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532 Uppsatser om Temperature thresholds - Sida 11 av 36

En undersökning av tre olika behandlingsmedels effekt på vegetabiliskt garvat läder för bokband

Title in original language: En undersökning av tre olika behandlingsmedels effekt påvegetabiliskt garvat läder för bokbandLanguage of text: SwedishNumber of pages: 32.

Gravar i stenskepp : Osteologisk analys av brända och obrända ben från skeppssättningar på Gotland

In this study bone material from six stone ship settings and a total of seven deposits of bones from two sites on the island of Gotland have been analyzed. Four ship settings from the burial site at Gålrum in Alskog parish and two from Tängelgårda in Lärbro parish. The ships contained both cremated remains and inhumations.  Human remains were identified in five of the analyzed ship settings and a minimum of six individuals was identified in total.  Animals were found in three of the ship settings, where one of them contained only the burned remains of a dog. Two of the ships contained inhumations, one in Gålrum and one in Tängelgårda.

Modellbaserad temperaturregleringav partikelfiltrets regenereringsprocess

Due to increasing regulations regarding new diesel vehicles particulate matteremissions the new Scania truck, Scania Euro 6, has been equipped with a particulatefilter. This component effectively stores the particles in the exhaust gas but must becleaned in order to prevent itself from clogging. The filter is cleaned through aprocess named regeneration which is a thermodynamic process in which thetemperature of the filter is raised through fuel supplied to the exhaust gas.The purpose of this thesis is to contribute to the development of improved controlstrategies of the temperature during the regeneration process through thedevelopment of model-based controllers. These controllers are designed in order tohave good performance in stationary as well as automatic regeneration.In order to develop these model-based controllers a model of the system isconstructed. The model is described as a linear thermodynamic grey-box model withflow varying parameters, showing good results in validation.The model provides a simulation environment during the controller design, which isfocused around the development of linear regulators with the exhaust gas mass flowas a scheduling variable whose size determines controllers? mode of operation.

Tidsupplösning vid miljövärdering av fjärrvärme : Kontorsbyggnad med solvärmeproduktion - en fallstudie

The demand for environmental assessments on buildings and energy consumption is increasing as well as the energy performance requirements for buildings. At the same time it is increasingly common with self-producers of heat and electricity generation.The main purpose with this master thesis is to investigate how time resolution affects the environmental assessment of energy consumption in office buildings connected to district heating (DH). Environmental assessments were done with both attributional LCA and consequential LCA with system expansion.Fortum´s DH system in Stockholm was analyzed and district heating production was simulated in a Matlab-model. Greenhouse gas (GHG) emissions for the production were calculated. The heat demand of the office Gångaren 16 in Stockholm was simulated in IDA ICE.

Samspel mellan amerikansk blomtrips, Frankliniella occidentalis,och kruk-gerbera, Gerbera jamesonii :

Gerbera jamesonii is a plant with a large amount of pollen and various flower colours and a favourite host plant for Frankliniella occidentalis. The best growing temperature for gerbera is approximately 20°C. Frankliniella occidentalis or the Western Flower Thrips is a small insect that has become an important pest in greenhouse cultivation all over the world. The high temperatures in the greenhouse are favourable for F. occidentalis.

Utnyttjandet av ligghallar hos dikor och kvigor av köttras under vintern :

Cattle used for meat production can be held outside all year round and due to the legislation they should have access to shelters or other buildings for protection against the elements giving them a dry and clean bedding. There are different opinions concerning their need of protection and the question about necessity of shelters for cattle is of current interest due to a less profitable economy in meat production and the investment costs for shelters. The aim of this study was to acquire more knowledge about the natural behaviour of cattle concerning their use of shelters. The basis of the study was a series of questions regarding when animals choose to stay in shelters, if shelters were used less when they had access to protecting vegetation, how temperature and weather conditions affected the use of shelters and the influence of distance between shelter and feed. Behavioural studies was conducted at five different farms where six groups of suckler cows and heifers of following breeds and crossbreeds were observed; Aberdeen Angus, Charolais, Hereford, Scottish Highland Cattle, Simmental and the Swedish breeds SKB and SRB.

Analys av energiförbrukning, Akzo Nobel Functional Chemicals AB

The main purpose of this project was to make a survey of the steam and electricity consumption at Akzo Nobel Functional Chemistry AB and give suggestions of how to minimize them. These three different areas were focused on. First to make a survey of all the most important consumers, second to find the electricity consumption of the air compressors and the amount of waste heat produced from them. The third area was to calculate a model of how much fresh water that is used during a cooling sequence in the water based heating/cooling system of the reactors and give a suggestion of a suitable reuse for this water.The main result is a total survey of the energy consumption in steam and electricity. The survey shows that the second largest group after drying is heating of ventilation which gives big potentials of reducing the total steam consumption if there is a way of being self supporting in ventilation heat.

