Search
Filters
total: 23
Search results for: partial conductivity
-
Electrochemical impedance spectroscopy measurements - conductivity vs. temperature and conductivity vs. oxygen partial pressure - BaCe0.6Zr0.2Y0.1Tb0.1O3-δ
Open Research DataThe dataset consists of two main catalogs consisting of measurement data: of the electrical conductivity of the BaCe0.6Zr0.2Y0.1Tb0.1O3-δ (BCZYTb) sample as a function of temperature and of the electrical conductivity as a function of oxygen partial pressure (pO2). Measurements as a function of temperature were carried out in dry and wet air (pH2O ~...
-
Electrical conductivity of the Sr0.86Ti0.65Fe0.35O3-d pellet at different oxygen partial pressures
Open Research DataThis dataset contains results electrical conductivity measurements of dense Sr0.86Ti0.65Fe0.35O3-d (STF35) pellet. DC electrical conductivity measurements of STF35 were performed by the Van der Pauw method. Studies were performed at different oxygen partial pressures (20%, 1% and 0.1%) under humidified (~4 vol%) gas flow rate of 50 ml min -1.
-
Electrical conductivity of the (Ce0.80Gd0.20)O1.90 pellet at different oxygen partial pressures
Open Research DataThis dataset contains results electrical conductivity measurements of dense (Ce0.80Gd0.20)O1.90 (CGO-20) pellet. DC electrical conductivity measurements of CGO-20 were performed by the Van der Pauw method between 900 °C and 450 °C with 50 °C step. Studies were performed at different oxygen partial pressures (100%, 20% and 1%) under humidified (~4...
-
Hebb–Wagner polarization method for determining the oxygen ion conductivity in barium cerate-zirconate
PublicationIn this work, the partial conductivity of oxygen ions in BaCe0.6Zr0.2Y0.2O3 was studied at different temperatures and water partial pressures. For this purpose, a modified DC Hebb–Wagner polarization method with an electrode blocking for protons and electrons was used. A new type of measuring cell as well as a suitable calculation model were proposed for the determination of partial oxygen ionic conductivity in materials with three...
-
Conductivity and viscosity changes of imidazolium ionic liquids induced by H2O and CO2
PublicationSeveral solutions of ionic liquids based on 1-ethyl-3-methylimidazolium cation saturated and unsaturated with carbon dioxide were prepared and characterized by electrochemical impedance spectroscopy. The in fluence of ILs saturation on its electrical conductivity was determined. Additionally, the in fluence of the water presence and variations of temperature on electrical properties of ionic liquids were investigated. Changes of...
-
Determination of the ionic conductivity of Sr-doped lanthanum manganite by modified Hebb–Wagner technique
PublicationThe Hebb–Wagne rpolarization method with the electron blocking electrode has been discussed in this paper in aim to determine a partial ionic conductivity of Sr-doped lanthanum manganite.The “limiting current” in the proposed system was measured using the two-point DC technique with additional Pt electrode between LSM and blocking electrode.The electrochemical model based on bulk diffusion processes and Boltzmann statistics has...
-
Electrical conductivity of the SrTi1-xFexO3-d pellets at 20% pO2
Open Research DataThis dataset contains results electrical conductivity measurements of dense SrTi1-xFexO3-d (x=0.35, 0.50, 0.70) pellets. DC electrical conductivity measurements were performed by the Van der Pauw method between 900 °C and 200 °C. Studies were performed at 20% of oxygen partial pressure under humidified (~4 vol%) gas flow rate of 50 ml min -1.
-
Electrical conductivity relaxation measurements - water uptake of BaCe0.6Zr0.2Y0.1Tb0.1O3-δ
Open Research DataFor Electrical Conductivity Relaxation (ECR) measurements, platinum reversible electrodes were applied in a four-probe arrangement and the BaCe0.6Zr0.2Y0.1Tb0.1O3-δ sample was measured in the ProboStat™ measurement system. The ECR measurements were performed in air in the temperature range of 450-800 ℃ after switching water partial pressure between...
