In order to obtain a good performance and predict the properties of alloys, it is necessary to control the contents of alloying elements and to evaluate a largest inclusion in the product. Thus, improved techniques for both control of alloy elements and evaluation of the large inclusion in products will enable us to provide better qualities of the final products. In the case of one Ni alloy, (NW2201, >99 mass%Ni), the precise control technique of Mg content is important to obtain a good hot-workability. Hereby, the slag/metal reaction experiments in a laboratory have been carried out at 1873 K, so that the equilibrium Mg content and kinetic behavior can be understood. More addition of Al in the melt as well as higher CaO/Al2O3 value of slag resulted in higher amount of Mg content in Ni. For the same conditions of Al content and slag composition, the mass transfer coefficient of Mg in molten Ni was determined as 0.0175 cm/s. By applying several countermeasures regarding the equilibrium and kinetic process to the plant trials, the value of the standard deviation for the Mg content in an alloy was decreased till 0.003 from 0.007 mass%. The size measurements of largest inclusions in the various alloys (an Fe-10mass%Ni alloy, 17CrMo4 of low-C steel and 304 stainless steel) were carried out by using statistics of extreme values (SEV). In order to improve the prediction accuracy of this method, three dimensional (3D) observations were applied after electrolytic extraction. In addition, the relationship of extreme value distribution (EVD) in the different stages of the production processes was studied. This was done to predict the largest inclusion in the products at an early stage of the process. A comparison of EVDs for single Al2O3 inclusion particles obtained by 2D and 3D observations has clarified that 3D observations result in more accurate EVD because of the absence of pores. Also, it was found that EVD of clusters were larger than that of single particles. In addition, when applying SEV to sulfide inclusions with various morphologies, especially for elongated sulfides, the real maximum sizes of them were able to be measured by 3D observations. Geometrical considerations of these particles clarified the possibility of an appearance of the real maximum inclusion sizes on a cross section to be low. The EVDs of deoxidation products in 304 stainless steel showed good agreement between the molten steel and slab samples of the same heat. Furthermore, the EVD of fractured inclusion lengths in the rolled steel were estimated from the initial sizes of undeformed inclusions which were equivalent with fragmented inclusions. On the other hand, from the viewpoint of inclusion width, EVD obtained from perpendicular cross section of strips was found to be useful to predict the largest inclusion in the final product with less time consumption compared to a slab sample. In summary, it can be concluded that the improvement of the techniques by this study has enabled to precisely control of alloy compositions as well as to evaluate the largest inclusion size in them more accurately and at an earlier stage of the production process. / QC 20101222

In this thesis are extreme value theory used to estimate the probability that large insuranceclaims are exceeding a certain threshold. The expected claim size, given that the claimhas exceeded a certain limit, are also estimated. Two different models are used for thispurpose. The first model is based on maximum domain of attraction conditions. A Paretodistribution is used in the other model. Different graphical tools are used to check thevalidity for both models. Länsförsäkring Kronoberg has provided us with insurance datato perform the study.Conclusions, which have been drawn, are that both models seem to be valid and theresults from both models are essential equal. / I detta arbete används extremvärdesteori för att uppskatta sannolikheten att stora försäkringsskadoröverträffar en vis nivå. Även den förväntade storleken på skadan, givetatt skadan överstiger ett visst belopp, uppskattas. Två olika modeller används. Den förstamodellen bygger på antagandet att underliggande slumpvariabler tillhör maximat aven extremvärdesfördelning. I den andra modellen används en Pareto fördelning. Olikagrafiska verktyg används för att besluta om modellernas giltighet. För att kunna genomförastudien har Länsförsäkring Kronoberg ställt upp med försäkringsdata.Slutsatser som dras är att båda modellerna verkar vara giltiga och att resultaten ärlikvärdiga.

