Den europeiska blankålen (Anguilla anguilla) har genomgått en stor populationsminskning de senaste decennierna på grund av antropogena strukturer i form av vattenkraftverk som orsakar fragmentering. Vid vattenkraftverks intagskanaler finns intagsgaller installerade för att förhindra drivgods från att skada turbinerna. Forskning har utvecklat lösningar i form av anpassade galler, med låg lutning, som leder fisken till en flyktöppning vid sidan av kraftverket. Det har observerats att utformningen av gallret påverkar fiskars beteenden och beteendeobservationer kan därför ge viktig kunskap om hur väl åtgärder funkar och vilka förbättringar som krävs. Syftet med denna studie var att undersöka beteenderespons och passageframgång för europeisk blankål (Anguilla anguilla) vid tre olika typer av låglutande ß-galler med 30 mm spaltvidd. Man ville också undersöka om det finns någon koppling mellan ålarnas beteenderespons och gallrens vägledande funktion.  Experimentet utfördes vid Vattenfalls Research and Development laboratorium i Älvkarleby. En artificiell miljö i form av en ränna användes för att simulera ett turbinintag. Här testades blankålars (n=69) beteende och passage av tre olika typer av ß-galler med (i) horisontella järn orienterade i linje med vattnets strömriktning (H0), (ii) vertikala järn orienterade i linje med vattnets strömriktning (V0) och (iii) vertikala järn med 60° vinkel mot strömmen (V60). Resultatet visar att det inte finns någon signifikant skillnad i ålarnas beteenderespons mellan de tre olika gallren. Däremot såg man att det fanns en koppling mellan ålarnas beteenderespons och gallrens vägledande förmåga. De ålar som vägleddes av gallren hade huvud som första fysiska kontakt med gallret. Vidare forskning på ålbeteenden vid intagsgaller är nödvändigt för att öka migrationsframgången hos europeisk ål. / The European silver eel (Anguilla anguilla) has undergone a large population decline in recent decades due to anthropogenic factors such as hydropower plant river fragmentation. At the intake channel of hydropower plants there are trash racks for preventing drifting obstacles to damage the turbines. Research has developed solutions such as angled bar racks, which guide fish to a bypass. The design of the racks has been observed has an effect on fish behavior and its therefore important to provide actions and improvements. The aim of this study was to investigate behavioral and passage success of the European silver eel (Anguilla anguilla) of three different types of low-sloping angled bar racks with 30 mm clear spacing and whether there is any connection between the behavioral response of the eels and the guiding function of the racks. The experiment took place at Vattenfall's Research and Development laboratory located in Älvkarleby. A flume resembling an intake channel was used. Here (n=69) eels were tested on three different types of low-sloping angled bar racks: (i) horizontally bars oriented in line with the water current streamwise (H0), (ii) vertical bars oriented in line with the water current streamwise (V0) and (iii) vertical bars with a 60° angle to the current (V60). The result shows that there is no significant difference in the eels behavioral response between the three different racks. However, it was seen that there was a connection between the behavioral response of the eels and the guiding ability of the racks. Al eels that were guided by the racks, only had head as first physical contact with the rack. Further research on eel behaviors at intake racks is necessary to increase the migration success of European eel.

Die schweizerische Bibliothekslandschaft, ihre Vernetzung und Gewichtung ihrer inhaltlichen Erschließung können anhand der Organisations-und Struktur-Analyse der 1. Bibliotheksverbünde 2. Spezialbibliotheken 3. Universitäts-und Technischen Universitätsbibliotheken parametrisiert werden Quellen: •Internet-Zugang zu allen schweizerischen Hochschulbibliotheken http://www.ub.unibas.ch/lib/schweiz.htm •Schweizer Virtueller Katalog http://www.chvk.ch/

Bearing layers are used in road and building constructions as underlying soil layers to provide stability and support to the top layer that takes up the load. A normal bearing layer contains different amounts of materials such as stone, gravel, and filler. That mixture of materials contains a large amount of filler to give the product tightness and stability. Draining bearing layers usually contain less filler than ordinary bearing layers, because their purpose is to improve the drainage properties and reduce the risk of damage due to water collection.This thesis work took place at NCC's quarries in Sälgsjö and Hammarby. At NCC's rock quarry, there already is a standard bearing layer with a grain size of 0/32 and a filler content of approximately 4–5%. In this degree project, a production process has been created to obtain a drain bearing layer where the filler content is reduced to approximately 2–3%. The requirement for a draining carrier layer is 2–3% filler content and this requirement has been followed in this production process. The draining bearing layer has been produced based on a standard product with the same grain size.There are practical limitations in how the operations work and what capabilities are required. Moisture in the material has also been a limitation. In this project, work is done with freshly crushed material, which has a relatively low moisture content (1–2%). A vibration-free screen like the function of the harp has been designed and built. Then the standard product was run through the harp at different gradients and the new product was analyzed in the lab to see what filler content was achieved. A simulation test was performed using a FEM design program called Digiroad at Chalmers University of Technology in Gothenburg.The results demonstrate that the utilization of the developed models of harp screens reduces the proportion of filler in the material. Additionally, the conducted harp screen analyses confirm that the designed harp screens are effective in transforming a standard bearing layer into a draining bearing layer, which helps to prevent water accumulation under roads or buildings and thus reduces the risk of damage and problems. The efficient production process for producing draining bearing layers can be of great importance to ensure a sustainable and safe infrastructure.