Classifying Error States of PEMFCs by Current Mapping and Cell Voltage Monitoring

Error states in PEMFC stacks typically cause distortions of the local current distribution and the cell voltage. Measuring those properties can be used for identification of those error states, e.g., membrane dry-out, channel blockage, reactant media contamination, local starvation, gross starvation, overall stack starvation and pinholes. Two techniques for online diagnosis are introduced, measuring the current density distribution by a printed circuit board, and measuring the local cell voltage by a multipoint cell voltage monitoring. A non-invasive experimental setup is proposed for both techniques to gain reliable measurement data. The relationship of the cell voltage distribution over the stack and the current density distribution within the cells is discussed and used to discriminate different error states. Experimental measurement data of those techniques is shown for several common error states. Finally, a categorization of error states is proposed, based on their characteristic patterns of disturbed local current density and cell voltage

Onset Shift of Li Plating on Si/Graphite Anodes with Increasing Si Content

Mixing graphite with Si particles in anodes of Li-ion batteries provides increased specific energy. In addition, higher Si contents lead to thinner anode coatings at constant areal capacity. In the present study, we systematically investigated the influence of the Si content on the susceptibility of Li plating on Si/graphite anodes. Si/graphite anodes with Si contents from 0 to 20.8 wt% combined with NMC622 cathodes were manufactured on pilot-scale. After initial characterization in coin half cells and by SEM, pouch full cells with fixed N/P ratios were built. Rate capability at different temperatures, and Post-Mortem analysis were carried out. Results from voltage relaxation, Li stripping, SEM measurements, glow discharge optical emission spectroscopy (GD-OES) depth profiling, and optical microscopy were validated against each other. A decreasing susceptibility to Li plating with increasing Si content in the anodes could be clearly observed. A critical C-rate was defined, at which Li plating was detected for the first time. It was also found that at 0 °C the critical C-rate increases with increasing Si contents. At 23 °C the SOC at which Li dendrites were first observed on the anode also increased with higher Si content

«Diseño para todos» en la investigación social sobre personas con discapacidad

[EN] Social studies on disability have increased in number and importance in Spain and other countries over the last few years. Nevertheless, the majority of the available sources and studies do not adequately represent this heterogeneous group, which currently makes up about 9 per cent of the Spanish population. The implementation of social measures requires representative sources and studies containing relevant information. The aim of this paper is to identify the main diffi culties involved in designing and developing social research methods concerning persons with disabilities, and offer proposals and recommendations in order to advance towards a more inclusive social research using the concepts of accessibility and design for all.[ES] Los estudios sociales sobre la discapacidad han aumentado en número e importancia en España y otros países durante los últimos años. Sin embargo, la mayoría de fuentes de información y estudios disponibles no recogen de manera adecuada la realidad de un colectivo muy heterogéneo, que supone en la actualidad aproximadamente el 9 por ciento de la población española. La implementación de medidas sociales requiere de fuentes y estudios representativos que aporten información precisa acerca de estas personas. El objetivo de esta nota es identifi car las principales difi cultades que se plantean a la hora de diseñar y llevar a la práctica metodologías de investigación social adecuadas hacia las personas con discapacidad, así como ofrecer propuestas y recomendaciones para avanzar hacia una investigación social más inclusiva, mediante los conceptos de accesibilidad y diseño para todos.Work carried out as part of the framework of research projects: “Qualitative Tracking with Young Disabled in European States. Quali-TYDES” (European Science Foundation, 09-ECRP-032) and “Hidden Innovation: paradigm shift in innovation studies” (Spanish Ministry of Economy and Competitiveness, FFI2011-25475).Peer reviewe

Peri-operative red blood cell transfusion in neonates and infants: NEonate and Children audiT of Anaesthesia pRactice IN Europe: A prospective European multicentre observational study

BACKGROUND: Little is known about current clinical practice concerning peri-operative red blood cell transfusion in neonates and small infants. Guidelines suggest transfusions based on haemoglobin thresholds ranging from 8.5 to 12 g dl-1, distinguishing between children from birth to day 7 (week 1), from day 8 to day 14 (week 2) or from day 15 (≥week 3) onwards. OBJECTIVE: To observe peri-operative red blood cell transfusion practice according to guidelines in relation to patient outcome. DESIGN: A multicentre observational study. SETTING: The NEonate-Children sTudy of Anaesthesia pRactice IN Europe (NECTARINE) trial recruited patients up to 60 weeks' postmenstrual age undergoing anaesthesia for surgical or diagnostic procedures from 165 centres in 31 European countries between March 2016 and January 2017. PATIENTS: The data included 5609 patients undergoing 6542 procedures. Inclusion criteria was a peri-operative red blood cell transfusion. MAIN OUTCOME MEASURES: The primary endpoint was the haemoglobin level triggering a transfusion for neonates in week 1, week 2 and week 3. Secondary endpoints were transfusion volumes, 'delta haemoglobin' (preprocedure - transfusion-triggering) and 30-day and 90-day morbidity and mortality. RESULTS: Peri-operative red blood cell transfusions were recorded during 447 procedures (6.9%). The median haemoglobin levels triggering a transfusion were 9.6 [IQR 8.7 to 10.9] g dl-1 for neonates in week 1, 9.6 [7.7 to 10.4] g dl-1 in week 2 and 8.0 [7.3 to 9.0] g dl-1 in week 3. The median transfusion volume was 17.1 [11.1 to 26.4] ml kg-1 with a median delta haemoglobin of 1.8 [0.0 to 3.6] g dl-1. Thirty-day morbidity was 47.8% with an overall mortality of 11.3%. CONCLUSIONS: Results indicate lower transfusion-triggering haemoglobin thresholds in clinical practice than suggested by current guidelines. The high morbidity and mortality of this NECTARINE sub-cohort calls for investigative action and evidence-based guidelines addressing peri-operative red blood cell transfusions strategies. TRIAL REGISTRATION: ClinicalTrials.gov, identifier: NCT02350348

