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254 Uppsatser om Density - Sida 4 av 17

Habitat preferences and reproductive success forthe threatened longhorn beetle Plagionotusdetritus

Plagionotus detritus is a threatend longhorn beetle that only exists at one site in Sweden. It is saproxylic and depending on recently dead coarse oak wood for its larval development. Trees at Djurgården, Stockholm that have been colonized by Plagionotus detritus has been studied to find out the habitat preferences of the species and to see what affects the Density of beetles in a tree. The bark of some trees and wood from the breeding project at Nordens Ark has also been studied to find out what affects the species reproductive success. The reproductive success was measured in two ways, the larval mortality and the size of the hatching holes.

Höghöjdsanpassning av BvS10 : Konceptstudie för optimering av överladdningssystem

This report relate a concept study that consider a number of different proposals to improve the overcharging system in BAE Systems Ha?gglunds tracked vehicle series BvS10, to maintain sealevel power at extreme altitude.At high altitude the power losses beacuase of the air Density that decreases, which results in less fuel can be burned. The decreasing of air Density also gives rise to fatigue failure of the turbocharger unless power is reduced.The proposals shall be as required by BAE Systems Ha?gglunds economically sustainable and defensible from a packing perspective. That means the selected solution must have a reasonable price tag and at the same time a minimal impact on adjacent components.The basis for this thesis is based on benchmarking of both the auto industry as the flight industry, to find inspiration and tips for improvement.Some of the concepts have after gathering facts and calculations been excluded while other solutions has been considered as workable and thus interesting for BAE Systems Ha?gglunds.Initially the current turbochargingsystem was analyzed in order to determine the starting point and thus be able to fix the current problems surrounding high altitude driving.

Nyckeltal för älg och fodertillgång på tall Pinus sylvestris och rönn Sorbus aucuparia

It has been shown that moose can affect plant community composition and structure. Selective browsing with other damages of large herbivores on tree species with different tolerance to disturbance could reshape the tree layer in both managed and natural forests. Rowan Sorbus aucuparia is widely distributed throughout Sweden and Europe. Research has shown that browsing by moose may prevent rowan from reaching browsing safe heights. The goal has been formulated that, where rowan is indigenous, it should have a good competition status and be able to reach tree level.

Pelletering av tallspån : grundläggande studier

Wood pellets are an upgraded product of residuals from several wood processing industries, for example saw mills and pulp industries. The pellets are produced by pressing the milled and dried sawdust to cylindrical units with a higher Density than the initial raw material. Pellets have great benefits compared to the raw material: high energy per volume, good transport and storage properties and homogeneity. Several parameters collaborate in the whole process, which makes it complex. Wood is a heterogeneous material, chemically and structurally dependent on wood parts, habitat and storage procedures.

Elektronstrukturbaserad magnetiseringsdynamik

In this project a method used for performing accurate simulations on magnetization dynamics based on constrained field Density functional theory has been validated and used for performing computations on a few magnetic materials. The method has been shown to simulate systems consisting of iron well, but there are still problems with simulations of alloys containing both magnetic and non-magnetic materials..

Logistik för stråbränsle :

Summary Today energy prices are rising. As a result biomass fuel is getting more and more interesting. Wood chips is very popular, but also straw from grain production is on the table. Lunds Energi AB project a combined power and heating plant in Örtofta out of Lund. Wood chips is meant to be the main energy source, complemented by straw. In this thesis the transportation of straw for fuel is studied.

Lufttäta byggnader

The viscosity of air buildings is a hot topic within the construction performers, which the industry feel they have too little knowledge about. This study is mainly aimed against air Density in apartment buildings and airflow measurement. The study consists of a theoretical reference, educational visit, interviews and a survey conducted among construction workers at Magistratshagen in Linkoping.Earlier requirement in terms of air leakage through the climate screen was removed and today there are only energy requirement for a dwelling in Boverkets Building Regulations. The difference between a passive and a typical air tight construction is that the passive house have a maximum requirement of 0.3 l /s m2 of air leakage through the building climate screen. The requirement imposed on passive houses is to minimize the supply of power and energy for heating the building.Air tight constructions have heavy demands on the performance and accuracy of everyone involved with the project. The client must specify their requirements and also be prepared to pay for any additional costs. The architect and building planners have to design the building with regard to air tightness. Finally, the construction workers are required to do a careful work in order to get all the connections in the building air tight.The study suggests that an air tight building is a closed system where no forced ventilation exists. There are no reasons not to build too tight as long as there is a functioning ventilation. In this study the authors ask themselves how an air tight building changes over time. No theoretical information has been found on these changes, but the respondents assume that air Density decreases with time. The deterioration is mainly assumed to be caused by construction materials changes over time. The study shows that construction workers knowledge of air tight construction is mixed, which they themselves admit in the survey..

Planteringsförbandets inverkan på bildningen av kärnved hos tall (Pinus sylvestris L.) : en modellsimulering av planteringsförbandets inverkan?

