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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.
731

Källor i Lagga, en uppländsk slättbygd : Geografisk och geologisk påverkan på källvattens egenskaper / Springs in Lagga, within the flat land of Uppland, central Sweden

Beckholmen, Ingrid January 2014 (has links)
For centuries, springs have played a significant role in our society as water supplies, reasons for where to settle down, and in folklore. There are different reasons why and where a spring forms, e.g. in what kind of soil it has its outflow. Geographic and geochemical surroundings have an influence on spring-water quality.For this project some of the springs in the Lagga perish, Knivsta municipality, Sweden, were selected for a closer study. Water samples were collected from springs for analysis. A short-term study was performed of temperature and conductivity changes during spring 2014. The investigated springs of this project were divided into four major groups according to their location in the landscape and their chemical properties: 1) springs that have their outflow in clay in valley bottoms, 2) springs that lie in the transition between glacial till soil and clay, 3) springs in till soil, and 4) springs in till soil with large boulders. Analyses show that the ion content in spring-water is higher in the valley than in the surrounding forest tills. Together with previous data it is shown that temperature and conductivity are more stable in the springs in the valley clay than in the uphill springs in till. / Källor har under århundraden spelat en viktig roll i människors liv genom behovet av vattenförsörjning, vid val av plats för att bosätta sig och inom folkloristiken. Källors förekomst styrs av var och hur de uppträder; t ex i vilken sorts jordart utströmningen sker. Den geografiska och geologiska närkemin påverkar källvattenkemin. I detta projekt undersöktes källor i Lagga socken, Knivsta kommun. Källvattenprover samlades in för analys av vattenkemin. En kort tidsserie under våren 2014 för temperatur och konduktivitet upprättades. Källorna delades in i fyra större grupper efter hur de ligger i landskapet och efter deras kemiska egenskaper: 1) Källor som kommer upp genom leran i dalgången, 2) källor som ligger i kanten av lerslätten, 3) källor som ligger i morän och 4) i storblockig morän. Efter analys visas att källor nära och i dalgången har högre jonhalt än de källor som ligger i moränen, uppe i skogarna. Vid en jämförelse med tidigare mätdata ser man att temperatur och konduktivitet är stabilare i källor som kommer ut i den leriga dalgången än i moränkällorna.
732

Transboundary Water Cooperation between Bangladesh and India in the Ganges River Basin: Exploring a Benefit-sharing Approach

Karim, Sajid January 2020 (has links)
Bangladesh and India share 54 transboundary rivers. Despite that, the transboundary water management between these two countries is heavily concentrated on the Ganges river basin, in which, mode of cooperation is still based on physical sharing of water. The study is developed on the argument that Bangladesh and India need a shift of focus in their current mode of transboundary water management from physical sharing of water to sharing of benefits derived from the use (and non-use) water in order to foster transboundary water cooperation in the Ganges river basin. Based on a single-case study, the research work aims to explore the scope of benefit-sharing in the transboundary water cooperation in the Ganges river basin and how benefit-sharing can be facilitated between these two countries. The findings show that the water negotiation in the Ganges basin would become much more complicated in the future, primarily due to the growing gap between the demand and the availability of water. The adverse impact of climate change will further deteriorate the situation. Besides, the changing nature of India’s domestic politics and the growing internal conflict between its provincial states will weaken the Indian central government’s authority to manage transboundary water resources jointly. Therefore, in the future, Bangladesh and India would find it difficult to elicit a positive-sum outcome from any water negotiation in Ganges river if they still focus on the volumetric allocation of water. The study suggests that inland navigation and water transit, multipurpose storage dam projects and joint management of the Sundarbans can be the potential areas for benefit-sharing in the Ganges basin. The study stresses the importance of shifting the policy outlook and developing institutional arrangements between Bangladesh and India to introduce and facilitate benefit-sharing in the Ganges river basin that will help to share benefits equitably, hence foster cooperation.
733