During the last three decades, the hub height of wind turbines has increased from 24 to 162 meters and with an increasing demand for break-through innovations in green energy production it seems likely that this trend will continue. The meteorological preconditions for extreme-scale wind turbines are investigated for Scandinavia using 33 years of reanalysis data from MERRA (Modern-Era Retrospective Analysis for Research and Applications). Second degree polynomials are fitted to the wind and temperature profiles and evaluated at 100, 200 and 300 m above ground level (AGL). The spatial and temporal variation of average wind speed and median wind power density is studied. Simple metrics such as the wind shear and risk of icing, measured as occasions with temperature below freezing, are used to give an idea of the loads on the wind turbines. Winter is the windiest season, and generally the wind speed is highest over sea and in the Scandinavian mountain range. Going from 100 to 300 m AGL the average wind speed increases with 1 m/s over sea and 2 m/s over land. During night the wind speed increases over land but decreases over sea compared to daytime values. On average the wind shear is about 3.6 times larger in the 50-100 m layer than in the 100-300 m layer. The calculated wind field at 100 m AGL has been compared with results from the MIUU-model, developed at the Department of Meteorology, Uppsala University. The general features are captured but there are important discrepancies between the coast and the mountains in the northern part of Sweden. MERRA data has been validated in different ways, for example by comparing with measured wind speed and temperature profiles. The temperature profiles are in good agreement while the wind profiles differ significantly. It is also shown that MERRA data is not internally consistent in the mountain range, causing a large uncertainty. In future studies, the risk of icing could be explored further. Also, the distribution of sound from extreme-scale wind turbines could be investigated. / Under de senaste tre decennierna har navhöjden för vindkraftverk ökat från 24 till 162 meter och med en ökande efterfrågan på banbrytande innovationer inom produktion av grön energi är det troligt att denna trend kommer att fortsätta. De meteorologiska förutsättningarna för extremskaliga vindkraftverk i Skandinavien undersöks baserat på 33 års återanalysdata från MERRA (Modern-Era Retrospective Analysis for Research and Applications). Andragradspolynom anpassas till vind- och temperaturprofilerna och evalueras på höjderna 100, 200 och 300 meter över markytan. Variationen i rummet och med tiden av medelvindhastigheten och medianen av vindenergiintensiteten studeras. Enkla mått som vindskjuvningen och risken för nedisning, mätt som antalet tillfällen då temperaturen understiger fryspunkten, används för att ge en uppfattning om risken för belastningarna på vindkraftverken. Vintern är den årstid då det blåser mest och i allmänhet är vindstyrkan högst över hav och i fjälltrakterna. Förflyttar man sig från 100 till 300 m över markytan ökar medelvindhastigheten med 1 m/s över hav och med 2 m/s över land. Under natten ökar vinden över land men minskar över hav i jämförelse med värdena under dagen. I medeltal är vindskjuvningen 3.6 gånger större i 50-100 m skiktet jämfört med 100-300 m skiktet. Det beräknade vindfältet på 100 m över markytan har jämförts med resultat från MIUU-modellen, utvecklad vid institutionen för meteorologi, Uppsala universitet. De allmänna dragen är samma men det finns viktiga avvikelser mellan kusten och fjälltrakterna i norra Sverige. MERRA-data har validerats på olika sätt, till exempel genom att jämföra med uppmätta vind- och temperaturprofiler. Temperaturprofilerna visar god överensstämmelse men det är signifikanta skillnader mellan vindprofilerna. Det visas också att MERRA-data inte är konsistent i fjälltrakten, vilket medför en stor osäkerhet. I framtida studier kan risken för nedisning studeras utförligare liksom ljudutbredningen från extremskaliga vindkraftverk.

The Earth's climate is changing and cities are facing a warmer future. As the locus of economic activity and concentrated populations on the planet, cities are both a primary driver of greenhouse gas emissions and places where the human health impacts of climate change are directly felt. Cities increase local temperatures through the conversion of natural land covers to urban uses, and exposures to elevated temperatures represent a serious and growing health threat for urban residents. This work is concerned with understanding the interactions of global trends in climate with local influences tied to urban land covers. First, it examines temperatures during an extended period of extreme heat and asks whether changes in land surface temperatures during a heat wave are consistent in space and time across all land cover types. Second, the influences of land covers on temperatures are considered for normal and extreme summer weather to find out which characteristics of the built environment most influence temperatures during periods of extreme heat. Finally, the distribution of health vulnerabilities related to extreme heat in cities are described and examined for spatial patterns. These topics are investigated using meteorology from the summer of 2006 to identify extremely hot days in the cities of Atlanta, Chicago, Philadelphia, and Phoenix and their surrounding metropolitan regions. Remotely sensed temperature data were examined with physical and social characteristics of the urban environment to answer the questions posed above. The findings confirm that urban land covers consistently exhibit higher temperatures than surrounding rural areas and are much more likely to be among the hottest in the region, during a heat wave specifically. In some cities urban thermal anomalies grew between the beginning and end of a heat wave. The importance of previously recognized built environment thermal influences (impervious cover and tree canopy) were present, and in some cases, emphasized during extreme summer weather. Extreme heat health health vulnerability related to environmental factors coincided spatially with risks related to social status. This finding suggests that populations with fewer resources for coping with extreme heat tend to reside in built environments that increase temperatures, and thus they may be experiencing increased thermal exposures. Physical interventions and policies related to the built environment can help to reduce urban temperatures, especially during periods of extremely hot weather which are predicted to become more frequent with global climate change. In portions of the city where populations with limited adaptive capacity are concentrated, modification of the urban landscape to decrease near surface longwave radiation can reduce the chances of adverse health effects related to extreme heat. The specific programs, policies, and design strategies pursued by cities and regions must be tailored with respect to scale, location, and cultural context. This work concludes with suggestions for such strategies.

