Många stadsdelscentrum upplevs idag som otrygga. Oftast handlar det om centrum belägna i stadsdelar som karaktäriseras av miljonprogrammets byggande, med bostäder, arbetsplatser och service var för sig. I dessa centrum är kriminalitet och otrygghet ett stort problem. Det här arbetet undersöker därför sambandet mellan den fysiska miljön i dessa centrum och brottslighet och trygghet. Med hjälp av teorier om brottslighet, rädsla för brott och trygghetsfrämjande åtgärder analyseras kommunernas planering och hur de anser att man kan planera för att skapa trygga centrum. Intervjuer med politiker verksamma inom stads-/samhällsplanering har gjorts för att få en insikt i beslutsfattares föreställningar inom ämnet. Då stadsdelscentrum anses ha ett antal viktiga funktioner är de också något som kommunerna vill bevara och utveckla. Utifrån kommunernas översiktsplaner och intervjuerna kan man dra slutsatsen att de faktorer som kommunerna och politikerna anser kan ha en påverkan på förebyggande av brott och ett främjande av trygghet är: en funktionsblandad bebyggelse, platser för olika grupper, attraktiva stråk samt att det ska vara rent och snyggt. Det finns dock teorier som både argumenterar för och emot några av dessa faktorer, vilket gör det svårt att dra slutsatser om deras effekter har någon påverkan på brottslighet och trygghet. Däremot kan man konstatera att medan kommunerna tar upp ämnet trygghet, är åtgärder mot förebyggande av brottslighet inget som nämns i någon större mån. Trygghet och brottslighet har visats gå hand i hand, varför det kan diskuteras om inte brottsförebyggande åtgärder borde få en större plats i planeringen.

No description available.

No description available.

One of the major issues with radiation from the natural isotopes 40K, 226Ra (238U) and 232Th and their decay products is the forthcoming legislation from the European Commission in relation to its Basic Safety Directive (2014). The European legislation is mandatory and could not be overthrown by national legislation. Hence, even though the BSS is still a directive it is foreseen as becoming a regulation in due time. The reference value of the natural isotopes, from a radiation point of view, set for building materials is 1 mSv per year (EC, 2014). Earlier recommendations (The Radiation Protection Authorities in Denmark, Finland, Iceland, Norway and Sweden, 2000) within the Nordic countries set an upper limit at 2 mSv per year of radiation from building materials. The main objective within the frame of the thesis was to investigate gamma radiation in relation to Swedish aggregates and their use as final construction products and the applicability and use of a model (EC, 1999) for building materials to calculate the effective dose within a pre-defined room. Part of the thesis also investigates different methodologies that can be used to assess the radiation in a construction material made up of several constituents (building materials) and aims to show that for some purposes as for the construction industries (precast concrete), that a hand-held spectrometer can be used with good accuracy, even though the object is limited in thickness and size. Secondly, the author proposes a simplified way of assessing the radiation in a construction material by use of correlation coefficient of a specified recipe by use of a hand-held spectrometer. Moreover, an understanding of the different building materials´ contribution to the finalized construction product, e.g. concrete is demonstrated, and how to achieve a good control of the radiation levels in the concrete building. / <p>QC 20160926</p>

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From a comparison of available thermal energy storage (TES) technologies it can be concluded that the most mature and suitable storage methods for modern commercial buildings in Sweden are storage tanks, either for heat or cold energy, and underground storage solutions such as borehole thermal energy storage (BTES), aquifer storage and energy piles. In this study an integrated solar energy storage system for heating purpose has been designed with BTES, hot water storage tank(s) and solar thermal collectors. The system has been constructed for three different reference buildings in Stockholm and Malmö using the simulation software Polysun, as to investigate the optimal size of BTES system from an economical and energy perspective. The results showed that the optimal storage dimension for the three reference buildings from an economic perspective for a BTES system was 50 % of a building’s peak power demand for heating and tap warm water. The specific energy demand could be lowered significantly for all three buildings, even if applying a weighting factor on the electricity used for the heat pumps. The investment return in the integrated energy storage system turned out to be positive in most cases; however the net present value (NPV) was negative for some of the storage dimensions in the sensitivity analysis. The conclusion from the study is that BTES systems have potential to increase the use of solar energy in modern commercial buildings in a cost effective way, making it easier to reach the future goals of near zero energy buildings (NZEB).

