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610 Uppsatser om Cultivated plants - Sida 3 av 41
Risken för översvämningar vid de svenska kärnkraftverken : en statistisk och historisk extremvärdesanalys
This thesis investigates the overall risks of flooding over the Design Basis Flooding Level (DBFL) at the Swedish nuclear power plants (Oskarshamn, Ringhals and Forsmark), using statistical data and methods, but also considers historical events which might affect the overall risk of flooding at the specified sites.Considering the nuclear accident which happened in Fukushima in conjuction with the earthquake and tsunami which struck eastern Japan on 11 March 2011, operators and licensors of nuclear power plants all over the world conducted reviews and investigations on the overall risks posed to the plants from external events. One important such event is extreme water level.One part of the thesis includes an extreme value analysis (using Generalized Extreme Value distribution and Generalized Pareto distribution) of water level data from SMHI (Sweden's Meteorological and Hydrological Institute) measured at stations close to the Swedish nuclear power plants. The results of the statistical studies indicate that considering the return period used in the thesis (100 000 years), the water levels at the Swedish nuclear power plants are not expected to exceed DBFL.The other part of the thesis consists of a historical study of extreme weather-related events. The results of this study indicate that no historical events seem to have occured which would indicate a higher risk of flooding than the one suggested by the statistical study. .
Towards a function for an Arabidopsis protein involved in sucrose dynamics
System based models of plants rely on descriptions and assigned functions of genes, and currently 50% of the genes in Arabidopsis thaliana has either no assigned function or a function based on homology only. Mitogen activated protein kinases (MAPK's) are key players in cell signalling and are conserved among eukaryotes, though their targets are highly diverse. A recent study has described a small Arabidopsis protein (80), without homology to any described protein, as a phosphorylation target of the MAPK's MPK3/6. Further work established ?-glucan phosphorylase (PHS) as interacting with 80 and described a delayed senescence phenotype for 80 knock-out plants.
The effect of domestication on insect resistance in cotton : bioassays with the insect herbivores Spodoptera littoralis and Agriotes spp.
A plant's defensive ability against herbivore attack can be influenced by many different factors, one of them being domestication. During human selection to improve the yield of plants, the resistance against herbivore attack can have been lowered, due to a trade-off for use of resources between these traits in the plants.
In this thesis I investigated the effect of domestication on resistance against herbivorous insects in cotton plants. I used different varieties and species of wild and domesticated cotton in three different experiments. A feeding assay was conducted, the mortality, development
time and pupal weight of larvae of the Egyptian cotton leaf worm Spodoptera littoralis was studied. In a second experiment the preference of the root-feeding beetle Agriotes spp.
Gottsunda torg : program och gestaltningsförslag för Gottsunda centrum
Det är mycket viktigt att förhindra att bekämpningsmedelsubstanser läcker ut i miljön
och orsakar skada. Lagstiftningen kräver därför att läckaget av bekämpningsmedel från odlad mark minskas. Olika myndigheter och organisationer har olika ansvarsområden
beträffande bekämpningsmedel. Bekämpningsmedelssubstanser kan, om de inte hanteras rätt, vara skadliga och därför finns det tydliga bestämmelser om hur dessa substanser ska
hanteras.
Många oberoende undersökningar visar tydligt på att det förekommer läckage av bekämpningsmedel i samband med att de används i behandlingar av odlad mark. Undersökningar har pågått under lång tid både i Sverige och i andra länder.
Ett flertal åtgärder och metoder mot läckage av bekämpningsmedel från odlad mark har framtagits och utvecklats som radikalt kan minska läckaget av bekämpningsmedel.
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.
Jordbruk och mjölkproduktion med kor i Etiopien :
Ethiopia is the country with most livestock per capita on the continent of Africa. There are 34.5 million cattle that are used for drought, meat- and milkproduction and 85% of the population rely on agriculture for their survival in some way. Milk is produced in four main systems, through pastoralism in the lowlands, in mixed crop-livestock systems in the highlands, in and near big cities with only one or two cows, and in intensive farming systems. There are 17 cattle breeds in Ethiopia and some of them are more suitable for milk production than others. Several environmental and economic problems arise from livestock holding in the country, for example overgrazing, low production due to feed shortage, low quality of the avaible feed and non-existing breeding programs.
Olfactory responses of the parasitic wasp, Trybliographa rapae (Hymenoptera: Figitidae)
Delia flies (Diptera: Anthomyiidae) are economically important pests in several horticultural crops. The control is commonly relying on chemical insecticides, though there are possibilities with biological control from the natural enemies in the field. An important natural enemy is the parasitic wasp, Trybliographa rapae Westwood (Hymenoptera: Figitidae) that lays eggs in the Delia fly larvae. The parasitoid larva and the host larva have a parallel development until the host dies within its puparium and an adult parasitoid emerges.
The aim of this thesis was to understand the attraction to host- and food-associated plant volatiles of T. rapae, in order to enhance the effectiveness of the parasitic wasp as a biological control agent.
