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Search results for: bi4v2-xfexo11-δ
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Deposition and growth of thin ceramic films
Publication: Thin ceramic films play an important role in modern technology. One of the more utilized methods of deposition of ceramic films is spin coating. In this paper we investigate optimal deposition parameters for LaNi0.6Fe0.4O3−δ thin layers spin coated from a polymeric precursor. The quality of the obtained layers is checked using scanning electron microscopy. Additionally, we investigate the growth of grains in ceramic films annealed at...
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Mechanical and Microstructural Characterization of TIG Welded Dissimilar Joints between 304L Austenitic Stainless Steel and Incoloy 800HT Nickel Alloy
PublicationIn this article, the mechanical properties and microstructure of 304L austenitic stainless steel/Incoloy 800HT nickel alloy dissimilar welded joints are investigated. The joints were made of 21.3 mm × 7.47 mm tubes using the TIG process with the use of S Ni 6082 nickel filler metal. No welding imperfections were found and high strength properties of joints were obtained, meeting the assumed acceptance criteria of the product’s...
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Investigation of thin perovskite layers between cathode and doped ceria used as buffer layer in solid oxide fuel cells
PublicationIn this paper, thin perovskite layers between cathode material of solid oxide fuel cells and gadolinia-doped ceria buffer layer are investigated. Thin layers made of LaNi0.6Fe0.4O3-δ (LNF), La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF), or SrTi0.65Fe0.35O3-δ (STF) were symmetrically deposited by spin coating method from metallo-organic polymer precursors on a Ce0.8Gd0.2O2-δ (CGO) substrate. Porous and about 40-μm-thick LNF cathodes were deposited...
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Novel Class of Proton Conducting Materials—High Entropy Oxides
PublicationHere, for the first time, we present data on proton conductivity of high-entropy, single-phase perovskites. The BaZr0.2Sn0.2Ti0.2Hf0.2Ce0.2O3−δ, BaZr0.2Sn0.2Ti0.2Hf0.2Y0.2O3−δ, BaZr1/7Sn1/7Ti1/7Hf1/7Ce1/7Nb1/7Y1/7O3−δ, and BaZr0.15Sn0.15Ti0.15Hf0.15Ce0.15Nb0.15Y0.10O3−δ single-phase perovskites were synthesized. Before electrical measurements, materials were characterized using X-ray diffraction (XRD), scanning electron microscopy...
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Molecular basis of essentiality of early critical steps in the lipopolysaccharide biogenesis in Escherichia coli K-12: requirement of MsbA, cardiolipin, LpxL, LpxM and GcvB
PublicationTo identify the physiological factors that limit the growth of Escherichia coli K-12 strains synthesizing minimal lipopolysaccharide (LPS), we describe the first construction of strains devoid of the entire waa locus and concomitantly lacking all three acyltransferases (LpxL/LpxM/LpxP), synthesizing minimal lipid IVA derivatives with a restricted ability to grow at around 21 °C. Suppressors restoring growth up to 37 °C of Δ(gmhD-waaA)...
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Energetics of formation and stability in high pressure steam of barium lanthanide cobaltite double perovskites
PublicationThis study concerns energetics of formation and the stability in high water partial pressure of BaLnCo2O6−δ, (Ln = La, Pr, Nd, and Gd) (BLnC) and BaGd1−xLaxCo2O6−δ, where x = 0.2, 0.5, and 0.7 (BGLC) double perovskite cobaltites. Those materials are extensively studied due to their potential applications as a positrode in electrochemical devices. Therefore, their stability under such conditions is a key issue. All investigated...
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Thermoelectric and electrical properties of triple-conducting multicomponent oxides based on substituted barium cerate-zirconate
PublicationMulticomponent oxides often have exceptional thermal stability and interesting electronic properties. The present work presents the thermoelectric and electrical properties of the Ba(Zr0.2Hf0.2Sn0.2Ti0.2Fe0.2)O3−δ and Ba(Zr0.1Hf0.1Sn0.1Ti0.1Co0.1Ce0.1Bi0.1Fe0.1Y0.1Zn0.1)O3−δ multicomponent perovskites. Single-phase cubic perovskites were synthesized using the solid-state reaction method. They were characterized using X-ray...
