Space-borne radar interferometry provides a global vantage point to understand climate change, global weather phenomenon, and other Earth dynamics. For climate change observations, space-borne interferometers can be utilized to relate ocean topography to temperature, thus providing a global map of ocean temperatures. Since the oceans are in constant motion, a single-pass interferometer is needed to successfully make these measurements of ocean height. The feasibility of a single-pass measurement is dependent on the physical size of the instrument, hence it is cheaper and more practical to launch a small, light weight instrument into space. Since instrument size scales inversely with operating frequency, high frequency microwave technology (Ku-band and Ka-band) is preferred for these types of applications. However, space-borne deployments become more difficult to implement at these frequencies since the physical structure of the instrument changes in the harsh environment of space. For that reason, a ground-based Ku-band (13.245GHz) radar interferometer has been developed at the University of Massachusetts, Amherst Microwave Remote Sensing Laboratory (MIRSL). In this thesis, a description of the radar hardware as well as interferometric results from Mount Sugarloaf provide a measure of the performance of the radar and demonstrate the capabilities of using a ground-based interferometer as a test-bed for space-borne applications.

Syftet med denna studie är att belysa högstadieelevers behärskning av pronomenen de och dem i skrift samt identifiera om det finns ett samband mellan lärares attityder till de, dem och dom och elevers behärskning av de och dem. För att uppnå syftet har kvantitativ och kvalitativ metod använts. Den kvantitativa metoden består av ett lucktestet som genomfördes av sammanlagt 132 elever i årskurs 7–9 på en grundskola belägen i västra Skåne. Den kvalitativa metoden består av semistrukturerade intervjuer med de tre årskursernas respektive lärare. Resultatet visar att vissa elever behärskar de och dem väl, andra relativt väl och vissa brister i behärskningen. Vidare visar resultatet att lärarnas attityder till de, dem och dom varierar och man kan utläsa en tydlig koppling mellan lärarnas olika attityder och elevernas behärskning av de och dem. Slutsatserna som kan dras av studien är att högstadieeleverna varierar i normenlig behärskning av de och dem i skrift och att lärarnas attityder till de, dem och dom i hög grad påverkar elevernas behärskning.

Himalayan glaciers are key components of earth's cryosphere, acting as hydrological reservoirs vital to many human and natural systems. Most Himalayan glaciers are shrinking in response to changing climate, which will potentially impact water resources, natural hazards, sea level rise, and many other aspects. However, there is much uncertainty regarding the state of these glaciers, as direct field data are difficult to obtain. Accordingly, long-timespan remote sensing techniques are needed to measure changing glaciers, which have memory and often respond to climate on decadal timescales. This study uses declassified historical imagery from the Hexagon spy satellite database to fulfill this requirement. A new highly-automated, computer-vision based solution is used to extract historical terrain models from Hexagon imagery, which are used as a baseline to compute geomorphic change for glaciers in the Kingdom of Bhutan and Tibet Autonomous Region of the eastern Himalayas. In addition to glaciers, the new method is used to quantify changes resulting from the Thistle Creek Landslide (surface elevation changes resulting from the landslide show an average elevation decrease of 14.4 ± 4.3 meters in the source area, an increase of 17.6 ± 4.7 meters in the deposition area, and a decrease of 30.2 ± 5.1 meters resulting from a new roadcut) and Mount St. Helens eruption in western North America (results show an estimated 2.48 ± 0.03 km3 of material was excavated during the eruption-triggered debris slide). These additional results illustrate the applicability of Hexagon imagery to a variety of landscape processes. Regarding the primary application in the Himalayas, all studied glaciers show significant ice loss. Futhermore, the multi-decadal timespan reveals important aspects of glacier dynamics not detectable with temporally shorter datasets. Some glaciers exhibit inverted mass-balance gradients due to variations in debris-cover, while enhanced ice losses are prominent on glacier toes terminating in moraine-dammed proglacial lakes, resulting from calving caused by thermal undercutting. Remarkably, debris-covered glaciers show significant thinning despite insulating effects of the debris, likely due to poorly-understood ice cliff and melt pond mechanisms. The mean annual geodetic mass balance of 22 studied glaciers over a 32-year period is estimated to be -0.16 ± 0.03 m yr-1 water equivalent. Thus, these glaciers are not in equilibrium with current climate, and appear to be losing significant amounts of ice regardless of debris-cover.