Extreme rainfall events associated with global warming are likely to produce an increasing number of flooding scenarios. A large magnitude of hydrologic events can often result in submerged orifice flow (also called pressure flow) or embankment and bridge overtopping flow, in which the foundation of a bridge is subjected to severe scour at the sediment bed. This phenomenon can cause bridge failure during large floods. However, current laboratory studies have focused on only cases of free-surface flow conditions, and they do not take bridge submergence into account. In this study, abutment scour experiments were carried out in a compound channel to investigate the characteristics of abutment scour in free-surface flow, submerged orifice flow, and overtopping flow cases. Detailed bed contours and three components of velocities and turbulent intensities were measured by acoustic Doppler velocimeters. The results show that the contracted flow around an abutment because of lateral and/or vertical contraction and local turbulent structures at the downstream region of the bridge are the main features of the flow responsible for the maximum scour depth around an abutment. The effects of local turbulent structures on abutment scour are discussed in terms of turbulent kinetic energy (TKE) profiles measured in a wide range of flow contraction ratios. The experimental results showed that maximum abutment scour can be predicted by a suggested single relationship even in different flow types (i.e., free, submerged orifice, and overtopping flow) if the turbulent kinetic energy and discharge under the bridge can be accurately measured.

Esta tesis doctoral se ha centrado en el estudio de la variabilidad climática de los valores extremos de oleaje, abordando distintas escalas espaciales, en las que se tienen en cuenta los procesos físicos propios de cada una de ellas, y diferentes escalas temporales. Se han utilizado distintos modelos y técnicas estadísticas aportando avances y mejoras en ellos. Se ha hecho un análisis histórico con distintas bases de datos caracterizando el clima marítimo extremal en profundidades indefinidas, a escala global y regional (Sur de Europa y América Latina) y en profundidades reducidas (Mediterráneo español y Golfo de Cádiz). Se han estudiado también las proyecciones de clima marítimo extremal a distintos escenarios de cambio climático, para lo que se aporta una metodología innovadora basada en un downscaling estadístico que combina climatología sinóptica y extremos de oleaje. / The study of extreme wave climate variability dealing with different spatial and temporal scales is presented. We have conducted the characterization of extreme wave climate in deep and shallow waters using different numerical models and statistical methods which have been tested and improved. First, a historical analysis of wave data has been performed analyzing temporal variability of global and regional (South of Europe and South America) extreme wave height. In the local scale an integral methodology has been developed to characterize extreme wave climate variability in shell waters and has been applied to the Spanish Mediterranean coasts. The study of climate change projections of extreme wave heights is also conducted. A new methodology based on statistical downscaling, which combines synoptic climatology with extreme wave events, has been developed to project the extreme wave height to different climate change scenarios.

