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Wyniki wyszukiwania dla: SOLID STATE POST-CONDENSATION
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Electrochemical oscillations and bistability during anodic dissolution of vanadium elektrode in acidic media. part 1. Experiment
PublikacjaDynamiczne niestabilności, oscylacje prądowe i bistabilność obserwowane były podczas anodowego roztwarzania elektrody wanadowej w trakcie badań wykorzystujących techniki stało i zmienno prądowe. Analizowany był wpływ warunków eksperymentalnych jak: stężenia kwasu, temperatury itd. Badania pozwoliły stworzyć diagramy przedstawiające regiony występowania oscylacji i bistabilności.
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Synthesis, crystal structure and electrical properties of A-site cation ordered BaErMn2O5 and BaErMn2O6
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Modification of Ruddlesden-Popper-type Nd2-xNi0.75Cu0.2M0.05O4±δ by the Nd-site cationic deficiency and doping with Sc, Ga or In: Crystal structure, oxygen content, transport properties and oxygen permeability
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Indium doping in SrCeO3 proton-conducting perovskites
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The homometallic warwickite V 2 OBO 3
PublikacjaThe synthesis, structure and elementary magnetic characterization of the homometallic warwickite V2OBO3 are reported. The material adopts the orthorhombic warwickite structure type at room temperature, space group Pnma (No. 62) with lattice parameters a = 9.2317(1) Å, b = 3.1172(1) Å, and c = 9.5313(1) Å. Temperature-dependent magnetic susceptibility, electrical resistivity, and specific heat measurements show anomalies near 35 K,...
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La 15 Nb x Ge 9 : a superstructure of the Mn 5 Si 3 structure type with interstitial Nb atoms
PublikacjaThe crystal structure and elementary properties of La15NbxGe9 are reported. Single-crystal X-ray diffraction,from a crystallite with only 0.12 Nb/formula unit, reveals that this compound, although transition metal deficient, crystallizes in a hexagonal “15-1-9”-like structure type, space group P63mc (no. 186) with lattice parameters a = b = 15.5017(2) Å, c = 6.9173(2) Å. The physical properties were examined by specific heat and resistivity...
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Crystal structure and physical properties of new Ca2TGe3 (T = Pd and Pt) germanides
PublikacjaThe crystallographic, electronic transport and thermal properties of Ca2PdGe3 and Ca2PtGe3 are reported. The compounds crystalize in an ordered variant of the AlB2 crystal structure, in space group P6/mmm, with the lattice parameters a = 8.4876(4) Å/8.4503(5) Å and c = 4.1911(3) Å/4.2302(3) Å for Ca2PdGe3 and Ca2PtGe3, respectively. The resistivity data exhibit metallic behavior with residual-resistivity-ratios (RRR) of 13 for...
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Optimization of boron-doping process of titania nanotubes via electrochemical method toward enhanced photoactivity
PublikacjaIn this work, we were focused on the development of the electrochemical approach resulting in a stable boron doping of titania nanotubes. The doping procedure concerns anodic polarization of as-anodized titania in a H3BO3 solution acting as n boron precursor. The series of attempts were taken in order to elaborate the most beneficial doping conditions. The parameters of electrochemical doping allowing to obtain boron-doped titania...
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Optimization of electrochemical doping approach resulting in highly photoactive iodine-doped titania nanotubes
PublikacjaThe paper focuses on the optimization procedure concerning the synthesis method resulting in highly ordered titania nanotubes doped with iodine atoms. The doping process was based on the electrochemical treatment of a titania nanotube layer immersed in a potassium iodide (KI) solution acting as an iodine precursor. A number of endeavors were undertaken in order to optimize the doping conditions. Electrolyte concentration, reaction...
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A complete impedance analysis of electrochemical cells used as energy sources
PublikacjaA comprehensive description of impedance ofelectrochemical systems has been presented, along withthe assumptions of the method used. In this method, amultisinusoidal current excitation signal is used. Thechanges of potential of both the electrodes and thepotential difference between these electrodes are allregistered simultaneously as a function of time. Theproposed method offers the possibility of separatelydetermining the instantaneous...
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Crystal structure and low-energy Einstein mode in ErV2Al20 intermetallic cage compound
PublikacjaSingle crystals of a new ternary aluminide ErV2Al20 were grown using a self-flux method. The crystal structure was determined by powder X-ray diffraction measurements and Rietveld refinement, and physical properties were studied by means of electrical resistivity, magnetic susceptibility and specific heat measurements. These measurements reveal that ErV2Al20 is a Curie-Weiss paramagnet down to 1.95 K with an effective magnetic...
