The study of euarthropod evolution in the Cambrian is challenging due to controversies surrounding the identification of various anatomical features. Radiodontans are supported to be a monophyletic group to the lower stem of euarthropods. Radiodontans have complex bodies made up of powerful frontal appendages called “long” great appendages and an oral opening. Similarly, megacheirans are also a group of Cambrian marine organisms, however, with an uncertain placement in the arthropod family tree. They are characterized by their “short” great appendages. Megacheirans are thought to either be stem-group chelicerates or the basal upper stem-group euarthropods. Parapeytoia yunnanensis, which shows morphological aspects of both radiodontans and megacheirans, could be the “missing link” between the megacheirans and the radiodontans, and shed light on what stem-group the megacheirans belong to.  P. yunnanensis frontal appendages share great similarity between the frontal appendages of megacheirans suggesting that P. yunnanensis might have been a stem-group chelicerate. However, the gnathobases of P. yunnanensis resemble closely that of radiodontans. Furthermore, P. yunnanensis oral morphology is deeply rooted in stem-group euarthropods. Therefore, it is indicated that megacheirans were stem-group euarthropods, and not chelicerates. Completing a transition in the euarthropod stem-group with P. yunnanensis as a transition from radiodontans to megacheirans. / Att forska på utvecklingen hos kambriska äkta leddjur är utmanande på grund av svårigheter kring identifieringen av olika anatomiska egenskaper. Radiodonter ses som en monofyletisk grupp under stammen äkta leddjur. Radiodonter har komplexa kroppar som består av kraftfulla frontallemmar, som kallas ”långa” stora lemmar, samt en distinkt mun. Å andra sidan är megacheiraner en grupp av kambriska marina organismer med en osäker placering i leddjurens släktträd. De kännetecknas av sina ”korta” stora lemmar. Megacheiraner tros antingen vara del av stamgruppen palpkäkar eller stamgruppen äkta-leddjur. Parapeytoia yunnanensis, som visar morfologiska aspekter av både radiodonter och megacheirans, kan vara länken mellan dem. P. yunnanensis kan i sådana fall avgöra vilken grupp megacheirans tillhör. P. yunnanensis frontallem delar stor likhet mellan frontallemmen hos megacheirans, vilket skulle kunna innebära att P. yunnanensis kan ha varit en stamgrupp till palpkäkarna. Gnatobaserna hos P. yunnanensis liknar dock gnatobaserna hos radiodonterna. Dessutom är morfologin av P. yunnanensis mun vanligt förekommande i stamgruppen äkta-leddjur. Ett rimligt antagande är därför att megacheiraner hör till stamgruppen äkta-leddjur och inte stamgruppen palpkäkar. Därmed skulle P. yunnanensis utgöra en tydlig övergång mellan radiodontanerna och megacheiranerna.

Production and consumption of food have several environmental impacts, regardless of the type of food production. However, food production can have a particularly large impact on the environment, as it often causes pollution and spreads harmful contaminants in nature. Additionally, a lot of food is produced today, which leads to a significant amount being wasted and contributing to environmental problems. In Sweden, approximately 1.3 million meals are served daily in schools. There is a need to study food waste, its causes, amounts, and what can be done to reduce it. Therefore, the factors affecting food waste in school cafeterias must be known, and different methods can be used, such as interviews and surveys. By investigating the causes of food waste, problem areas can be identified, and solutions can be found to reduce food waste. The study underscores the importance of studying food waste and increasing awareness to promote sustainability. It is an important task that requires cooperation and commitment from all involved parties and can have positive effects on both the environment and society as a whole. In this study, several factors contributing to the problem were identified, and suggestions for measures to reduce waste were presented. One of the major challenges is the lack of awareness and education about food waste among both students and teachers. The results indicated that the topic is rarely discussed in the classroom, resulting in insufficient knowledge about how to reduce waste. Another important factor is students' dissatisfaction with the taste of the food, which leads to incomplete meals or leftovers on their plates. To address students' needs, improvements in menu planning are proposed, including collaboration with professional chefs and dieticians to offer a diverse menu that can reduce waste. A short lunchtime and the pressure to return to classes on time also contribute to food waste. To mitigate waste, measures such as increasing awareness through classroom discussions and information campaigns are suggested. Involving students in menu planning and ensuring they have sufficient time to eat can also contribute to waste reduction. Education on nutrition, healthy eating habits, and portion control is emphasized as crucial.

