9 research outputs found

    Brazed metal-ceramic components for space applications

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    Brazed metal-ceramic components play an important role in the manufacturing of specialized scientific instruments for space applications, where a compact, lightweight, and robust construction is always needed. Soldering and brazing are the best joining techniques if dissimilar materials are involved. For the current ESA mission JUICE, an optimized ion source main structure consisting of a stack of concentric metal electrodes and ceramic rings was to be brazed in vacuum. In the improved design one-piece electrodes manufactured from a molybdenum-copper composite were used having the same coefficient of thermal expansion as alumina. Different coating systems were evaluated for the composite material. The effectiveness of TiAlN as diffusion barrier for gold could be demonstrated in a first brazing test between the coated Mo85Cu15 and metallized Al₂O₃ parts joined with Incusil® ABATM. Several main structures satisfying all technical requirements were successfully brazed

    The Evolution of Health Care Utilisation and Costs for Inflammatory Bowel Disease Over Ten Years.

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    Inflammatory bowel disease [IBD] places an economic strain on health systems due to expensive pharmaceutical therapy, risk of hospitalisation and surgery, and long-term monitoring. The evolving treatment guidelines advocate rapid scale-up to biologic agents in order to improve health outcomes and quality of life. This study evaluated changes in health care utilisation and expenditures for IBD in Switzerland over time. We extracted clinical, patient, and resource consumption data from the Swiss IBD Cohort Study between 2006 and 2016. Average unit costs for IBD-related events were derived from Swiss claims data and pharmaceutical price lists. We used multivariate regression, controlling for patient-level characteristics, to estimate trends and determinants of direct and indirect costs and resource utilisation. We included 2365 adults diagnosed with Crohn's disease [CD; N = 1353] and ulcerative colitis [UC; N = 1012]. From 2006-16, mean health care expenditures per patient per year were 9504 euros [70% drugs, 23% inpatient, 7% outpatient] for CD and 5704 euros [68% drugs, 22% inpatient, 10% outpatient] for UC. Health care costs increased by 7% [CD] and 10% [UC] per year, largely due to rising pharmaceutical expenditures driven by increased biologic agent use. Inpatient, outpatient, and indirect costs fluctuated and did not offset increased pharmaceutical costs. Disease characteristics were important predictors of costs. Increased expenditure for IBD was marked by a shift towards greater pharmaceutical management over the past decade. This study highlights the need to identify cost-effective treatment strategies in the face of increased uptake and expenditures associated with innovative treatments

    Polyhedral Methods for the QAP

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    For many combinatorial optimization problems investigations of associated polyhedra have led to enormous successes with respect to both theoretical insights into the structures of the problems as well as to their algorithmic solvability. Among these problems are quite prominent NP-hard ones, like, e.g., the traveling salesman problem, the stable set problem, or the maximum cut problem. In this chapter we overview the polyhedral work that has been done on the quadratic assignment problem (QAP). Our treatment includes a brief introduction to the methods of polyhedral combinatorics in general, descriptions of the most important polyhedral results that are known about the QAP, explanations of the techniques that are used to prove such results, and a discussion of the practical results obtained by cutting plane algorithms that exploit the polyhedral knowledge. We close by some remarks on the perspectives of this kind of approach to the QAP

    Endocrine and Growth Abnormalities in Children with Chronic Renal Disease

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