Anode Fabrication for Solid Oxide Fuel Cells: Electroless and Electrodeposition of Nickel and Silver into Doped Ceria Scaffolds

© 2016 The Authors.A novel fabrication method using electroless and electrodeposited Ni/Ag/GDC for SOFC anodes is presented. First a porous Ce0.9Gd0.1O2-x (GDC) scaffold was deposited on a YSZ electrolyte by screen printing and sintering. The scaffold was then metallized with silver using Tollens reaction, followed by electrodeposition of nickel from a Watts bath. The electrodes (Ni/Ag/GDC) were tested in both symmetrical and fuel cell configurations. The microstructures of the Ni/Ag/GDC anodes were analyzed using scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDX). Nano-particles of Ni formed in the porous GDC scaffold provided triple phase boundaries (TPB). The electronic conductivity of the Ni/Ag/GDC (3.5/24.7/71.8 vol%) electrode was good even at relatively low Ni volume fractions. The electrochemical performance was examined in different concentrations of humidified hydrogen (3% H2O) and over a range of temperatures (600-750 °C). The total area specific resistance (ASR) of the anode at 750 °C in humidified 97 vol% H2 was 1.12 Ω cm2, with low-frequency polarization (R-l) as the largest contributor. The electrodes were successfully integrated into a fuel cell and operated in both H2 and syngas

Focusing on the Big Picture: Insights into a Systems Approach to Deep Learning for Satellite Imagery

Deep learning tasks are often complicated and require a variety of components working together efficiently to perform well. Due to the often large scale of these tasks, there is a necessity to iterate quickly in order to attempt a variety of methods and to find and fix bugs. While participating in IARPA's Functional Map of the World challenge, we identified challenges along the entire deep learning pipeline and found various solutions to these challenges. In this paper, we present the performance, engineering, and deep learning considerations with processing and modeling data, as well as underlying infrastructure considerations that support large-scale deep learning tasks. We also discuss insights and observations with regard to satellite imagery and deep learning for image classification.Comment: Accepted to IEEE Big Data 201

Validation of a physically-based solid oxide fuel cell anode model combining 3D tomography and impedance spectroscopy

This study presents a physically-based model for the simulation of impedance spectra in solid oxide fuel cell (SOFC) composite anodes. The model takes into account the charge transport and the charge-transfer reaction at the three-phase boundary distributed along the anode thickness, as well as the phenomena at the electrode/electrolyte interface and the multicomponent gas diffusion in the test rig. The model is calibrated with experimental impedance spectra of cermet anodes made of nickel and scandia-stabilized zirconia and satisfactorily validated in electrodes with different microstructural properties, quantified through focused ion beam SEM tomography. Besides providing the material-specific kinetic parameters of the electrochemical hydrogen oxidation, this study shows that the correlation between electrode microstructure and electrochemical performance can be successfully addressed by combining physically-based modelling, impedance spectroscopy and 3D tomography. This approach overcomes the limits of phenomenological equivalent circuits and is suitable for the interpretation of experimental data and for the optimisation of the electrode microstructure

New method for the deposition of nickel oxide in porous scaffolds for electrodes in solid oxide fuel cells and electrolyzers

A simple chemical bath deposition is used to coat a complex porous ceramic scaffold with a conformal nickel layer. The resulting composite is used as a Solid Oxide Fuel Cell electrode and its electrochemical response is measured in humidified hydrogen. X-Ray tomography is used to determine microstructural parameters of the uncoated and Ni-coated porous structure, among other, the surface area to total volume, the radial pore size and size of the necks between pores

Metallizing porous scaffolds as an alternative fabrication method for solid oxide fuel cell anodes

AbstractA combination of electroless and electrolytic techniques is used to incorporate nickel into a porous Ce0.9Gd0.1O1.90 scaffold. First a porous backbone was screen printed into a YSZ electrolyte using an ink that contains sacrificial pore formers. Once sintered, the scaffold was coated with silver using Tollens' reaction followed by electrodeposition of nickel in a Watts bath. At high temperatures the silver forms droplets enabling direct contact between the gadolinia-doped ceria and nickel. Using impedance spectroscopy analysis in a symmetrical cell a total area specific resistance of 1 Ωcm2 at 700 °C in 97% H2 with 3% H2O was found, indicating the potential of this fabrication method for scaling up

Enhanced mechanical stability of Ni-YSZ scaffold demonstrated by nanoindentation and electrochemical impedance spectroscopy