The current state of knowledge indicates that there is more than one factor that initiates heartwood transition. This study supports its hypothesis on the theory that heartwood is formed by a fixed fraction of the annual growthring, 0,5 to 0,8 rings. To calculate heartwood volume modelings were carried out in four different pine stands with different spacings, 0,75, 1,25, 1,5 and three meters. The model indicates heartwood diameter (HWD) and is based on four explanatory variables, height (H), crown ratio (CR%), diameter breast height (DBH) and tree height (TH). The shifting plant spacing results in varying growth rate in the juvenile stage.

Del projekt inom ClampCal - Utvärdering av mätmetoder för temperatur, viskositet och densitet samt röregenskaper

The dissertation were performed on SP, Technical Institute of Sweden. The dissertation were carried out on the measurement technical department, this dissertation is a part of a bigger project, project ClampCal. One of SP?s returning assignments are flow-measurement. When flow-measurement is performed, the flow has to be stopped so that a meter can be installed in the pipes where measurement is going to take place. At every stop there is time delay in the flow which causes the customers to loose money. This is why SP wanted to find a better solution so that measurement can be done without any stops in the flow. Usage of a so-called Clamp-on meter was considered, but since the measurement uncertainty is too large it takes some investigation on the parts where the largest uncertainties occur and thus find a solution that can diminish the uncertainty as much as possible. The parts that were considered to have an opportunity to reduce measurement uncertainties were the fluid temperature, its characteristics and the pipe geometry and its characteristics. For the fluid temperature a Pt100-sensor with four different radii for various pipes was used.

Movement patterns of Eurasian lynx (Lynx lynx) around their kills in southern Sweden

During the last ten- fifteen years the Eurasian lynx (Lynx lynx) population in southern Sweden has increased considerably. This area has a high Density of both people and roads and have a higher roe deer (main prey of lynx) Density than the rest of the country. Movement patterns such as how long animals utilize their kills and how far they travel from their kills between revisits is unknown for lynx in southern Sweden. The aim of this study was to examine how different factors affected the time lynx used their kills and the distances they travelled from the kill between revisits. The data was prepared and calculated using ArcGIS and the study is based on 98 ungulate kills and 12 lynx individuals.

Torrfoder till katt : påverkan och konsekvenser

The cat has evolutionary become an obligate carnivore. Today it is common to feed the cat a dry food. Studies have shown that the dry formula can have negative consequences for the cat. A literature study where conducted to investigate whether the cats origin makes it incapable to compensate for the changes a dry food entails. The impact and implications regarding water intake, energy intake and blood glucose concentration when feeding the cat dry food where examined.

The efficiency of the newly launched predatory mite Amblydromalus limonicus : biological control of thrips in cucumber

In this study, the efficiency of a newly launched predatory mite, Amblydromalus limonicus, has been examined for its potential to use as a biological control agent in cucumber production. A. limonicus can be used for biological control of two thrips species, Frankliniella occidentalis and Thrips tabaci. Field trials were conducted in greenhouses of two conventional cucumber growers in Scania, the southern part of Sweden. The basic control agent used against thrips was the predatory mite Amblyseius swirskii. In selected areas, additional A.

Användande av avskjutningsstatistik i förvaltning : påverkar tidigare jakt CPUE?

In fisheries, there is a long tradition to use catch data when evaluating changes in the stock and effects from harvesting. It is a common practice to use Catch Per Unit Effort (CPUE) as an index of population size, and several studies have investigated the properties of CPUE in relation to population abundance, spatial distribution and efficiency of gear. In research, catch rate on trap-transects is used as an index of abundance for wildlife species but CPUE is rarely applied as a tool in harvest management.In 1993, more than 60 000 km2 of the state managed mountain range in Sweden was opened to the public for small game hunting, under the responsibility of the county administrative boards in Jämtland, Västerbotten and Norrbotten. The total area is now divided into 332 hunting units (median=73 km2) and an internet based system is used to administer licences and reporting bag statistic. Each hunter has to register the results within two weeks after the hunt.

3D-modellen som kommunikationsverktyg

If one looks at physical planning in Sweden today one can see that while talking about densification of existing development, reduced emissions and careful use of important land, urban sprawl is a fact with development of sheer residential districts in the urban edges and shopping malls in each and every municipality. As sustainable development is an essential goal for physical planning to strive towards, it is worth questioning if the direction of today?s planning will lead to the goal. A sustainable development can be seen as an obvious to goal aim at. In reality the aim means a hard and complex work.

Vattensork och åkersork - skadegörare i svensk fruktodling

There are two species of voles that cause damage in Swedish fruit production: the water vole (Arvicola terrestris) and the field vole (Microtus agrestis). Both species make the most damage during the winter season. The water vole makes subterranean burrows and cause serious damage by gnawing on the tree roots. The field vole seldom makes burrows and gnaws the bark at the base of the tree trunk. In recent years there have been several reports about increasing vole damage.

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