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  • Yosifova, Eliz
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Baban, Zanwer
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Nybyggnation av hotell: Gestaltning av hotell på en ljudutsatt plats i Stockholms stad2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    One major problem today in Stockholm City is to be able to build functional housing and offices becuase of the impact from the noise large interchanges distribute in the City. In order to build housing and offices it is important to achieve the requirements that Boverkets Byggregler, which is the Swedish rules for constructions. The county in Stockholm has to plan and observe the noise exposed properties in the inner City. One obstacle to build more housing and offices which the city needs, is the rules and demands on the areas but also the growth of the traffic in Stockholm city. This problem results for increased noiselevels which also affects the acoustic comfort for housig and offices. To be able to solve the problem for the challenges that is caused by the lack of housing in Stockholm, hotels can be built on these areas that are located close to traffic in the city. In order to solve this problem a hotel that screen the exessive noise towards residental areas can be a solution, because Boverket does not require any guidelines and regulations for noise on hotel constructions. The fact that hotels can be built on properties that is close to the traffic can benefit the social development of the city. A hotel can open opportunities for different people and groups to meet in the same point which can be used to increase the city´s social development. The tourism in Stockholm City is developing a lot today and more visitors visits the city day by day. The increase of visitors creates challenges for the range of hotels in the city. Utilizing areas in the inner city of Stockholm and urban areas that are exposed to noise from traffic is an advantage to build a hotel since Boverket does not require any benchmarks for noise. To make use of these kinds of properties, can also increase the range of hotels for the visitors in the city. This project will present a hotel that is located in Årstafältet in the southern part of Stockholm City. Årstafältet is a place that is exposed to high noise because of the highway on Huddingevägen that passes through the place. The problem with the location is the traffic noise which has a negative effect on housing constructions in the area. The noise problem in the area gives the chosen property good conditions for building a hotel and allows the residents close to the hotel property, to be less affected by the noise level coming from the traffic jam.

  • Unell, Mathias
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Ruuska, Natalie
    Gatuutformning med autonoma fordon.: En undersökning över möjliga förändringar i Stockholm.2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The development with automated functions in vehicles is moving forward and in the future it is possible that cars is completely self-driving. Stockholm is growing and also the traffic, which poses challenges to solve, such as increasing accessibility, availability and sustainability. Therefore, the City of Stockholm has developed goals for clarifying what the future street areas should fulfill. The purpose of this report was to compile information on how autonomous vehicles can influence street design and compare the results with the goals of street planning in the City of Stockholm. The result showed that autonomous vehicles can enable an increased sharing economy within the transport system, which means that fewer people own their own vehicle. Instead, the vehicles can be included in new mobility solutions. This can lead to improved land use and new opportunities for how we use the street space. For example, the street room is mentioned as being able to be switched off for traffic after rush hour and providing space for other activities. The results also showed that the vehicles need more integrated technology in the street space and requirements for higher readability of line markings and road signs. One conclusion was that many of Stockholm's goals can be achieved, such as environmental goals, less congestion and higher road safety. The result shows that the two most important factors are the political and technical development of autonomous vehicles.

  • Andersson, Jennifer
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Franke, Klara
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Arken: Bostäder i stadens skärgård2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A few steps away from the district of Liljeholmen in Stockholm lies the area of Lövholmen. A largely abandoned industrial zone where visitors are greeted by crushed window panes, dilapidated buildings and defaced facades. Stockholm City has along with a number of different developers made a proposal for a change in the detailed development plan, from an industrial area to a residential area. The urban planning Strukturplan och Ramverk för Lövholmen contains proposed guidelines for the design of a new neighborhood. Our purpose in this thesis is to design a residential proposal as if the detailed development plan has won legal force, also to examine how floor plans can affect human health and well-being. The proposal will relate to urban development guidelines by Stockholm stad, where the aim is to make Lövholmen a safer and nicer place. This will be done with the help of analyzes and surveys from the public's wishes and views. The result of our vision; Arken, will consist a housing proposal with an architectural connection to the place that will make Lövholmen a more harmonious site. The housing proposal will bring a sense of community to people who settle in the neighborhood as well as elaborated floor plans based on surveys on human well-being.

