An audiogram is not sufficient to indicate cochlear dead regions. Aim: To investigate cochlear dead regions in sensorineural hearing loss subjects using the TEN test. Site: CEDALVI/ HRAC-USP-Bauru/Sao Paulo/Brazil, Au...
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This paper presents a diagnosis framework based on a qualitative model of the process. Starting from a dynamic abstraction procedure under a defined operating mode a fuzzy partitioning of the variables evolution is ma...
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We generalize the definition of an antiregular graph by subjecting antiregularity to the presence of a given set P of graph properties. In this paper, we study the case where this set contains only vertex-connectivity...
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The pervoskite material, La0.75Sr0.25Cr 0.5Mn0.5O3 (LSCM), was synthesized through solid-state reactions and successfully applied as anode in solid oxide fuel cell for direct oxidation of methane. Optimum sintering te...
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The pervoskite material, La0.75Sr0.25Cr 0.5Mn0.5O3 (LSCM), was synthesized through solid-state reactions and successfully applied as anode in solid oxide fuel cell for direct oxidation of methane. Optimum sintering temperature of 1200°C was found for the LSCM/YSZ composite anode (50 wt% LSCM/50 wt% YSZ). Although the performance of the composite anode is lower than a Ni/YSZ anode, it exhibits high stability in methane. No carbon deposition and performance deterioration were observed for the LSCM/YSZ composite anode even if the dry methane was fed into the anode as the fuel. The observed OCV in 3% H2O-97% CH 4/Air for LSCM/YSZ/Pt system is much lower than the theoretical value calculated from the equilibrium concentration of the mixture gases, CH 4, CO, CO2, H2O and H2, implying the slow steam reforming processes of Cut at LSCM surface. The voltage difference between the experimental and simulation results decreases with the increase of the operating temperature (0.34 V at 750°C and 0.21 V at 950°C) suggesting that the high operating temperature favors the steam reforming processes of CU4 at LSCM surface.
The initial stages of the interaction between the Fe-Cr alloy metallic interconnect and Sr-doped LaMnO3 (LSM) electrode a of solid oxide fuel cell (SOFC) were investigated under cathodic polarization at 700-900°C...
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The initial stages of the interaction between the Fe-Cr alloy metallic interconnect and Sr-doped LaMnO3 (LSM) electrode a of solid oxide fuel cell (SOFC) were investigated under cathodic polarization at 700-900°C. Deposition of Cr species occurred on the Y2O3-ZrO 2 (YSZ) electrolyte surface with no preferential deposition at the three phase boundary areas at the LSM electrode/YSZ electrolyte interface region. The Cr deposits were Cr2U3 fine grains and (Cr,Mn)3O4 spinel crystals. With the decrease of temperature the Cr species deposition reduced significantly, probably due to the significant reduction in the partial pressure of the gaseous Cr species and the cationic diffusion in the LSM electrode. The results clearly demonstrated that the deposition of Cr species at the LSM electrode/YSZ electrolyte is basically a chemical reaction and is controlled by the nucleation reaction between Mn 2+ species generated under cathodic polarization potential and gaseous Cr species.
A bilayered yttria-doped bismuth (YDB) and gadolinia-doped ceria (GDC) composite electrolyte has been developed using painting/screen printing method. SOFC fabricated from the composite electrolyte showed 70-100 mV in...
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A bilayered yttria-doped bismuth (YDB) and gadolinia-doped ceria (GDC) composite electrolyte has been developed using painting/screen printing method. SOFC fabricated from the composite electrolyte showed 70-100 mV increase in open-circuit potential at 500°C, depending on the thickness ratio of YDB layer to GDC substrate, as compared to that from a single GDC layer. Moreover, under fuel cell operation condition, YDB/GDC composite electrolyte demonstrated higher specific conductivity than single GDC layer electrolyte at 600°C. These results showed the YDB/GDC composite electrolyte as a promising candidate for electrolyte for low temperature solid oxide fuel cells.
The effect of polarization on the electrode behavior and microstructure of freshly-prepared (La0.8Sr0.2)0.9MnO3 (LSM) electrodes was investigated. The electrode polarization (i.e., interface) resistance (RE) decreased...
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The effect of polarization on the electrode behavior and microstructure of freshly-prepared (La0.8Sr0.2)0.9MnO3 (LSM) electrodes was investigated. The electrode polarization (i.e., interface) resistance (RE) decreased significantly with the cathodic polarization while in the case of the anodic polarization RE increased initially, followed by a gradual decrease. In addition, the polarization treatment has significant effect on the microstructure of the LSM electrode. The original and large agglomerates in freshly-prepared LSM electrodes were broken down into sphere-shaped grains when exposed to cathodic or anodic current passage of 200 mAcm-2 at 800°C in air for 3 hr. The grain growth of the LSM electrodes was inhibited under cathodic polarization as compared to that under open circuit. This explains the observed high stability of the LSM cathode under solid oxide fuel cell operation conditions. The cathodic or anodic polarization treatment also has significant effect on the morphology and topography of the LSM electrode/Y2O3-ZrO2 (YSZ) electrolyte interface.
The Process Approach is a method to solving problems in Operations Strategy Management (OMS).This method drives the conception and development of an operationalization process of conceptualframeworks,
The Process Approach is a method to solving problems in Operations Strategy Management (OMS).This method drives the conception and development of an operationalization process of conceptualframeworks,
This paper presents a diagnosis framework based on a qualitative model of the process. Starting from a dynamic abstraction procedure under a defined operating mode a fuzzy partitioning of the variables evolution is ma...
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This paper presents a diagnosis framework based on a qualitative model of the process. Starting from a dynamic abstraction procedure under a defined operating mode a fuzzy partitioning of the variables evolution is made, defining for each measured or observable variable a number of qualitative states. Then time Fuzzy intervals representing the moment of state change are defined. The process behaviour of the operating mode is represented by Time Fuzzy Petri nets (TFPN) model and its evolution is the consequence of events detection due to the partitioning bounds crossing. According to the membership possibility of an event to the estimated time interval and to fuzzy influence knowledge, it is possible to reason about a fault occurrence. The fuzzy data issue from the TFPN components allows evaluating the causes of the fault or failure mode. A model-based diagnosis of a hybrid system is presented.
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