The electrochemical performance of Ni-YSZ SOFC anodes can quickly degrade during redox cycling. Mechanical damage at interfaces significantly decreases the number of active triple phase boundaries. This study firstly focuses on the sintering temperature impact on YSZ scaffold mechanical properties. The YSZ scaffold sintered at 1200 °C exhibited 56% porosity, 28.3 GPa elastic modulus and 0.97 GPa hardness and was selected for further redox cycling study. The Ni infiltrated YSZ scaffold operated at 550 °C had an initial stabilized polarisation resistance equal to 0.62 Ω cm2 and only degraded to 2.85 Ω cm2 after 15 redox cycles. The active triple phase boundary density was evaluated by FIB-SEM tomography, and degraded from 28.54 μm−2 to 19.36 μm−2. The YSZ scaffold structure was robust after 15 redox cycles, as there was no observation of the framework fracturing in both SEM and FIB-SEM images, which indicated that the mechanical stability of YSZ scaffold improves the anode stability during redox cycling. Nonetheless, Ni agglomeration could not be prevented within Ni-YSZ scaffolds and this needs further consideration

Características maternas asociadas al diagnóstico de macrosomía fetal en un hospital III-1 de la capital de Perú: Maternal characteristics associated with the fetal macrosomy diagnosis in a hospital III-1 of the capital of Peru

Objective: To identify the maternal characteristics associated with the diagnosis of fetal macrosomia at Sergio E. Bernales Hospital from January to December 2018. Methods: An observational, analytical, retrospective, case-control study was carried out. The population studied was pregnant women with a diagnosis of fetal macrosomia treated in the gynecoobstetrics service of Sergio E. Bernales Hospital from January to December 2018. Through a data collection sheet, the information from the medical records was extracted; the data was then processed according to the IBM SPSS Statistics v25 program. Results: Of 532 patients studied, 133 cases and 399 controls were obtained. Maternal age varies between 14 and 45 years (average age of 27.01). A statistically significant association was found between fetal macrosomia and the following variables: post-term pregnancy (OR = 13,613 95% CI 2,901-63,891), gestational diabetes (OR 5.7 IC95% 2.5 -12.7), excessive weight gain (OR 1,833 95% CI 1,154-2,911), sex of the newborn (OR 1.83 95% CI 1.2-2.7) and age of the mother (OR 1.7 95% CI 1.0-2.9). When performing the multivariate analysis, no association was found with the variables age of the mother (P = 0.228, OR 1.510 95% CI 0.773-2.950) and BMI (P = 0.331, OR 0.740 95% CI 0.403-1.358), so they were considered confusing variables. Conclusion: The maternal characteristics associated with the diagnosis of fetal macrosomia are post-term delivery, gestational diabetes, excessive weight gain and sex of the newborn.Objetivo: Identificar cuáles son las características maternas asociadas al diagnóstico de macrosomía fetal en el Hospital Sergio E. Bernales de enero a diciembre del 2018. Métodos: Se realizó un estudio de tipo observacional, analítico, retrospectivo, de casos y controles. La población estudiada fueron las gestantes con el diagnostico de macrosomía fetal atendidas en el servicio de ginecoobstetricia del Hospital Sergio E. Bernales enero a diciembre del 2018. A través de una ficha de recolección de datos, se extrajo la información de las historias clínicas, las cuales después fueron procesadas según el programa de IBM SPSS Statistics v25. Resultados: De 532 pacientes estudiados se obtuvieron 133 casos y 399 controles. La edad materna varía entre 14 y 45 años (edad media de 27,01). Se encontró asociación estadísticamente significativa entre macrosomía fetal y las siguientes variables: embarazo postérmino (OR=13,613 IC95% 2,901-63,891), diabetes gestacional (OR 5,7 IC95%2,5 -12,7), ganancia de peso excesiva (OR 1,833 IC95%1,154-2,911), sexo del recién nacido (OR 1,83 IC95%1,2-2,7) y edad de la madre (OR 1,7 IC95%1,0-2,9). Al realizar el análisis multivariado no se encontró asociación con las variables edad de la madre (P =0,228, OR 1,510 IC95%0,773- 2,950) e IMC (P=0,331, OR 0,740 IC95%0,403-1,358), por lo que se consideraron variables confusoras. Conclusión: Las características maternas asociadas al diagnóstico de macrosomía fetal son parto postérmino, diabetes gestacional, ganancia de peso excesiva y sexo del recién nacido

Evaluación del posicionamiento preciso a través de los receptores GPS LEA-6T, NEO-M8T y ZED-F9P de bajo costo

