CE-märkta stålbalkar byggdes in i två konstruktioner innan det upptäcktes att det fanns porer i hattbalkarnas svets. Den defekta svetsen innebar att byggnadernas bärförmåga inte kunde garanteras. Kunskapen kring inbyggt stål stommaterial med defekt svets är liten. Det är dessutom svårt att reparera och undersöka stålbalkarnas svets när de är inbyggda i konstruktionen. Syftet med examensarbetet är att hitta förstärkningsmetoder och därmed främja kortare hanteringstid vid händelse av att defekta stålbalkar byggs in i en konstruktion. Metoden består av litteraturstudie och intervjuer. Först granskas litteratur för att förstå problematiken med defekt svets i stål stommaterial. Därefter utförs intervjuer med personer erfarna inom stål och byggteknik. Examensarbetets resultat är ett flertal förstärkningsmetoder för inbyggda stålbalkar med defekt svets. Några av förstärkningsmetoderna är möjliga att utföra med den kunskap som finns idag medan andra behöver undersökas och värderas innan de kan implementeras. Förstärkningsmetoderna som är möjliga att utföra med dagens kunskap är: att svetsa om balken från insidan eller att placera en balk/fackverksbalk under den befintliga balken. De metoder som behöver undersökas och värderas vidare är: skruvförband genom balken, efterspänna balken med vajrar eller GWS-stag och sedan fylla den med betong, föra in en balk inne i balken och fylla balken med betong och att kolfiberförstärka svetsen. Slutsatsen är att den här studien kan ligga till grund för framtagning av åtgärder för inbyggda stålbalkar med defekt svets med mål att uppnå den dimensionerade hållfastheten och en lösning som är tidseffektiv, kostnadseffektiv och har låg klimatpåverkan. / Before the discovery of pores in the weld, CE-certified steel beams were embedded in two constructions. Since the weld was defective, the carrying capacity of the two buildings was questioned. There is a lack of knowledge about embedded steel beams with a damaged weld. It is difficult to repair and analyze the weld when the beams are embedded in the construction. The aim of the study is to find reinforcement methods for steel beams. The expectation is to shorten time in the production in case that defective steel beams are detected in the construction. The method consists of a literature study complemented by interviews. Literature is examined to understand the problem of defective welding in the steel framework. Subsequently, interviews are conducted with professionals within steel and building technology. The result of the report is multiple reinforcement methods for embedded steel beams with a defective weld. Some of the methods are possible to implement with the knowledge available today. Other methods need to be examined and assessed before executed. The reinforcement methods that are possible to perform are: weld the beam from the inside or place a beam underneath the existing beam. The methods that need further analysis are: drill a screw joint through the beam, strain the beam with steel-wires and fill the inside with concrete, place a beam inside the existing beam and fill the inside with concrete and last to reinforce the weld with carbon fibers. The conclusion is that this study can be used when reinforcement methods are needed for embedded steel beams with a defective weld. The objective with these methods is to restore the load-bearing capacity as well as finding a solution that is time efficient, economic and has low climatic influence.

Cell cycle regulation is an important part for the detection and destruction of mutated and dysregulated cells as it is a natural protection against degenerative diseases and cancer. The ability of the body to detect and destroy these cells is a vital part in maintaining homeostasis in the body. Once cells have circumvented this line of defence, dismantling these cells would become very difficult.  Research into new ways to target and destroy mutated cells are constantly evolving in hopes of being able to control and direct lysis of target cells using therapeutic drugs. One of the possibilities for such a method are Cholesterol Dependent Cytolysins (CDC), specific proteins found in bacteria. These proteins are dependent on the ability to bind to cholesterol in cell-walls to form pores that lyse and effectively destroy cells.   This project aims to study the structure and mechanistic details of pore formation by CDC mitilysin using cryogenic electron microscopy (cryo-EM). Mitilysin was purified by affinity chromatography and its pore formation ability was confirmed by calcein release assay and hemolysis assay. The pore structures of mitilysin were observed by transmission electron microscopy (TEM) using liposomes composed of both 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and cholesterol as model membranes. Detergent screening directed separation of pores from liposomes; so that they could be visualized by cryo-EM. While these steps were optimized and proven successful, they were time-consuming. An initial 3D-model of pore-structures was rendered, but no molecular characteristics could be determined at the end of the allotted time. The study does lay the ground steps for obtaining the complete structure of mitilysin pores.

Cemented carbide tools are subjected to high loads and temperatures during use. Long before any significant wear can occur on the tool, the material will experience plastic deformation. The purpose of this master thesis was to investigate how Kernel Average Misorientation (KAM) can be utilised to analyse plastic deformation within the microstructure or grains of cemented carbides. Six different cemented carbides were investigated. The materials were plastically deformed by utilizing cutting tests with a feed rate staircase method to induce the plastic deformation. Each material was characterised by using Scanning Electron Microscopy (SEM) either equipped with a secondary electron detector or an Electron Backscatter Diffraction detector (EBSD). This made it possible to investigate the WC grain size, Co infiltration, step formation, cavities and pores, KAM and the average grain size. It was concluded that KAM showed to be a valuable tool to visualise the plastic deformation in the materials. There were some limitations to KAM regarding materials with similar amounts of plastic deformation. Additionally, the data from KAM could be used to create graphs to more easily display the misorientation. However, KAM cannot showcase the mechanisms that lead to plastic deformation. Other characterisation methods are needed as a compliment to completely understand what is happening in the material on a microstructural level.