A large part of the center of the city of Uppsala is located on postglacial clay. This clay often contain sulfur, this in the form of sulfide, and thus it is generally called sulfide clay (or sulfidlera in Swedish). The amount of sulfide in the clay varies from location to location. When the sulfide-rich postglacial clay comes in contact with the air it oxidizes and can give rise to acid leachate and leaching of heavy metals that were bound to the sediments. The knowledge of this has made the interest of sulfide content in soils greater in recent years, this during for example excavations on building sites. The aim of this project is therefore to summarize and present data related to sulfiderich sediments in a perspicuous way, and thus make it easier to survey the measures that could be necessary to take into consideration for construction work in the city of Uppsala. A lot of the data is taken from the archive of Bjerking AB, but some of the information on sites with sulfide rich clay is taken from Miljökontoret. Using the computer program MapInfo, the locations with sulfide rich soils has been marked on a map of Uppsala and additional information about for instance layering, NNP and pH is connected to these markings, though this is only viewable together with the map in a program supporting the “.tab” file format. / Uppsala stad ligger till stor del på postglacial lera. Denna lera innehåller ofta svavel i form av sulfid och brukar kallas ”sulfidlera”. Lerans sulfidhalt varierar från lokal till lokal. När den sulfidhaltiga postglaciala leran kommer i kontakt med luft oxiderar den och kan då ge upphov till surt lakvatten och urlakning av tungmetaller som är bundna i sedimenten. Vetskapen om detta har gjort att man på senare år börjat intressera sig mer för markens sulfidhalt vid exempelvis schaktning. Syftet med detta arbete att på ett enkelt sätt sammanställa data relaterade till sulfidhaltiga sediment och på så vis ge en överblick över vilka åtgärder som skulle behöva vidtas vid byggnation i Uppsala stad. Mycket data är taget från Bjerking AB's arkiv men också enstaka uppgifter om sulfidlera hämtade från Miljökontoret har använts. Med hjälp av programmet MapInfo har de platser, där sulfidhaltiga sediment hittats, märkts ut på en karta över Uppsala och information om bland annat lagerföljd, NNP och pH har kopplats till dessa punkter.

Sedan några år tillbaks utvecklas vid Institutionen för geovetenskap, sedimentologi, Uppsala Universitet en modell för att simulera transportförloppet av radionuklider vid ett eventuellt läckage av kärnbränsleavfall deponerat långt nere i berggrunden. Som en viktig del av transportförloppet ingår adsorption av cesiumjoner på bergets sprickväggar. Adsorptionsprocessen har i detta examensarbete studerats genom att blanda varierande koncentrationer av granitpartiklar från olika fraktioner med cesiumkontaminerat grundvatten. Koncentrationen av cesiumjoner mättes m h a en gammaräknare tills jämvikt mellan de adsorberade och de lösta jonerna infann sig. Adsorptionen karakteriserades beroende på partikelstorleken av en enstegskinetik eller en tvåstegskinetik. Tvåstegsadsorptionen är en följd av att större partiklar innehåller betydligt fler mikrosprickor än vad de mindre partiklarna gör. Resultaten utvärderades m a p dels distributionskoefficienten kd och dels reaktionskonstanten kr. Anpassningen av kd-värdena gav ett mycket bra resultat med ett R2-värde över 0,99 medan anpassningen av kr inte alls var lika bra (R2 ≈ 0.36), vilket antas bero på att uttrycket för nettoadsorptionen G är felaktigt. / Over the last few years, a model that simulates the transport of radionuclides in fractured rock has been developed at the Department of Earth Sciences/Sedimentology, Uppsala University, Sweden. The aim has been to predict the outcome of a possible leak from deposits of nuclear waste fuel in deep bedrock. The adsorption of cesium ions at the fractures is an important part of the transport mechanism. This study has attempted to explore the adsorption kinetics of cesium ions at the surface of granite particles. A certain amount of cesium was mixed with synthetic groundwater along with different fractions and amounts of clean granite particles. The concentration of cesium in the liquid was frequently measured in order to estimate the change in cesium adsorption with time. The measurements were carried out until an equilibrium between adsorbed and solute ions was achieved. Depending on the size of the particles, the adsorption was characterized by either a one- or a two step kinetics. The reason for this was that larger particles contain micro fractures which affect the adsorption curve. The results were evaluated from the estimated values of the distribution coefficient kd and the reactivity coefficient kr. A model that evaluates the available surface of the rock gave very good results for the kd-values with a R2-value above 0.99. The fitting of kr was not by near equally good (R2 ≈ 0.36), and this is assumed to depend on an incorrect expression of the net adsorption G.

