High performance cutting tools are essential in many industry areas. Cemented carbides (WC-Co) are common materials used for these applications due to the excellent mechanical properties. The mechanical properties of the material are manly dependent on the WC grain size distribution.To be able to tailor the material properties it is important to be able to characterize and control the WC grain size.In this study a quantitative method for WC grain size distribution measurements has been developed using the automated electron backscatter diffraction (EBSD) technique. The EBSD system was optimized for a fast and accurate measurement. Using the method approximately 2000-3000 WC grains can be measured in approximately 25 minutes. This will give reliable statistics and information about the material.The method was used to compare materials produced with three different milling methods; traditional 30l ball mill, method A and B. Two WC raw materials with different initial particle sizes, one coarser and one finer, was milled aiming for similar grain sizes in the sintered structure. The results showed some tendency for a larger fraction of large grains in the materials produced using the ball mill compared to the materials produced with method A and B. The difference between the milling methods was larger using a raw material with a coarser initial particle size.The developed quantitative method was successfully used to compare grain size distributions of different materials in a fast and quantitative way. The differences between the materials were small and materials with similar grain size distribution and mechanical properties could be produced using both the traditional ball mill method and method A and B.

Purpose: The purpose of this study is to investigate whether the Relative Age Effect iscrucial for winning the senior, U20, and U18 Men's Ice Hockey World Championships. Wealso aim to gain a better understanding of the significance of the Relative Age Effect for ateam's success. Success can be measured in various ways, but in this study, we have chosen todefine success in ice hockey by focusing on the teams that have won the championships.Method: This study adopts a quantitative design and relies on secondary analysis of publiclyavailable statistics. We have employed a deductive approach to examine the subject of theRelative Age Effect. To conduct the study, we have placed significant emphasis on previousresearch in the field and used it as the theoretical foundation. To gather information and data,we have utilized scientific articles, relevant literature, as well as general sources and websitesthat have contributed to the analysis of our study. By reviewing and referencing previousresearch, we have been able to draw conclusions and benefit from prior insights into theRelative Age Effect.Results and Conclusions: The results we obtained regarding the winning teams between2001-2022 of the senior, U20, and U18 Men's Ice Hockey World Championships indicate thatthe Relative Age Effect is not present at the senior level but is observed in the U20 and U18categories. The results also showed that the younger the age group, the more evident theRelative Age Effect was among the teams, with significant differences between the winningteams in the U20 and U18 divisions. Based on the results of our study, we can conclude thatthe Relative Age Effect is not a decisive factor for winning at the senior level. However, itbecomes more difficult to draw a clear conclusion at the junior level since our researchindicates that the winning teams exhibit the Relative Age Effect, but it remains uncertainwhether it has been decisive or how it has practically influenced the teams' success.Therefore, talent identification and development in younger generations should reassess theselection process and factors deemed crucial for participation in these championships. Furtherresearch is required to determine which individuals within the teams are truly instrumental intheir victories and whether all teams in the tournaments are already influenced by theRelative Age Effect.

WC cemented carbides are composites consisting of WC and a binder phase. WC/Co is widely used as cutting tools due to its excellent combination of hardness and toughness. This thesis work was performed at the R&D department of Sandvik Coromant and aimed to find the alternative binder phase to substitute cobalt. Several compositions of Fe-Ni and Fe-Ni-Co binder have been investigated in this study. The WC/Co reference samples were also prepared. The initial compositions were decided by the CALPHAD method. The samples were then produced by the means of powder metallurgy. The producing conditions, especially the sintering conditions, were manipulated to achieve full dense and uniform samples. The samples were analyzed by XRD, LOM, SEM, and EDS. Mechanical properties test has also been performed.The results showed that adjustment on carbon content is necessary to attain desirable structure. Increasing Fe content in the binder tends to make the materials harder. For Fe-Ni and Fe-Ni-Co, the martensitic transformation is essential to the mechanical performance. The induced “transformation toughening” in 72Fe28Ni and 82Fe18Ni binders significantly promoted the toughness. Furthermore, the grain growth inhibition by Fe was confirmed. The relations between sintering temperature, grain size and mechanical properties have been discussed. Compared with the WC/Co references, several compositions showed close and even superior mechanical performance which might provide solutions for the future alternative binder phase.