  • Ekman, Anna
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Molla Omar, Soulin
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Utbyggnad av Gröna Lund: Ett förslag till utformning av Skeppsholmsviken 62019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Aim: The aim of the thesis is to investigate and design the extension of Gröna Lund within the property of Skeppsholmsviken 6 in regards to the factors that affected the formation. Methods: Interviews were conducted with people involved in the current project. A survey was administered on social media to explore public opinion and requisition tied to the extension work. Furthermore, an audit of detailed plans, reports and drawings was carried through. Results: The constructions resulted in five buildings placed along the coastline facing Saltsjön and a public board walk in terms of a dock which should be accessible for passage through Skeppsholmsviken 6. Conclusions: The results show that the extension of Gröna Lund has a strong cultural and historical attachment and will benefit the public and visitors of Gröna Lund. Additionally, the extension will have positive ecological, social and economic consequences such as increased safety, tourism, job opportunities and reduced traffic. The extension can be made ecologically sustainable by using wood as a building material, build it on piles and raising the dock a bit over the water surface to get a larger light transmission.

  • Hjelm, Vivien
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Optimizing a Single Atom Catalyst for theOxygen Evolution Reaction using DensityFunctional Theory2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The growing interest of renewable fuel and energy sources has steadily increased over time due to climate changes. Research is being made around the world to find solutions for the different problems; one possible solution is to produce hydrogen gas to help phase out the usage of fossil fuels. So far, the technology for the hydrogen gas production is expensive for various reasons, one of the challenges is to minimize the energy usage for the production. Hydrogen could be used in fuel cells which can be used to fuel an electric car. In a fuel cell, hydrogen and oxygen gas are mixed to produce electrical energy as the main product, but it also forms thermal energy and water. Hydrogen gas can be produced from the reversed reaction; by electrolysis of water. This reaction requires energy and one way to minimize the energy usage for this is by using acatalyst.

    The goal with this master thesis was to see how the reaction rate of the oxygen evolution reaction can be affected by different single atom catalyst systems. The main structure for this catalyst in this thesis is aporphyrin molecule where different transition metals were tried as the active site. Different modifications on the structure were also made by exchanging some of the structures atoms and by adding different ligands.The purpose of this is to see how these modifications change the activity of the catalyst. The catalysts were optimized and calculated in a computational chemistry program called Gaussian 16. The calculations was made by using the DFT functional PBE0 and the basis sets Def2svp and Def2tzvpp.

    The results show that different modifications do affect the activity of the catalyst. The biggest variations in activity are from placing ligands under the active site while exchanging hydrogens to other substituents on the outer radial position can fine tune the results. The best active sites for this system came by using iridium, rhodium and cobalt which are all elements in group 9 of the periodic table. The lowest overpotential of 0.513 V was given by an iridium based system with four hydrogens exchanged by fluorides.