Mercury is regarded as a pollution element and is transported via the atmosphere. Mercury binds to organic matter and my results show that this is the case also in the drainage area of Two- Boat Lake. Silty peat samples show the same trend in mercury concentrations with depth as those of organic matter concnetratrions. A long sediment core (30 cm) show the similar trend in mercury with depth as silty peat cores, with higher levels close to the top of the profiles as  can be explaned by the industrialization that started around year 1850. Soil samples with vegetation by grass and birch show higher mercury than in the soil without vegetation (mineral soil), but wetlands with silty peat contains both higher mercury concnetrations and higher mercury inventories (mg Hg m-2). Lake sediment samples show higher carbon level in sediment taken from shallow areas with aquatic plants, but the mercury concentrations still increase with increased water depth. This is because light mineral particles and degraded organic material rich in Hg preferentially accumulate in the deep basin of the lake. Throughout the area, the terrestrial pool contains more mercury than the aquatic pool. In the terrestrial system, peat contains most mercury even though it has the smallest area and mercury per square meter is highest in peat.

No description available.

Permafrost is a strongly controlling factor on Arctic hydrology due to its effect on ground permeability, and thus surface and ground water flow paths. As wildfires are increasing in occurrence and magnitude in permafrost regions, they may alter the hydrological regime via permafrost thaw and degradation that increases ground permeability. Thus, it is hypothesized that in permafrost regions catchments exposed to severe wildfire burn may display a river discharge behavior different to that of unburned catchments, with reduced maximum and increased minimum flows corresponding to higher infiltration of precipitation and extended sub-surface flow paths. This study compares the seasonality and magnitude of runoff in severely burned (Odei River) and unburned (Taylor River) catchments in the sporadic permafrost region in the Canadian Shield Taiga. The investigated time span consists of 25 full calendar years with complete daily and monthly river discharge data between 1980 and 2016. They are used in conjunction with burned area data, climate data and landcover data to investigate patterns in hydrology behavior. An emerging trend is a sharply declining maximum flow and increasing minimum flow relative to precipitation in the burned catchment, indicating an accelerated increase in infiltration and buffer capacity of the soil relative to the unburned catchment. Over the entire period the apparent annual catchment storage change is decreasing in both catchments, but at a 115% faster rate in the burned catchment despite being exposed to ~1.5 C lower mean annual temperature, a factor that likely increases the rate of climate-driven aggradation of permafrost in the contrasting unburned catchment. The discrepancy found in catchment streamflow regime between the burned and unburned catchment and its alignment with the suggested permafrost disturbance effects from previous studies suggest that streamflow may serve as a useful and resource efficient indicator of wildfire-driven permafrost degradation.

Syftet med projektet var att analysera och kartlägga vilken typ av vegetation som brann under skogsbränderna sommaren 2018. Geografiskt informationssystem, GIS, nyttjades för att analysera den geografiska data som användes för att få fram vegetationsfördelningar i brandområdena. I analysen och kartläggningen användes Naturvårdsverkets öppna Nationella Marktäckedata tillsammans med Skogsstyrelsens dataset Ungefärligt brandområde. Marktäckedata är uppbyggd av olika klasser och representerar olika typer av information, exempelvis dominerande vegetationstyp. Genom arbetet i GIS togs det fram kartor över brandområdenas marktäckedata samt cirkeldiagram och tabeller med vegetationsfördelningar. Dessa analyserades för att hitta trender i vegetationens fördelning som förklarar skogsbrändernas spridning. Efter analysen kunde slutsatsen dras att det framförallt var barrskog som brann, där vegetationstypen tallskog utgjorde den största andelen. Samtidigt stod lövskog för en mycket liten del av vegetationsfördelningen i de sex största bränderna. Eftersom det generellt var lite lövskog i områdena kring skogsbränderna var det svårt att dra slutsatser kring huruvida lövskog är brandhämmande. Våtmarker verkar i vissa fall hindrat brandspridning men brann även de när det var torrt och varmt. I det initiala skedet i brandförloppet dominerade tallskog och temporärt ej skog såsom kalhyggen eller stormfällda områden, medan andra vegetationstyper involverades allt eftersom bränderna tog fart och spred sig.

