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894 Uppsatser om Plant nursery - Sida 40 av 60

The effects of Gotland pony grazing on forest composition and structure in Lojsta hed, south eastern Sweden

Livestock animals affect their environment in a number of different ways, mostly through grazing and trampling. This study focused on the effects of Gotland pony grazing on forest structure and diversity, and the impact on ground cover. To compare the fenced and grazed area with a reference area outside the enclosure a number of transects were used. The study showed that there was no significant difference in height structure and diversity between the compared sites; however, there were a significantly higher proportion of damaged trees inside the enclosure. The ground cover variables showed a higher amount of bare soil, plant litter and wood-rush (Luzula sp.) inside the enclosure whilst grass was more frequent in the reference area.

Photovoltaic installations and land allocation under uncertainty : a real option approach

A real option model is developed to examine the crucial factors affecting the agricultural firms? decision to quit the production and rent out the land to a company building a PV power plant. The public policies in support of investments in renewable energies have created the conditions for a market regarding investments in PV installations in agricultural areas.The decision to switch offers to the agricultural firm and to society several economical, social and environmental benefits, representing sustainability. However, PV installations in agricultural areas require the allocation of a certain land area. By assigning a part of land to PV installations, thereby the area of land allocated to agricultural production decreases.

Pelletskvalitet : Test av olika råvarumixer i pelletstillverkningen vid Rindi Västerdala AB:s bioenergikombinat i Vansbro

Fuel pellets are a refined bio fuel mostly consisting of residues from sawmills and wood industry. At Rindi Västerdala AB's combined bio energy plant in Vansbro fuel pellets are produced, while the waste heat from the process is used for district heating. The pellets are produced from sawdust, wood shavings and dry wood chips that is dried, milled and pressed into small cylindrical rods. The advantage of refining the wood material in this manner is that the energy value is greater per unit volume and unit weight, thereby the cost of transportation per energy unit is reduced. Also, less storage space is needed.Pellet manufacturing is a complex process since many parameters affects the final results.

Antipredator behavior by the red-tailed guenon, Cercopithecus ascanius

This master thesis was conducted in order to investigate the effects of the browsing species Yeheb on animal tissues in Swedish landrace goats and to make a literature review in order to increase the knowledge of the importance of this plant for livestock production in Somalia. The evergreen Yeheb bush is a very important feeding source for grazing and browsing animals in Somalia during the dry period. Yeheb contains cordeauxiaquinone that stains the bones of the animals red/pink, which has been an increasing problem when exporting meat to foreign countries. In an experiment, two goats were fed dry and fresh leaves from the Yeheb bush for one and two months, respectively. The goats did not feed the intended amount of dry leaves, since the supply and palatability was not as high as estimated.

Magasin för lagring av vatten och växtnäring

Structural rationalizations and regionalization of the agricultural sector in Sweden has lead to unevenness in thedistribution of plant nutrients. Nutrients are lost from crop producing farms as harvest products are sold, whilefarms with animal production often have manure in excess of their needs. In addition to this the retention ofwater and nutrients in naturally occurring wetlands has decreased due to a reduction of wetlands in number andsize in the agricultural landscape. This increases nutrient levels in agricultural run-off and causes eutrophicationas well as nutrient losses from arable soils. One potential solution to both problems would be to store nutrientrichsurface water from agricultural areas and use it for irrigation of agricultural crops.

Energianvändning på Volvo Lastvagnar Tuve

Volvo Trucks is the second largest manufacturer of heavy trucks, with factories in several countries and with around 21 000 employees. At the plant in Tuve, trucks have been built since 1982 and the activity mainly consists of producing side members and to assemble and packing kits of trucks. In 2005, the factory in Tuve launched the ambition to be the first carbon dioxide neutral vehicle factory in the world. This will be implemented by streamlining and investing in renewable energy. The aim of this degree thesis is to map the usage of energy within production, and also to prepare a method to measure key figures (use of energy per produced unit).

V?n eller Fiende? En Studie om Kommunalt Milj?ansvarigas Perspektiv kring Invasiva Fr?mmande V?xtarter

Invasive alien plant species have historically caused major damage to ecosystems and are considered to be amongst the greatest threats to biodiversity globally. The lurking threat of harm to well functioning ecosystems has led to the development of global and regional goals and regulations which seek to stop the spread of invasive species. The Swedish Environmental Protection Agency has proposed a list of species that are specifically harmful to the Swedish flora and fauna, which includes (amongst others) garden lupin. The management of invasive species is however largely dependent on local actions, making municipal public servants key players. This qualitative study uses interviews to investigate how municipal public servants who are responsible for managing invasive alien species view this work.

Markberedningens, planteringspunktens och behållardjupets inflytande på granminiplantors etablering i fält :

A new type of forest tree seedling, called mini seedling, has been developed by the University of Dalarna in Garpenberg, Sweden. Compared to traditional containerized seedlings that are grown for 1 ? 2 years, mini seedlings are grown for only 10 weeks. The mini seedlings are small, easily planted, cost effective, and reduce the amount of chemicals used in the nursery. Research has shown that mini seedlings tend to have higher overall survival rates than traditional container seedlings.