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Synthesis, microstructure and electrical properties of nanocrystalline calcium doped lanthanum orthoniobate
PublikacjaThe single phase lanthanum orthoniobate with tetragonal structure has been synthesized by the means of mechanosynthesis method. The studies have shown the crystal structure of La0.98Ca0.02NbO4 depends on the synthesis stage. The samples were predominantly in the tetragonal phase with a trace amount of the monoclinic phase. The SEM studies of morphology and microstructure have shown nanocrystallinity of the materials. The Raman...
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Electrochemical Charakterization of Prussian blue type nickel hexacyanoferrate redox mediator for potential application as charge relay in dye-sensitized solar cells
PublikacjaMateriał nieorganiczny o mieszanym przewodnictwie elektronowo jonowym jakim jest heksacyjanożelazian (II,III) niklu (II) (NiHCF) rozpatrywany był jako potencjalny przenośnik ładunku w ogniwach słonecznych sensybilizowanych pigmentem (DSSC). Stwierdzono, że reakcje redoksowe NiHCF są szybkie i odwracalne nie tylko w obecności elektrolitu wspomagającego ale również w stanie stałym. Użyteczność NiHCF zbadana została za pomocą tradycyjnego...
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Single crystal growth and physical properties of MCo2Al9 (M= Sr, Ba)
PublikacjaSingle crystals of SrCo2Al and BaCo2Al9 were grown using a self-flux method. A LeBail analysis of the powder X-ray diffraction patterns show that both compounds crystallize in a hexagonal (P6/mmm) crystal structure with lattice parameters: a = 7.8995(1) Å, c = 3.9159(1) Å for SrCo2Al9, and a = 7.9162(2) Å, c = 3.9702(1) Å for BaCo2Al9 aluminide. The low temperature analysis of the heat capacity measurements give a Sommerfeld...
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Impedance monitoring of fuel cell stacks
PublikacjaThis paper presents an innovative, electrochemical impedance method for monitoring of electrochemical behaviour of a multi-cell, direct methanol fuel cell (DMFC) device. This method not only provides classical voltage changes at successive cells but also allows their detailed impedance behaviour to be presented. Impedance characteristics of individual cells within a fuel cell stack (depending on actual operating conditions) are...
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Review on robust laser light interaction with titania – Patterning, crystallisation and ablation processes
PublikacjaTitanium dioxide is regarded as a very promising semiconducting material that is widely applied in many everyday-use products, devices, and processes. In general, those applications can be divided into energy or environmental categories, where a high conversion rate, and energy and power density are of particular interest. Therefore, many efforts are being put towards the elaboration of novel production routes, and improving the...
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Hydrogen activated axial inter-conversion in SiC nanowires
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Microwave-assisted hydrothermal synthesis and electrochemical studies of α- and h-MoO3
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Synthesis, structural, electronic and linear electro-optical features of new quaternary Ag2Ga2SiS6 compound
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Ellipsometric study of oxide formation on Cu electrode in 0.1 M NaOH
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Analysis of electrochemical noise by means bispectral techniques
PublikacjaProcesy o charakterze nieliniowym są często spotykane w praktyce pomiarów elektrochemicznych oraz korozyjnych. Przykładem mogą być procesy elektrodowe kontrolowane aktywacyjnie, dla których często stosowanym podejściem jest linearyzacja. W niniejszym, wprowadzającym doniesieniu przedstawione zostały możliwości analizy nieliniowości szumu elektrochemicznego z wykorzystaniem widm wyższych rzędów. W pracy przedstawiono wyniki analizy...
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Synthesis and properties of the double perovskites La2NiVO6, La2CoVO6, and La2CoTiO6
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Synthesis, structure and physical properties of Ru ferrites: BaMRu5O11 (M=Li and Cu) and BaM′2Ru4O11 (M′=Mn, Fe and Co)
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Synthesis, structure and physical properties of Ru ferrites: BaMRu5O11 (M= Li and Cu) and BaM'2Ru4O11 (M'=Mn, Fe and Co)
PublikacjaW pracy opisano syntezę, strukturę i właściwości fizyczne pięciu nowych związków z rodziny ferrytów na bazie Ru, których wzór chemiczny jest BaMRu5O11 (M = Li, Cu) i BaM'2Ru4O11 (M' = Mn, Fe, Co).
