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Vid samverkansbroar fästes tvärförband mellan huvudbalkar med funktion att leda laster ut mot huvudbalkarna. Dessa kan fästas via s.k. livavstyvningsplåtar mot huvudbalkens liv samt flänsar. Denna infästning kan ske med svetsförband. Vid ett antal fall har utmattningssprickor uppkommit i svetsanslutningen mellan livavstyvningsplåten samt överfläns på huvudbalk. Tydliga riktlinjer finns ej i dagsläget för vilken typ av svetsförband som bör nyttjas vid uppförande av benämnd konstruktionsanslutning. Här genomförs en jämförande studie av kälsvetsförband mot stumsvetsförband, med samt utan svetsutbredning. Då risk för sprickinitiering till följd av utmattning i kälsvetsförbandet studerades beaktades risk för brott i såväl svetstå som svetsrot. Den aktuella studien ämnade ge svar på huruvida en korrelation mellan geometriska parametrar såsom avstånd mellan huvudbalkar samt konsollängd på farbana kunde kopplas till rekommendation gällande vilket svetsutförande som borde nyttjas vid olika dimensioner av dessa båda geometrier. Vidare ämnade studien utröna om eventuella gränsvärden för val av svetsanslutningar kunde fastställas. För framtagande av data nyttjades BRIGADE PLUS, ett beräkningsprogram som nyttjar FEM-modellering. Här användes ett uppfört projekt, Viadukt Söder, beläget i Östersund, som grundmodell för parameterstudien i BRIGADE PLUS. Detta var projekterat av ELU Konsult, på uppdrag av Trafikverket. Beräkningsmodellen bestod av en begränsad del av den aktuella bron, där utmattningslastfordon 3 i SS EN 1993-2 användes för att via influenslinjer återspegla trafiklast på bron och därmed finna värsta lastpositioner. Dessa positioner nyttjades sedermera för beräkning av påverkan från Utmattningslastfordon 3 på den studerade detaljen i form av spänningsamplitud. Analys av dessa spänningsamplituder omräknades sedermera till ett antal lastcykler till brott som sedan ställdes mot de riktlinjer som återfinns i SS EN 1993-1-9:2005. Här nyttjades de förbandsklasser som enligt nationella normer ses som gällande. Resultatet påvisade en exponentiell minskning av antal lastcykler till brott, med avseende på utmattning, då brogeometrin utökades. Utmärkande här var att risk för brott i livavstyvningsplåten klart översteg risk för brott i överflänsen, som i sin tur näst intill kunde bortses ifrån. Den geometriska parameter som blev styrande var konsollängd på farbana. Tydlig differens i livslängd mätt i antal cykler gick att utläsa för de olika svetsförbanden, där styrande faktor blev de respektive förbandsklasserna vid analys av sprickinitiering. Gränsvärden för då antal cykler till brott understeg gränsvärden enligt SS EN 1993-1-9:2005 kopplat till de geometriska parametrarna, gick att fastställa för respektive svetsförband. Kälsvetsens kapacitet med avseende på utmattning understeg vida stumsvetsens kapacitet. / For composite bridges, transverse bracings are attached between main girders with the function of distributing loads between the main girders. These can be attached via so-called web stiffeners against the main girders web and flanges. This attachment can be done via welded joints. In the event of emergence, fatigue cracks have arisen in the welding connection between the web stiffener and the top flange of the main girder. Clear guidelines do not exist at present for the type of welded joints that should be used in the construction of the termed design connection. Here, a comparative study is carried out between fillet welded joints and butt welded joints, with flat and inclined welds. When the risk of crack initiation as a result of fatigue in the fillet weld was studied, the risk of breakage in both toe and root was considered. The current study intended to provide answers as to whether a correlation between geometric parameters such as distance between main girders and cantilever length of the deck slab could be linked to recommendation regarding which welding design should be used at different dimensions of these two properties. Furthermore, the study intended to determine whether any limit values for the selection of welding connections could be determined. For the production of data, BRIGADE PLUS, a calculation program that utilizes FEM modeling, was used. Here, a constructed project, Viadukt Söder, situated in Östersund, was used as the basic model for the parameter study in BRIGADE PLUS. This was designed by ELU Konsult, on behalf of the Swedish Transport Administration. The calculation model consisted of a limited part of the current bridge, where Fatigue Load Vehicle 3 in SS EN 1993-2 was used to reflect traffic loads on the bridge via influenza lines and thereby find the worst load positions. These positions were subsequently used for calculating the influence of Fatigue Load Vehicle 3 on the studied part in the form of stress amplitude. Analysis of these stress amplitudes was subsequently recalculated to a number of load cycles to offenses that were then set against the guidelines found in SS EN 1993-1-9: 2005. Here, the fatigue resistance values were used which according to national standards are regarded as valid. The result showed an exponential decrease in the number of load cycles to fracture, with respect to fatigue, as the bridge geometry was increased. The characteristic feature here was that the risk of breakage in the web stiffener clearly exceeded the risk of breakage in the upper flange, which in turn could almost be disregarded. The geometric parameter that became guiding was cantilever length on the deck. Clear difference in service life measured in number of cycles could be read out for the different welded joints, where the controlling factor became the respective fatigue resistance values when analyzing crack initiation. Limit values for when the number of cycles to break below the limit values according to SS EN 1993-1-9:2005 linked to the geometric parameters, could be determined for each welded joint. The capacity of the fillet weld with respect to fatigue is far below the capacity of the butt weld.

