4 resultados para farm tools
em Dalarna University College Electronic Archive
Resumo:
Choosing a new plastic material for a container includes several different steps. In this case,the Finnish company Hackman needed a new type of packaging material for theircutlery- and kitchentool series »Hackman tools«. The project was carried out in cooperationwith the design agency Ytterborn & Fuentes, which has Hackman as a client.Several different demands were put on the material in order to fulfill as many of the clientswishes as possible. The most urgent problem with the existing container was the difficultysfor the customer to clearly see the contents in the container. Because of this problemthe customer tried to open the container in the shop. To avoid this from happening,Hackman wanted a more transparent plastic material that still fulfilled all other necessaryproperties such as strength, viscosity, printability, sealability and exhaustion strength.The final result and recommendation of a polypropylen-plastic (Evacast) was based ondetailed studies of packaging plastics and their properties as well as discussions with plasticconvertersand suppliers. The recommended plastic is avaliable in several different modelsthat fulfill all demands on material properties, environmental aspects, cost aspects and transparency.Apart from the material problem the project also included drafting some sketches and ideason new construction solutions for the container. The construction of the exsisting containerwas also a problem because of its complexity. As a result of the change of material it has beenpossible to simplify the construction.
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:
Over the last decade, we have seen a massive increase in the construction of wind farms in northern Fennoscandia. Wind farms comprising hundreds of wind turbines are being built, with little knowledge of the possible cumulative adverse effects on the habitat use and migration of semi-domesticated free-ranging reindeer. We assessed how reindeer responded to wind farm construction in an already fragmented landscape, with specific reference to the effects on use of movement corridors and reindeer habitat selection. We used GPS-data from reindeer during calving and post-calving in the MalAyen reindeer herding community in Sweden. We analysed data from the pre-development years compared to the construction years of two relatively small wind farms. During construction of the wind farms, use of original migration routes and movement corridors within 2 km of development declined by 76 %. This decline in use corresponded to an increase in activity of the reindeer measured by increased step lengths within 0-5 km. The step length was highest nearest the development and declining with distance, as animals moved towards migration corridors and turned around or were observed in holding patterns while not crossing. During construction, reindeer avoided the wind farms at both regional and landscape scale of selection. The combined construction activities associated with even a few wind turbines combined with power lines and roads in or close to central movement corridors caused a reduction in the use of such corridors and grazing habitat and increased the fragmentation of the reindeer calving ranges.