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Structure redetermination, transport and thermal properties of the YNi3Al9 compound
PublikacjaSingle crystals of completely ordered variant of the YNi3Al9 compound were grown by self-flux method with excess of aluminum. The crystal structure of the title compound was redetermined from single crystal X-ray diffraction data. The structure adopts ErNi3Al9 type, space group R32, parameters of the unit cell a = 7.2838(2) Å, c = 27.4004(8) Å. The growth of relatively large single crystals of the YNi3Al9 compound, having completely...
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Investigation of the structural and thermal properties of aluminum-rich Ca–Al–Si–O–N glasses
PublikacjaIn this paper, we investigate the structure and thermal properties of aluminum-rich transparent Ca–Al–Si–O–N glasses. The obtained glasses were prepared by a traditional melt-quenching technique at 1650 °C using AlN as the nitrogen source. The obtained glasses have a nAl/nSi>1 and contain up to 17 eq.% of N. The structure of the glasses was characterized by X-ray diffraction, X-ray photoelectron spectroscopy, infrared, and Raman...
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An unusual four-nuclear Pb(II)-pyrrole-2-carboxylato polymer: The effect of the lone pair and non-covalent interactions on the supramolecular assembly and fluorescence properties
PublikacjaThe reaction of Pb(NO3)2 with 1H-pyrrole-2-carboxylic acid (2prCOOH) leads to the formation of a new four-nuclear Pb(II) polymer, [Pb4(2prCOO)8(H2O)]n, which has been characterized by CHN, FT-IR, TG, PL and single-crystal X-ray diffraction methods. In view of the primary Pb–O bonds, Pb1 and Pb3 show hemidirected pentagonal pyramidal geometries, while Pb2 and Pb4 display hemidirected octahedral geometries. The topology of the strongest...
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The optimization of CuxO microwires synthesis for improvement in photoelectrochemical performance
PublikacjaOne of the most important challenges in the fabrication of CuxO microstructures via the electrochemical method is formation of long, regular and well-packed microwires with good adhesion on the Cu substrate and to achieve better photoelectrochemical properties, which can be potentially applied in solar-driven water splitting and CO2 conversion to light hydrocarbons. In this paper, Cu2O photoelectrode has been fabricated by direct...
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Does the low optical band gap of yellow Bi3YO6 guarantee the photocatalytical activity under visible light illumination?
PublikacjaBi3YO6, which is known as an ionic conductor, was tested here as an electrode and photoanode in contact with aqueous electrolytes. Bi3YO6 was deposited onto the Pt substrate and the such prepared electrode was polarized in various aqueous electrolytes. The optical energy band gap of the material equal to 1.89 eV was determined using the Kubelka-Munk function resulting from the UV-Vis spectrum (allowed indirect transition) and also...
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Composites of tin oxide and different carbonaceous materials as negative electrodes in lithium-ion batteries
PublikacjaAbstract Tin and tin oxide have been considered as suitable materials with high theoretical capacity for lithium ion batteries. Their low cost, high safety and other technical benefits placed them as promising replacements for graphite negative electrodes. The problem to overcome with tin oxide, as well as with other metallic materials, is high volume changes during alloying/dealloying, subsequent pulverization, delamination from...
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Biosilica from sea water diatoms algae—electrochemical impedance spectroscopy study
PublikacjaHere, 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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A miniaturized solid-contact potentiometric multisensor platform for determination of ionic profiles in human saliva
PublikacjaThis paper describes a miniaturized multisensor platform (MP-ISES) consisting of electrodes: a reference one (RE) and ion-selective electrodes (ISEs) for monitoring Na+, K+, Ca2+, Mg2+, Cl−, and SCN− ions and pH in human saliva. Gold electrode surface was modified by deposition of two layers: electrosynthesized PEDOT:PSS forming an intermediate layer, and ion-selective membrane. The developed ISEs were characterized by a wide linear...
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Effect of composition on the thermal properties and structure of M-Al-Si-O-N glasses, M = Na, Mg, Ca
PublikacjaThe primary objective of this study is to explore the relationship between the composition, structure, and thermal characteristics of M-Al-Si-O-N glasses, with M representing sodium (Na), magnesium (Mg), or calcium (Ca). The glasses were prepared by melting in a quartz crucible at 1650 °C and AlN precursor (powder) was utilized as a nitrogen source. The measured thermal properties studied were glass transition temperature (Tg),...
