46 research outputs found

    Weatherability and Leach Resistance of Wood Impregnated with Nano-Zinc Oxide

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    Southern pine specimens vacuum-treated with nano-zinc oxide (nano-ZnO) dispersions were evaluated for leach resistance and UV protection. Virtually, no leaching occurred in any of the nano-ZnO–treated specimens in a laboratory leach test, even at the highest retention of 13 kg/m3. However, specimens treated with high concentrations of nano-ZnO showed 58–65% chemical depletion after 12 months of outdoor exposure. Protection from UV damage after 12 months exposure is visibly obvious on both exposed and unexposed surfaces compared to untreated controls. Graying was markedly diminished, although checking occurred in all specimens. Nano-zinc oxide treatment at a concentration of 2.5% or greater provided substantial resistance to water absorption following 12 months of outdoor exposure compared to untreated and unweathered southern pine. We conclude that nano-zinc oxide can be utilized in new wood preservative formulations to impart resistance to leaching, water absorption and UV damage of wood

    Bronchopulmonary dysplasia: clinical aspects and preventive and therapeutic strategies

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    Abstract Background Bronchopulmonary dysplasia (BPD) is the result of a complex process in which several prenatal and/or postnatal factors interfere with lower respiratory tract development, leading to a severe, lifelong disease. In this review, what is presently known regarding BPD pathogenesis, its impact on long-term pulmonary morbidity and mortality and the available preventive and therapeutic strategies are discussed. Main body Bronchopulmonary dysplasia is associated with persistent lung impairment later in life, significantly impacting health services because subjects with BPD have, in most cases, frequent respiratory diseases and reductions in quality of life and life expectancy. Prematurity per se is associated with an increased risk of long-term lung problems. However, in children with BPD, impairment of pulmonary structures and function is even greater, although the characterization of long-term outcomes of BPD is difficult because the adults presently available to study have received outdated treatment. Prenatal and postnatal preventive measures are extremely important to reduce the risk of BPD. Conclusion Bronchopulmonary dysplasia is a respiratory condition that presently occurs in preterm neonates and can lead to chronic respiratory problems. Although knowledge about BPD pathogenesis has significantly increased in recent years, not all of the mechanisms that lead to lung damage are completely understood, which explains why therapeutic approaches that are theoretically effective have been only partly satisfactory or useless and, in some cases, potentially negative. However, prevention of prematurity, systematic use of nonaggressive ventilator measures, avoiding supraphysiologic oxygen exposure and administration of surfactant, caffeine and vitamin A can significantly reduce the risk of BPD development. Cell therapy is the most fascinating new measure to address the lung damage due to BPD. It is desirable that ongoing studies yield positive results to definitively solve a major clinical, social and economic problem

    Theologumena Aristotelia : dissertatio inauguralis / auctor O.H. Weichelt.

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    Erfassung oekologisch relevanter Zustandsparameter in anthropogen stark beanspruchten Gebieten auf der Grundlage von PRIRODA-Multisensor-Daten Forschungsbericht

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    Opportunities for making use of PRIRODA multi-sensor remote surveying data in the monitoring of ecologically relevant land surface processes in areas heavily influenced by antropogenous activities are being investigated in accordance with the conditions of the international PRIRODA programme. The project under report deals particularly with urbanization processes in the urban/suburban area of a large city (for instance Berlin) and land reclamation processes in spoil banks of decommissioned or still active brown coal open-pit mines (for instance, Welzow-Sued). Regarding both issues, a methodological approach was hammered out and tested by the project in accordance with its aims. (orig./SR)SIGLEAvailable from TIB Hannover: F97B2137+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

    Riccati-Based Boundary Feedback Stabilization of Incompressible Navier-Stokes Flow

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    Optimal Control-Based Feedback Stabilization of Multi-Field Flow Problems

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