Idag spolar den stora majoriteten av alla invånare i Sverige med dricksvattnen itoaletten. Spolning med regnvatten i WC är något som på flera håll i världenanvänds flitigt främst i områden med någon slags vattenbrist. Men i Sverige harregnanvändande anläggningars popularitet inte riktigt slagit igenom ännu.Orsaken till detta kan härledas till flera faktorer. De viktigaste och de sompåverkar mest är; den goda tillgången och således låga priset på dricksvatten iSverige, samt begränsad konkurrens bland företag och återförsäljare vilket ger etthögt investeringspris på regnanvändande anläggningar för konsumenten.Fokus i detta examensarbete ligger på att göra en grundläggande analys avregnvatten och möjligheterna att genom en regnanvändande anläggning kunnaanvända regnvatten istället för dricksvatten för att spola i toaletten med.Tillvägagångssättet har varit att genom en studie av olika källor sammanställainformation relevant till ämnet regnvatten och regnvattenanvändning till WCspolning,följt av en analys och jämförelse av hur ekonomiskt hållbar enregnanvändande anläggning i ett standardhus beläget i Malmö är, i förhållande tillsamma standardhus med en traditionell dricksvattenförsörjning för WC-spolning.Resultatet av analysen visar tydligt att en regnvattenanvändande anläggning ifallet med standardhuset i dagsläget inte går att rättfärdiga ur ekonomisksynpunkt, men även att det finns möjlighet till en realistisk ekonomisk förtjänst iandra byggnader eller i framtiden. / The vast majority of the Swedish population today flushes their toilet withdrinking water. Flushing the toilet with rain water is used diligently on multiplelocations around the world, typically where there is a shortage of fresh water. InSweden though, the popularity of rain water harvesting has not yet beensuccessful. The cause of this can be deducted to several factors, where the mostimportant and the most influential are the abundant source, and therefore low cost,of fresh water in Sweden and the lack of competition among retailers, whichresults in a high investment cost of rain water harvesting equipment for theconsumer.The focal point of this Bachelor’s Degree project is to make a fundamentalanalysis of rain water and the possibilities of using rain water instead of drinkingwater for flushing the toilet. The procedure of the project has consisted of a studyof sources, a compilation of information relevant to rain water and the use of rainwater as flushing water in the toilet and an analysis of a calculated average housein Malmo, Sweden, and a comparison between a traditional toilet flushing systemand a rain water toilet flushing system of the same average house.The result of the analysis clearly shows that a rain water toilet flushing systemcan not be justified from a economical standpoint in the case of the average house,but also that there is a realistic chance of an economical profit in the future or ifused with other building types.

The Bergman & Beving sphere is a group of Swedish companies that have been successfulduring the last decades as serial acquirers. This study examines how the Bergman & Bevingsphere operates and how management makes capital allocation decisions; this has beenexamined through interviews with key individuals and large owners within these companiesand has by that taken a qualitative approach to the research questions outlined.The business model of the Bergman & Beving sphere revolves around continuously acquiringniched companies, with a long track record of profitable growth and with a culture that alignswith that of their own. What distinguishes them from many serial acquirers is that they do nottry to integrate the acquired company into a bigger one and/or find synergies between them,but instead, they operate with a highly decentralized model where the companies actindependently. The group has for a long time used internal financial metrics, with theirtrademark metric being Profit/Working capital (P/WC), to guide their subsidiaries and aidmanagement in capital allocation decisions.

