165 research outputs found

    The structural behavior of tiled laminate GFRP composites, a class of robust materials for civil applications

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    This paper focuses on the structural behavior of tiled laminate composites. Such laminates, in which the plies are not parallel to the outer surfaces are found in GFRP bridge deck panels. The technology is developed for the construction of robust GFRP panels useful in highly loaded structures such as bridges or lock gates. In civil structures, the drawback in traditional FRP sandwich structures has always been debonding of skin and core. Such a debonding problem may occur after unintentional impact, followed by fatigue loading. Through the concept of using overlapping Z-shaped and two-flanged web laminates, alternating with polyurethane foam cores, debonding is no longer possible in vacuum infused GFRP bridge deck panels. In such panels, the fibers in the upper and lower skins as well as in the vertical webs run in all directions, rendering a resin-dominated crack propagation impossible. As a result of the integration of core and skin reinforcement, a skin material is created in which the reinforcement is not parallel to the outer surfaces, but tiled. Based on experimental results and numerical simulations the relevance of tiled laminates for civil applications is demonstrated

    The influence of inorganic and organic pollutants on the rate of reproduction of a marine hypotrichous ciliate: <i>Euplotes vannus</i> Muller

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    Within the Belgian interdisciplinary research program "Mathematical model of the North-Sea", experiments are being carried out in order to determine the toxicity of various inorganic and organic compounds on marine pelagic and benthic organisms. Several concentrations of 5 heavy metal ions, 5 common pesticides and one PCB have been tested. The present report concerns the effect of lead, copper, mercury, zinc and cadmium ions, as well as DDT, DDE, hexachlorobenzene, heptachlor, hexachlorcyclohexane and Aroclor ® 1245, on the rate of reproduction of a common marine hypotrichous ciliate: Euplotes vannus Muller. Among the heavy metals tested mercury is the most toxic: total inhibition at the 1 ppm level; copper gives a 50 % inhibition at 1 ppm and is lethal at 10 ppm. Lead, cadmium and zinc start to affect the rate of division between 1 and 10 ppm, total inhibition occurring at 100 ppm. The organic pollutants tested seem to be much less toxic; indeed the highest concentration tested (10 ppm) reduces the rate of reproduction only for about 10 %

    Outcomes of ICU patients with and without perceptions of excessive care:a comparison between cancer and non-cancer patients

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    BACKGROUND: Whether Intensive Care Unit (ICU) clinicians display unconscious bias towards cancer patients is unknown. The aim of this study was to compare the outcomes of critically ill patients with and without perceptions of excessive care (PECs) by ICU clinicians in patients with and without cancer.METHODS: This study is a sub-analysis of the large multicentre DISPROPRICUS study. Clinicians of 56 ICUs in Europe and the United States completed a daily questionnaire about the appropriateness of care during a 28-day period. We compared the cumulative incidence of patients with concordant PECs, treatment limitation decisions (TLDs) and death between patients with uncontrolled and controlled cancer, and patients without cancer.RESULTS: Of the 1641 patients, 117 (7.1%) had uncontrolled cancer and 270 (16.4%) had controlled cancer. The cumulative incidence of concordant PECs in patients with uncontrolled and controlled cancer versus patients without cancer was 20.5%, 8.1%, and 9.1% (p &lt; 0.001 and p = 0.62, respectively). In patients with concordant PECs, we found no evidence for a difference in time from admission until death (HR 1.02, 95% CI 0.60-1.72 and HR 0.87, 95% CI 0.49-1.54) and TLDs (HR 0.81, 95% CI 0.33-1.99 and HR 0.70, 95% CI 0.27-1.81) across subgroups. In patients without concordant PECs, we found differences between the time from admission until death (HR 2.23, 95% CI 1.58-3.15 and 1.66, 95% CI 1.28-2.15), without a corresponding increase in time until TLDs (NA, p = 0.3 and 0.7) across subgroups.CONCLUSIONS: The absence of a difference in time from admission until TLDs and death in patients with concordant PECs makes bias by ICU clinicians towards cancer patients unlikely. However, the differences between the time from admission until death, without a corresponding increase in time until TLDs, suggest prognostic unawareness, uncertainty or optimism in ICU clinicians who did not provide PECs, more specifically in patients with uncontrolled cancer. This study highlights the need to improve intra- and interdisciplinary ethical reflection and subsequent decision-making at the ICU.</p
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