”Longboards” är ett examensarbete utfört av Leo Ekbom och Sammy-Sebastian Tawakkoli för innovations- och designingejörsprogrammet vid fakulteten för teknik och naturvetenskap på Karlstads Universitet. Uppdragsgivaren är Space Production AB, projektägare är Dan Edanius, art director och projektledare på företaget. Ett av företagets projekt var våren 2008 att producera Slalom Skateboarding VM och med anknytning till detta växte ett examensarbete fram.   Space Production AB började som ett montersnickeri men har idag utvecklats till ett företag som driver fullständiga utställnings- och eventprojekt. Företaget tillhandahåller allt från idéskiss till montering och servning även då huvudsysslan ligger i att producera, installera och lagra utformning från annan part.   Uppgiften var att ta fram en produktserie innehållande tre modeller av longbaords med bred spridning. Produkterna skulle vara unika och nischade men ändå säljbara och tillhöra ett övre segment av marknaden. Därtill gavs lite friare händer i att ta fram en rad vilda koncept som idébank för senare projekt.   Genom en djupgående researchfas, där information rörande materialkunskap, marknad, målgrupper och kultur, mynnade projektet ut i en kreativ designprocess. Målgruppsanalysen lade grunden till en rad referenskunder vars behov inspirerade och analyserades. Två skilda idegenereringstillfällen lade grunden till en kategorisering där åtta starka koncept presenterades för en sammansatt styrgrupp.   Arbetet resulterade i tre längre utvecklade koncept vilka har potential att bredda den befintliga marknaden för longboard försäljning samt en idébank för framtida utveckling av produkter. / ”Longboards” is a degree project in the Innovations- and design engineering program at Karlstad University. The job requestor is Space Production AB with Dan Edanius, Art director and senior project manager, as the project owner.   Space Production AB started out as a showcase carpentry company but has today evolved into a company that operates complete exhibitions and events. The company’s main business is to produce, install and store branded environments designed by another party but also supplies everything from idea sketches to assemblage and service. One of Space projects spring 2008 was the production of Slalom Skateboarding World Championships and it was through this a degree project was created.   The task was to create a diverse product line containing three models of longboards. The products would be unique and aimed at a niche market but yet be sellable and appeal to the upper segment buyer. Further the opportunity to create more wild concepts that could be used in future projects was given.    An extensive research on materials, market, target group and culture, resulted in a creative design process. Through a target group analysis a number of reference consumers were created. Their needs worked as inspiration and was analysed. Two separate sessions of idea generating were the fundament of a categorization that eventually resulted in eight strong concepts that was presented to the management group.   The project has resulted in three developed concepts that could potentially broaden the existing longboard market as well as a band of ideas that could be used for inspiration of future projects.

In traditional software development, bug detection or testing comes as an afterthought. However, bugs are difficult to detect in the later stages of software development that result in long debugging time. Usually, bugs are left out because of higher concentration on development effort, leaving lesser time for testing. Test-Driven Development (TDD) is a software development process that can reduce the debugging time by catching most of the bugs during development. The development is carried on in small and repeated steps based on test cases. However, TDD is designed to work for object-oriented languages. This thesis investigates the suitability of TDD for non-Object Oriented (OO) languages such as C. TDD can be used with C language with the help of stubbing concept. This thesis also evolves the concepts of stubs and mocks in TDD to be used with C to solve dependency related problems. Finally this thesis analyses some frameworks for TDD in C and provides the trade-offs between them.

The complex interplay between biotic and abiotic factors, believed to be responsible for several oak declines in European oak stands during the last three decades, remains poorly understood. Hence, this study aims at clarifying the temporal process of oak declines, as well as identifying individual tree and environmental variables that increase the risk of oak mortality. The study was performed in one of the few areas in northern Europe still holding high densities of old oaks (Quercus robur L.). Cross dating revealed that most trees had died during the last decade. Averaged chronologies and multiple chronological clustering suggested that the onset of the oak decline happened in 1992, when a severe drought took place. Two of the sites showed a rather short time period of heavily reduced growth prior to death, most likely caused by an insect defoliation in combination with a mildew infection of the replacement shoots. Environmental variables presented a rather weak influence on oak mortality. The results support the idea of attributing oak mortality to a combination of long- and short-term stresses, and emphasize the importance of including present as well as past factors when analysing the causes of oak declines.

As Si-manufacturing compatible SiGe HBTs are making rapid in-roads into RF through mm-wave circuit applications, with performance levels steadily marching upward, the use of these devices under extreme environment conditions are being studied extensively. In this work, test structures of SiGe HBTs were designed and put into extremely low temperatures, and a new negative differential resistance effect and a novel collector current kink effect are investigated in the cryogenically-operated SiGe HBTs. Theory based on an enhanced positive feedback mechanism associated with heterojunction barrier effect at deep cryogenic temperatures is proposed. The accumulated charge induced by the barrier effect acts at low temperatures to enhance the total collector current, indirectly producing both phenomena. This theory is confirmed using calibrated 2-D DESSIS simulations over temperature. These unique cryogenic effects also have significant impact on the ac performance of SiGe HBTs operating at high-injection. Technology evolution plays an important role in determining the magnitude of the observed phenomena, and the scaling implications are addressed. Circuit implication is discussed.