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1038 Uppsatser om Signal species - Sida 40 av 70

Restaurerade ängs- och betesmarker : restaureringseffekten på växter och insekter

Semi-natural grasslands have a high biodiversity and host ecologically and economically valuable ecosystems and species. Restoration on these types of land is often done by removing trees and scrubs, mowing, grazing, changing the soil by removing nutrition or changing the structure of the ground. Another way of restoration is planting seeds of common grassland plants. By comparing 18 scientific publications I investigated if the restoration was affecting the plants in a positive way and if the effect was similar for insects. By comparing the publications, time seemed to have an important effect on insects. They needed time to recolonize restored areas.

Den interaktiva djurparken / The interactive zoo

The purpose of this thesis project is to develop a set of interactive digital solutions designed to enhance the interest and knowledge intake of visitors at Skånes Djurpark (Zoo of Scania) in Höör. The project was carried out in collaboration with Skånes Djurpark and representatives from its visitors. Our thesis is based on academic works in the fields of interaction design, exhibit design and contextual learning. Ethnographical field studies have been conducted at Skånes Djurpark with additional field studies at Tropikariet in Helsingborg, Copenhagen Zoo and Regionmuseet Kristianstad. Existing information signs in Skånes Djurpark are primarily image- and textbased, forcing visitors to divert their attention from the different species of Nordic animals that inhabit the zoological park.

Vermicompost for reduction of vegetable waste - and a possible means to produce fish feed in aquaponic systems?

Aquaponics is a food production system consisting of a consecutive cultivation of plants and aquatic animals, fish or shellfish, in recirculating water. The plants feed on the nutritious effluents from the fish tank and bacteria converts ammonia from the fish tank into nitrate that is absorbed by the plants. The plants receive nutrition and the fish gain purified water. The environmental impact of the production of fish meal and fish oil used in conventional fish feed includes a large consumption of fossil fuels with subsequent carbon dioxide emission. The aquaponic system can be made environmentally sustainable and self-supporting if supplemented with a vermicompost/vermiculture for the production of worm protein as a fish feed. Vegetable waste from the hydroponic part of the system can be reused as worm feed in the compost and the protein rich worms can be harvested, dried and grinded and brought back to the aquaculture as fish feed. As a first step in this direction, I have investigated the effect of recycling of vegetable waste in vermicomposts on the growth and number of earthworms (this was evaluated after harvesting). The hypotheses were that earthworms can be cultivated in the vegetable waste and that by adding manure to the vermicompost it is possible to obtain a nutrient content adequate to support a continuous worm harvest, in other words create a vermiculture. Eisenia fetida and Dendrobaena veneta were grown in 20 L bins containing peat mixed with either poultry or cattle manure. The proportions were 70% peat and 30 % manure. Discarded plant parts from lettuce cultivation was added to the vermicomposts (35 g per week) and water was supplied with 0.8 L per week.

Trådlös kamerastyrning

As an amateur it can be difficult filming from several angles at the same time as this requires several cameras. It´s also hard to film at occasions when it´s not appropriate to manoeuvre the camera manually. Systems for solving these problems already exist, but it´s either more expensive, professionalsystems or cheaper systems with limited functionality.The purpose of this project is to develop a cost efficient solution to the problem above that offers a better functionality then existing commercial systems. The biggest difference from existing products is the wireless video feedback from the camera to the remote unit.The result of the project is a system consisting of two units, a manoeuvre unit with a cradle for the video camera and a remote unit from which the operator can control pan and tilt of the video camera.Communication between the two units is wireless.On the remote unit there is a joystick and a display mounted. In addition to this, there is also an IR receiver that is capable of reading the signal from the cameras own remote and sending it to the manoeuvre unit.The manoeuvre unit is equipped with one motor to control the tilt function and one motor to control the pan.

Undersökning av självspridning av contortatallen i norra Sverige

Over the past 40 years 600 000 ha of lodgepole pine (Pinus contorta ssp. latifolia (Engelm.) Critchf.) has been planted in Sweden (280 000 ha on SCA's forest land alone which represents about 15% of the company's total forest land area). In the early 70's SCA situated a number of experimental stands in order to investigate different aspects of the exotic tree, primarily growth rate. To be able to compare the two species plots with scots pine (Pinus sylvestris L.), this species was also planted at the same time and under the same conditions. A number of questions should always be raised when exotic species are introduced in an ecosystem. Invasiveness, the pathogen situation and purely ethical issues should be discussed.

Historisk markanvändning på Färsna gårds inägor och utmarker

Semi-natural grasslands are threatened biotopes in the landscape and without conservation measures high values of nature will be lost. Meanwhile, the biological values associated with cultural values of the traditional agricultural landscape in Sweden. Studies of land use history may help to understand how today biological diversity has evolved and how it can be preserved. Färsna farm in Norrtälje has left some of the old heritage of biological diversity in the form of nature - forest and grassland, which hosts an unusual herb-rich flora. Through the study of historic maps and från1673/1767/1801/1901 1952 and orthophoto of the area has a picture of how land use has changed over time emerged.

