Interphase chemistry of Si electrodes used as anodes in Li-ion batteries

International audienceThe effect of the Si electrode morphology (amorphous hydrogenated silicon thin films - a-Si:H as a model electrode and Si nanowires - SiNWs electrode) on the interphase chemistry was thoroughly investigated by the surface science techniques: X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). XPS analysis shows a strong attenuation and positive shift of the Si 2p peaks after a complete charge/discharge performed in PC- and EC:DMC-based electrolytes for both electrodes (a-Si:H and SiNW), confirming a formation of a passive film (called solid electrolyte interphase - SEI layer). As evidenced from the XPS analysis performed on the model electrode, the thicker SEI layer was formed after cycling in PC-based electrolyte as compared to EC:DMC electrolyte. XPS and ToF-SIMS investigations reveal the presence of organic carbonate species on the outer surface and inorganic salt decomposition species in the inner part of the SEI layer. Significant modification of the surface morphol- ogy for the both electrodes and a full surface coverage by the SEI layer was confirmed by the scanning electron microscopy (SEM) analysis

Deep Eutectic Solvents (DESs) and their applications [forthcoming]

Deep Eutectic Solvents (DESs) and Their Application

Global Role and Burden of Influenza in Pediatric Respiratory Hospitalizations, 1982-2012:A Systematic Analysis

BACKGROUND:The global burden of pediatric severe respiratory illness is substantial, and influenza viruses contribute to this burden. Systematic surveillance and testing for influenza among hospitalized children has expanded globally over the past decade. However, only a fraction of the data has been used to estimate influenza burden. In this analysis, we use surveillance data to provide an estimate of influenza-associated hospitalizations among children worldwide. METHODS AND FINDINGS:We aggregated data from a systematic review (n = 108) and surveillance platforms (n = 37) to calculate a pooled estimate of the proportion of samples collected from children hospitalized with respiratory illnesses and positive for influenza by age group (<6 mo, <1 y, <2 y, <5 y, 5-17 y, and <18 y). We applied this proportion to global estimates of acute lower respiratory infection hospitalizations among children aged <1 y and <5 y, to obtain the number and per capita rate of influenza-associated hospitalizations by geographic region and socio-economic status. Influenza was associated with 10% (95% CI 8%-11%) of respiratory hospitalizations in children <18 y worldwide, ranging from 5% (95% CI 3%-7%) among children <6 mo to 16% (95% CI 14%-20%) among children 5-17 y. On average, we estimated that influenza results in approximately 374,000 (95% CI 264,000 to 539,000) hospitalizations in children <1 y-of which 228,000 (95% CI 150,000 to 344,000) occur in children <6 mo-and 870,000 (95% CI 610,000 to 1,237,000) hospitalizations in children <5 y annually. Influenza-associated hospitalization rates were more than three times higher in developing countries than in industrialized countries (150/100,000 children/year versus 48/100,000). However, differences in hospitalization practices between settings are an important limitation in interpreting these findings. CONCLUSIONS:Influenza is an important contributor to respiratory hospitalizations among young children worldwide. Increasing influenza vaccination coverage among young children and pregnant women could reduce this burden and protect infants <6 mo

Synthesis and characterization of single-walled carbon nanotube via low-pressure chemical vapor deposition from FeMo catalyst

International audienceMaterials science of carbon nanotubes (CNTs) lies at the intersection of various paradigms from fundamental to applied physics and chemistry. However, understanding the mechanism of CNTs formation through different concepts remains a considerable challenge. Currently, to be able to use CNTs for specific applications

Synthesis and characterization of single-walled carbon nanotube via low-pressure chemical vapor deposition from FeMo catalyst

International audienceMaterials science of carbon nanotubes (CNTs) lies at the intersection of various paradigms from fundamental to applied physics and chemistry. However, understanding the mechanism of CNTs formation through different concepts remains a considerable challenge. Currently, to be able to use CNTs for specific applications

MicroValid: A validation framework for automatically decomposed microservices

In a dynamic world of software development, the architectural styles are continuously evolving, adapting to new technologies and trends. Microservice architecture (MSA) is gaining adoption among industry practitioners due to its advantages compared to the monolithic architecture. Although MSA builds on the core concepts of Service Oriented Architecture (SOA), it pushes for a finer granularity, with stricter boundaries. Due to cost rationale, numerous companies choose to migrate from the monolithic style instead of developing from scratch. Recently, semi-automatic decomposition tools assist the migration process, yet a crucial part is still missing: validation. The current study focuses on providing a validation framework for microservices decomposed from monolithic applications and complete the puzzle of architectural migrations. From previous work we select quality attributes of microservices that may be assessed using static analysis. We then provide an implementation specification of the validation framework. We use five applications to evaluate our approach, and the results show that our solution is scalable while providing insightful measurements of the assessed quality attributes of microservices

On the dielectric behavior of annealed plasma sprayed forsterite and alumina coatings

Atmospheric plasma spray (APS) is an efficient technique for depositing high performance dielectric coatings at a low cost, with high deposition rate and on complex-shaped parts. Due to its availability, low price, ease to spray and good dielectric properties, alumina (Al2O3) is a very common choice of material for insulating applications. However, the coefficient of thermal expansion (CTE) of alumina does not represent the best match for the CTE of most metallic substrates hence alternative high CTE ceramic materials are of interest. We report on the microstructural and electrical properties of a dense high CTE forsterite (Mg2SiO4) coating deposited by APS. Annealed forsterite coatings' microstructure and dielectric properties are compared to that of annealed alumina coatings. The ceramics' electrical properties were evaluated by performing impedance measurements on as-sprayed coatings and coatings exposed to different annealing temperatures. We show that both materials exhibit important degradation after exposure to a threshold temperature. An equivalent electrical model is used to extract relevant coating properties such as resistivity and dielectric constant. The coating electrical degradation mechanisms are discussed.Peer reviewed: YesNRC publication: Ye