I vårt arbete har vi undersökt hur de identitetsskapande processerna på friskolor medelever i grundskolans senare år ser ut. Genom kvalitativa intervjuer på tre friskolor, enmed uttalad kristen värdegrund och två allmänpedagogiska, ville vi ta reda på hureleverna anser att skolorna påverkar deras identitet, om det finns det en tydligaregruppidentitet på friskolor med religiös inriktning, samt vad skolledningens har sommål i arbetet med identitetsskapandet och hur detta uppfattas av eleverna.Vi har använt oss av sociologerna Giddens och Ziehes teorier kringidentitetsskapande, samt kunskapssociologerna Berger och Luckmann och av Foucaultsteorier kring diskursiva ordningar.Utifrån vår undersökning kan vi konstatera att samtliga elever anser att derasrespektive skola påverkar dem i deras identitetsskapande. På de allmänpedagogiskaskolorna menar eleverna att skolornas pedagogiska inriktning hjälper dem att utvecklastill självständiga och toleranta individer. Eleverna på skolan med en uttalad kristenvärdegrund anser att skolan delvis hjälper dem att få ett större självförtroende i derasreligiositet.Det framkommer också tydligt att den gemensamma religiösa gruppidentiteten intehar någon motsvarighet på de allmänpedagogiska inriktade friskolorna. En förklaringtill detta anser vi vara att eleverna på den kristna friskolan ser sig själva som avvikandefrån normen i det sekulariserade samhället och därför skapar ett starkare Vi.Vi finner också en överensstämmelse mellan skolledningens mål i hur eleverna skauppfatta sig själva och hur de faktiskt gör det. Utifrån Foucaults diskursteori och Bergeroch Luckmanns kunskapssociologiska teorier kan detta tolkas som att elevernasocialiseras in i ett sätt att tänka kring sig själva och att skolorna via vissa metoder haren viss kontroll över denna process.Vi anser att de religiösa friskolorna fyller en viktig funktion då eleverna på dessaskolor upplever att de där i högre grad får definiera sig själva än i det omgivandesamhället.

Syftet med detta examensarbete är att klarlägga vad den svenska nationella identiteten kan sägas bestå av. Vidare vill vi undersöka om, och i så fall hur, svensk nationell identitet förmedlas genom läroböcker skrivna för gymnasieskolans Samhällskunskap A. Detta gör vi genom att utföra en semiotisk bildanalys av utvalda bilder från tre läroböcker. I en sådan analys läses bilder på samma sätt som text. Vi grundar vår analysmodell på Barthes semiotiska metod för att analysera bilder och deras myter. Vi kommer fram till att den svenska nationella identiteten är starkt förknippad med socialdemokratin och folkhemmet. I folkhemmet vävs tre centrala begrepp samman vilka utgör grunden för den svenska nationella identiteten. Dessa tre är demokrati, medborgarskap och modernitet. I vår analys kommer vi fram till att böckernas bilder förmedlar en svensk nationell identitet baserad på dessa tre begrepp. Vidare finner vi att den svenska nationella identiteten visar sig tydligast i jämförelse med bilder som representerar andra nationer och deras medborgare. Detta betyder att ett kollektivt vi framträder i kontrast till framställningarna av dem i läroböckerna. I den avslutande diskussionen reflekterar vi kring de problem som kan uppstå när den svenska identiteten manifesteras genom att man utmålar den andre som stereotyp. Vi lyfter fram att detta ställer krav på pedagogen att ha ett kritiskt förhållningssätt till de läroböcker som används i undervisningen. / The aim of this essay is to sort out what the Swedish national identity is said to consist of. Further, we aim to examine if, and how, Swedish national identity is conveyed through textbooks written for the course Samhällskunskap A in the Swedish gymnasieskola. In order to do this, we perform a semiotic analysis of selected images from three textbooks. In an analysis of this kind one reads the images as text. Our model for the analysis is based on Bathes’ semiotic model for analysing images and the myths they convey. We come to the conclusion that the Swedish national identity is strongly connected to social democracy and folkhemmet. In folkhemmet three central concepts form the foundation of the Swedish national identity. These three concepts are democracy, citizenship and modernity. In the analysis we come to the conclusion that the textbooks’ images convey a Swedish national identity based on these three concepts. Further, we find that the Swedish national identity is made clearest in a comparison to images representing other nations and their citizens. This means that a collective us is visible in contrast to the representations of them in the textbooks. We reflect upon the problems that can arise when the Swedish identity is manifested through stereotyping the other, in our closing discussion. We focus on the demands that this puts on the teacher to have a critical approach towards the textbooks that are used in the education.