Se comparó el posicionamiento obtenido en dos casos de estudios dependientes de las distancias (~31 y ~4.9 Km) a través del método estático mediante el uso de receptores de bajo costo de simple (LEA-6T y NEO-M8T) y doble frecuencia (ZED-F9P); tomando como referencia un receptor de orden geodésico Geomax Zenith 25. Asimismo, el posicionamiento fue evaluado con a la normativa vigente en México para el Circulo de Error Probable (CEP) y Exactitud Posicional Vertical (EPV) con una incertidumbre del 95%. Seencuentran discrepancias entre coordenadas para un mismo punto en el sistema ENU, valores mínimos de ~ 2 mm y ~ 10 mm, para una distancia ~31 y ~4.9 Km, respectivamente, obteniendo el mejor resultado con el receptor de una frecuencia LEA-M8T para la distancia de ~31 km; para el caso ~4.9 km se presenta con el receptor ZED-F9P en conjunto con una antena de orden Geodésico. Por otro lado, los resultados muestran un grado de cumplimiento en el posicionamiento de los receptores de bajo costo favorable donde; se obtienen valores de 8 mm de variación máxima para CEP; para EPV al 95% de confiabilidad, 1 cm de discrepancia. Presentando los mejores resultados los receptores LEA-6T y NEO-M8T, caso ~31 km, en cuanto a CEP y EPV.   A comparative study between the positioning obtained in two case studies depending on distances (~31 and ~4.9 km) was carried out through the static method of survey using the low-cost receivers of single (LEA-6T and NEO-M8T) and double frequency (ZED-F9P). The reference was taken as Geomax Zenith 25 geodetic order receiver. The positioning was evaluated with the current regulations in Mexico for the Circle of Probable Error (CEP) and Vertical Positional Accuracy (EPV) with an uncertainty of 95%. The discrepancies between coordinates for the same point in the ENU system were found to be the minimum values of ~ 2 mm and ~ 10 mm for a distance of ~31 and ~4.9 Km, respectively. The best results were obtained with the NEO-M8T single frequency receiver for the distance of ~31 km and for the distance of ~4.9 km, it is presented with the ZED-F9P receiver in conjunction with a geodetic antenna. Whereas on the other hand, the results show a degree of compliance in the positioning of low-cost receivers wherein the variation values of a maximum of 8 mm are obtained for CEP and for EPV 1 cm discrepancy was observed at 95% reliability. The LEA-6T and NEO-M8T receivers presented the best results for the case of ~31 km, in terms of CEP and EPV

FOTOGRAMETRÍA UAS DE LA DEGRADACIÓN ANTRÓPICA DE SUELO DE LA NANOCUENCA 9 LA MESA, ACAXOCHITLÁN, HIDALGO, MÉXICO

Unlike traditional photogrammetry, the technique of photogrammetry through unmanned aerial systems (UAS) allowsthe fast generation of information and its processing. Due to the fact that in Mexico a significant part of the surfacepresents irregular relief, the UAS technology becomes important for the fast and efficient quantification ofdegraded areas. In this study the orthomosaic and Digital Surface Model (DSM) were generated withthe objective of zoning the types of human-induced soil degradation modified for the nano-basin9 La Mesa, Acaxochitlán, which belongs to the sub-basin of the San Marcos River (RH27Cb)through UAS photogrammetry. It was found that the largest surfacearea with degradation is located in agricultural and grassland landuse. It was also found that it is possible to define areas withdegradation in greater detail, as well as to identify processesof land use change through photointerpretation of georeferencedorthomosaics.diferencia de la fotogrametría tradicional, la técnica de fotogrametría a través de sistemas aéreos no tripulados (UAS),permite la generación rápida de información y su procesamiento. Debido a que en México una parte importante de lasuperficie presenta relieve irregular, la tecnología UAS cobra importancia para la cuantificación rápida y eficiente de zonasdegradadas. En este trabajo se generó el ortomosaico y Modelo Digital de Superficie (MDS) con el objetivo de zonificar lostipos de degradación de suelo causada por el hombre modificada para la nanocuenca 9 La Mesa, Acaxochitlán pertenecientea la subcuenca del Río San Marcos (RH27Cb) a través de fotogrametría UAS. Se encontró que la mayor superficie condegradación se ubica en uso de suelo agrícola y pastizal. También se comprobó que es posible definir con mayor detallezonas con degradación, así como identificar procesos de cambio de uso de suelo a través de fotointerpretación deortomosaicos georreferenciados