4 resultados para Drag force,
em Dalarna University College Electronic Archive
Resumo:
The objective with this study has been to build general models of the mechanics in tree felling with chain-saw and to compare felling torque for different tools. The theoretical models are completed and validated with a comparative study. The study includes a great number of felling tools of which some are used with different methods. Felling torque was measured using a naturally like measuring arrangement where a tree is cut at about 3.7 m height and then anchored with a dynamometer to a tree opposite to the felling direction. Notch and felling cut was made as ordinary with exception that the hinge was made extra thin to reduce bending resistance. The tree was consequently not felled during the trials and several combinations of felling tools and individuals could be used on the same tree.The results show big differences between tools, methods and persons. The differences were, however, not general, but could vary depending on conditions (first of all tree diameters). Tools and methods that push or pull on the stem are little affected by the size of the tree, while tools that press on the stump are very much dependent of a large stump-diameter. Hand force asserted on a simple pole is consequently a powerful tool on small trees. For trees of medium size there are several alternative methods with different sizes and brands of felling levers and wedges. Larger and more ungainly tools and methods like tree pusher, winch, etc. develop very high felling torque on all tree sizes. On large trees also the felling wedge and especially the use of several wedges together develop very high felling torque.
Resumo:
Crowd-pulling names or energetic activists? On symbolic capital as a power resource in the local organizational work within the global justice movement The article explores the global emergence of local Social Forums by means of an ethnographic study of the organization of the Stockholm Social Forum. In international academic debate, the forums are often discussed as a “globalization from below” and a new deliberative democratic process. However, empirical research on the organizational process, and its power relations, has been very limited. The theoretical concept symbolic capital (Bourdieu) and concepts from conversation analysis (CA) are used to analyze how power in terms of priority of interpretation is constructed in conversations between activists with differing political backgrounds. A detailed empirical analysis is based on the case of an internal discussion about inviting keynote speakers to the local forum. The results show how transnational networks and specific knowledge about the global social forum process became symbolic capital in the organizational process. Holders of this specific form of symbolic capital gained priority of interpretation in the internal discussions. This had an impact on the practical outcome of the organizational process in terms of the symbolic framing of the Social Forum. It is argued that the social forum process produces specific forms of cultural distinctions, social hierarchies and patterns of exclusion.