<p>Cemented carbides (WC-Co) are powder metallurgical products produced by liquid phase sintering. WC-Co is widely used for making a large variety of cutting tools, such as drills and inserts turning applications, due to its great mechanical properties, where the hardness of the WC grains is combined with the toughness of the of the Co binder. WC grain size and grain size distribution are the two most important factors to control the mechanical properties of the products.</p><p>This study examined the grain growth dependence of different milling and sintering times. The resulting grain size and grain size distribution were measured using image analysis on scanning electron microscopy images (SEM) and by using electron backscatter diffraction (EBSD). In addition, the correlation between hardness and coercivity, the most common indirect measures of grain size, and different methods of calculating average grain radius were investigated. An attempt was also made to study the contribution of defects to grain growth. This work also includes an overview of various grain growth equations and a numerical implementation of these.</p><p>Experimental results show that for shorter sintering times, powders milled for short times (15 min and 1 h) have larger average grain radii. There is a crossover after 6 to 8 h of sintering, where the powders milled for a long time (40 h and 200 h), have larger average radii. The measured hardness values correlate well with the average grain radius calculated from the grain surface area and the coercivity correlates with the established equations. EBSD measurements detected boundaries that could not be detected by image analysis, and that were not Sigma 2 boundaries. It is likely that these boundaries are either low energy boundaries or boundaries between grains that are very closely oriented. Comparing heat-treated powder with the untreated resulted in a lower average grain size after sintering for the heat-treated powder. None of the growth equations investigated in this work could fully describe the experimental grain growth.</p><p>Through increased understanding of the grain growth, the growth can be controlled and the end product can have the desired tool properties. The occurrence of abnormal grains in cutting tool applications can cause breakage, which is especially important to avoid in applications such as PCB drills. A correlation between hardness and grain size provides further means for cheap and fast indirect measures of the grain size in production.</p> / <p>Hårdmetall är ett pulvermetallurgiskt material som tillverkas genom smältfassintring och som kännetecknas av hårdhet, styvhet och god slitstyrka. Volframkarbidens (WC) kornstorlek och kornstorleksfördelning är två viktiga faktorer för att kontrollera de mekaniska egenskaperna i hårdmetall.</p><p>I den här studien har korntillväxtens beroende på malning och sintring undersökts. WC-Co maldes och sintrades fyra olika tider och kornstorleksfördelningen mättes med bildanalys på svepelektronmikroskopbilder samt med ``electron backscatter diffraction'' (EBSD). I arbetet har även korrelationen mellan hårdhet, koercivitet och olika sätt att beräkna medelkornstorleken undersökts. Ett försök har också genomförts för att studera hur defekterna i det malda pulvret påverkar korntillväxten. I arbetet har även ett flertal olika tillväxtekvationer modellerats numeriskt och för och nackdelar med de olika tillväxtekvationerna har vägts mot varandra.</p><p>En lång maltid (40 h och 200 h) visade sig ge liten kornstorlek för sintring kortare än 6 h, men för sintringar längre än 8 h gav istället kort malning (15 min och 1 h) den mindre kornstorleken. Det visade sig att uppmätt hårdhet korrelerar bäst med den medelkornstorleksradie som räknats fram från kornytan. I EBSD mätningarna kunde man observera ett flertal korngränser, utöver Sigma 2 korngränser, som inte hade detekterats med bildanalys. Värmebehandlingen av det malda pulvret minskade korntillväxten under efterföljande sintring. Ingen av de undersökta tillväxtekvationerna kunde beskriva de experimentella resultaten fullt ut.</p><p>Genom ökad förståelse för korntillväxt kan man kontrollera tillväxten och slutprodukten kan få önskade egenskaper. Förekomsten av abnorm korntillväxt i skärverktyg i hårdmetall är en av de vanligaste kritiska defekterna och det är speciellt viktigt är undvika korntillväxt i tillverkning av små verktyg, som till exempel kretskortsborrar. Hårdhet och koercivitet är de vanligaste indirekta mätmetoderna för att mäta kornstorlek i produktion. En bra korrelation mellan kornstorlek och indirekta mätmetoder ger utökade verktyg för snabba och billiga mätningar.</p>

No description available.

The proposed dissertation thesis deals with the characterization of HVOF and APS-thermally sprayed coatings prepared on the AZ31 and AZ91 magnesium substrates. The theoretical part of the thesis describes in-detail Mg substrates used in the experimental part of the thesis. There are also characterized materials and coatings based on NiCrAlY and FeCrNiMoSiC metals, WC-CoCr cermets, and YSZ ceramic materials. At the end of the theoretical part, the literary research summarizing the characterization and analysis performed on thermally sprayed coatings on Mg alloys. Based on the theoretical knowledge, the characterization of Mg substrates and deposited coatings was performed in terms of the surface morphology, microstructure, and the chemical composition using the light microscopy (LM) and scanning electron microscopy with energy-dispersive spectroscopy (SEM+EDS). The phase composition of the coatings was analyzed using the X-ray diffraction (XRD). The diffractions corresponding to the sprayed coatings were compared with the feedstock powders, i.e. materials used for the spraying of the coatings. The characterization of the prepared coatings in terms of the mechanical and tribological properties was performed. The hardness and microhardness of the coatings as well as the coefficient of friction, and the wear rate were measured. The last chapter of the experimental part deals with the evaluation of the electrochemical corrosion properties by the potentiodynamic measurements in a 3.5% NaCl solution. In the case of exposed samples, the evaluation of the surface and coating/substrate interface was performed using LM and SEM with EDS. The mechanism of the corrosion attack and degradation was determined from the acquired knowledge and base on the results of the short-term measurements. Based on the measured results, it can be stated that the deposited coatings were successfully applied on the surface of both Mg alloys. All the coatings increase the surface hardness of the Mg alloys and significantly improve their tribological properties. However, except for FeCrNiMoSiC coatings, the corrosion properties of Mg alloys deteriorate due to the fact that the corrosion environment can pass through the coating to the less noble Mg substrate and the corrosion microcells are created.