No description available.

Many of today’s engineering advancements rely on minerals such as copper, gold and iron. For this reason, the mining industry plays an important role for the development of society and technological wonders. Mining excavators are commonly used tools for extracting the minerals from the mine. Mining excavators are large machines used to breakdown, penetrate and load the rock ores onto trucks that transport the minerals. During the dynamic loading, the excavator bucket experiences significant amount of wear and tear that negatively affects the production by increasing the downtime. The bucket teeth are arguably the most worn parts of the bucket and are responsible for significant amounts of downtime. This thesis aims to provide a better understanding of the load and wear on the bucket teeth of large scale mining excavators used in Bolidens Aitik copper mine in Sweden. Because of how much wear and tear the bucket teeth are exposed to, there is a need to better understand the wear behaviour of the teeth and for the whole bucket in general. This understanding can then be used to improve the service life of the teeth and other parts of the bucket and thus increase work efficiency and reduce downtime. This project was divided into two parts. The first part consisted of regular field measurements to follow the wear on the bucket for about two weeks of digging and loading. The gathered data was then analysed to provide a better understand about the wear behaviour. The second part was to develop a numerical model that could predict the wear on the bucket and could be verified by the field measurements. The field measurements consisted of seven 3D laser scans of the bucket starting with brand new teeth. At the time of the last scan, the buckets total loaded tonnage was approximately 542 kton and the excavator had operated in total of approximately 195 hours. After the raw data from the scans was gathered and analysed, various information about the wear behaviour on the teeth was achieved. The 3D scanned data was also used to provide a complete wear development cycle which allowed to track the wear of any point in the bucket. The method could also be used to create animations of the teeth as they were being worn. From the results, it was concluded that the wear rate for the teeth slowed down and even converged as the geometry changed due to wear. When comparing all nine teeth on the bucket, it was also found that the middle teeth on the bucket were most exposed to wear. The most worn tooth was found to lose around 50 kg of weight after approximately 117 operating hours, which accounts for 40 % of the original weight. The animations from the complete wear development results also showed how the individual teeth and the whole leading edge with all nine teeth were being worn as the buckets loaded tonnage increased from 0 to 542 kton. The numerical model consisted of simulations of loading with the rocks being modelled with the Discrete Element Method (DEM). These were divided into four cases, the first being with the bucket with all new teeth. The second bucket with a mixture of new and worn teeth. The third bucket with all worn teeth and then finally the fourth bucket in which a new tooth geometry was tested. The numerical model showed promising results and potential for being a reliable way to predict the wear on the bucket. The results showed that both the penetration force and wear for the middle teeth was higher than the other neighbouring teeth. It also showed that the completely worn teeth had a lower wear rate than the new teeth which is in agreement with the results from field measurements. Other factors such as tooth shape and length were also observed to have a significant impact on the wear and penetration force. Lastly, the new teeth geometry also showed potential for design improvements in terms of wear resistance but can be further optimised. From the new teeth geometry, a suggestion was given for using an existing tooth system that might be more wear resistant.

