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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

En resa tillbaka i tiden för att förstå framtiden : En undersökning av organiskt material i eoliska lössjordssediment på västra Grönland, Kangerlussuaq. / A Journey Back in Time to Understand the Future : A Study of Organic Material in Aeolian Loess Sediments in Western Greenland, Kangerlussuaq.

Morin, Caroline, Sundman, Jessica January 2021 (has links)
Today's changing climate on Earth makes climate research more important than ever. By providing an understanding of the Earth's history and in particular places where large-scale climate change is taking place, for example Greenland, can one get an understanding about how the Earth will react in the future. In this report has eolian loess deposits been analyzed from the permafrost region on Greenland, near the city Kangerlussuaq (Hällberg 2018). The eolian sediment can contain organic carbon that shows climate conditions during the time when the sedimentation occurred. In this report, the organic carbon has been measured using loss of ignition (LOI). The method is well-tried and measures the loss of weight in the samples, which answers to the loss of organic carbon (Dean 1974). The samples were heated to 100°C and thereafter burned at 550°C. The results from the LOI have been analyzed and compared to other data from the same location. This includes data from carbon-14 dating, X-ray fluorescence, grain size and magnetic susceptibility. The final data set has been mapped in the geographical information system. The maps gave an overview of the changes in the area. Results shows that there are connections between organic carbon and climate change in Greenland, which also is proved by correlation to other studies. / Det rådande klimathotet och det föränderliga klimatet på jorden gör att klimatstudier är viktigare än någonsin. Genom att få en förståelse för jordens historia i synnerhet på platser där stora klimatförändringar sker, så som på Grönland, kan en uppfattning fås om hur vår jord kommer påverkas. I uppsatsen har eoliskt avsatt lössjord analyserats från permafrostområdet på Grönland, nära staden Kangerlussuaq (Hällberg 2018). Det eoliska sedimentet innehåller organiskt material som avspeglar klimatförhållanden på platsen för tiden då sedimentationen inträffade. I arbetet har innehållet av organiskt material undersökts genom metoden Loss of Ignition (LOI). Metoden är välbeprövad och går ut på att mäta förlust i vikt vilket motsvarar förlust av organiskt material (Dean 1974). Proverna har torkats i 100°C och därefter bränts i 550°C. Resultatet som gavs av LOI har analyserats och jämförts med annan data från samma lokaler. De innefattar kol 14-metoden, röntgenfluorescens, kornstorlek och magnetisk susceptibilitet. Den slutgiltiga datauppsätningen har genom kartverktyget Geografisk Informationssystem karterats. Kartorna gav övergripande bild på de rumsliga förändringarna i området. Resultaten visar att det finns samband mellan organiskt material och klimatet på Grönland vilket även bevisas av korrelation med andra studier.
2

Misstänkt sulfidjord i deponi vid Stöcke, Umeå / Suspected sulphide soil in landfill at Stöcke, Umeå

Hägglund, Emma January 2015 (has links)
In the north of Sweden lots of the soil is naturally contaminated by acid sulfate. When soil gets in contact with oxygen an oxidation process begins which releases elements that may be harmful to the surroundings. When the Botniabanan was built, soil had to be transported from the railroad area to deposit sites. This study was made to investigate the suspicions a landowner had regarding if his estate had been contaminated sulphide soil soil during the building of the Botniabanan. To do that four pits were dug in the area where the soil had been deposited. Then the soil was analyzed to see the content of sulfate, iron, organic matters and water. When the results was compared to other studies it showed that the content of sulfate and organic matters was to low to classify the soil as an acid sulfate soil.
3

Loess as an Environmental Proxy for Reconstruction of Palaeoclimate in the High Arctic / Lössjord som miljöindikator för rekonstruktion av forntida klimat i Arktis

Rognås, Sara January 2023 (has links)
We are currently speeding towards significant changes in the climate of the earth which, if ignored, will lead to severely altered climatic conditions with serious consequences for several species and ecosystems. The polar regions especially are very sensitive to climate changes, and the changes these regions undergo affect the climate on a global scale. To slow the global warming, it is crucial that we understand earth’s climatic and environmental history, and how it responds to changes in the climate. Palaeoclimatic archives hold much information of past climate variations stored in proxies that can be analysed to understand past environments. This study focuses on loess as one such proxy to analyse grain sizes, carbon storage and organic matter in a sequence from Adventdalen, Svalbard. The study has been conducted using grain size analysis and loss on ignition (LOI) as main methods to reconstruct late Holocene climate changes in the region. The results have provided an overview of temperature oscillations, many of which coincide with main climatic events of the past, and have been used to estimate the depositional ages of the different layers of the sequence. / Dagens klimatförändringar går allt snabbare mot en framtid med svårt omkastade klimatförhållanden som medför allvarliga konsekvenser för flera arter och ekosystem. Polarområdena är särskilt känsliga för klimatförändringar, och de förändringar som sker här påverkar klimatet på global nivå. En avgörande faktor för att bromsa den globala uppvärmningen är att vi förstår jordens klimathistoria och hur jorden reagerar på förändringar i klimatet. Paleoklimatiska arkiv innehåller mycket information om klimatvariationer förr. Sådan information finns lagrad i material som kan analyseras för att vidare förstå miljöer från förr. Den här studien fokuserar på lössjord som ett sådant material för att analysera kornstorlekar och organiskt material i en lössekvens från Adventdalen i Svalbard. Studien har genomförts genom att använda en kornstorleksanalysator och loss on ignition (LOI) som huvudsakliga metoder för att rekonstruera klimatförändringar under yngre Holocen i området. Resultaten har givit en överblick av temperaturförändringar, av vilka flera sammanfaller med större förflutna klimathändelser, och har använts för att göra en uppskattning av åldrar på de olika lagren av sekvensen.
4