Global wealth disparities drive adherence to COVID-safe pathways in head and neck cancer surgery

Peer reviewe

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Mitochondrial mRNA Polymorphisms in Different Arabidopsis Accessions1[W][OA]

In our analysis of 5′ and 3′ end formation in plant mitochondria, we compared the major transcript ends of all mitochondrial protein-coding genes between the three Arabidopsis (Arabidopsis thaliana) accessions Columbia (Col), C24, and Landsberg erecta (Ler). Differences between transcript patterns were found for seven genes. For atp6-2, no transcripts at all were detected in Ler. This and further analyses suggest that the atp6-2 gene arrangement is absent from the mitochondrial DNA of this accession. All other transcript polymorphisms are attributed to variations at the 5′ termini and were consistently observed in all tissues investigated. mRNA phenotyping of reciprocal Col/Ler, Col/C24, and Ler/C24 F1 hybrids revealed the differing transcript patterns of ccmC to be inherited maternally, suggesting these to arise from differences in the mitochondrial DNA. Biparental inheritance was observed for the polymorphic transcripts of nad4, nad9, ccmB, and rpl5, indicating these differences to be caused by nuclear-encoded trans-factors. Deviant transcript patterns were tested in further accessions and were found in at least three additional accessions. Detailed examination of the nad4 and the nad9 transcripts demonstrates that the respective polymorphisms affect the major mRNAs of these genes. This study shows that natural genetic variation in Arabidopsis can also affect mitochondrial mRNA end processing. These variations can now be used to identify the nuclear genes responsible, as well as the mitochondrial cis-elements required, for 5′ end generation of mitochondrial transcripts

Charge Relaxation within Silicon/Graphite Anodes – A Multi-Method Study

As silicon/graphite (SiG) composites are more commonly used as the anode active material in commercial Li-ion batteries, investigation of the (de-)lithiation behavior of the blended anodes becomes increasingly important. In this study, the charge redistribution between graphite and silicon was investigated in graphite-NMC 622 and SiG (23 wt.-% Si) – NMC 622 bilayer pouch cells using in situ and operando X-ray diffraction (XRD). In addition to XRD, ex situ and in situ optical microscopy (IOM), as well as microstructural resolved simulations using digital twins of the cells, were used. Different SOC values (0%, 25%, 50%, 75%, and 100%) and two different C-rates (0.1C and 0.5C) were compared in cells during operation and in the relaxed state. Insights into the relaxation process at 75% SOC were gained by tracking of the charge redistribution in IOM cells. Ex situ optical microscopy measurements reinforced the findings of the IOM measurements. Both XRD and optical microscopy showed the disappearance of charge in the graphite component of the SiG anode during the relaxation period (≥24h) at SOC ≤75%, indicating a redistribution of Li from graphite into Si in the anode. The simulations allowed tracking of the concentration of Li in both active material components, verifying the observations on the charge relaxation processes observed in the XRD and microscopy experiments. The gained insights can support a better understanding of aging of blended SiG anodes during operation

Critical Review of Intelligent Battery Systems: Challenges, Implementation, and Potential for Electric Vehicles

This review provides an overview of new strategies to address the current challenges of automotive battery systems: Intelligent Battery Systems. They have the potential to make battery systems more performant and future-proof for coming generations of electric vehicles. The essential features of Intelligent Battery Systems are the accurate and robust determination of cell individual states and the ability to control the current of each cell by reconfiguration. They enable high-level functions like fault diagnostics, multi-objective balancing strategies, multilevel inverters, and hybrid energy storage systems. State of the art and recent advances in these topics are compiled and critically discussed in this article. A comprising, critical discussion of the implementation aspects of Intelligent Battery Systems complements the review. We touch on sensing, battery topologies and management, switching elements, communication architecture, and impact on the single-cell. This review contributes to transferring the best technologies from research to product development