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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Radon i flerbostadshus : Kartläggning av fastighetsförvaltarnas egenkontroll avseende radon

Willenius, Ann-Christin January 2010 (has links)
<p>Radon is a hazardous substance that cannot be perceived by our senses. It has long been known that exposure to high radon levels for a long period of time will ultimately cause lung cancer. The Swedish Radiation Safety Authority estimates that 500 people die annually due to this. Although most of them are smokers, even non-smokers suffer from lung cancer caused by radon. The statutory value for radon in homes today is 200 Bq/m³. Several years of research points to the fact that 63% of all those who develop lung cancer have been exposed to radon levels between 100-200 Bq/m³. This is why the WHO has lowered the recommended value to  100 Bq/m³,  and The Radiation Safety Authority of Sweden also has the same recommendation today. This study has been rendered to the Municipality of Eskilstuna, and its environmental and emergency management. The study has identified 72 % of the rental properties for radon measurements and action through personal visits to 14 large and medium-sized property managers in Eskilstuna. Several conclusions can be made from the study. Generally, very few measurements have been made and these have shown 6 % of high radon levels. The various property managers are at very different levels regarding their work with radon and there are very big differences amongst them as regards giving priority to the issue with radon. In 2020, the Swedish parliament has decided that no one should be exposed to radon levels above 200 Bq/m³ in their homes. Today there is legislation that applies against radon in apartment buildings as well as effective methods to reduce radon levels. However, the problem is instead the fact that there is a lack of resources at hand for the public health inspectors. Consequently, it seems rather impossible achieving the goal set for 2020. Thus it is of utmost interest to highlight this problem for the politicians that ultimately set the budget for the services in the municipality.</p>
2

Radon i flerbostadshus : Kartläggning av fastighetsförvaltarnas egenkontroll avseende radon

Willenius, Ann-Christin January 2010 (has links)
Radon is a hazardous substance that cannot be perceived by our senses. It has long been known that exposure to high radon levels for a long period of time will ultimately cause lung cancer. The Swedish Radiation Safety Authority estimates that 500 people die annually due to this. Although most of them are smokers, even non-smokers suffer from lung cancer caused by radon. The statutory value for radon in homes today is 200 Bq/m³. Several years of research points to the fact that 63% of all those who develop lung cancer have been exposed to radon levels between 100-200 Bq/m³. This is why the WHO has lowered the recommended value to  100 Bq/m³,  and The Radiation Safety Authority of Sweden also has the same recommendation today. This study has been rendered to the Municipality of Eskilstuna, and its environmental and emergency management. The study has identified 72 % of the rental properties for radon measurements and action through personal visits to 14 large and medium-sized property managers in Eskilstuna. Several conclusions can be made from the study. Generally, very few measurements have been made and these have shown 6 % of high radon levels. The various property managers are at very different levels regarding their work with radon and there are very big differences amongst them as regards giving priority to the issue with radon. In 2020, the Swedish parliament has decided that no one should be exposed to radon levels above 200 Bq/m³ in their homes. Today there is legislation that applies against radon in apartment buildings as well as effective methods to reduce radon levels. However, the problem is instead the fact that there is a lack of resources at hand for the public health inspectors. Consequently, it seems rather impossible achieving the goal set for 2020. Thus it is of utmost interest to highlight this problem for the politicians that ultimately set the budget for the services in the municipality.
3

Calculating Minimum Detectable Activity for a moving scintillator detector using real-time speed measurement : Implementing a monitoring system to improve accuracy of surface contamination measurement systems / Beräkning av minsta detekterbara aktivitet för en mobil scintillatordetektor med hastighetsmätning i realtid : Implementation av ett övervakande system som förbättrar mätsäkerheten vid detektion av radioaktiv ytkontamination

Amcoff, Artur, Persson, Oscar January 2021 (has links)
Surface contamination occurs in nuclear facilities, something that is important to detect easily and efficiently. Using today’s methods to detect nuclear surface contamination may cause certain inconsistencies as the human operator is solely trusted to keep the detector at the correct distance and move it at the correct speed. This thesis project aims to address the problem of inconsistent measurements with respect to the current measurement methods. A system is designed to monitor the measurement process with regards to detector velocity and height. The system will trigger a warning when the minimum detectable activity is too high, as it would lead to inconsistent results. This system consists of a cart-detector setup with a scintillation detector and velocity measurement device(s). Software will utilize the measurement data to implement the aforementioned monitoring. The system aims to be compliant with international standards, such as the ISO 11929 and the ISO 7503 standards, and will thus make use of these standards. The result of the part-analysis for each component of the system showed a large inaccuracy regarding the Intertial Measurement Units (IMUs); hence, the robotic wheels were chosen as the main method of measuring speed for this project. The robotic wheels and the detector were shown to be sufficiently accurate for the desired measurements. The Raspberry Pi 4 model B, the on- board computer, was also shown to be performance-wise and property-wise well suited for the project. This project showed that there is a theoretical way to implement the speed of a moving detector-rig into the Minimum Detectable Activity (MDA) formula. However, the implementation investigated in this project suggests that full compatibility with ISO 7503 was not achievable. / Radioaktiv ytkontaminering förekommer i kärnkraftverk, vilket är viktigt att upptäcka snabbt och effektivt. Dagens metoder för att upptäcka radioaktiv ytkontaminering kan lida av viss osäkerhet eftersom man förlitar sig helt på att operatören kan manövrera detektorn på rätt höjd och hastighet. Detta examensarbete behandlar en lösning till det ovan nämnda problemet. Ett ”proof-of-concept”-system som kan övervaka mätprocessen designas. Genom att mäta hastighet och känna till höjden över marken kan en varning meddelas användaren när den minsta detekterbara aktiviteten (MDA) når ett tröskelvärde. Det färdiga systemet är en plattform på hjul med en scintillator- detektor monterad tillsammans med en eller flesta hastighetsmätningsenheter. Systemet bör vara kompatibelt med internationella standarder, till exempel ISO 11929 och ISO 7503. Resultaten från den utvärdering av varje individuell komponent som gjorts visade på en stor mätosäkerhet i de två utvärderade IMUerna. Detta medförde att robothjulen valdes som enda källa för hastighetsmätning. Robothjulen, samt detektorn påvisade god mätsäkerhet, väl lämpad för detta projekt. Även mikrodatorn, Raspberry Pi 4 model B, visade sig vara lämplig sett till prestanda och egenskaper. Projektet resulterade i att det är trott att det finns en lämpligt sätt att i teorin implementera hastighet som en parameter i formeln för MDA. Det är dock värt att nämna att resultaten tyder på att det i denna implementation inte var möjligt att uppnå fullständig kompabilitet ISO 7503.

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