LCC-analys parametrar för underhåll av inklädda tunnlar

Bascunan, Daniel January 2020 (has links)
Syftet med detta examensarbete är att undersöka och få fram underhållsparametrar för LCC-analysen (LivsCykelKostnad) av de nya inklädda tunnlarna. För arbetet har elektroniska källor använts samt intervjuer med tre yrkesverksamma från Trafikverket gällande bergtunnlar och de inklädda tunnlarna. Arbetet undersökte inte skillnaden mellan olika typer av tunnlar samt inkluderar inte utforskandet av andra länders LCC-analys parameterval. Trafikverket är en Svensk myndighet vars uppgift är att ansvara för och upprätthålla Sveriges transportsystem. Trafikverket har verksamhet inom sex områden: planering, trafik, underhåll, investering, stora projekt samt informations- och kommunikationsteknik. Huvudsakligen finns det två inklädnadssystem, fullinklädd, i vilket används antingen prefabricerad betong eller plastingjuten betong som inklädnad runt tunnel, samt halvinklädd, då en duk/membran med- eller utan sprutbetong används. Dessa inklädnadsystem har i uppgift att ta hand om vattenläckage och isbildning i tunneln. Fullinklädnad kan också användas som bärande element. En lättinklädd tunnel kan bestå av följande delar: duk/membranet, brandskydd, täckande nät, infästningsbultar och mindre delar. En fullinklädd tunnel består av antingen prefabricerad betong eller plastingjuten betong. Underhåll görs för att säkerställa den fortlöpande användningen av tunneln/anläggningen genom att åtgärda skador och fel som har uppkommit. En tunnel kan få skador på själva berget eller materialet. Underhåll av tunnlar består av flera steg. Först ut är tillståndsmätning, sedan objektplanering och sist åtgärd. En viktig del av åtgärd är trafikupphållet som uppstår när den utförs, kostnaden som uppstår påverkas av var tunneln är och hur länge det tar att åtgärda felet. LCC-analys är ett system som ger ett mått på ett objekts totalkostnad under dess hela livstid. LCC används på systemnivå för analys av tunnlarna och för att jämföra olika investeringsmetoder. För att utföra LCC-analys på systemnivå måste gränser för analysen sättas upp, LCC-modell och indata väljas. LCC-metoden som redovisas i rapporten använder investeringskostnaden och nuvärdet av underhållet- samt driftstoppskostnaden för att få fram LCC-värdet av underhållet för en komponent. Utifrån källorna och intervjuerna har det framgått att de avgörande parametrarna för LLC-analysen är följande: bergets tillstånd, materialets/konstruktionens tillstånd, kostnader för avstängning samt kostnaden för att ta ner inklädnaden.
734

Gas Emissions from Contaminated Fibrous Sediments in Sweden / Gasutsläpp från svenska fiberbankar