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Nättraby Verktygs AB i Ronneby konstruerar och producerar balpressar vars funktion är att pressa samman kartong, plast eller liknande material till kompakta balar. Dessa balar medför underlättad hantering av material som kan återvinnas för företag. Balpressarna används främst inom verksamhetsområden med stor åtgång av återvinningsbart material, exempelvis livsmedelsaffärer. Problemställningen vid detta examensarbete är att i en äldre version av en balpress har sprickbildning på pressplattan upptäckts efter en viss tids användning. Huvuduppgiften för detta examensarbete har därför varit att utföra hållfasthetsanalyser på pressplattorna för tre olika balpressar i deras sortiment. Denna rapport beskriver momenten samt arbetsgången för att genomföra dessa analyser och beskriver utförligt metoderna som använts. Hållfasthetsanalyserna är uppdelade i två delar, en statisk FEM-analys och en utmattningsanalys av konstruktionen. I den första delen av rapporten genomförs en FEM-analys på den gamla varianten av pressplattan för att se om analysen påvisar samma kritiska områden som företaget upptäckt. Resultatet visade att spänningen var högre i dessa områden än i övriga konstruktionen men under sträckgränsen för materialet. Därför beskriver nästa del av rapporten utförandet av en utmattningsanalys av pressplattan. Denna analys består av en svetsanalys för de svetsförband som finns i de kritiska områdena. Som metod vid svetsanalysen har “hot spot-metoden” använts vilken ger en uppskattning av hur många lastcykler dessa svetsförband kan belastas innan sprickbildning sker. Därefter har samma analyser genomförts på den nuvarande pressplattan och en pressplatta för en kommande modell. I sista delen av rapporten tas ett koncept av en möjlig framtida pressplatta fram där fokus ligger på minskad vikt, minskat antalet detaljer samt ökad hållfasthet. Det framtagna konceptet analyseras på samma sätt som de tidigare tre pressplattorna för att verifiera om detta koncept har ökad hållfasthet och livslängd.