The purpose of this study was to determine if light detection and ranging (LiDAR) imagery could provide a significantly more accurate data set for modeling near line-of-sight (LOS) propagation at higher frequencies, specifically 27.810 GHz. than a USGS digital elevation model (DEM). In addition, the study tested for significant differences in LiDAR elevation data created at various resolutions ranging from 1 to 100 meters. Finally, this study examined the effects of various classification thresholds for transforming continuous signal strength measurements into LOS or non-LOS (NLOS) classifications used in determining prediction accuracy. The capability to transmit information via higher frequency wireless equipment requires a near LOS path between the transmitter and the antenna receiving the signal. USGS DEMs, commonly used in GIS programs to predict communication viewsheds (commsheds), represent the bare earth topography and do not reflect surface features such as vegetation and buildings. In actuality these surface features can significantly influence near LOS paths and therefore a data set that contains these features can greatly improve the ability to predict commshed areas. LiDAR is a form of active imagery that records both the bare-earth as well as these surface features, at a high resolution, making it well suited for wireless modeling applications. Results indicate that signal strength threshold classification has a direct influence on the accuracy of predicted commsheds across all resolutions. Secondly, LiDAR resolutions lower than 40m as well as bare-earth DEMs were unsuccessful in predicting an accurate commshed while LiDAR resolutions coarser than 15m provided significant predictions of equal accuracy. These results indicate that high resolution LiDAR is needed to accurately model commsheds but signal strength threshold classification determines which of these higher resolutions are significant. / Master of Science

Current climate change poses a threat to the Arctic due to increasing temperatures, which cause the permafrost and glaciers to melt and thaw. This thesis focused on analyzing water balances in Tarfala catchment between 2000 and 2020 and using GIS as a support for tracer test results measured in Tarfala in 2021. The results suggest that high resolution DEM data are more useful compared to low resolution DEM when it comes to understanding local hydrology. In addition, analyses regarding tracer test data suggest that permafrost can act both as a hinder and water flow pathway changer in Tarfala. Water balance calculations show that the area is highly affected by snow, permafrost and climate change and may come to change towards wetter and snow and permafrost free conditions due to climate change. / Den pågående klimatförändringen har en markant effekt på det arktiska ekosystemet på grund av de stigande temperaturerna vilket orsakar permafrosttining. Denna uppsats fokuserade på att analysera vattenbalanser mellan 2000 och 2020 i Tarfalas avrinningsområde samt diskutera hur spårämnesförsök och GIS kan användas för att analysera de lokala förhållandena i områden med permafrost. Resultaten tyder på att högupplöst DEM data kan användas som stöd för spårämnestester som påverkas starkt av jordartssammansättningen och permafrost i Tarfalas avrinningsområde. Resultaten tyder också på att vattenbalans i Tarfala påverkas och har påverkats av flera olika faktorer såsom permafrost, snö och klimatförändringar och kan komma att förändras i framtiden till mer våta samt snö- och permafrostfria förhållanden.

Cone crushers are used in both the construction and mining industries for the production of aggregates and extraction of ores. Aggregates are used when building for example houses, roads and railways, hence the cone crushers are a vital part of modern society. To ensure the performance of the cone crusher, it is important to properly adjust the feeding conditions. Using computational methods to virtually analyze the performance of the crushers is a more time and cost efficient solution compared to physical testing. This thesis was divided into two parts, where the main objective of the first part was to use the discrete element method (DEM) to analyze the segregation in cone crushers. Three different methods were developed, which later were utilized to compare the segregation for four different feeding conditions. Two of the analysis methods only considered the segregation in the feed hopper, whilst the third method aimed to give an understanding ofthe segregation inside the crushing chamber. The two first methods could successfully be used to compare how segregated the feed material was for the four feeding conditions, however, the third method proved to be both hard to validate and highly dependent on proper material flow inside the crushing chamber. The main objective during the second part of the thesis was to investigate the possibility of running the DEM simulations coupled to a multibody simulation (MBS) software. The simulation routine was then used to compare the foundation loads for the same four feeding conditions as in the first part. The subframe was later modeled as a flexible body to analyze and compare the stresses the subframe was subject to during operation for the same four feeding conditions. Setting up and running the coupled simulation was successful. Different simulation settings were tested, anda general guideline on how those settings should be defined was set up. The actual impact the coupling had on the foundation loads and stresses in the subframe was however almost non-existent. This could probably be directly related to the fact that the crushing forces in EDEM are known to be many times smaller than what they have been measured to in experiments. This also meant that changing the feeding conditions to alter the segregation did not have a noticeable effect on the results.