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500 Uppsatser om Sub surface scattering - Sida 27 av 34
Energieffektivisering av aerbo reningsprocess : Tillsats av biprodukter i skogsindustriellt avloppsvatten
In the production of pulp, paper and cardboard, a large amount of water is used daily. The water has to be purified in the internal purifying plant before it reaches the receiving body of water. In the biological purifying stage at the Stora Enso Skoghall mill, an aerated basin is used where the microorganisms, using oxygen, oxidize the organic material to carbon dioxide. The air is pumped from the bottom of the basin and the oxygen can then be transported from the air bubbles to the water through diffusion. The problem with aeration of waste water from the forest industry is that wood residues, such as fatty acids, are making the transport of oxygen in water more difficult.
Landscape? Urbanism : om semantik och språkets betydelse
I och med Landscape Urbanism har landskapsbegreppet sedan en tid upplevt en hausse inom arkitektur- och stadsbyggnadsdiskurs. I och med denna nya uppmärksamhet för landskapet har ett nytt behov uppstått: att diskutera vad
som egentligen menas när man använder detta mångtydiga begrepp. Med detta fokus behandlar denna uppsats komplikationerna som uppstår när ordet landskap och dess ofta motstridiga betydelser används utan att kommunicera vad som avses. Med utgångspunkt i lingvistiska teorier hävdar jag därför att språket och således semantiken, ordens innebörd, är av yttersta vikt för att formulera och konstruera nya stadsbyggnadsteorier såsom Landscape Urbanism. För vad betyder egentligen Landscape inom Landscape Urbanism? Hur kommer det sig att ordet dels används för att referera till ytorna ?mellan husen?, men även används som ett begrepp som beskriver hela stadens
dynamik? Hur kan dessa mycket olika tolkningar av ordet landskap existera under en och samma paroll ? Landscape Urbanism? Denna uppsats behandlar dessa olika tolkningar, men presenterar även ett sätt att hantera detta till synes alldagliga men mångfacetterade ord.
Due to Landscape Urbanism the term landscape has experienced a recent hausse within architecture and urban design discourse.
Utvärdering av metoder för framställning och kontroll av digitala terrängmodeller
Today there are many applications of digital terrain models (DTM) and the requirements of low uncertainty increases. Most of the DTM are produced with Global Navigation Satellite System (GNSS), terrestrial laser scanning (TLS), airborne laser scanning (ALS) and total stations. Guidelines for the preparation and verification of DTM are found in Swedish Standards Institute ? Technical Specifications (SIS-TS) 21144:2007 and SIS-TS 21145:2007. These were defined in collaboration between Swedish National Rail Administration, Banverket, and Swedish Road Administration, Vägverket, to satisfy the needs of requirement formulations in the production of DTM planning, design and construction. The purpose of this paper is to produce and control DTM over Åkermans kulle, located west of the University of Gävle, according to SIS TS 21144:2007 using GNSS with network-RTK, TLS and ALS.
Ytstrukturer och processer för hårdbearbetning av kugghjul och axlar
Detta examensarbete har utförts vid Linköpings universitet i samarbete med Scania Transmission i Södertälje och behandlar kravsättning av ytstrukturer samt processer för hårdbearbetning av kugghjul och axlar. Aktuella artikelritningar innefattar endast krav för Ra-värde, den aritmetiska medelavvikelsen för ytjämnhetsprofilen (R-profilen). Förslag på nya parametrar enligt av Scania tillämpade SS-EN ISO standards har tagits fram, detta för att ge en noggrannare beskrivning av vilken ytstruktur som skall uppnås. Resultatet är generellt tillämpningsbart men fokuseras mot kugghjulens hål, plan och diametrar. Vidare presenteras en jämförelse mellan metoder så att transmissionsverkstäderna kan tillverka kugghjul/axlar på ett kostnadseffektivare sätt.
Fire impact in the wood quality and a fertilization experiment in Eucalyptus plantations in Guangxi, southern China
Chinas government has a multifunctional program for a more sustainable forestry since 2000. This six key forest programs goal is to develop a more sustainable forest sector but also take environment consideration. The state forest administration in China has decided to create 5.8 million hectare of fast growing and high yield forest. Eucalyptus has showed to have good properties for pulp and timber production and therefore Eucalyptus plantations are under development in costal areas in southern China. By adding extra nutrients, growth can be enhanced in Eucalyptus plantations.
Nedbrytning av propylenglykol i uppsamlingssystem för avisningsvätskor : En studie utförd vid Stockholm Arlanda flygplats
Deicing fluids based on Propylene glycol are used at Stockholm Arlanda airport to remove or prevent ice on aircrafts. The high oxygen demand of propylene glycol can cause oxygen depletion in rivers downstream from the airport if not collected. Mass balance calculations made by Swedavia indicate that the actual amount of gathered propylene glycol is underestimated. Suspicions that propylene glycol is degraded in the stormwatersystem designed to collect deicingfluids, called the B-glycolsystem, have to be investigated in order to establish with certainty that no propylene glycol in other ways leaves the B-glycol system.The purpose of this study was to determine if degradation of propylene glycol is present in the B-glycol system and also to estimate the extent of the degradation. Propylene glycols high biological oxygen demand can cause oxygen depletion in waters downstream from Stockholm Arlanda airport if not collected.