Förslag till kväverening i Forsåsystemet genom våtmarksetablering

The last hundred years humans have drastically changed the amount of available nitrogen in nature. Today human activities release twice as much available nitrogen as all natural processes are doing together. We also have degraded nature´s possibilities to take care of nitrogen through the draining of wetlands and straightening of rivers. In order to regain the potential of nitrogen retention in the water systems there now requires a reshape of the landscape we live in. A planned expansion of the mining activities in Garpenberg, Dalarna, would double the content of nitrogen in the waters below the mine.

Storjuktan ? Rekonstruktion av ett sekels kvicksilverbelastning. : En undersökning av kvicksilverkoncentrationer i daterat bottensediment.

The aim of this study was to examine the current and historic mercury(Hg) load of the lake Storjuktan due to its recent exposure to a local potential source of Hg in form of the Sulphide mine Blaikengruvan(2006) and an earlier potential sources of Hg-load, the damming of the lake(1960s). Sediments were extracted using a HTH-sampler, freeze-dried, and analyzed for tot-Hg, LOI and activity of 210Pb and compared to samples extracted prior to the opening of the mine(2006). Constant initial concentration (CIC)-dating model was used for dating the samples. Low levels of Hg (100ng/g) were found throughout the lakes sediment. The highest levels of Hg(220ng/g) was detected at a depth of 4-5cm dating back to the mid 1970:s, suggesting that increased levels of atmospheric Hg rather than damming of the lake has caused the increase of Hg.

Analys ac konstruktionsprocessen inom FTC

This thesis work was made to optimize the writing of the construction specificationsat FKA. These construction specifications are created before each plant modificationsthat is started because requirements from the Swedish radiation safety authority(SSM) and internally on Forsmarks nuclear group as constructions / implementationdocumentationThe study was done through seven interviews of two people at three different groupsinvolved in the construction specification and an interview from the group accreditedverification. The four selected groups were selected through an extensive analyticalwork resulted in an elimination matrix where these four groups was considered to bemost involved with the construction specification.The questions asked to these individuals were based on the instructions and sampletext that are described in the construction specification. To ensure the quality of thethesis were to limit itself to the chapters that were considered most relevant toimprove. The analysis revealed a number of points that should be improved, partlyinto the routines when writing the construction specification and when ether sampletext or suggestions should be changed and complemented.

Validering av vattenkraftmodeller i ARISTO

This master thesis was made to validate hydropower models of a turbine governor,Kaplan turbine and a Francis turbine in the power system simulator ARISTO atSvenska Kraftnät. The validation was made in three steps. The first step was to makesure the models was implement correctly in the simulator. The second was tocompare the simulation results from the Kaplan turbine model to data from a realhydropower plant. The comparison was made to see how the models could generatesimulation result that was similar to the reference power station.

Exosomes as a potential mechanism of intercellular spread of prion protein

Structural rationalizations and regionalization of the agricultural sector in Sweden has lead to unevenness in thedistribution of plant nutrients. Nutrients are lost from crop producing farms as harvest products are sold, whilefarms with animal production often have manure in excess of their needs. In addition to this the retention ofwater and nutrients in naturally occurring wetlands has decreased due to a reduction of wetlands in number andsize in the agricultural landscape. This increases nutrient levels in agricultural run-off and causes eutrophicationas well as nutrient losses from arable soils. One potential solution to both problems would be to store nutrientrichsurface water from agricultural areas and use it for irrigation of agricultural crops.

Termoelektrisk lagring i system med fjärrvärmeproduktion

With increased deployment ofintermittent renewable energy, such aswind and solar power, energy storagebecomes necessary to help reduceproduction peaks. Thermoelectric EnergyStorage is a method still in researchphase, which stores electricity in hotwater at a temperature of 120 ° C. Thisthesis aims to examine whether theThermoelectric Energy Storage would bepossible to integrate into existingpower generation such as a combined heatand power plant, and how the technologypotentially could function in theelectricity market. ThermoelectricEnergy Storage consists of a chargingprocess and a discharging process, bothoperating by the working fluid CO2. Toincrease the efficiency of theThermoelectric Energy Storage, wasteheat from the district heating networkis integrated.A model of the Thermoelectric EnergyStorage has been developed and it wascalculated by thermodynamic propertiesof the working fluid, CO2, in thevarious process steps.

Side effects of biological control agents in agriculture : does the bacteria Bacillus amyloliquefaciens affect the earthworm Aporrectodea longa?

Pathogenic microorganisms pose a big threat towards food production. Meanwhile, negative impacts on humans and environment are seen by the use of pesticides. Biological control agents are an alternative to the use of chemical pesticides, and plant-growth promoting rhizobacteria, such as Bacillus amyloliquefaciens has been shown to have good properties as biocontrol agents. Before these bacteria can be used commercially their impact on other soil organisms has to be evaluated. This thesis looks into what biocontrol bacteria are and how they might affect earthworms.

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