Hur mycket frö sprids från Pinus contorta? : kottproduktion, serotinitet och frökvalitet i relation till beståndsålder i södra Norrland

Contortatall (Pinus contorta ssp. latifolia) började planteras storskaligt i Sverige runt år 1970 men det dröjde till 1987 förrän Sverige lagstiftade begränsningar för hur den fick användas i skogsbruket. Detta gjordes bland annat på grund av att det saknades information om dess spridningsförmåga. Contortans spridningsförmåga i Sverige är fortfarande okänd och lagstiftningen är densamma. För att kunna beräkna spridningsförmågan och i förlängningen den potentiella etableringsframgången behövs kännedom om contortans fröproduktion i Sverige.

Fodertillgång och stereotypa beteenden under natten hos Asiatisk elefant (Elephas maximus)

Animals in zoos live in more barren environments than their conspecifics in nature. In nature, elephants spend more than 75 % of the day foraging and have been observed lying down two hours during night. Stereotypies are common in many different species in zoos. Stereotypic behaviors may constitute up to 50 % of the daily activity budget of zoo elephants. Modern zoos try to reduce stereotypic behaviors by means of environmental enrichment.

Rekursiv greyboxidentifiering av drivsystem i industrirobot.

In modern industrial robots the components in the transmission contain nonlinearities. These nonlinearities need to be to estimated either for better control or to use the parameters for diagnosis of the system. There is a lot of work done within system identification and mainly within the field of iterative parameter estimation.This thesis considers recursive grey-box identification for a nonlinear model of the transmission in an industrial robot. The nonlinearities that are identified are friction, spring stiffnes, hysteresis and backlash. These nonlinearities are a part of the models that are presented in this thesis.

Detektering av sprickor i vägytor med hjälp av Datorseende

This thesis describes new methods for automatic crack detection in pavements. Cracks in pavements can be used as an early indication for the need of reparation.Automatic crack detection is preferable compared to manual inventory; the repeatability can be better, the inventory can be done at a higher speed and can be done without interruption of the traffic.The automatic and semi-automatic crack detection systems that exist today use Image Analysis methods. There are today powerful methods available in the area of Computer Vision. These methods work in higher dimensions with greater complexity and generate measures of local signal properties, while Image Analyses methods for crack detection use morphological operations on binary images.Methods for digitalizing video data on VHS-cassettes and stitching images from nearby frames have been developed.Four methods for crack detection have been evaluated, and two of them have been used to form a crack detection and classification program implemented in the calculation program Matlab.One image set was used during the implementation and another image set was used for validation. The crack detection system did perform correct detection on 99.2 percent when analysing the images which were used during implementation.

Perspektiv på läraruppdraget

Syftet med examensarbetet är att ta reda på hur fem lärare uppfattar sitt läraruppdrag. Sedan jämför jag dessa uppfattningar med hur litteratur och styrdokument uppfattar läraruppdraget. Min övergripande frågeställning är: Hur uppfattar fem utvalda lärare sitt läraruppdrag och hur förhåller sig deras uppfattningar till det som framhålls om uppdraget i styrdokument och litteratur? Examensarbetet är utfört utifrån en kvalitativ surveyundersökning där resultaten från intervjuer med fem lärare tolkas och jämförs med hur litteratur och styrdokument uppfattar läraruppdraget. Styrdokumenten fokuserar på att läraruppdraget går ut på att vara kunskapsförmedling och att utveckla elevernas etiska förhållningssätt.

Accelerometertillbehör till mobiltelefon : - Utveckling av Blåtands ansluten accelerometermodul till smartphone

This master thesis has been carried out as a prototype development project. The project hasbeen performed in cooperation with ÅF Combra AB. The purpose with the master thesis is toconstruct a Bluetooth interface between an accelerometer and a smartphone and constructinga physical prototype containing an accelerometer. This is done to test a new user interface tomobile phones. The master thesis has also included a research about the possibility toimplement distance measuring with Bluetooth.

Kan förändringar i bottenfaunan påvisas två år efter en bäckrestaurering?

The aim of this work is to analyze if a change in the benthic community can be detected two years after a restoration of a small stream. The samples were taken in a small stream at Tinnerö Eklandskap just south of Linköping. In addition to the restored area, two reference sites upstream and downstream of the restored area were sampled to compare to the restored site. The method used for sampling of benthic fauna in the stream was kick sampling. ASPT, Berger-Parker and Renkonen-indices were used to find out if there was any difference between the reference areas and the restored area.

HMX detektering i transparent plastslang

Orica Miningsservices är ett företag som tillverkar sprängämnen till civil förbrukning. I deras produktutbud finns ett sätt att initiera en sprängning utan att använda elektriska sprängkapslar.  De använder en plastslang som är belagd med ett tunt sprängämnesskikt runt kanten på insidan, och sprängämnen kallas HMX.De finns idag ett analogt detekteringssystem som är baserat på optisk detektering. En lasergivare skickar ljuset igenom plastslangen och den detekteras med en fotocell. För ett säkert mätresultat används två lasergivare med respektive fotodetektorer, de mäter horisontellt respektive vertikalt. Deras resultatvärden summeras i en OP-förstärkare.

Klöver i ensilage till suggor - effekter på reproduktion och produktivitet

The weather has been extremely rainy the last summers in Sweden. Because of the rain, a lot of harvested straw has been lost since it was too wet to store. When the pig producers couldn?t get enough straw to use as bedding, an alternative was requested. Silage is a realistic alternative to straw but since silage often contains clover, it may not be suitable to use in pig production since clover is rich in phytoestrogens.

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