Collin, Fredrik January 2020 (has links)
Gas Emissions from Contaminated Fibrous Sediments in Sweden The discharge of untreated wastewater from pulp and paper mills have resulted in the accumulation offibrous sediments on the bottom of many nearby aquatic recipients. Some accumulations are multiplemeters thick and consist almost entirely of cellulose fibre or wood chips; these are called fiberbanks.The often hypoxic conditions and high organic content in fiberbanks makes them favourable for methaneproducing microorganisms, and gas release by ebullition has been observed. CH4 has high globalwarming potential and this study therefore aims to investigate GHG emissions from Swedish fiberbanks.Since methanogenesis is influenced by temperature and organic content, the gas ebullition is expectedto vary with season and between fiberbanks. As such it was necessary to examine differences inebullition rate, bubble volume and bubble quantity between different fiberbanks and to test the influenceof temperature on ebullition. To achieve this, the gas ebullition from two fiberbanks with very differentcomposition (Väja and Sandviken), were investigated using optical ebullition sensors measuring thequantity and volume of released gas bubbles. The ebullition measurements were performed in laboratoryat room temperature (20oC) and with sediments in incubation (4 – 15oC). The results indicate differencesin both ebullition rate and mean bubble volume between these two fiberbanks, with only minordifferences in the quantity of bubbles released. In a period of stable ebullition over five consecutivedays, sediment from Väja released 83 – 90% larger volumes of gas per day, and also produced bubblesthat were on average 67 – 89 % larger in volume when compared to Sandviken. The incubationexperiments show that ebullition from both fiberbanks increases exponentially with temperature, at ratessimilar to those found in natural sediments (Väja Q10 3.9, Sandviken Q10 4.9). The rate of accelerationin ebullition from both sediments is very strong >10oC, which is also similar to what has been observedin natural sediments. If estimating the combined GHG emissions from Swedish fiberbanks based on theresults from this study, it shows that fiberbanks could emit as much as 550 000 – 900 000 tonnes of CO2equivalents annually. That would correspond to 1.1 – 1.7% of the combined annual Swedish GHGemissions in 2018, and with fiberbank ebullition showing such a strong temperature dependence, thatestimate would grow rapidly when water temperatures increase with a warming climate / Utsläpp av orenat processvatten från svensk pappersindustri har resulterat i ansamlingar av fiberhaltigasediment på botten av närliggande vattendrag. På vissa platser bildar de fiberhaltiga sedimenten flerameter tjocka fiberbankar som består nästan uteslutande av cellulosafibrer eller träflis. Det högaorganiska innehållet i fiberbankarna resulterar ofta i syrefria förhållanden vilket gör dem gynnsammaför metanproducerande mikroorganismer, och frisläppning av gasbubblor har observerats. Metangasbidrar starkt till växthuseffekten och det här projektet utformades därför med huvudmålet att uppskattaväxthusgasutsläppen via ebullition från svenska fiberbankar. Eftersom metangasproduktionenförväntades variera beroende på temperatur och fiberbankskomposition, undersöktes skillnader igasutsläpp från två olika fiberbankar, gällande koncentrationen på utsläppt gas, mängd utsläppt gas,volym på bubblor, antal bubblor, samt hur gasutsläppen från fiberbankarna påverkades av temperatur.Undersökningen inkluderade sediment från två fiberbankar med väldigt olika sammansättning (Väja ochSandviken) och gasutsläppen studerades med hjälp av optiska sensorer i rumstemperatur och underinkubation vid temperaturer från 4 – 15oC. Data från undersökningarna användas sedan till att uppskattade årliga växthusgasutsläppen från svenska fiberbankar. Resultaten indikerar att det är stora skillnader imängden utsläppt gas och volymen på frisläppta bubblor mellan dessa två fiberbanksediment, menendast små skillnader i antalet frisläppta bubblor. Fiberbankssediment från Väja släppte ut en 83 - 90%större gasvolym per dag och producerade också i genomsnitt 67 - 89% större bubblor jämfört medsediment från Sandviken. Inkubationsexperimenten visar att gasutsläppen från de bådafiberbanksedimenten ökar exponentiellt med temperatur, och tilltar i liknande hastighet som hosnaturliga sediment (Väja Q10 3.9, Sandviken Q10 4.9). Ökningen i gasutsläpp vid temperaturer över 10oCär mycket stark hos båda sedimenten, vilket också liknar observationer från naturliga sediment. Närresultaten används för att uppskatta växthusgasutsläppen från den totala mängden fiberbanksedimentsom kan finnas i Sverige, visar de att fiberbankar kan släppa ut så mycket som 550 000 - 900 000 tonCO2-ekvivalenter årligen. Det skulle innebära 1.1 – 1.7% av de sammanlagda årliga svenskaväxthusgasutsläppen.
735

Requirements of implementing a circular leasing & rental model on technical garments : Challenges and opportunities in the Swedish outdoor industry