Structure and tree diversity of lowland limestone forest on Seram Island, Indonesia
There have previously been very few studies of forests on Seram Island in the Eastern Indonesian archipelago and none before on lowland limestone primary forests. The COLUPSIA project on collaborative land use planning has therefore chosen Seram as one of two project sites. The objective of the COLUPSIA project is to establish collaborative and equitable land use planning. In order to achieve its objective the COLUPSIA project aims to improve understanding of traditional resource management and how it interacts with governmental systems, as well as enhancing knowledge about tropical landscapes and ecosystem services.The aim of this study was to contribute to the COLUPSIA project through describing lowland limestone forest on Seram Island in respect to (1) forest structure, (2) tree species richness and (3) tree species composition. We set up 5 plots, each of 0.2 ha, at one site, Mawalai, and collected data on tree variables (tree diameter ?10 cm) as well as for some other life forms and environmental data.
Användning av CAD-data vid NC-programmering
The degree project is performed at Metso Kamfab. The production is aimed on machines everything from handling of fiber to paper pulp. Metso Fiber and Kamfab are using Pro/Engineer for design and blueprint production. The processing department types the NC-programs in notepad on the basis of the blueprints, the CAD-dates that already is there are not used. The aim with the work is to study if Kamfab can use CAM-system for processing and production of programs for their NC-machines.
Migration och vegetationsupptag av radiocesium i åkermark - en långtidsserie av mätdata samt en långsiktig simuleringsmodell :
Abstract
The accident in 1986 at the nuclear power station in Chernobyl, Ukraine, dispersed radioactive cesium over large areas of Europe. The half life of 137Cs is 30 years and this radionuclide also behaves like potassium, which means that it can easily be taken up by the vegetation or be adsorbed in to the structure of clays, principally illitic clays. When radiocesium decays ionizing radiation is emitted, which is harmful to humans that are exposed, either directly or indirectly through food intake. It is there-fore important to know what happens to the cesium that is dispersed into the environ-ment.
In this project a simulation model was constructed to simulate the adsorption and transport of radiocesium in the soil and plant uptake.
El Niño Southern Oscillation och dess atmosfäriska fjärrpåverkan.
This paper is a literature study aiming to describe scientists newest theories andknowledge concerning the El Niño and Southern Oscillation. Firstly I have described the?normal? conditions with rising and sinking air in Hadley- and Walker-cells in theequatorial Pacific and from there moved on to explaining the reversed circulation patternsand higher sea surface temperatures (SST) leading to rising air and anomalousprecipitation in eastern Pacific constituting the El Niño phenomenon. My outermostinterest regarding El Niño has been the associated teleconnections, especially in nontropicalareas. I have described the El Niño effect on the Indian summer monsoon, ontropical cyclones and on storms and precipitation on higher latitudes.
Jordbearbetningsstrategier på hösten inför vårsådd på tyngre lerjordar :
It is important for today?s farmers to minimize the costs for crop establishment, because
of decreased prices and support from the EU. Farmers, who plow in autumn on heavy
clay soil, often do some kind of tillage in autumn to get better soil structure before
spring seeding. This is especially important when growing small seed crop, e.g. sugar
beet and oil plants.
Nedfästning av oljemåleri på puts.En fallstudie från salongen på Mostorps slott i Halland
This thesis, designed as a case study, is about complications concerning conservation of a decorative oil paint on lime plaster from the drawing-room in Mostorp castle sited in the county of Halland in south-west of Sweden. The building was built 1878-80 with an exterior of granite. The interior walls were made of clay bricks, lime mortar and lime plaster. The oil paint is applied to a layer of putty. The combination of different materials, which are organic and inorganic, affects the movement caused by internal and external stress.
Specificering av produktionstransformatorer : Rekommenderade avsteg från IEC 60076 för att vid upphandling beskriva en robust enhet
As break downs of production transformers are costly and often result in long outages it is essential for reliability of operation that the transformers are manufactured to be robust. The aim of this M.Sc. thesis is to investigate if deviations should be made from the standard IEC 60076 ? Power Transformers in order to describe a robust large power transformer for procurement.The investigation has been conducted in three stages. In the first stage a definition of the term robust was developed in consultation with the client Vattenfall Vattenkraft.
Närklimat vid avvänjning av smågrisar :
SUMMARY
Several studies have shown that weaning pigs are in great need of heat. The reason for this is
mainly because the pigs are given very little feed just after weaning. Some of the pig producers
of today have tried to get along with these problems by building some kind of hut for the
pigs. Some of these pig houses have been included in this study.The study has shown shortcoming
functions for the pig cottage. The expected heat increase has not occurred.
Järnets förekomst i grundvattnet i isälvsavlagringar i Dalarna : Bakgrundshalter och rörmaterialets inverkan vid grundvattenprovtagning
A study has been performed that investigates the variation of iron content in groundwater.The study was initiated by Midvatten AB, which noticed that the iron content in groundwater samples can vary greatly over small distances. The purpose of this study was to geochemically and geohydrologically determine the factors that influence the content of iron and manganese in groundwater from a selection of eskers in Dalarna, and determine how to best sample groundwater with the method used by Midvatten AB. An evaluation was made of how the vertical variation in soil material, water composition, pumping time and pipe material affects the content of iron in groundwater. Piper diagrams were used to study the relationship between the chemical composition of the groundwater and the content of iron and manganese in groundwater samples from the studied areas. The groundwater from the studied areas was then classified in the Piper diagrams, according to the content of the major ions.