Utvärdering och framtagande av åtgärdsförslag för de mindre avloppsreningsanläggningarna i Laholms kommun : En studie av fem avloppsreningsanläggningar upp till 500 pe
The aim of this project was to describe and to evaluate five small sewage treatment plants in the municipality of Laholm, Sweden, in order to investigate the treatment efficiency and to evaluate if effluents comply with discharge permits. The treatment systems were designed to treat effluents from 90 to 500 population equivalents. A report on the design and the present state of each sewage treatment plant has been made. This was made based upon previous documentation on water quality and by new sampling campaign as there were only a few previous measurements. Data has been evaluated and remedial actions proposed for those treatment plants that don?t fulfill discharge permits.
Vemmenhögsprojektet : ett framgångsrikt sätt att minska läckage av bekämpningsmedel från odlad mark
Det är mycket viktigt att förhindra att bekämpningsmedelsubstanser läcker ut i miljön
och orsakar skada. Lagstiftningen kräver därför att läckaget av bekämpningsmedel från odlad mark minskas. Olika myndigheter och organisationer har olika ansvarsområden
beträffande bekämpningsmedel. Bekämpningsmedelssubstanser kan, om de inte hanteras rätt, vara skadliga och därför finns det tydliga bestämmelser om hur dessa substanser ska
hanteras.
Många oberoende undersökningar visar tydligt på att det förekommer läckage av bekämpningsmedel i samband med att de används i behandlingar av odlad mark. Undersökningar har pågått under lång tid både i Sverige och i andra länder.
Ett flertal åtgärder och metoder mot läckage av bekämpningsmedel från odlad mark har framtagits och utvecklats som radikalt kan minska läckaget av bekämpningsmedel.
Att växa i lekmiljöer : hållbar och funktionell växtanvändning i lekmiljöer för förskolebarn
The preschool constitutes a big part of many
children's everyday existence. Its contents are
therefore of great importance and the environment
deserves a well thoughtout design. In this
study, surveys in field and literature have resulted
in conclusions around how plants can be used in
children's play environments, in order to contribute
to the experiencerelated values. The aim
is to present conclusions to lean on when drawing
up designproposals for new playgrounds,
especially where the natural conditions are not so
favorable. The first question that is responded to
is how plants can be used in order to enrich the
children's play environments.
Etablering av höstvete med reducerad jordbearbetning :
The payment for produced grain is constantly going down in price. It is important for farmers to become more effective in cultivating more land in a shorter time perspective. At the same time we have to calculate with the risk of getting lowered subsidies from the EU. This is why I would like to find out the possibilities for establishing winter wheat without ploughing.
I hope to find a difference in the number of plants due to different soil preparations. With this experiment I expect to find out whether I can establish winter wheat at a lower cost, with the same numbers of plants per square meter.
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.
Elevers föreställningar om vattnets kretslopp och växtens liv : Har eleverna tillräcklig kunskap inom dessa områden för att diskutera hur miljöförstörning påverkar vatten och växter?
The purpose of this investigation is mainly to study if pupils have enough knowledge concerning the water cycle and the life of the plants?, and what kinds of household word they have, to discuss pollution within these areas. I also studied how the pupils? knowledge are holding up against what the course-plans says, since it have come to light by other investigations that knowledge are insufficient within the nature-oriented (No) subject in school.The survey has carried out on 28 pupils in a 5th grade, with help of a questionnaire survey. Their teacher has been interviewed and I have studied their local course-plans and also the pupils? schoolbooks in No.The result of the questionnaire survey indicates that the pupils had insufficient knowledge within the areas of plants? life and pollution, something their teacher had a presentiment about.The conclusion is that they need to go out more often in the nature and see how the plants and the environment are affected by different factors.
Effekter av upphörd hävd i Lurö skärgård : Har diversiteten av kärlväxtarter förändrats?
One of the main reasons for the massive loss in plant species diversity is the fragmentation of habitats. In Europe, open pastures and meadows are the habitats going through the most changes during the 20th century, according to the agricultural changes. In this study vascular plants were invented at five different islands in the Lurö archipelago, Vänern, Sweden. The aim of the study was to sort out whether the diversity of plants has gone through any changes in abandoned managed grasslands compared to continuous managed grasslands. The aim was also to study if a change in the landscape has made any differences for the species development or decline.
Faktorer som påverkar vindkraftsutbyggnaden
Wind power is expanding rapidly in Sweden. Increasing amounts of wind power sets higher requirements on balancing power and grid expansions and would affect the whole Swedish electricity system. The aim of this report is to examine the factors affecting the wind power expansion in Sweden. How many wind power plants projects will obtain building permissions and what costs and revenues can be expected? How much balancing power will be required and does a changing geographical distribution of the wind power plants reduce the need of balancing power?A survey of the county board?s official applications has been made and out of all the applications, corresponding to 80 TWh produced per year, about half of the applications are expected to obtain a permit with a major portion of them located in the north of Sweden.Especially older wind power plants, deriving revenue from Nord pool, find themselves today in a complicated financial situation.