26 research outputs found

    Characterization of edge damage induced on REBCO superconducting tape by mechanical slitting

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    Rare-earth barium-copper-oxide (REBCO) superconductors are high-field superconductors fabricated in a tape geometry that can be utilized in magnet applications well in excess of 20 T. Due to the multilayer architecture of the tape, delamination is one cause of mechanical failure in REBCO tapes. During a mechanical slitting step in the manufacturing process, edge cracks can be introduced into the tape. These cracks are thought to be potential initiation sites for crack propagation in the tapes when subjected to stresses in the fabrication and operation of magnet systems. We sought to understand which layers were the mechanically weakest by locating the crack initiation layer and identifying the geometrical conditions of the slitter that promoted or suppressed crack formation. The described cracking was investigated by selectively etching and characterizing each layer with scanning electron microscopy, laser confocal microscopy, and digital image analysis. Our analysis showed that the average crack lengths in the REBCO, LaMnO3 (LMO) and Al2O3 layers were 34 μm, 28 μm, and 15 μm, respectively. The total number of cracks measured in 30mmof wire length was between 3000 and 5700 depending on the layer and their crack densities were 102 cracks mm-1 for REBCO, 108 cracks mm-1 for LMO, and 183 cracks mm-1 for Al2O3. These results indicated that there are separate crack initiation mechanisms for the REBCO and the LMO layers, as detailed in the paper. With a better understanding of the crack growth behavior exhibited by REBCO tapes, the fabrication process can be improved to provide a more mechanically stable and cost-effective superconductor

    Application of the quick scan audit methodology in an industrial filter production process

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    The quick scan audit methodology (QSAM) is an established investigative tool to assess the health of business processes and supply chains within short schedules. This study extends the standard QSAM procedure to include the simulation step. It also extends the QSAM to a wider industry platform by applying it into the precision mechanical engineering industry, where managers have been under competitive pressure to reduce an industrial filter production lead time. Following a review of the relevant literature, this paper presents the research design adopted in the study. The QSAM has been conducted using various data collection techniques (such as observations, process activity mapping, interviews, questionnaires, brainstorming and access to company documents) and data analysis methods (including cause and effect analysis, Pareto analysis and time series plot). This is followed by the development of a set of improvement strategies, namely, direct information sharing, priority planning, and additional data recording and analysis. In addition to testing the potential benefits of changing scheduling approaches for the paint plant, simulation has been utilized in this study as a communication means to increase employee participation in the QSAM process and enhance the audit accuracy. It has also provided the case company with a better understanding of the behaviour and characteristics of the system under study, thus facilitating more thoughtful decisions to improve the system. The paper concludes with further research opportunities derived from this study

    A meta-analysis of genome-wide association studies for serum total IgE in diverse study populations

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    BACKGROUND: Immunoglobulin E (IgE) is both a marker and mediator of allergic inflammation. Despite reported differences in serum total IgE levels by race-ethnicity, African American and Latino individuals have not been well represented in genetic studies of total IgE. OBJECTIVE: To identify the genetic predictors of serum total IgE levels. METHODS: We used genome wide association (GWA) data from 4,292 individuals (2,469 African Americans, 1,564 European Americans, and 259 Latinos) in the EVE Asthma Genetics Consortium. Tests for association were performed within each cohort by race-ethnic group (i.e., African American, Latino, and European American) and asthma status. The resulting p-values were meta-analyzed accounting for sample size and direction of effect. Top single nucleotide polymorphism (SNP) associations from the meta-analysis were reassessed in six additional cohorts comprising 5,767 individuals. RESULTS: We identified 10 unique regions where the combined association statistic was associated with total serum IgE levels (P-value <5.0×10(−6)) and the minor allele frequency was ≥5% in two or more population groups. Variant rs9469220, corresponding to HLA-DQB1, was the most significantly associated SNP with serum total IgE levels when assessed in both the replication cohorts and the discovery and replication sets combined (P-value = 0.007 and 2.45×10(−7), respectively). In addition, findings from earlier GWA studies were also validated in the current meta-analysis. CONCLUSION: This meta-analysis independently identified a variant near HLA-DQB1 as a predictor of total serum IgE in multiple race-ethnic groups. This study also extends and confirms the findings of earlier GWA analyses in African American and Latino individuals

    Development of a Core Outcome Set for Therapeutic Studies in Eosinophilic Esophagitis (COREOS).

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    BACKGROUND Endpoints used to determine treatment efficacy in eosinophilic esophagitis (EoE) have evolved over time. With multiple novel therapies in development for EoE, harmonization of outcomes measures will facilitate evidence synthesis and appraisal when comparing different treatments. OBJECTIVE To develop a core outcome set (COS) for controlled and observational studies of pharmacologic and diet interventions in adult and pediatric patients with EoE. METHODS Candidate outcomes were generated from systematic literature reviews and patient engagement interviews and surveys. Consensus was established using an iterative Delphi process, with items voted on using a 9-point Likert scale and with feedback from other participants to allow score refinement. Consensus meetings were held to ratify the outcome domains of importance and the core outcome measures. Stakeholders were recruited internationally and included adult and pediatric gastroenterologists, allergists, dieticians, pathologists, psychologists, researchers, and methodologists. RESULTS The COS consists of four outcome domains for controlled and observational studies: histopathology, endoscopy, patient-reported symptoms, and EoE-specific quality of life (QoL). A total of 69 stakeholders (response rate 95.8%) prioritized 42 outcomes in a two-round Delphi process and the final ratification meeting generated consensus on 33 outcome measures. These included measurement of the peak eosinophil count, EoE Histology Scoring System, EoE Endoscopic Reference Score, and patient-reported measures of dysphagia and QoL. CONCLUSIONS This interdisciplinary collaboration involving global stakeholders has produced a COS that can be applied to adult and pediatric studies of pharmacologic and diet therapies for EoE, which will facilitate meaningful treatment comparisons and improve the quality of data synthesis

    Valuing Public Goods: The Life Satisfaction Approach

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    "This paper discusses a novel approach to elicit people's preferences fornpublic goods, namely the life satisfaction approach. Reported subjective well-beingndata are used to directly evaluate utility consequences of public goods. The strengthsnof this approach are compared to traditional approaches and identification issues arenaddressed. Moreover, it is applied to estimate utility losses caused by terroristnactivities in France, the UK and the Republic of Ireland. Terrorism in these countriesndepresses life satisfaction in a sizeable and robust way. However, the calculation ofnthe trade-off between terrorism and income requires improved measurement of thenmarginal utility of income.
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