930 research outputs found

    Investigating microstructural evolution during the electroreduction of UO2 to U in LiCl-KCl eutectic using focused ion beam tomography

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    Reprocessing of spent nuclear fuels using molten salt media is an attractive alternative to liquid-liquid extraction techniques. Pyroelectrochemical processing utilizes direct, selective, electrochemical reduction of uranium dioxide, followed by selective electroplating of a uranium metal. Thermodynamic prediction of the electrochemical reduction of UO2 to U in LiCl-KCl eutectic has shown to be a function of the oxide ion activity. The pO2āˆ’ of the salt may be affected by the microstructure of the UO2 electrode. A uranium dioxide filled ā€œmicro-bucketā€ electrode has been partially electroreduced to uranium metal in molten lithium chloride-potassium chloride eutectic. This partial electroreduction resulted in two distinct microstructures: a dense UO2 and a porous U metal structure were characterised by energy dispersive X-ray spectroscopy. Focused ion beam tomography was performed on five regions of this electrode which revealed an overall porosity ranging from 17.36% at the outer edge to 3.91% towards the centre, commensurate with the expected extent of reaction in each location. The pore connectivity was also seen to reduce from 88.32% to 17.86% in the same regions and the tortuosity through the sample was modelled along the axis of propagation of the electroreduction, which was seen to increase from a value of 4.42 to a value of infinity (disconnected pores). These microstructural characteristics could impede the transport of O2āˆ’ ions resulting in a change in the local pO2āˆ’ which could result in the inability to perform the electroreduction

    On the origin and application of the Bruggeman Correlation for analysing transport phenomena in electrochemical systems

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    The widely used Bruggeman equations correlate tortuosity factors of porous media with their porosity. Finding diverse application from optics to bubble formation, it received considerable attention in fuel cell and battery research, recently. The ability to estimate tortuous mass transport resistance based on porosity alone is attractive, because direct access to the tortuosity factors is notoriously difficult. The correlation, however, has limitations, which are not widely appreciated owing to the limited accessibility of the original manuscript. We retrace Bruggemans derivation, together with its initial assumptions, and comment on validity and limitations apparent from the original work to offer some guidance on its use.<br/

    The resource group method in severe mental illness:Study protocol for a randomized controlled trial and a qualitative multiple case study

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    Background The resource group method provides a structure to facilitate patientsā€™ empowerment and recovery processes, and to systematically engage significant others in treatment and care. A patient chooses members of a resource group (RG) that will work together on fulfilling patientsā€™ recovery plan. By adopting shared decision-making processes and stimulating collaboration of different support systems, a broad and continuous support of patientsā€™ chosen goals and wishes is preserved and problem solving and communication skills of the RG members are addressed. Objective The objectives of this study are (1) to establish the effectiveness of the RG method in increasing empowerment in patients with severe mental illnesses (SMI) in the Netherlands; (2) to investigate the cost-effectiveness and cost utility of the RG method; and (3) to qualitatively explore its dynamics and processes. Methods/design This multisite randomized controlled trial will compare the effects of the RG-method integrated in Flexible Assertive Community Treatment (FACT) (90 patients) with those of standard FACT (90 patients). Baseline assessments and 9-month and 18-month follow-up assessments will be conducted in face-to-face home visits. The primary outcome measure, empowerment, will be assessed using the Netherlands Empowerment List (NEL). The secondary outcomes will be quality of life (MANSA); personal, community and clinical recovery (I.ROC); general, social and community functioning (WHODAS 2.0); general psychopathological signs and symptoms (BSI-18); and societal costs (TiC-P). An economic evaluation of the cost-effectiveness and cost utility of the RG method will also be conducted. A qualitative multiple case-study will be added to collect patientsā€™, RG membersā€™ and professionalsā€™ perspectives by in-depth interviews, observations and focus groups. Discussion This trial will be the first to study the effects of the RG method on empowerment in patients with SMI. By combining clinical-effectiveness data with an economic evaluation and in-depth qualitative information from primary stakeholders, it will provide a detailed overview of the RG method as a mean of improving care for patients with SMI

    A Comparison of Women of Color and Non-Hispanic White Women on Factors Related to Leaving a Violent Relationship

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    This study compares women of color and non-Hispanic White women regarding the influence of socioeconomic status, family investment, and psychological abuse on leaving a violent relationship. It was found that most women who left stayed away for less than a month. Women of color and non-Hispanic White women did not differ in their length or rate of leaving, although women of color left more frequently when they did leave. Factors associated with leaving for both groups were threat with a weapon, psychological abuse, being single, and having fewer adults in the household. Women of color with higher socioeconomic status were less likely to leave, which was not the case for non-Hispanic White women. Non-Hispanic White women were more likely to leave if they had lived with their partners less than 5 years and had children at home.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90886/1/Lacey-Saunders-Zhang 2011-Women of color vs white women - factors in leaving violent relationahip JIV .pd

    Attachment as a framework to facilitate empowerment for people with severe mental illness

