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

Implications for Dual Language Administrative Leadership: A Comparison of the English Reading Achievement of Third Grade Students among Three Instructional Programs in a Rural School District

This quantitative study is derived from a need to know how the leadership can support the teachers in a Two Way Dual Language (TWDL) program and a need of a comparative analysis to compare the English reading Texas Assessment of Knowledge and Skills (TAKS) scores achievement of Spanish and English speakers in third grade enrolled in a Two Way Dual Language (TWDL), Bilingual Transitional (BT) program and an English-only (EO) instructional program in a rural district. A comparative analysis was conducted for the following comparisons: (a) compare the TAKS reading scores of native speaker of Spanish in a Two Way Dual Language program to native speaker of Spanish in a Bilingual Transitional program (b) compare the English TAKS reading scores of native speakers of Spanish (NSOS) in a Two Way Dual Language program to native speakers of English (NSOE) in an English-only program (c) compare the English TAKS reading scores of native speaker of English in a Two Way Dual Language program to native speaker of English in an English-only program (d) compare English TAKS reading scores of native speaker of English to the native speaker of Spanish in a Two Way Dual Language program. The research indicates that English TAKS scores of native speaker of English in the Dual Language program had a higher score than those English reading TAKS scores of native speaker of English in the English-only program. The English reading TAKS scores of native speaker of Spanish in the Dual Language Program indicated no evidence for the difference in the English reading scores between the native speakers of English in the English-only program. Also, the English reading TAKS scores of native speaker of English in the Dual Language program had higher English reading TAKS scores than native speaker of Spanish in the Dual Language Program. The participants consisted of 205 students: 46 native speakers of Spanish (NSOS) and 162 native speakers of English (NSOE)

The Skills of Female Immigrants to Australia, Canada, and the United States

Census data for 1990/91 indicate that Australian and Canadian female immigrants appear to have higher levels of English fluency, education, and income (relative to natives) than do U.S. female immigrants. This skill deficit for U.S. female immigrants arises in large part because the United States receives a much larger share of immigrants from Latin America than do the other two countries. However, even among women originating outside Latin America, the proportion of foreign-born women in the United States who are fluent in English is much lower than among foreign-born women in Australia. Furthermore, immigrant/native education gaps are reduced but not eliminated by the exclusion of Latin American women from the analysis. In contrast, other evidence for men suggests that the gap in observed skills among male immigrants to the United States is completely eliminated when Latin American immigrants are excluded from the estimation sample (Borjas, 1993; Antecol, et al., 2001). The importance of national origin and the general consistency in the results for men (who are routinely subjected to the selection criteria of various immigration programs) and women (who are not) suggests that many factors other than immigration policy per se are at work in producing skill variation among these three immigration streams.

Group B streptococcal infection and activation of human astrocytes.

BACKGROUND:Streptococcus agalactiae (Group B Streptococcus, GBS) is the leading cause of life-threatening meningitis in human newborns in industrialized countries. Meningitis results from neonatal infection that occurs when GBS leaves the bloodstream (bacteremia), crosses the blood-brain barrier (BBB), and enters the central nervous system (CNS), where the bacteria contact the meninges. Although GBS is known to invade the BBB, subsequent interaction with astrocytes that physically associate with brain endothelium has not been well studied. METHODOLOGY/PRINCIPAL FINDINGS:We hypothesize that human astrocytes play a unique role in GBS infection and contribute to the development of meningitis. To address this, we used a well- characterized human fetal astrocyte cell line, SVG-A, and examined GBS infection in vitro. We observed that all GBS strains of representative clinically dominant serotypes (Ia, Ib, III, and V) were able to adhere to and invade astrocytes. Cellular invasion was dependent on host actin cytoskeleton rearrangements, and was specific to GBS as Streptococcus gordonii failed to enter astrocytes. Analysis of isogenic mutant GBS strains deficient in various cell surface organelles showed that anchored LTA, serine-rich repeat protein (Srr1) and fibronectin binding (SfbA) proteins all contribute to host cell internalization. Wild-type GBS also displayed an ability to persist and survive within an intracellular compartment for at least 12 h following invasion. Moreover, GBS infection resulted in increased astrocyte transcription of interleukin (IL)-1β, IL-6 and VEGF. CONCLUSIONS/SIGNIFICANCE:This study has further characterized the interaction of GBS with human astrocytes, and has identified the importance of specific virulence factors in these interactions. Understanding the role of astrocytes during GBS infection will provide important information regarding BBB disruption and the development of neonatal meningitis

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