-
Electrical properties of A-site Ca-doped LaNb1-xAsxO4-δ ceramics
PublicationThe electrical properties of A-site Ca-doped LaNbO4 with the addition of As in the B-site, have been investigated. Total, grain- and specific grain boundary electric conductivities in different oxygen partial pressure, and water vapour partial pressure were determined. Additional conductivity measurements were performed in nitrogen, to suppress the possible p-type conductivity, focusing on protonic conductivity. The maximum measured...
-
Influence of iron content on water uptake and charge transport in BaCe0.6Zr0.2Y0.2−xFexO3−δ triple-conducting oxides
PublicationIn this work, we studied the BaCe0.6Zr0.2Y0.2−xFexO3−δ system which belongs to the triple-conducting oxides (TCOs) group. The electrochemical properties of BaCe0.6Zr0.2Y0.2−xFexO3−δ were investigated using electrochemical impedance spectroscopy (EIS) and the water uptake was analyzed using thermogravimetry (TG). All investigated materials exhibited water uptake, with proton concentration increasing with decreasing iron content....
-
Effects of Na+, K+ and B3+ Substitutions on the Electrical Properties of La10Si6O27 Ceramics
PublicationDoping of Na and K at La sites and of B at Si site in La10Si6O27 with oxyapatite structure and fabrication of their ceramics were made by the solid-state reaction method. It was found that partial substitution of Na+ and K+ on La sites decreased the sinterability of the La10Si6O27 based ceramics, whereas partial substitution of B3+ on the Si site improved the sinterability. Na+ and K+ substitutions in La10−xNaxSi6O27−x and La10−xKxSi6O27−x...
-
Electrical conductivity relaxation measurements - oxidation and reduction of BaCe0.6Zr0.2Y0.1Tb0.1O3-δ
Open Research DataThe dataset consists of 2 main catalogs: measurements performed for oxidation/reduction in dry conditions and in humid conditions. For Electrical Conductivity Relaxation (ECR) measurements, platinum reversible electrodes were applied in a four-probe arrangement and the sample was measured in the ProboStat™ measurement system. The ECR measurements were...
-
Proton-Electron Hole Interactions in Sr(Ti,Fe)O3−δ Mixed-Conducting Perovskites
PublicationOxides in which total electrical conductivity is determined by the partial conductivities of three types of charge carriers i.e. holes/ electrons, oxygen ions, and protons are key components of well-functioning proton ceramic fuel cells. Apart from electrochemical properties also easily modified microstructure is an important feature of the electrodes. In the paper, a group of SrTi1−xFexO3−δ (STF, x = 0.2–0.8) perovskites prepared...
-
Effects of Na+, K+ and B3+ Substitutions on the Electrical Properties of La10Si6O27 Ceramics
PublicationDoping of Na and K at La sites and of B at Si site in La10Si6O27 with oxyapatite structure and fabrication of their ceramics were made by solid-state reaction method. It was found that partial substitution of Na+ and K+ on La sites decreased the sinterability of the La10Si6O27 based ceramics, whereas partial substitution of B3+ on Si site imporved the sinterability. Na+ and K+ substitutions in La10-xNaxSi6O27-x and La10-xKxSi6O27-x...
-
Signature of Oxide-Ion Conduction in Alkaline-Earth-Metal-Doped Y3GaO6
PublicationWe have studied alkaline-earth-metal-doped Y3GaO6 as a new family of oxide-ion conductor. Solid solutions of Y3GaO6 and 2% −Ca2+-, −Sr2+-, and −Ba2+-doped Y3GaO6, i.e., Y(3−0.06)M0.06GaO6−δ (M = Ca2+, Sr2+, and Ba2+), were prepared via a conventional solid-state reaction route. X-ray Rietveld refined diffractograms of all the compositions showed the formation of an orthorhombic structure having the Cmc21 space group. Scanning electron...
-
Water uptake kinetics and electrical transport in BaCe0.6Zr0.2Y0.1M0.1O3−δ (M = Tb, Pr, Fe) protonic conductors
PublicationBaCe0.6Zr0.2Y0.1M0.1O3−d (M = Fe, Pr, Tb) is a mixed conducting oxide in which three mobile charge carriers – oxygen ion, electron/hole, and protonic defects – are present. These types of materials have gained much interest as electrode materials for protonic ceramic fuel cells (PCFCs) and protonic ceramic electrolysis cells (PCECs). In this study, the water uptake and oxygen transport properties of different BaCe0.6Zr0.2Y0.1M0.1O3−d...