Oscarson, Frida January 2020 (has links)
The Fashion industry has grown rapidly over the past decade. The industry is one of the world’s most polluting industries and the way we produce and consume clothes has to change, to reach sustainability across the industry. The fashion industry requires a new “textile economy” where business models are developed to keep products in use and continuously circulate. Therefore, developing business model that can keep products in use and make them circulate is one way forward. Product-Service-Systems (PSS) have become a discussion amongst researchers to be a possible way of reaching more sustainable practices across the industry. This study therefore looks at one form of PSS, leasing and rental. The study will investigate, technical garments because from a durability and quality perspective they are ideal to incorporate in this type of model. Therefore, this study aimed at developing an ideal circular leasing and rental model to see what requirements is needed to keep activity-based, technical garments in use. It was also of interest to investigate what challenges and opportunities the Swedish outdoor industry face when implementing a leasing and rental model, and if they can fulfil the requirements of the ideal circular model. A qualitative method was used through semi-structured interviews to collect the empirical data. The results show that the requirements of an ideal circular leasing and rental model includes Sustainability, Investments/Economic profit, Human resources, Logistics, Product design and Upcycling. The empirical results from the Swedish outdoor industry shows that they require the same factors as the model, however two more requirements are highlighted by the industry, Thirdparty-partner and customer demand. The results also shows that today it is too challenging for the Swedish outdoor industry fulfil the requirements of an ideal circular leasing and rental model. Collaborating with a third-party-partner is one aspect the industry see as an opportunity. The products have an opportunity to be kept in use because the brands will care for them. However, the industry face more challenges than opportunities, some of the challenges are investments and economic profit, logistics and upcycling processes of activity-based technical garments.
736

The designer perspective: Opportunities and Obstacles toward circular fashion

Ridler, Sophie Joyce January 2020 (has links)
Circular fashion has become a favoured option for the fashion industry to transition toward as the fast fashion industry becomes unsustainable. Current research within academia, business and policy focuses on the lifecycle stages of the garments, with the designer and design phase in focus. Research on circular economy predominantly looks at material flows and the lifecycle. This however fails to acknowledge potential innovation and the capacity for this change to occur. This study uncovers the perspectives of the designer, who are largely absent from the current research agenda, in order to identify leverage points in the current system which would allow accelerated transition toward a circular fashion system. Using workshops as a method to involve designers, paired together with critical systems theory; the study first highlights a large gap between academia and reality, and reveals that there is a large misconception between designers from fast fashion and designers from luxury fashion and the power influences they allow, while, underlying internal organizational structures pose as an obstacle minimizing capacities for change. Finally, using a three horizons framework as a technique, six leverage points are identified: cultural norm, strong teams, digitalization, leadership for sustainability, education & knowledge and reducing intergenerational conflicts. Overall, the study provides a holistic view of the current environment and the transition toward circular fashion, how lifecycle phases connect to circular economy frameworks and highlights innovation and the ways in which the designer can be re-empowered. The study bridges fashion business with sustainability science in a straightforward way and sets and refines the future research on solutions and challenges.
737

Greenhouse gas emissions and carbon burial in a small pond / Växthusgasutsläpp och kolbindning i en liten damm