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Synthesis and physical properties of Sm2PdGe3 in a context of RE2PdGe3 family
PublikacjaIn this study, we present the crystallographic and magnetic characterization of a new intermetallic compound Sm2PdGe3, which was synthetized by a two stage method employing an eutectic alloy. The investigations carried out exhibited, that Sm2PdGe3 crystallize in AlB2-type structure with lattice parameters a = 4.2189(1) Å and c = 4.1031(2) Å. This compound can be classified as a cluster-glass with a spin freezing temperature Tf...
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Evaluating the performance of organic coatings under mechanical stress using electrochemical impedance spectroscopy
PublikacjaMimo, iż znaczna liczba konstrukcji zabezpieczanych przy pomocy powłok poddawana jest cyklicznym naprężeniom mechanicznym, czynnik ten wydaje się być niedoceniany jako przyczyniający się do przyspieszonego niszczenia organicznych układów powłokowych. Celem pracy było zweryfikowanie czy powtarzające się naprężenia mechaniczne stanowią istotny element wpływający na skrócenie czasu eksploatacji systemów powłokowych. W tym celu układ:...
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Dynamic elektrochemical impedance spectroscopy measurements of passive layer cracking under static tensile stresses.
PublikacjaDynamiczna elektrochemiczna spektroskopia impedancyjna umożliwia badanie podatności i odporności korozyjnej różnych materiałów konstrukcyjnych, a w szczególności określenie właściwości elektrochemicznych warstw pasywnych występujących na ich powierzchni. W wielu przypadkach pęknięcie warstwy pasywnej pod wpływem działania naprężeń rozciągających prowadzi do korozji naprężeniowej. Z tego względu badania pękania warstw pasywnych...
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Lanthanum investigations in ceramics annealed in a dry and wet atmosphere
Dane BadawczeCeramics based on Barium, Lanthanum, Gadolinium and Cobaltium were produced by standard solid state reaction from oxides and carbonate powders. After sintring, samples were annealed for 2 hours or 72 hours at 300 Celsius degree in a both: wet and dry atmosphere. Results of annealing on a chemical composition and valence state of lanthanum were observed...
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Two-photon microperimetry with picosecond pulses
PublikacjaTwo-photon vision is a phenomenon associated with the perception of short pulsesof near-infrared radiation (900-1200 nm) as a visible light. It is caused by the nonlinear processof two-photon absorption by visual pigments. Here we present results showing the influence ofpulse duration and repetition rate of short pulsed lasers on the visual threshold. We comparedtwo-photon sensitivity maps of the retina obtained for subjects with...
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Experimental validation of pressure drop models during flow boiling of R134a – effect of flow acceleration and entrainment
PublikacjaA crucial step to assure proficient work of power and process apparatus is their proper design. A wide array of those devices operates within boiling or condensation of the working fluid to benefit from high heat transfer rates. Two-phase flows are associated with high heat transfer coefficients because of the latent heat of evaporation and high turbulence level between the liquid and the solid surface. Predicting heat transfer...
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Magnetic properties of α-KCoPO4 compound with a chiral polar crystal structure
PublikacjaWe have obtained polycrystalline samples of a metastable α variant of KCoPO4 by low temperature (350–400 °C) solid state metathesis reaction of potassium oxalate and ammonium cobalt orthophosphate. The material crystallizes in a polar chiral structure (sg. P63, no. 173). Measurements of magnetic properties reveal antiferromagnetic interactions and no ordering observed down to T = 1.9 K, well below the Weiss temperature |Θcw| =...
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The Progress in Electron Microscopy Studies of Particulate Matters to Be Used as a Standard Monitoring Method for Air Dust Pollution
PublikacjaThe present article reviews studies on air solid particles carried out with the use of electron microscopy. Particle analysis combining scanning and transmission electron microscopy (SEM and TEM) can be used to derive size-resolved information of the composition, mixing state, morphology, and complex refractive index of atmospheric aerosol particles. It seems that electron microscopy is more widely used in atmospheric particulate...
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The influence of synthesis method on the microstructure and catalytic performance of Y 0.07 Sr 0.93 Ti 0.8 Fe 0.2 O 3-δ in synthetic biogas operated solid oxide fuel cells
PublikacjaThe Y0.07Sr0.93Ti0.8Fe0.2O3-δ (YSTF) material was fabricated using three different synthesis methods: modified polymer precursor method (MPP), Pechini method and a solid state reaction method. It was applied as an anode catalytic material for biogas reforming in solid oxide fuel cells. Clear differences in the microstructure of fabricated catalytic layers were found, mainly with respect to a grain size and distribution of grains....
