.63, 3.86, 3.23, and 3.25 in the first period of research and 1.35, 3.42,...
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Synthesis and characterization of ruthenium and rhenium dyes with phosphonate anchoring groups
PublicationRe(L1)–Re(L3), a series of rhenium(I) tricarbonyl chloride complexes with bpy-R2 derivatives L1–L3 (bpy = 2,2′-bipyridine, R represents the substitution at the 4- and 4′-positions), and their corresponding trishomoleptic Ru(L1)3–Ru(L3)3 as well as heteroleptic ruthenium(II) complexes Ru(tbbpy)2(L1) and Ru(tbbpy)2(L2) have been synthesized and characterized. Their applicability as immobilizable metal–organic chromophores in solar...
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Towards large-scale application of nanoporous materials in membranes for separation of energy-relevant gas mixtures
PublicationMembranes containing nanoporous materials (such as zeolites, metal–organic materials and 2D materials such as graphene derivatives) may allow more efficient separation of gas mixtures relevant to emerging energy technologies. For example, such membranes could be applied in the separation of gases containing mixtures of carbon dioxide (CO2) and hydrogen (H2). However, these membranes are currently at a relatively low technology...
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MXenes Antibacterial Properties and Applications: A Review and Perspective
PublicationThe mutations of bacteria due to the excessive use of antibiotics, and generation of antibiotic-resistant bacteria have made the development of new antibacterial compounds a necessity. MXenes have emerged as biocompatible transition metal carbide structures with extensive biomedical applications. This is related to the MXenes’ unique combination of properties, including multifarious elemental compositions, 2D-layered structure,...
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Simultaneous removal of heavy metals and dyes in water using a MgO-coated Fe3O4 nanocomposite: Role of micro-mixing effect induced by bubble generation
PublicationThis study focused on the development of a nano-adsorbent for contaminant removal without the use of any external energy. An eco-friendly Fe3O4@MgO core-shell nanocomposite was synthesized and tested for the removal of a heavy metal, lead (Pb2+) and a dye, rhodamine B (RhB). The addition of H2O2 into the system enabled the self-mixing of the aqueous solution containing Fe3O4@MgO through the generation of bubbles. This system showed...
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Is the Solid Electrolyte Interphase an Extra-Charge Reservoir in Li-Ion Batteries?
PublicationAdvanced metal oxide electrodes in Li-ion batteries usually show reversible capacities exceeding the theoretically expected ones. Despite many studies and tentative interpretations, the origin of this extra-capacity is not assessed yet. Lithium storage can be increased through different chemical processes developing in the electrodes during charging cycles. The solid electrolyte interface (SEI), formed already during the first...
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High-Temperature Tensile Behaviour of GTAW Joints of P92 Steel and Alloy 617 for Two Different Fillers
PublicationThis study explores the high-temperature (HT) tensile rupture characteristics of a dissimilar gas-tungsten-arc-welded (GTAW) joint between P92 steel and Alloy 617, fabricated using ER62SB9 and ERNiCrCoMo-1 fillers. The high-temperature tensile tests were performed at elevated temperatures of 550 ◦C and 650 ◦C. An optical microscope (OM) and a field emission scanning electron microscope (FESEM) were utilized to characterize the...
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NOx Photooxidation over Different Noble Metals Modified TiO2
PublicationWe compared the activity enhancement effect of noble metal deposited on TiO2 in photocatalytic nitrogen oxides oxidation. Titanium dioxide was decorated with Ag, Au, Pt or Pd in the sol-gel process. Synthesized catalysts were characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller measurement (BET), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and energy dispersive X-ray analysis (EDX)....
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Submicron inorganic particles as an additional filler in hybrid epoxy matrix composites reinforced with glass fibres
PublicationIn this study, the effect of selected submicron metal oxide (zinc oxide, titanium oxide) or non-metal oxide (silicon dioxide) particles on mechanical and thermo-mechanical properties of epoxy/glass composites was investigated. The applied epoxy resin was a diglycidyl ether of bisphenol-A cured with triethylenetetramine. As a reinforcement twill weave E-glass fabric was used. Hybrid composites (contained particulate and fibrous...
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Accurate modeling of layout parasitic to forecast EMI emitted from a DC-DC converter.
PublicationThis paper illustrates how to account for all parasitic due to the layout of a power converter (inductive and capacitive), in order to forecast electromagnetic interferences (EMI). The method is generic, and is validated here in the simple example of a DC-DC converter, realized on different technologies: insulated metal substrate (IMS), printed circuit board (PCB). In addition, several layouts aspects will be investigated. Conclusions...