Master of Science / Department of Agronomy / Jianming Yu / Tan spot, caused by Pyrenophora tritici-repentis (Ptr), is an economically important foliar disease worldwide. Race 1 of the fungus, which produces the necrosis toxin Ptr ToxA and the chlorosis toxin Ptr ToxC, is the most prevalent race in the Great Plains of the United States. The purposes of this study are to 1) identify and map novel quantitative trait loci (QTL) involved in resistance to tan spot race 1 in common wheat (Triticum aestivum L.) and 2) explore the inverse gene-for-gene interaction in the wheat-P. tritici-repentis pathosystem. A population of 288 F2:6 recombinant inbred lines (RILs) developed from the cross between Chinese landrace WSB (resistant) and Ning7840 (highly susceptible) was firstly used to identify genomic regions harboring novel sources of resistance. Two QTLs associated with resistance to chlorosis were mapped to the short arm of chromosome 1A and 2B in the WSB/Ning7840 population. No interaction was found between the two QTL. To further explore the specific wheat-ToxC model, three other populations were developed based on two susceptible parents, Ning7840 and Wheaton. QTL analysis revealed that common QTL were detected in populations shared with the same susceptible parents. The observations suggested that susceptibility rather than resistance for tan spot chlorosis is specific and presented evidence for the inverse gene-for-gene theory in the WSB-ToxC pathosystem. Leaf rust, caused by Puccinia triticina Eriks., is another important foliar disease of common wheat worldwide. The rust-resistance genes Lr41 and Lr42 from T. tauschii accessions TA2460 (Lr41) and TA2450 (Lr42) have been used as sources of rust resistance in breeding programs. Molecular markers linked to these genes are essential tools for gene pyramiding. Two BC3F2:6 mapping populations were evaluated for leaf rust resistance at both seedling and adult plant stages and analyzed with simple sequence repeat (SSR) markers. Both genetic and physical mapping confirmed that markers linked to Lr41 and Lr42 were on chromosome arm 2DS and 1DS, respectively. Marker analysis in a diverse set of wheat germplasm indicated that tightly linked markers for Lr41 and Lr42 can be used for marker-assisted selection (MAS) in breeding programs.

Master of Science / Department of Computing and Information Sciences / Gurdip Singh / The Patient Monitoring System is a wireless sensor network application used for dynamically tracking a patient’s physical activity using 3D Accelerometer Sensors in the Sun Small Programmable Object Technology (SPOT) platform. The system is able to detect different postures of a person and recognize high-level actions performed by a patient by monitoring different pattern of postures. This activity can be monitored remotely from a nurse station or a handheld device. The monitoring system can be used for alerting the nurse station in a hospital, if a patient performs some abnormal action. In the proposed system, the Sun SPOTs are affixed on a person's chest, thigh, leg and arm. The application determines the posture of a person by sensing the acceleration and tilt values of the SPOT in the direction of X, Y and Z axis. Based on these values the application can determine the postures of a person such as Lying Down, Sitting, Standing, Walking, Bending, and Arm Moving. We provide user mechanisms to define high level actions such as “attempting to get up from Lying Down position”, in terms of patterns of lower-level posture sequences. The system detects these patterns from the posture sequences reported by the Sun SPOTs, and reports them at desired locations.

This paper seeks to investigate the current state of market integration among European electricity day-ahead spot prices. We provide reasoning that market integration brings about benefits, such as lower average prices and increased welfare from allocative efficiency. Yet, price convergence leads to higher prices in the low-price market and to lower prices in the high-price market, which creates winners and losers and thus makes the political implementation of market integration cumbersome. In our empirical analysis, we utilize a large sample of hourly spot prices of 25 European markets for the period 01.01.2010-30.06.2015 and combine it with other relevant data such as interconnector capacities and the existence of market coupling. Firstly, empirical results from cointegration analysis indicate that market integration increased from 2010 to 2012 but then declined until 2015, most likely due to increased feed-in from intermittent renewables. Secondly, we empirically assess the speed of adjustment from price shocks and reach the conclusion that the resulting efficiency of integration is rather modest. In general, our findings suggest that integration among European electricity markets has a large potential for improvements from additional capacity investments and further promotion of market coupling. (authors' abstract) / Series: Department of Economics Working Paper Series

Traffic safety at intersections is a particularly difficult phenomenon to study, given the fact that accidents occur randomly in time and space thereby making short-term measurement, assessment and comparison difficult. The EU directive 2008/96/EC introduced road infrastructure safety management, which offers a five layer structure for developing safer road infrastructure has been used to develop tools for accident prediction and black spot management analysis which has been applied in this work to assess the safety level of intersections in Norrköping city in Sweden. Accident data history from STRADA (Swedish Traffic Accident Data Acquisition) and the network demand model for Norrköping city were used to model black spots and predict the expected number of accidents at intersections using PTV Visum Safety tool, after STRADA accident classification was restructured and the Swedish accident prediction model (APM) was configured and tested to work within the tool using the model from the Swedish road administration (SRA). The performance of the default (Swiss) and the Swedish APM was compared and identified locations with the high accident records, predicted accident counts and traffic volumes were audited using qualitative assessment checklist from Street-Audit tool. The results from these methods were analysed, validated and compared. This work provides recommendations on the used quantitative and qualitative methods to prevent accident occurrence at the identified locations.