Carlson, Maria January 2023 (has links)
There are a lot of uncertainties when it comes to global greenhouse gas (GHG) emissions which affects society’s ability to effectively respond to climate change. Small ponds have been found to potentially play a large role in global warming. More research is needed, however, to determine to what extent they act as sources or sinks for GHGs, and what factors may contribute. The aim of this thesis was to study carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) emissions, and carbon burial in a small pond in Uppsala, Sweden. The pond was a source for both CO2 and CH4, but a sink for N2O. About 50% of CH4 emissions came from ebullition (bubbles). CO2 flux was higher in the vegetated area than in the open water area, no difference was found for CH4 flux. Both CO2 and CH4 flux were higher on colder days, while CH4 ebullition was higher on warmer days. Limited accumulation of CO2 and CH4 occurred under the winter ice coverage. For water chemistry, CO2 flux had the strongest negative relationship with electrical conductivity (EC), nitrate (NO3−) and nitrite (NO2−), and positive with total phosphorous (TP). CH4 flux showed the strongest negative correlation with chlorophyll-a (chl-a) and total nitrogen (TN), and positive with EC and total dissolved solids (TDS). For extracellular enzyme activity, CO2 flux had a very strong positive correlation with β-D-glucosidase (BG), as did CH4 with N-acetyl-β-D-glucosaminidase (NAG). Carbon burial rate was low making the pond a carbon source and inefficient at burying carbon / Det finns många osäkerheter vad gäller globala utsläpp av växthusgaser vilket påverkar samhällets förmåga att effektivt motarbeta den globala uppvärmningen. Små dammar har potentiellt förmågan att ha en stor påverkan på klimatet, men mer forskning behövs för att avgöra i vilken utsträckning de fungerar som källor eller sänkor för växthusgaser, samt vilka faktorer som påverkar deras utsläpp eller förmåga att binda kol. Målet med denna studie var att undersöka utsläpp av koldioxid (CO2), metan (CH4) och lustgas (N2O), samt kolbindning i en liten damm i Uppsala, Sverige. Dammen var en nettoutsläppare av CO2 och CH4, men en nettoupptagare av N2O. CH4 i form av ebullition (bubblor) stod för ungefär 50% av CH4 utsläppen. CO2 flödet var högre i områden med växtlighet jämfört med områden med öppet vatten, för CH4 hittades ingen skillnad mellan dessa områden. Under kallare dagar var CO2 och CH4 flödet högre, medan ebullition av CH4 var högre under varmare dagar. Under vintern skedde minimal ackumulation av CO2 och CH4 under istäcket. För vattenkemin hade CO2 flödet starkast negativ korrelation med elektrisk konduktivitet (EC), nitrat (NO3−) och nitrit (NO2−), och positiv korrelation med totalfosfor (TP). CH4 flödet visade det starkaste negativa förhållandet med klorofyll a (chl-a) och totalkväve (TN), och positiv korrelation med EC och totalt upplösta fasta ämnen (TDS). För extracellulär enzymaktivitet hade CO2 flödet en mycket stark positiv korrelation med β-D-glucosidase (BG), medan CH4 flödet hade en mycket stark positiv korrelation med N-acetyl-β-D-glucosaminidase (NAG). Kolbegravningshastigheten var låg vilket resulterade i att dammen var en kolkälla med låg förmåga att binda kol.
738

Investigation of above-ground biomass with terrestrial laser scanning : A case study of Valls Hage in Gävle

Billenberg, Mathias January 2023 (has links)
The thesis investigates above-ground biomass (AGB) with terrestrial laser scanning (TLS) for estimating AGB in a study area in Valls Hage, Gävle. The study used TLS for field measurements to collect highly detailed point clouds of two tree species for AGB estimation and comparison against validation data. TLS-derived data were validated using a non-destructive method involving direct field measurements using tape measures and a Trimble SX12 for extracting diameter at breast height (DBH), tree height, and crown diameter. Wood density was obtained from the literature. Data processing for segmentation, filtering, and generation of the quantitative structure model (QSM) was performed by using SimpleForest tool in Computree software. A statistical analysis was performed using linear regression, and AGB was estimated using QSM-derived volume multiplied by wood density. The finding in the results for the comparison of AGB estimation between TLS QSM and field validation from DBH-based tree-specific allometric equation had an RMSE of 154 kg, with a near-perfect agreement of 0.997 %, and RMSE of 189 kg, with the agreement of 0.990% for TLS QSM and TLS validation DBH-based tree specific equation. The comparison between TLS-derived DBH and field validation was accurate, leaving with insignificant differences, while the tree height had noticeable differences, and crown diameter had relatively low differences. The challenges during data processing were highlighted and the importance of TLS data for accurate AGB estimation, with the potential for refinement and integrating internal tree structure information to improve allometric models for future studies.
739

Spatialanalys av markgeokemi : Hur utlakningshalter av markgeokemin varierar i Sveriges morän enligt interpolationsmetoder / Spatial analysis of geochemistry in till : How leaching levels of geochemistry varies across Sweden according to interpolations