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Nanocrystalline cathode functional layer for SOFC
PublicationRecently, it was shown that thin functional layers introduced between an electrolyte and cathode might improve cathode performance. However, the mechanism of this improvement still needs analysis. In this paper, a thin (∼140 nm), spin-coated perovskite layer (La0.6Sr0.4Co0.2Fe0.8O3-δ) was placed between a cathode (La0.6Sr0.4Co0.2Fe0.8O3-δ) and an electrolyte (Ce0.8Gd0.2O2-δ) and the effects of this investigated. The microstructure...
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Escherichia coli K-12 suppressor-free mutants lacking early glycosyltransferases and late acyltransferases. Minimal lipopolysaccharide structure and induction of envelope stress response.
PublicationTo elucidate the minimal lipopolysaccharide (LPS) structure needed for the viability of Escherichia coli, suppressor-free strains lacking either the 3-deoxy-d-manno-oct-2-ulosonic acid transferase waaA gene or derivatives of the heptosyltransferase I waaC deletion with lack of one or all late acyltransferases (lpxL/M/P) and/or various outer membrane biogenesis factors were constructed. Δ(waaC lpxL lpxM lpxP) and waaA mutants exhibited...
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Structural and electrical properties of titanium-doped yttrium niobate
PublicationIn this work, the influence of the substitution of niobium by titanium in Y3Nb1-xTixO7-δ on the structural and electrical properties is reported. Several experimental techniques, i.e. X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), X-Ray Photoelectron Spectroscopy (XPS) and Electrochemical Impedance Spectroscopy (EIS), were applied to investigate the system Y3Nb1-xTixO7-δ. Titanium in Y3Nb1-xTixO7-δ is an acceptor-type...
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Structural and catalytic properties of ceria layers doped with transition metals for SOFCs fueled by biogas
PublicationThe aim of this paper was to investigate an influence of the nanocrystalline Ce0.8A0.2O2-δ (A = Mn, Fe, Co, Ni, Cu) materials on the direct internal reforming of biogas in SOFC. Structural analysis of fabricated compounds has been done. An in-situ analysis of a composition of outlet gases from operating SOFC was performed using FTIR spectroscopy with simultaneous electrical tests. It was found out, that type of dopant strongly...
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Rendezvous of Distance-Aware Mobile Agents in Unknown Graphs
PublicationWe study the problem of rendezvous of two mobile agents starting at distinct locations in an unknown graph. The agents have distinct labels and walk in synchronous steps. However the graph is unlabelled and the agents have no means of marking the nodes of the graph and cannot communicate with or see each other until they meet at a node. When the graph is very large we want the time to rendezvous to be independent of the graph size...
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Characteristics of La0.8Sr0.2Ga0.8Mg0.2O3-delta -supported micro-tubular solid oxide fuel cells with bi-layer and tri-layer electrolytes
PublicationIn this study, La0.8Sr0.2Ga0.8Mg0.2O3−δ (LSGM)-supported micro tubular solid oxide fuel cells (T-SOFCs) with two different configurations, one containing an LSGM–Ce0.6La0.4O2−δ (LDC) bi-layer electrolyte (Cell A) and one containing an LDC–LSGM–LDC tri-layer electrolyte (Cell B), were fabricated using extrusion and dip-coating. After optimizing the paste formulation for extrusion, the flexural strength of the dense and uniform LSGM...