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Multianalyte Calibration Methods for Potentiometric Integrated Sensors System for Determination of Ions Concentration in a Body Fluids
PublikacjaIn recent years, integration and miniaturization of ion-selective electrodes (ISEs) have brought many benefits resulting in the possibility of simultaneous determination of the ions concentration in a small sample volume. One of the key problems related to the preparation of integrated sensors systems (ISSs) is a calibration procedure due to the necessity to calibrate each particular sensor separately. The main aim of the research...
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Magnetism from fundamentals to spintronics 22/23
Kursy Online1. Basic magnetic quantities2. Magnetism of atoms and molecules, atoms in external magnetic fields3. Solid state magnetism, types of magnetic materials (dia-, para-, and ferromagnetism)4. Ferromagnetism and domain structures5. Magnetism of small particles, single domain particles (StonerWohlfarth model), thin films6. Experimental techniques of magnetic properties and magnetisation state determination. Domain structurevisualisation...
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Conductivity, structure, and thermodynamics of Y2Ti2O7–Y3NbO7 solid solutions
PublikacjaThe defect fluorite yttrium niobate Y3NbO7 and pyrochlore yttrium titanate Y2Ti2O7 solid solutions have been synthesized via a solid state synthesis route. The resulting stoichiometry of the oxides is Y2+xTi2−2xNbxO7, where x = 0 to x = 1. All of the samples were single-phase; however, for those with a predominant fluorite phase, a small amount of additional pyrochlore phase was detected. The volume of the solid solution unit cells...
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Abdominal Aortic Aneurysm segmentation from contrast-enhanced computed tomography angiography using deep convolutional networks
PublikacjaOne of the most common imaging methods for diagnosing an abdominal aortic aneurysm, and an endoleak detection is computed tomography angiography. In this paper, we address the problem of aorta and thrombus semantic segmentation, what is a mandatory step to estimate aortic aneurysm diameter. Three end-to-end convolutional neural networks were trained and evaluated. Finally, we proposed an ensemble of deep neural networks with underlying...
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Application of Multivariate Adaptive Regression Splines (MARSplines) Methodology for Screening of Dicarboxylic Acids Cocrystal Using 1D and 2D Molecular Descriptors
PublikacjaDicarboxylic acids (DiAs) are probably one of the most popular cocrystals formers. Due to the high hydrophilicity and non-toxicity, they are promising solubilizes of active pharmaceutical ingredients (APIs). Although DiAs appear to be highly capable of forming multicomponent crystals with various compounds, some systems reported in the literature are physical mixtures the solid state without forming stable intermolecular complex....
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Structural and electrical transport properties of Pr-doped SrTi0.93Co0.07O3-δ a novel SOEC fuel electrode materials
PublikacjaSolid Oxide Electrolyzer Cells (SOECs) are very promising electrochemical devices for the production of syngas (H2/CO) by H2O and CO2 co-electrolysis. The structure, microstructure and electrical properties of the fuel electrode material play a crucial role in the performance of the whole cell and efficiency of electrocatalytic reduction of steam into hydrogen. In the present work, a novel Co and Pr co-doped SrTiO3-δ material attracted...
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Cooperativity of Halogen- and Chalcogen-Bonding Interactions in the Self-Assembly of 4‑Iodoethynyl- and 4,7-Bis(iodoethynyl)benzo-2,1,3-chalcogenadiazoles: Crystal Structures, Hirshfeld Surface Analyses, and Crystal Lattice Energy Calculations
PublikacjaSeveral new 4-iodoethynyl- and 4,7-bis- (iodoethynyl)benzo-2,1,3-chalcogenadiazoles were prepared, and a comprehensive analysis of the most prominent secondary bonding interactions responsible for the crystal self-assembly was performed using X-ray diffraction. The presence of both the iodoethynyl and chalcogenadiazole moieties allows an evaluation of the preference of these molecules to aggregate through either chalcogen- or halogen-bonding...
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Low temperature processed MnCo2O4 and MnCo1.8Fe0.2O4 as effective protective coatings for solid oxide fuel cell interconnects at 750 °C
PublikacjaIn this study two materials, MnCo2O4 and MnCo1.8Fe0.2O4 are studied as potential protective coatings for Solid Oxide Fuel Cell interconnects working at 750 °C. First powder fabrication by a modified Pechini method is described followed by a description of the coating procedure. The protective action of the coating applied on Crofer 22 APU is evaluated by following the area specific resistance (ASR) of the scale/coating for 5500...