Cemented carbides (WC-Co) are powder metallurgical products produced by liquid phase sintering. WC-Co is widely used for making a large variety of cutting tools, such as drills and inserts turning applications, due to its great mechanical properties, where the hardness of the WC grains is combined with the toughness of the of the Co binder. WC grain size and grain size distribution are the two most important factors to control the mechanical properties of the products. This study examined the grain growth dependence of different milling and sintering times. The resulting grain size and grain size distribution were measured using image analysis on scanning electron microscopy images (SEM) and by using electron backscatter diffraction (EBSD). In addition, the correlation between hardness and coercivity, the most common indirect measures of grain size, and different methods of calculating average grain radius were investigated. An attempt was also made to study the contribution of defects to grain growth. This work also includes an overview of various grain growth equations and a numerical implementation of these. Experimental results show that for shorter sintering times, powders milled for short times (15 min and 1 h) have larger average grain radii. There is a crossover after 6 to 8 h of sintering, where the powders milled for a long time (40 h and 200 h), have larger average radii. The measured hardness values correlate well with the average grain radius calculated from the grain surface area and the coercivity correlates with the established equations. EBSD measurements detected boundaries that could not be detected by image analysis, and that were not Sigma 2 boundaries. It is likely that these boundaries are either low energy boundaries or boundaries between grains that are very closely oriented. Comparing heat-treated powder with the untreated resulted in a lower average grain size after sintering for the heat-treated powder. None of the growth equations investigated in this work could fully describe the experimental grain growth. Through increased understanding of the grain growth, the growth can be controlled and the end product can have the desired tool properties. The occurrence of abnormal grains in cutting tool applications can cause breakage, which is especially important to avoid in applications such as PCB drills. A correlation between hardness and grain size provides further means for cheap and fast indirect measures of the grain size in production. / Hårdmetall är ett pulvermetallurgiskt material som tillverkas genom smältfassintring och som kännetecknas av hårdhet, styvhet och god slitstyrka. Volframkarbidens (WC) kornstorlek och kornstorleksfördelning är två viktiga faktorer för att kontrollera de mekaniska egenskaperna i hårdmetall. I den här studien har korntillväxtens beroende på malning och sintring undersökts. WC-Co maldes och sintrades fyra olika tider och kornstorleksfördelningen mättes med bildanalys på svepelektronmikroskopbilder samt med ``electron backscatter diffraction'' (EBSD). I arbetet har även korrelationen mellan hårdhet, koercivitet och olika sätt att beräkna medelkornstorleken undersökts. Ett försök har också genomförts för att studera hur defekterna i det malda pulvret påverkar korntillväxten. I arbetet har även ett flertal olika tillväxtekvationer modellerats numeriskt och för och nackdelar med de olika tillväxtekvationerna har vägts mot varandra. En lång maltid (40 h och 200 h) visade sig ge liten kornstorlek för sintring kortare än 6 h, men för sintringar längre än 8 h gav istället kort malning (15 min och 1 h) den mindre kornstorleken. Det visade sig att uppmätt hårdhet korrelerar bäst med den medelkornstorleksradie som räknats fram från kornytan. I EBSD mätningarna kunde man observera ett flertal korngränser, utöver Sigma 2 korngränser, som inte hade detekterats med bildanalys. Värmebehandlingen av det malda pulvret minskade korntillväxten under efterföljande sintring. Ingen av de undersökta tillväxtekvationerna kunde beskriva de experimentella resultaten fullt ut. Genom ökad förståelse för korntillväxt kan man kontrollera tillväxten och slutprodukten kan få önskade egenskaper. Förekomsten av abnorm korntillväxt i skärverktyg i hårdmetall är en av de vanligaste kritiska defekterna och det är speciellt viktigt är undvika korntillväxt i tillverkning av små verktyg, som till exempel kretskortsborrar. Hårdhet och koercivitet är de vanligaste indirekta mätmetoderna för att mäta kornstorlek i produktion. En bra korrelation mellan kornstorlek och indirekta mätmetoder ger utökade verktyg för snabba och billiga mätningar.