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NANOCRYSTALLINE CATHODES FOR SOLID OXIDE FUEL CELLS MADE OF NOBLE METALS
PublicationCathodes for solid oxide fuel cells prepared by the infiltration method at 600 °C are presented. The infiltration method allows to produce stable, nanostructured electrodes. Cathodes were prepared using gold, platinum, La2NiO4+δ (L2N) and La0.6Sr0.4Co0.2Fe0.8O3 δ (LSCF). Symmetrical cathode/electrolyte/cathode samples were prepared and examined with SEM microscopy and electrochemical impedance spectroscopy. Despite successful deposition...
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Assembly of Lipopolysaccharide in Escherichia coli Requires the Essential LapB Heat Shock Protein
PublicationHere, we describe two new heat shock proteins involved in the assembly of LPS in Escherichia coli, LapA and LapB (lipopolysaccharide assembly protein A and B). lapB mutants were identified based on an increased envelope stress response. Envelope stress responsive pathways control key steps in LPS biogenesis and respond to defects in the LPS assembly. Accordingly, the LPS content in ΔlapB or Δ(lapA lapB) mutants was elevated, with...
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An influence of the ship's block coefficient implementation on the evaluation of it's hull girder bending
PublicationAn influence of the three different ways of implementation ship's block coefficient δ (three geometrical models) on the stresses due to wave bending moment have been investigated. Two models have been applied and compared: beam one (description of the shape usingparameters) and FEM shell model (direct representation of the shape). The outcomes have been compared to Polish Register of Shipping (PRS) rules. The results show that...
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Forming Ni-Fe and Co-Fe Bimetallic Structures on SrTiO3-Based SOFC Anode Candidates
PublicationThe aim of this work was to verify the possibility of forming Ni-Fe and Co-Fe alloys via topotactic ion exchange exsolution in Fe-infiltrated (La,Sr,Ce)0.9(Ni,Ti)O3-δ or (La,Sr,Ce)0.9(Co,Ti)O3-δ ceramics. For this purpose, samples were synthesized using the Pechini method and then infiltrated with an iron nitrate solution. The reduction process in dry H2 forced the topotactic ion exchange exsolution, leading to the formation of...
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Wytwarzanie i badanie związków domieszkowanego tlenku ceru jako anodowych materiałów katalitycznych do tlenowych ogniw paliwowych zasilanych biogazem
PublicationW ramach pracy wytworzono tlenki ceru domieszkowane Pr, Y, La, Nd i Sm w stosunku 9:1 metodą strącania z odwróconej mikroemulsji. Wytworzone nanokrystaliczne proszki poddano analizie XRD, co dowiodło ich jednofazowości. Następnie, otrzymane tlenki nałożono w formie warstw katalitycznych na anody ogniw paliwowych. Korzystając z mikroskopii SEM, przeprowadzono obserwację powierzchni warstw z domieszką Pr, La, Nd i Sm po wygrzewaniu....
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Improvement of Oxygen Electrode Performance of Intermediate Temperature Solid Oxide Cells by Spray Pyrolysis Deposited Active Layers
PublicationIntermediate temperature solid oxide fuel cells oxygen electrodes are modified by active interfacial layers. Spray pyrolysis is used to produce thin (≈500 nm) layers of mixed ionic and electronic conductors: Sm0.5Sr0.5CoO3−δ (SSC), La0.6Sr0.4CoO3−δ (LSC), La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF), and Pr6O11 (PrOx) on the electrode–electrolyte interface. The influence of the annealing temperature on the electrode polarization (area specific...
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Enhanced acceptor concentration, proton conductivity, and hydration in multicomponent rare‐earth ortho‐niobates
PublicationThe structural properties of (La0.2Nd0.2Sm0.2Gd0.2Eu0.2)1−xCaxNbO4−δ (x = 0–0.05) series have been studied by X-ray powder diffraction at room temperature. The thermal properties were investigated using thermogravimetry, from which the concentration of proton defects was determined. Additionally, dilatometry studies were carried out, from which the thermal expansion coefficients and the phase transition temperature between low-...