Minskad trädtillväxt under Lilla sitiden? : En dendroklimatologisk jämförelse mellan nutid och 1600-talet invid trädgränsen i norra Skandinavien

During the period called Little Ice Age (1400 ~ 1900) the climate of northern Europe was in an annual year-basis overall colder than it was before and after that period. The numbers of short, cold and rainy summers and long, bitter-cold winters where often repetitive under the approximately 500-years the period lasted. In Scandinavia, the coldest time during this period is estimated to have started around the end of the 16th century and lasted to the beginning of the 18th century. Trees growing at the tree-line are limited by temperature for their annual growth and hence showing differences of growth during changes in the climate,  a method called dendroclimatology. The variations of growth can be read in the tree-rings either by analyze the width of the ring or by look into the density of the wood and is used to reconstruct past climates.

Hälsoeffekter från trafikbuller vid Bäckegatan

The purpose of the study is to investigate the possible effects of an unstable ventilation system and its influence on energy use and thermal comfort. The report also explores how qualified personal working with HVAC view and handles system control.In order to meet the requirements in energy efficiency and a comfortable indoor climate control regulation is a prerequisite. With optimized increased complexity of the climate systems, it becomes more challenging to control the system and the risk of unstable control increases. No previous studies about what affect an unstable system can have on energy use and thermal comfort have been found.The report is based on several tests were the controlling variable has been increased until the system becomes unstable. Two different types of unstable systems have been investigated.

Påverkan på energianvändning och termisk komfort vid reglerinstabilitet

The purpose of the study is to investigate the possible effects of an unstable ventilation system and its influence on energy use and thermal comfort. The report also explores how qualified personal working with HVAC view and handles system control.In order to meet the requirements in energy efficiency and a comfortable indoor climate control regulation is a prerequisite. With optimized increased complexity of the climate systems, it becomes more challenging to control the system and the risk of unstable control increases. No previous studies about what affect an unstable system can have on energy use and thermal comfort have been found.The report is based on several tests were the controlling variable has been increased until the system becomes unstable. Two different types of unstable systems have been investigated.

Fisk- och fågelpredations påverkan på den bentiska makroevertebratfaunans sammansättning under tidig vår i Tåkern

Predation is one of many factors that form the structure of the macroinvertebrate community in lakes, wetlands and watercourses. Earlier studies lack an examination concerning how fish- and waterfowl predation affect macroinvertebrates during shorter periods in the spring. I performed an exclosure study in the shallow eutrophic Lake Tåkern which is located in the western part of Östergötland County, Sweden. The experiment was performed during a three week period (1-21 April 2012) when the water temperature was low and the density of migrating diving ducks was high. The experimental cages used included three out of four different treatments; general predation (open cages), bird exclusion (net with mesh size 90*45mm) and no predation (net with mesh size 1*1mm).

Vattendragsrestaurering i teorin och fiskinventering i praktiken : en litteratur respektive metodstudie

Running water-pathways have played an important roll in Sweden and frequently been manipulated. One profound change was made during the period of logging when streams were cleared from obstacles as big boulders, sharp bends and side-streams. Dams and different constructions gave control of the stream water and the streams became channel-like with a homogen structure. This interference gave problems for many fish populations and resulted in a shortage of feeding habitat, over-wintering habitat, spawning habitat, unnatural flow regimes, sedimentation, unnatural temperature fluctuations. Many of these historical changes of the watersheds are now subjects for restoration, ie., bring back the streams to what we believed it was before the change. However, what once existed in terms of complexity is now gone and difficult toreplace.

Ekonomi i Passivhus : En studie av två verkliga byggnader

The aim of this report was to investigate the economy of passive houses. The work was focused on economy in total and on the economy of different components such as windows, insulation, heat exchanger and the air tightness of the climate shell. No attention was paid on the comfort factor or to the impacts on the environment.Two houses, aspiring to be passive were chosen; A big one and a small one. Hence, comparisons considering the size of the building have been possible to do as well.The comparisons were made by calculating ?break even? between two concepts; passive and BBR- concept.

Prestandaförändringen hos en bergvärmeanläggning efter fem års drifttid

The aim of this report was to do a case study at a geothermal heating system which has been in operation for about 5 years, and study if its performance has changed during this period of time. A literature study about the processes involved was also done in purpose of background knowledge.The tenant-owner?s association Duvan at Petterslundsgatan in Uppsala installed year 1999-2000 a geothermal heating system. The purpose of this installation was that they hoped it would lead to a smaller usage of district heating which would lead to a reduction of the heating expenses for their buildings. The geothermal heating system consists of 19 energy wells and 4 geothermal heat pumps, and it is one of the first systems of that size in the region of Uppsala.

Markavvattningsföretagens geografi och konsekvenser i Trosaåns avrinningsområde

Agricultural drainage is widely used to manage the amount of water in the ground in order to improve conditions for cultivation. However the effects of drainage companies on water regimes are considerable leading to runoff changes such as altered stream flows, peak flows and water levels. In a greater extent this could imply an increased risk for floods along affected watercourses. This study analyzes the extension of agricultural drainage within the drainage basin of Trosaån in Sweden by ArcGIS mapping. In a statistical analysis, historical variation in streamflow in relation to mean precipitation and mean temperature are investigated for the study area.

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