CRISPR-Cas ist ein adaptives Immunsystem, dass Bakterien und Archaeen vor eindringenden Nukleinsäuren schützt. Es besteht aus einem sogenannten CRISPR-Array, der als genetisches Gedächtnis vorangegangene Infektionen speichert und einem cas Lokus, welcher für die Abwehr essentielle Proteine codiert. Das CRISPR-assoziierte Protein 9 (Cas9) des Typ II CRISPR-Cas Systems aus Streptococcus pyogenes ist heutzutage das Mittel der Wahl für Gentherapie und Genom-Modifikationen. Allerdings gibt es nach wie vor Probleme mit der Ungenauigkeit dieses Systems, welche für eben genannte Ansätze behoben werden müssen. Aus diesem Grund ist es besonders wichtig zu verstehen, in welcher Weise die Spezifität von Cas9 beeinflusst wird. In dieser Arbeit wurden die Voraussetzungen für eine spezifische Erkennung der Zielsequenz durch drei verschiedene Cas9 Proteine des Typs II-A und ein Cas12a Protein des Typs V-A CRISPR-Cas Systems untersucht. Wir zeigen, dass Arginin Seitenketten der sogenannten „bridge“ Helix in Cas9 von S. pyogenes eine wichtige Rolle in der Bindung und Spaltung der DNS spielen. Diese Seitenketten können in zwei Gruppen unterteilt werden, welche die Spezifität von Cas9 entweder vergrößern oder verkleinern. Die Aminosäuren R63 und R66 reduzieren die Spezifität von Cas9 indem sie den sogenannten R-loop in Anwesenheit einer Fehlpaarung stabilisieren. Wir zeigen außerdem, dass Q768 eine erhöhte Toleranz von Cas9 zu Fehlpaarungen an Position 15 der Zielsequenz vermittelt und dass das Entfernen dieser Aminosäure die Spezifität von Cas9 im Bereich der Zielsequenz, die am weitesten von der PAM entfernt ist, erhöht. Eine Kombination der Mutationen der oben genannten Arginin und Glutamin Seitenketten führt zur Erhöhung der Gesamtspezifität von Cas9. Die Ergebnisse dieser Arbeit tragen zum Verständnis bei, wie Cas9 Fehlpaarungen innerhalb der Zielsequenz detektiert und können dabei helfen weitere Strategien für eine verbesserte Spezifität von Cas9 zu entwickeln. / CRISPR-Cas (CRISPR-associated) systems are adaptive immune systems that have evolved in bacteria and archaea for protection against invading nucleic acids. They consist of a CRISPR array, where the genetic memory of the infection is stored and ultimately transcribed and processed into CRISPR RNAs (crRNAs), and of an operon of cas genes that encodes the Cas proteins. This thesis is focused on class 2 CRISPR-Cas systems that employ single RNA-guided nucleases in the interference phase. Dual-RNA guided CRISPR-associated protein 9 (Cas9) of the type II CRISPR-Cas system has become the tool of choice for genome editing applications in life sciences. However, off-target cleavage by Cas9 is one major issue that needs to be addressed for applications of the CRISPR-Cas9 technology for therapeutic purposes. Therefore, understanding the features that govern Cas9 specificity is of great importance. In this thesis, seed sequence requirements of three Cas9 proteins from the class 2 type II-A and one Cas12a protein from the class 2 type V-A CRISPR-Cas system have been investigated. We analyze the influence of mismatches and show that they affect target binding and/or cleavage by S. pyogenes Cas9. Additionally, we demonstrate that the arginine residues from the bridge helix of S. pyogenes Cas9 are important for target DNA binding and cleavage. Furthermore, these residues comprise two groups that either increase or decrease Cas9 sensitivity to mismatches i.e. specificity. R63 and R66 reduce Cas9 specificity by stabilizing the R-loop in the presence of mismatches. We also show that Q768 mediates Cas9 tolerance to a mismatch at target position 15 and removal of Q768 increases Cas9 specificity in the PAM-distal part of the target. Combination of arginine mutations and Q768A increased overall the sensitivity to mismatches. The results of this thesis elucidate how Cas9 senses PAM-adjacent mismatches and provide a basis to develop strategies for Cas9 variants with enhanced specificity.