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High-Temperature Structural and Electrical Properties of BaLnCo2O6 Positrodes
PublicationThe application of double perovskite cobaltites BaLnCo2O6−δ (Ln = lanthanide element) in electrochemical devices for energy conversion requires control of their properties at operating conditions. This work presents a study of a series of BaLnCo2O6−δ (Ln = La, Pr, Nd) with a focus on the evolution of structural and electrical properties with temperature. Symmetry, oxygen non-stoichiometry, and cobalt valence state have been examined...
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Właściwości i struktura niobianu lantanu domieszkowanego pierwiastkami ziem rzadkich
PublicationW niniejszej rozprawie przedstawiono wyniki badań wpływu domieszkowania niobianu lantanu pierwiastkiem metali ziem rzadkich o zmiennym stopniu utlenienia. Za pomocą metody syntezy w fazie stałej wytworzono: jednofazowe związki niobianu lantanu z podstawieniem prazeodymem oraz terbem, niobian prazeodymu oraz niobian terbu (La1-xRExNbO4+δ, RENbO4+δ gdzie RE= Pr, Tb; 0≤x≤0,3). Syntezowane materiały zostały poddane badaniom struktury,...
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Kinetics of Intermetallic Phase Precipitation in Manual Metal Arc Welded Duplex Stainless Steels
PublicationThe article presents the influence of heat treatment on the kinetics of transformations in lean duplex LDX2101 steel and a weld made of standard duplex 2209 material, which was welded by manual metal arc welding. Changes in the microstructure, hardness, and magnetic phase content were analyzed after heat treatment was conducted at a temperature of 800 °C for a period ranging from 15 to 1440 min. Light and scanning microscopy, Vickers...
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Investigation of catalytic layers on anode for solid oxide fuel cells operating with synthetic biogas
PublicationIn this paper solid oxide fuel cells operating with dry synthetic biogas have been examined. In order to increase their stability the layers of CuO-CeO2, Cu1.3Mn1.7O4 and Y0.08Sr0.92Ti0.8Fe0.2O3 -δ have been deposited on the Ni-YSZ anode site. These layers should catalyze the internal biogas reforming and prevent the carbon deposition on the anode site. It has been found that CuO-CeO2 and Cu1.3Mn1.7O4 catalysts led to an increase...
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Investigation of praseodymium and samarium co-doped ceria as an anode catalyst for DIR-SOFC fueled by biogas
PublicationThe Pr and Sm co-doped ceria (with up to 20 mol.% of dopants) compounds were examined as catalytic layers on the surface of SOFC anode directly fed by biogas to increase a lifetime and the efficiency of commercially available DIR-SOFC without the usage of an external reformer. The XRD, SEM and EDX methods were used to investigate the structural properties and the composition of fabricated materials. Furthermore, the electrical...
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The adiabatic potentials of low-lying electronic states of the NaRb molecule
PublicationAdiabatic potential energy curves and spectroscopic constants have been calculated for the NaRb molecule. The results of ten states of the symmetry Σ+, six states of the symmetry Π, and two states of the symmetry Δ are obtained by the nonrelativistic quantum chemical method used with pseudopotentials describing the interaction of valence electrons with atomic cores. Analysis is based on a comparison with the results of other theoretical...
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Generalized Taylor formula and shell structures for the analysis of the interaction between geosythetics and engineering structures of transportation lines
PublicationThe analysis of the interaction between geosynthetics and engineering structures (e.g. railroad bed, soil foundation, pipeline) assumes that the geosynthetic form elastic membranes or shell laid on different types of foundations. The mathematical description of that problems in continuous domain employs Laplace operator Δ or d’Alembert operator □. In this paper we demonstrate the analysis based on generalize Taylor formula, and...
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On the size of identifying codes in triangle-free graphs
PublicationIn an undirected graph G, a subset C⊆V(G) such that C is a dominating set of G, and each vertex in V(G) is dominated by a distinct subset of vertices from C, is called an identifying code of G. The concept of identifying codes was introduced by Karpovsky, Chakrabarty and Levitin in 1998. For a given identifiable graph G, let gammaID(G) be the minimum cardinality of an identifying code in G. In this paper, we show that for any connected...
