579 research outputs found

    Factors affecting the occurrence of bark- and wood-boring beetles on Scots pine logging residues from pre-commercial thinning

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    A total of480 Scots pine (Pinus sylvestris L.) trees felled during pre-commercial thinning in a single stand in the Drahanska Highlands in the Czech Republic were examined for the occurrence of bark- and wood-boring beetles. Thinning was performed on different dates during 2006 and 2007 (February, May, August and November). Half of the felled trees were cut into 1 m-long sections, and the rest were left whole. The fauna inhabiting the logging residues were investigated by peeling off the bark ofthe felled trees during the first six months of the vegetative period following felling. The studied logging residues hosted species-rich assemblages of bark- and wood-boring beetles (28 species identified), including numerous populations of several pest species (Pityogenes chalcographus, Tomicus minor and Tomicus piniperda). The occurrence of species was significantly affected mainly by the part of the tree and its diameter and bark thickness and by the felling date and post-felling cutting of the trees

    The Tin Man Needs a Heart: A Proposed Framework for the Regulation of Bioprinted Organs

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    Each day, seventeen people die in the United States while waiting for an organ transplant. At least part of this need could be met by bioprinting, a technology that allows the on-demand production of custom-sized organs from a patient’s own cells. The field of bioprinting is progressing rapidly: the first bioprinted organs have already entered the clinic. Yet, developers of bioprinted organs face significant uncertainty as to how their potentially lifesaving products will be regulated—and by which government agency. Such regulatory uncertainty has the potential to decrease investment and stifle innovation in this promising technological field. This Note examines how the current framework for the regulation of medical products and human organs might be applied to bioprinted organs. This Note concludes that the existing regulatory schemes do not sufficiently address the specific regulatory needs created by bioprinted organs, which are uniquely interdisciplinary materials. Therefore, this Note proposes a new regulatory framework to reduce uncertainty for bioprinted organ developers and to promote patient access to these bioprinted materials that might soon serve as safe and effective replacements for donor organs

    Spreading with variable viscosity

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    Ausbreitung mit variabler Viskosität Die isotherme Ausbreitung eines Volumenstromes, , in Form von dünnen Schichten kann mit Hilfe selbstähnlicher Lösungen beschrieben werden (Huppert). Für die axialsymmetrische Ausbreitung eines konstanten Volumens mit einer variablen Viskosität von der Form existieren ebenfalls selbstähnliche Lösungen (Sakimoto, Zuber). Dieses Ergebnis wird auf den Fall einer eindimensionalen und einer axialsymmetrischen Ausbreitung für alle , erweitert

    IoT applications utilizing excess heat in electrical lighting fixtures

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    The development of IoT instrumentation will always be strongly influenced by the properties of the power supply system. A large number of IoT nodes creates a danger of extra expenditures when changing the battery. For this reason, the development of supply nodes tends to prefer systems capable of battery-less operation, obtaining energy from other sources. This article deals with an alternative method of electrical energy acquisition form the excessive heat appearing in LED lighting fixtures utilizing large-area LED chips. A Peltier cell was used for the conversion of heat energy to electrical energy, connected as thermo-electric generator into the thermal chain
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