The effects of burn severity on soil properties : Infiltration rate, moisture, grain size distribution and carbon content Hälleskogsbrännan as an example

Haddad, Ola January 2016 (has links)
This study focuses on soil hydrological parameters that are expected to be related to burn severity in forests; infiltration rate, soil moisture, grain size distribution and carbon content along a burn severity gradient in Västmanland Sweden, where a major fire occurred in 2014. Hälleskogsbrännan was divided into two burn severities: a moderate severity and a high severity, and a control area. Ten soil samples were taken for laboratory analyses at each severity level. Soil moisture and infiltration rate was measured in situ. Infiltration rates and soil moisture were highest in the most severely affected site, whereas fire effects on soil texture were insignificant. Soil organic carbon content was highest at the low fire severity site, followed by control and high severity fire sites. Inorganic carbon content followed the opposite trend. These results had clear trends but were insignificant, this call for more comprehensive sampling to separate possible confounding site effects.
5

Total Organic Carbon Reduction of Sorting by-Product Fractions

Al Saheb, Ahmad Abdul Rahman January 2020 (has links)
The drive of the EU countries and most of the world towards a circular economy and togenerate zero waste raised a need to study more efficient and less costly treatment processes. The treatment of secondary and by-product fractions to convert them from what is considered waste to a resource will contribute to the movement towards zero waste and circular economy. The fines fraction of construction and demolition waste (CDW) contains high organic materials measured as total organic carbon TOC above the allowed landfilling levels that are allowed for landfilling in Sweden, yet lower organic matter than is required for energy recovery by incineration. The need for new processes to reuse and recycle materials have emphasized the work of thisstudy, this thesis research aims to develop viable, simple treatment methods and pathways ofrecycling systems to convert by-products that are considered waste to reusable and treatable fractions by reducing the total organic carbon TOC. Which have been defined in the researchquestion of this study “How can functional recycling become more effective through the development of innovative treatment pathways for by-products of the recycling system”? and its sub-questions. This study examined a fines fraction from the CDW sorting in Norway using mechanicalseparation methods including single and combined sequential processes of air classificationand float/sink density separation. Using single process batch separation of float/sink had produced a 73.80% weight of the original fines fraction, with reduced TOC from originally 35.54% DM to 4.09% DM which can be considered to be landfilled as non-hazardous provided that it meets all other leachateanalysis criterion, on the other hand, the process produced concentrated the organic carbon inthe float fraction giving a TOC of 40.14% DM to consider treating it with energy recovery. Using a single separation process of high air velocity with the zigzag air classification has lowered the TOC of 19.49% weight of the treated fraction to 1.8% DM from 35.54% DM of the original fines fraction, which can be considered to be landfilled as inert waste if it meetsall other leachate analysis criterion, or can be considered to be used in road base layers, and concentrated the organic carbon in the other fraction to TOC of 19.90% DM that which need further treatment. Using sequential air classification followed by float/sink sequentialseparation produced different low TOC fractions suitable for landfilling in the categoriesinert, non-hazardous, and hazardous waste in Sweden and concentrated the organic content toTOC levels of 20-48% DM TOC which can be considered for energy recovery recycling. The use of sequential density separation processes can lead to better results and can be controlled more to produced better fractions. The conclusion of this study, using float/sink and airclassification separation methods as single or combined sequential processes had successfully produced two fractions firstly the reduced the total organic carbon separated fraction to be suitable the landfilling requirements in Sweden at the same time concentrated the organicmaterial of the other fraction to be suitable for incineration.
6

A Geochemical and Mineralogical Comparison of Soil Formation on Mine Spoil and Undisturbed Shale and their Contributions to Pore Water, Huff Run Watershed, Ohio

Zemanek, Laura Marie 11 October 2021 (has links)
No description available.

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