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Thermal and Chemical Expansion in Proton Ceramic Electrolytes and Compatible Electrodes
PublicationThis review paper focuses on the phenomenon of thermochemical expansion of two specific categories of conducting ceramics: Proton Conducting Ceramics (PCC) and Mixed Ionic-Electronic Conductors (MIEC). The theory of thermal expansion of ceramics is underlined from microscopic to macroscopic points of view while the chemical expansion is explained based on crystallography and defect chemistry. Modelling methods are used to predict...
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Development of iron doped strontium titanates as oxygen electrode for solid oxide fuel cells
PublicationProducing efficient solid oxide fuel cells (SOFC) without the use of harmful elements is one of the current challenges. Increasing the safety of people and reducing production costs is possible, among others, thanks to the use of iron doped strontium titanates as porous oxygen electrodes. In this thesis, the results of research on iron doped strontium titanates as potential oxygen electrodes for SOFC are presented. The research...
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Materiały katalityczne dla tlenkowych ogniw paliwowych zasilanych biogazem
PublicationTlenkowe ogniwa paliwowe (SOFC) są jednymi z najbardziej obiecujących przyrządów do konwersji energii ze względu na wysoką wydajność, niską emisję zanieczyszczeń i możliwość zastosowania szerokiej gamy paliw. Jednak zastosowanie biogazu jako paliwa w obecnie wytwarzanych ogniwach paliwowych, w których anoda jest zbudowana z niklu i tlenku itru stabilizowanego tlenkiem cyrkonu, powoduje osadzanie się węgla oraz degradację ogniwa....
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Synthesis and Testing of BCZY/LNZ Mixed Proton–electron Conducting Composites for Fuel Cell Applications
PublicationA composite of BaCe0.6Zr0.2Y0.2O3–δ and Li2O:NiO:ZnO was investigated for fuel cell applications. The composite was successfully synthesized and its phase stability was confirmed at temperatures up to 900 °C. The influence of sintering and pressing aids on density was also investigated. Electrical properties were measured. DC electrical conductivity was about 8•10-4 S/m at 845 K. Open circuit voltage measurements in wet hydrogen...
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Iridium 5d -electron driven superconductivity in ThIr3
PublicationA polycrystalline sample of superconducting ThI r 3 was obtained by arc-melting Th and Ir metals. Powder x-ray diffraction revealed that the compound crystalizes in a rhombohedral crystal structure (R-3m, s.g. #166) with the lattice parameters: a = 5.3394 ( 1 ) Å and c = 26.4228 ( 8 ) Å . Normal and superconducting states were studied by magnetic susceptibility, electrical resistivity, and heat capacity measurements. The results...
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Spray pyrolysis of doped-ceria barrier layers for solid oxide fuel cells
PublicationGadolinium doped ceria (Ce0.8Gd0.2O2 − x-CGO) layer fabricated by spray pyrolysis is investigated as the diffusion barrier for solid oxide fuel cell. It is deposited between the La0.6Sr0.4FeO3 − δ cathode and the yttria stabilized zirconia electrolyte to mitigate harmful interdiffusion of elements. The parameters of the fabrication process are linked to the measured area specific resistances of the symmetrical cells and the efficiency...
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Electrical and structural properties of Nb-doped SrTiO3
PublicationNiobium-doped strontium titanate synthesized via conventional solid-state reaction has been studied. Influence of niobium content on the lattice parameters and electrical conductivity has been reported. Various reduction conditions have been investigated. For samples reduced in hydrogen at 1400°C, a transition from thermally activated to metallic behavior has been observed. Maximum electrical conductivity (ca. 55 Scm−1 at 650°C)...