Hansen Österlund, Sara Emilie January 2023 (has links)
The purpose of this study was to evaluate the spatial distribution of geochemistry in Swedish till and whether interpolations could predict unknown values of geochemistry between samples at a national spatial level, Sweden, and a regional, the county of Västerbotten. The information of the spatial distribution of the elements and the interpolations accurateness has several applications. For example, the establishing of infrastructure.  Which, in Sweden, is regulated by Naturvårdsverkets guidelines for sensitive land management (KM) and less sensitive land management (MKM) since elements can be harmful for the environment and health above certain levels. The guidelines for waste disposal of soil with levels of less than slight risk (MRR) does also acquire knowledge about the background levels of an area which are found in the C-horizon. The aim of the study was therefore to answer the following questions 1) Which interpolation method provides the most accurate prediction for the various elements at the national and regional level? 2) How does the calculated levels of geochemistry differ from the sampled ones for the two spatial levels? The study was conducted by studying the levels of ten elements in the C-horizon at the two spatial levels were the regional had greater sample density than the national. The interpolations that were used for these elements were the local interpolation methods kriging, inverse distance weighting (IDW), natural neighbour, thiessen polygons and triangular irregular network (TIN). Samples were gathered from Sweden’s geological Surveys (SGU) for the elements that are regulated by Naturvårdsverkets guidelines which was why these ten elements were studied: arsenic, barium, cobalt, chromium, copper, nickel, lead, antimony, vanadium, and zinc. The interpolations were done with two thirds of  the data. A validation was done with the remaining third by calculating root mean square error (RMSE). For the interpolation method with the lowest RMSE, the mean absolute square error (MAPE) was calculated for all the validation points to see how the calculated levels differed from the samples. The result showed that kriging and IDW were the most accurate interpolation methods for the data but that some of the studied elements need even greater sample density to become more correct. This can be solved by doing a cross-validation of the existing data. Furthermore, the interpolations were more accurate at the regional level for elements except antimony. The higher accuracy can be explained by the higher sample density at the regional level. At the national level the interpolations worked better in the north of Sweden than in the south which needs further studying. Overall, the interpolations were the least accurate when the levels of the elements were low, which may be the reason why antimony showed higher RMSE at the regional level. In conclusion the study showed that it is possible to use interpolations to predict values at unknown places with different accurateness.
740

Aluminum levels in the O-horizon of soils near Sundsvall, Sweden : Are levels of Al elevated due to smelter emission? / Aluminium koncentrationer i jordars O horisont nära Sundsvall, Sverige : Är Al koncentrationerna förhöjda till följd av utsläpp från smältverket?

Sundin, Mattias January 2023 (has links)
Aluminum (Al) is a potentially toxic element for humans, animals, and plants. Al emitted from smelter plants is one source of Al that may be responsible for increased exposure to humans and the environment. In this study I investigated whether the Kubikenborg aluminum smelter (Kubal AB) emitted Al to such extent that it can be detected above regional background concentrations in soils and plants. The study was conducted by analyzing O- horizon cores and Scots’ pine (Pinus sylvestris) needles along two transects using X-ray fluorescence spectrometry (XRF). In the O-horizon cores, Al concentrations along the two transects (mean conc. 5250 mg kg-1 in T1 and 3472 mg kg-1 in T2) did not decrease with distance from the smelter. In Scots’ pine needles, Al concentrations (mean conc. 491 mg kg-1 in T1 and 590 mg kg-1 in T2) decreased significantly with distance along transect T2. Aluminum showed high negative co-variance with soil organic matter content (R2 = 0.47) and positive with silicon (Si) and titanium (Ti) in the soil (R = 0.84 and R = 0.86 respectively), suggesting that mineral dust is the main source of Al. However, the Al/Si ratio of the soil decreased with increasing distance from the smelter along T1, indicating a possible additional source of Al besides that of soil dust that may originate from smelter emission. Nevertheless, I found no strong support for detectable Al emissions in humus and Scots’ pine needles near the Kubal AB smelter.

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