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    Objectives:Ā  Recovery and empowerment have evolved into key objectives in the treatment and care of people with severe mental illness (SMI), and interest has grown in the role of social relationships in recovery. This study is the first to explore whether attachment styles are related to levels of empowerment, and secondly, whether attachment anxiety and attachment avoidance are associated with lower empowerment levels, independently of quality and frequency of social contact.Ā  Design:Ā  We used a cross-sectional design. Methods: In a sample of 157 participants with SMI in outpatient care, associations between attachment (Revised Adult Attachment Scale), self-reported social functioning, and empowerment (Netherlands Empowerment List) were assessed.Ā  Results:Ā  Attachment anxiety and attachment avoidance were both associated with lower levels of empowerment. A stepwise multiple regression analysis showed that the prediction of empowerment was significantly improved by adding attachment anxiety and attachment avoidance to quality and frequency of social contact. Attachment anxiety, attachment avoidance, and quality of social contact were significant predictors; frequency of social contact was not.Ā  Conclusions:Ā  Although our design does not allow causal conclusions, our results highlight the importance of interpersonal processes and behaviours as routes to improving empowerment for people with SMI. A promising approach might thus consist of securing attachment bonds with significant others so that the self and the other are perceived as reliable resources. Our findings also feature the importance of reciprocity and equality in social relationships. Taken together, our study emphasizes the value of social, contextualized interventions in recovery work for people with SMI.Ā  Practitioner points:Ā  Working towards attachment safety in interpersonal relations may be important in recovery-oriented treatment and care for people with severe mental illness (SMI). Helping people with SMI to recognize and change how they tend to relate themselves to others may promote engagement and effectiveness of recovery-oriented treatment and care. Reciprocity and equality in social relationships as vital complements to the more one-sided nature of ā€˜standing alongsideā€™ and offering support may be important requisites for empowerment

    Tracking internal temperature and structural dynamics during nail penetration of lithium-ion cells

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    Mechanical abuse of lithium-ion batteries is widely used during testing to induce thermal runaway, characterize associated risks, and expose cell and module vulnerabilities. However, the repeatability of puncture or ā€˜nail penetrationā€™ tests is a key issue as there is often a high degree of variability in the resulting thermal runaway process. In this work, the failure mechanisms of 18650 cells punctured at different locations and orientations are characterized with respect to their internal structural degradation, and both their internal and surface temperature, all of which are monitored in real time. The initiation and propagation of thermal runaway is visualized via high-speed synchrotron X-ray radiography at 2000 frames per second, and the surface and internal temperatures are recorded via infrared imaging and a thermocouple embedded in the tip of the penetrating nail, respectively. The influence of the nail, as well as how and where it penetrates the cell, on the initiation and propagation of thermal runaway is described and the suitability of this test method for representing in-field failures is discussed

    Precautionary Savings, Illiquid Assets, and the Aggregate Consequences of Shocks to Household Income Risk

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    Households face large income uncertainty that varies substantially over the business cycle. We examine the macroeconomic consequences of these variations in a model with incomplete markets, liquid and illiquid assets, and a nominal rigidity. Heightened uncertainty depresses aggregate demand as households respond by hoarding liquid ā€œpaperā€ assets for precautionary motives, thereby reducing both illiquid physical investment and consumption demand. We document the empirical response of portfolio liquidity and aggregate activity to surprise changes in idiosyncratic income uncertainty and find both to be quantitatively in line with our model. The welfare consequences of uncertainty shocks and of the policy response thereto depend crucially on a household's asset positio

    Concurrent Acquisition of a Single Nucleotide Polymorphism in Diverse Influenza H5N1 Clade 2.2 Sub-clades

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    Highly pathogenic Influenza A H5N1 was first identified in Guangdong Province in 1996, followed by human cases in Hong Kong in 1997. The number of confirmed human cases now exceeds 300, and the associated Case Fatality Rate exceeds 60%. The genetic diversity of the serotype continues to increase. Four distinct clades or sub-clades have been linked to human cases. The gradual genetic changes identified in the sub-clades have been attributed to copy errors by viral encoded polymerases that lack an editing function, thereby resulting in antigenic drift. We report here the concurrent acquisition of the same polymorphism by multiple, genetically distinct, clade 2.2 sub-clades in Egypt, Russia, and Ghana. These changes are not easily explained by the current theory of &#x201c;random mutation&#x201d; through copy error, and are more easily explained by recombination with a common source. This conclusion is supported by additional polymorphisms shared by clade 2.2 isolates in Egypt and Germany

    Aggregation of Single Nucleotide Polymorphisms in a Human H5N1 Clade 2.2 Hemagglutinin

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    The evolution of H5N1 has attracted significant interest 1-4 due to linkages with avian 5,6 and human infections 7,8. The basic tenets of influenza genetics 9 attribute genetic drift to replication errors caused by a polymerase complex that lacks a proof reading function. However, recent analysis 10 of swine influenza genes identifies regions copied with absolute fidelity for more than 25 years. In addition, polymorphism tracing of clade 2.2 H5N1 single nucleotide polymorphisms identify concurrent acquisition 11 of the same polymorphism onto multiple genetic backgrounds in widely dispersed geographical locations. Here we show the aggregation of regional clade 2.2 polymorphisms from Germany, Egypt, and sub-Sahara Africa onto a human Nigerian H5N1 hemagglutinin (HA), implicating recombination in the dispersal and aggregation of single nucleotide polymorphisms from closely related genomes
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