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237Np Mössbauer effect study on NpFeAsO
PublicationWe report 237Np Mössbauer measurements on NpFeAsO. The Np atoms were found to occupy only one crystallographic site. The value of the isomer shift (δ ∼ 9.1 mm s−1 versus NpAl2) indicates a 5f4 electronic configuration (Np3+ ions). The magnetic ordering of the Np sublattice below 60 K is established and the saturated ordered magnetic moment is determined to be 1.73μB at 3.6 K. The unique set of hyperfine parameters exclude a modulated...
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Monosaccharides as Potential Chiral Probes for the Determination of the Absolute Configuration of Secondary Alcohols
PublicationHerein, a new method for the elucidation of the absolute configuration of chiral secondary alcohols is proposed. This method is an alternative for a widely used approach reported by Mosher and Dale and similar methods that are based on the 1H NMR shift (δ) changes of protons that are attached to the substituents of the oxymethine carbon atom. The presented method is not based on tracking the chemical shift changes and utilizes...
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Seismic damage diagnosis in adjacent steel and RC MRFs considering pounding effects through improved wavelet-based damage-sensitive feature
PublicationThis paper aims to propose complex Morlet (cmorfb-fc) wavelet-based refined damage-sensitive feature (rDSF) as a new and more precise damage indicator to diagnose seismic damages in adjacent steel and Reinforced Concrete (RC) Moment Resisting Frames (MRFs) assuming pounding conditions using acceleration responses. The considered structures include 6- and 9-story steel and 4- and 8-story RC benchmark...
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Interval incidence coloring of bipartite graphs
PublicationIn this paper we study the problem of interval incidence coloring of bipartite graphs. We show the upper bound for interval incidence coloring number (χii) for bipartite graphs χii≤2Δ, and we prove that χii=2Δ holds for regular bipartite graphs. We solve this problem for subcubic bipartite graphs, i.e. we fully characterize the subcubic graphs that admit 4, 5 or 6 coloring, and we construct a linear time exact algorithm for subcubic...
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Performance of a single layer fuel cell based on a mixed proton-electron conducting composite
PublicationMany of the challenges in solid oxide fuel cell technology stem from chemical and mechanical incompatibilities between the anode, cathode and electrolyte materials. Numerous attempts have been made to identify compatible materials. Here, these challenges are circumvented by the introduction of a working single layer fuel cell, fabricated from a composite of proton conducting BaCe0.6Zr0.2Y0.2O3-δ and a mixture of semiconducting...
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Additive manufacturing of Proton-Conducting Ceramics by robocasting with integrated laser postprocessing
PublicationA hybrid system combining robocasting and NIR laser postprocessing has been designed to fabricate layers of mixed proton-electron conducting Ba0.5La0.5Co1-xFexO3-δ ceramic. The proposed manufacturing technique allows for the control of the geometry and microstructure and shortens the fabrication time to a range of a few minutes. Using 5 W laser power and a scanning speed of 500 mm⋅s− 1, sintering of a round-shaped layer with an...
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Molecular basis of lipopolysaccharide heterogeneity in Escherichia coli: envelope stress-responsive regulators control the incorporation of glycoforms with a third 3-deoxy-α-D-manno-oct-2-ulosonic acid and rhamnose.
PublicationMass spectrometric analyses of lipopolysaccharide (LPS) from isogenic Escherichia coli strains with nonpolar mutations in the waa locus or overexpression of their cognate genes revealed that waaZ and waaS are the structural genes required for the incorporation of the third 3-deoxy-α-D-manno-oct-2-ulosonic acid (Kdo) linked to Kdo disaccharide and rhamnose, respectively. The incorporation of rhamnose requires prior sequential incorporation...
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Influence of Soft Soil Samples Quality on the Compressibility and Undrained Shear Strength – Seven Lessons Learned From the Vistula Marshlands
PublicationThis technical article presents the influence of sample quality on the compressibility parameters and undrained shear strength ( c u ) of soft soils from the Vistula Marshlands. The analysis covers: (1) quality of soft soil according to three criteria: void ratio (Δ e / e 0 index), volumetric strain (Δ ɛ v ) and C r / C c ratio; (2) influence of storage time on quality; (3) influence of sample quality on undrained shear strength...