-
Characteristics of La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 3-δ -supported micro-tubular solid oxide fuel cells with LaCo 0.4 Ni 0.6-x Cu x O 3-δ cathodes
PublicationIn this study, micro-tubular solid oxide fuel cells (T-SOFCs) with extruded La0.8Sr0.2Ga0.8Mg0.2O3-δ (LSGM) electrolyte as the mechanical support and LaCo0.4Ni0.6O3-δ (LCNO) or LaCo0.4Ni0.4Cu0.2O3-δ (LCNCO) as cathodes were prepared and characterized. Partial substitution of Cu for the Ni-ion positions in the LCNO lattices was found to significantly enhance the densification and accelerate the grain growth. The porosity-corrected...
-
Effects of thermal history on the performance of low-temperature solid oxide fuel cells with Sm0.2Ce0.8O2-δ electrolyte and LiNi0.81Co0.15Al0.04O2 electrodes
PublicationIn this study, low-temperature solid oxide fuel cells with an ∼560 μm thick Sm0.2Ce0.8O2−δ (SDC) electrolyte and ∼890 μm thick LiNi0.81Co0.15Al0.04O2−δ (NCAL) electrodes are constructed and characterized under three experimental conditions. The cell with an NCAL cathode pre-reduced under an H2 atmosphere at 550 °C presents the best electrochemical performance. This is ascribed to facts that the reduction reaction generating Ni–Co...
-
Electroactive polymer/graphene oxide nanostructured composites; evidence for direct chemical interactions between PEDOT and GOx
PublicationThis work concerns electrochemical synthesis of nanocomposites consisting of conducting polymer and reduced graphene oxide (rGOx) as electrode materials for supercapacitors. The electrosynthesis was performed in an aqueous solution of the 3,4-ethylenedioxytiophene (EDOT) monomer and graphene oxide (GOx) without supporting electrolyte. The amount of GOx was optimized to obtain the best electrochemical performance of the nanocomposite...
-
The influence of crude glycerol and castor oil-based polyol on the structure and performance of rigid polyurethane-polyisocyanurate foams
PublicationIn this work, biopolyol obtained from two types of industrial crops’ processing products: crude glycerol and castor oil was used for preparation or rigid polyurethane-polyisocyanurate foams. Bio-based polyol was obtained via crude glycerol polymerization and further condensation of resulting polyglycerol with castor oil. Rigid polyurethane-polyisocyanurate foams were prepared at partial substitution (0–70 wt.%) of petrochemical...
-
Structure, Mechanical, Thermal and Fire Behavior Assessments of Environmentally Friendly Crude Glycerol-Based Rigid Polyisocyanurate Foams
PublicationIn this work, rigid polyisocyanurate foams were prepared at partial substitution (0–70 wt%) of commercially available petrochemical polyol, with previously synthesized biopolyol based on crude glycerol and castor oil. Influence of the biopolyol content on morphology, chemical structure, static and dynamic mechanical properties, thermal insulation properties, thermal stability and flammability was investigated. Incorporation of...
-
Theoretical calculation of the physico-chemical properties of 1-butyl-4-methylpyridinium based ionic liquids
PublicationACCEPTED MAIonic liquids (ILs) have attracted much attention for their unique physicochemical properties, which can be designed as needed by altering the ion combinations. Besides experimental work, numerous computational studies have been concerned with prediction of physical properties of ILs. The results of molecular dynamics simulations of ILs depend strongly on the proper force field parameterization. Classical force fields...
-
Assessment of the Bulgarian Wastewater Treatment Plants’ Impact on the Receiving Water Bodies
PublicationDeterioration of water quality is a major problem world widely according to many international non-governmental organizations (NGO). As one of the European Union (EU) countries, Bulgaria is also obliged by EU legislation to maintain best practices in assessing surface water quality and the efficiency of wastewater treatment processes. For these reasons studies were undertaken to utilize ecotoxicological (Microtox®, Phytotoxkit...