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No description available.

Vägar påverkas på olika sätt beroende på markförhållanden, belastning, temperaturförändringar och materialval. Denna rapport kommer undersöka möjligheterna att istället för de traditionella överbyggnadsmetoderna tillämpa asfaltarmering som är en typ av armeringsnät som placeras i överbyggnaden.Denna metod sägs förlänga vägens livslängd avsevärt enligt olika företag och studier, undersökningen skall alltså fastställa om asfaltarmering är ett nytt, mer miljövänligt och ekonomiskt alternativ vid konstruktion av vägöverbyggnader. För att tydliggöra det slutgiltiga resultatet kommer brister och fördelar presenteras för att läsaren ska få en överblick av de olika metoderna inom området vägöverbyggnader. Vidare kommer ytterligare frågeställningar besvaras angående grönt stål, processer, traditionella metoder, asfaltarmering, hur framtiden ser ut inom området och vad som behövs för att detta skall vara en metod som uppfyller alla krav och lagar som ställs av Trafikverket. Efter att metoden granskats och undersökts bör det slutgiltiga resultatet ge läsaren en tydlig uppfattning om metodens lämplighet i dagens och framtidens samhälle.

Safety assessment of existing dams becomes more and more important with their increasing age. In addition, new regulations, due to climate changes and changes in knowledge, demand a re-evaluation of the existing dams’ safety. One of the failure modes considered in safety assessments of concrete gravity dams is sliding at the dam-foundation contact. Sliding failure is assumed to occur when the applied load exceeds the shear strength of the interface. Thus, the shear strength of the concrete-rock interface will ultimately determine if sliding of the dam will occur or not and it is, therefore, of utmost importance to be able to quantify it. The shear strength of concrete-rock interfaces is in general defined based on the Mohr-Coulomb shear strength criterion, which is governed by the cohesion, friction angle and normal stress along the interface. This simplified model of the shear strength is subject to several uncertainties, due for example to the natural variability of the involved parameters, statistical errors etc. In addition, analyses are commonly performed using the averaged values of cohesion, friction angle, normal and shear stresses, based on the assumption of ductile failure. This may be incorrect for bonded or partly bonded interface since test results show that bonded concrete-rock cores exhibit brittle behaviour. The uncertainties related to bonded or partly bonded interfaces are taken into account in the Swedish guidelines, RIDAS, for by treating all concrete-rock interfaces as unbonded, i.e. the effect of cohesion is not included when evaluating the shear strength of the interface. This is a conservative method, but it may lead to expensive and unnecessary strengthening of existing dams. Other deterministic guidelines/regulations, e.g. FERC, allow the use of cohesion but apply higher target safety factors when both the cohesive and the frictional strength are taken into account. To evaluate the adequacy of using cohesion in sliding stability analyses of concrete dams, the effect of the uncertainties on the calculated sliding stability of the dam has to be assessed. This thesis highlights several uncertainties related to bonded concrete-rock interfaces. However, the thesis focuses mainly on increasing the knowledge regarding the model uncertainty due to the brittle failure mechanism in combination with a possible spatial variability of cohesion. The magnitude of the model uncertainty is studied using numerical analyses. Its influence on the assessed behaviour of a hypothetical dam monolith is then evaluated using probability based methods. A conclusion drawn from this particular case, but which is likely to be generalized to other dam-foundation systems, is that the ductile sliding failure is too coarse an approximation of the failure behaviour of dams with bonded interfaces and could lead to an overestimation of dam safety. In addition, the potential spatial variability of cohesion along the interface further diminishes the validity of the ductile failure model. Areas that require further research in order to take into account the most significant uncertainties related to bonded interfaces include the definition of the ratio of bonded area to total area and its influence on sliding stability. The statistical uncertainty due to the limited number of tests also needs to be studied. / <p>QC 20131015</p>