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Assessment of image processing methods for the determination of propagation of squat-type defects in rails
PublicationWe demonstrate the idea of squat-type defect measurement in the rail and the concept of tracking of the defect development using the techniques of image acquisition and image processing as well as the methods of metric spaces. We introduce the concepts of a set diameter δ(A) and the metric ρ1, which come from the properties of plane figures, to compare and to observe the development of the defects. We characterize the feasibility...
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Crystal Structures of d-Lyxono-1,4-lactone and Its O-Tosyl Derivative
Publicationγ- and δ-lactones were formed by bromine oxidation of commercially available D-lyxose, as confirmed by IR analysis. The former was isolated, and its structure was confirmed by NMR spectra and X-ray analysis. In this structure, the presence of both intermolecular and intramolecular hydrogen bonds was found. Intermolecular interactions in the crystal were illustrated using the Hirshfeld surfaces. Due to steric reasons, 3,5- O-isopropylidene-D-lyxono-1,4-lactone...
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Effects of La0.8Sr0.2MnO3 and Ag electrodes on bismuth-oxide-based low-temperature solid electrolyte oxygen generators
PublicationIn this study, La0.8Sr0.2MnO3 (LSM) was used as the ceramic electrode in a (Bi1.50Y0.50)0.98Zr0.04O3+δ (BYO)-based solid electrolyte oxygen generator (SEOG) and its performance was compared with that of a previously studied high-fire Ag electrode. Among La0.6Sr0.4Co0.2Fe0.8O3, LaNi0.6Fe0.4O3, Cu1.4Mn1.6O4, and LSM materials, only LSM materials did not trigger any chemical reaction or interdiffusion with BYO at temperatures up to...
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CGO as a barrier layer between LSCF electrodes and YSZ electrolyte fabricated by spray pyrolysis for solid oxide fuel cells
PublicationPerovskite La0.6Sr0.4Co0.2Fe0.8O3 − δ (LSCF) is often used as a cathode material for solid oxide fuel cells (SOFC) due to high mixed ionic and electronic conductivity and good catalytic activity. Unfortunately, sintering of the LSCF cathode together with the yttria stabilized zirconia (YSZ) electrolyte, leads to formation of the La2Zr2O7 and SrZrO3 phases in the interface. These phases increase the resistance of the cell. To avoid...
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Structure and transport properties of donor-doped barium strontium cobaltites
PublicationIn this work, Nb-substituted barium strontium cobaltites Ba0.5Sr0.5Co1-xNbxO3-δ (x = 0 – 0.4) have been fabricated and studied. The structural analysis showed that the Nb content influences the lattice constant as well as the distance between the (Co, Nb) and oxygen atoms. The study of morphology of samples showed that the Nb content does not change the porosity, grain size and morphology of the ceramics. The total electrical conductivity...
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Safety at railway level crossings and Vision Zero
PublicationIn this work, safety analysis at the railway level crossings is presented using advanced mathematical modelling. Resistivity of track subgrade panels is taken into account. The analysis does not refer to the assessment of the current regulations. Specific cases of generalized dynamic system are considered by introducing operations S=Δ, S=P defined in space C(N) of real sequences. In this model, generalized discrete exponential...
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Badanie własności transportowych kompozytu nadprzewodząco-ferromagnetycznego na bazie YBa2Cu3O7-x
PublicationCelem niniejszej pracy było sprawdzenie możliwości otrzymywania kompozytu nadprzewodząco-ferromagnetycznego, który mógłby potencjalnie znaleźć zastosowanie w konstrukcji sterownika, bądź przełącznika prądu nadprzewodzącego w sieciach energetycznych opartych na wysokotemperaturowych nadprzewodzących kablach energetycznych. W tym celu w pracy skoncentrowano się na otrzymywaniu ceramicznego porowatego nadprzewodnika YBa2Cu3O7-δ z...