Wind energy projects in cold climate areas are more and more favoured due to the presence of high wind potential and the availability of land in those areas. A serious problem, however, is the impact of icing on the wind turbine and on the energy production. The main objective of this Thesis is to present the available options for mitigating the risks of wind turbines’ blade icing and to evaluate the investment of the wind turbines’ anti-icing systems. To this end, a heuristic algorithmic method has been developed as well as a simple computational tool in order to assess the economic feasibility of anti-icing systems. The method has subsequently been applied in three case studies and relevant conclusions have been drawn Initially a literature review has been conducted that encompassed issues like the direct and indirect impacts of icing on wind turbines (reduced yield, increased loads and noise emission, health and safety risks, etc.), the difficulties of estimating icing formulation and icing production losses and the anti-icing and de-icing systems and their functionality, advantages and disadvantages. Subsequently, the heuristic algorithmic method has been developed which is based on estimating the energy production of a wind turbine for three scenarios - with no icing occurring, with icing but without any anti- and de-icing system installed and with an anti-icing system installed – followed by a sensitivity analysis of the economic performance parameter, the simple pay-back period. The method has been accommodated in a simple computational excel-based tool and has been applied to three case studies located in the north Norway, in central Sweden and in south Finland. The production losses related to icing are in the expected ranges typical for the geographic location and so is the economic performance parameter which indicate that the investment in an anti-icing system is recommended for the three case studies. Results showed that the wind resources, the electricity export price and the annual icing hours are the parameters that determine the feasibility of an anti-icing system for a wind farm project. Wind energy projects in cold climate areas are more and more favoured due to the presence of high wind potential and the availability of land in those areas. A serious problem, however, is the impact of icing on the wind turbine and on the energy production. The main objective of this Thesis is to present the available options for mitigating the risks of wind turbines’ blade icing and to evaluate the investment of the wind turbines’ anti-icing systems. To this end, a heuristic algorithmic method has been developed as well as a simple computational tool in order to assess the economic feasibility of anti-icing systems. The method has subsequently been applied in three case studies and relevant conclusions have been drawn Initially a literature review has been conducted that encompassed issues like the direct and indirect impacts of icing on wind turbines (reduced yield, increased loads and noise emission, health and safety risks, etc.), the difficulties of estimating icing formulation and icing production losses and the anti-icing and de-icing systems and their functionality, advantages and disadvantages. Subsequently, the heuristic algorithmic method has been developed which is based on estimating the energy production of a wind turbine for three scenarios - with no icing occurring, with icing but without any anti- and de-icing system installed and with an anti-icing system installed – followed by a sensitivity analysis of the economic performance parameter, the simple pay-back period. The method has been accommodated in a simple computational excel-based tool and has been applied to three case studies located in the north Norway, in central Sweden and in south Finland. The production losses related to icing are in the expected ranges typical for the geographic location and so is the economic performance parameter which indicate that the investment in an anti-icing system is recommended for the three case studies. Results showed that the wind resources, the electricity export price and the annual icing hours are the parameters that determine the feasibility of an anti-icing system for a wind farm project.

The sensitive response of glaciers to climate change can be recorded in sediments, in glacier fed lakes. By studying sediments from pro-glacial lakes it is possible to determine how glaciers have reacted to past climate change and variability. Therefore, proglacial lake sediments cores can be used as proxy archives for climate and glacier activity reconstructions. The aim of this study is to detect any glacier signal in the lacustrine sediment cores from Tarfalajaure and seek for correlation with glacier processes and variations recorded in the past literature. Sediment cores were retrieved from the deepest part (52 m) of Tarfalajaure (65°55’25”,18°35’23”) in September 2016. Tarfalajaure is situated within the Swedish part of the Scandinavian Caledonides, in the Kebnekaise Mountains, northern Sweden. There are four glaciers draining into Tarfalajaure, Kebnepakteglaciären (the closest and largest one), Sydöstra Kaskasatjåkkaglaciären, Sydöstra Kaskasapakteglaciären and SydvästraKaskasatjåkkaglaciären. It is assumed that the variations of the minerogenic input and sediment characteristics in the cores over time reflect variations in glacier activity or changes in the proglacial environment. XRF measurements (Ti, Si, K, Fe, Ca, Mn/Fe, Zr/Rb, Ca/Ti,Fe/Ti, Si/Ti, K/Ca and K/Ti), magnetic susceptibility, grain-size analysis and radiocarbon dating have been used to detect variations in the sediment core. Comparisons have been made with results from other studies of glacier activity in northern Scandinavia, and with reconstructions of temperature variation during the last millennia. The results indicate several periods of glacieradvances which were also identified in other studies. These advances occurred around 25 cal BP, between 300 and 375, 1000 and 1150 cal BP, and around 700 – 800, 1900, and 2200 –2275 cal BP.