  • Vranjkovina, Amir
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Spectroscopic evaluation of stability and homogeneity of formulated lubricant2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Lubricant is a common name for a large group of products that are essential for almost every engine or other machinery equipment that include mechanical part movements. Their main application is reduction of the friction between two rubbing surfaces by interposing a lubricating film between them. Other important functions of lubricants beside lubrication are; heat transfer, energy efficiency enhancement, corrosion and oxidation protection. All types of lubricants mainly consist of base oil and additives. Base oils are mainly hydrocarbon compounds, while additives are various chemical compounds added to the base oil to enhance some of the already existing properties, or to impose new properties that are beneficial for application purposes. During the storage period, where different storage conditions can occur, many of the requirements for lubricants chemical and physical stability needs to be fulfilled. Inappropriate storage conditions can cause physical and chemical changes in lubricants, which can make them unusable for the intended application. The effects of different storage conditions on lubricants stability were investigated in this work. The experimental part of this project was conducted at Fuchs Lubricants Sweden AB. At the beginning of the experiment, twelve 2L high density polyethylene bottles (HDPE) filled with the lubricant, were divided into three groups. The first group consisted of four closed HDPE bottles previously filled with the lubricant that were stored at 9 °C, 22 °C, 45 °C and 80 °C. The second and the third group consisted also of four open bottles and four bottles with added distilled water stored at the same storage temperatures. The amount of lubricant was approximately the same in all bottles. At different time intervals sample aliquots from the top, middle and the bottom layer were taken from these bottles and analyzed. The effects of different storage conditions on the lubricant’s stability and homogeneity were acquired by two distinctive spectroscopic methods. Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) was used for elemental composition analysis, while the Fourier Transform Infrared (FTIR) Spectroscopy was used for evaluation of chemical changes on molecular level. Results from ICP-AES analyses showed almost homogeneous elemental distribution, virtually unaffected by different storage conditions in all sample bottles. Results from FTIR analyses showed that observed changes in absorption peaks (673, 863, 972. and 1267 cm-1) took place almost simultaneously at all three layers in all bottles stored at four different temperatures. These results suggest that the analyzed lubricant was stable and homogeneous for the observed period. The lowest storage temperature caused minimal changes in the lubricant and can be considered as optimal storage temperature for this product. It was also observed that increased temperature, direct exposure to oxygen and presence of water catalytically affected the rate of these changes. A part of this project was to validate the method used for ICP analysis. For this purpose, the following method performance parameters were investigated: linearity, precision, accuracy, Limit of detection (LOD) and Limit of quantification (LOQ). The obtained results showed that linearity of the method for all elements, in the used standard, was confirmed based on the set criteria. Precision and accuracy were tested in repeatability conditions and at four different concentration levels. The obtained results showed that accuracy of the method increased with concentration, and was highest for 50 ppm, for almost all elements. The highest precision (< 2 % RSD), for almost all elements was obtained for the concentration of 25 ppm. The LOD values were between 0.01 and 1.42 ppm while calculated LOQ values were between 0.04 and 4.73 ppm.

  • Hall, Oscar
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Sjöberg, Måns
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Dimensionering av överbyggnader på tillfälliga vägar: En fallstudie i Hallonbergen2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    When temporary roads are being constructed there is normally no design made in advance, in most cases they are built and dimensioned from experience. If a temporary road will be used as a permanent road after the construction is finished, there will occasionally be a complete design of the road. Example of this is when roads are built for wind power stations or forest roads. The company Auctoritas Projektstyrning AB has been assigned to project lead any necessary property maintenance for Terränglöparen 9 situated in Hallonbergen, Sundbybergs county. To go through with the renovations, the company is investigating the possibilities for a temporary road to ease the logistics during the production time. The purpose with this report is to investigate technical solutions for the construction of a temporary road. The investigation should result in a suggestion for appropriate choices with regard to cost and rules. This is later applied like a case study with a temporary road to Terränglöparen 9. The authors have explored ten different road constructions with regards to current land ratio, service years, annual traffic per lane and cost. In addition to this, a proposed road section has been investigated with regards to current topography, turning radius of lorries and load-bearing capacity. This led to a choice of road construction and a road section for a temporary road to Terränglöparen 9.

  • Le Guillarme, Jonathan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Lindstam, Jakob
    Implementering av Structural Health Monitoring: SHM - system för detektering och övervakning av vanligt förekommande skador på betongbroar2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Like many countries around the world, Sweden has an aging infrastructure and the need for maintenance is increasing. In an article in Svenska Dagbladet from 21 / 9–2018, the analysis and engineering consulting company WSP reports a rough estimate that SEK 300 billion needs to be invested to upgrade existing infrastructure. After the upgrade, it would require approximately SEK 25 billion annually to carry out ongoing condition assessment and maintenance of Sweden's road and railway networks. Today, inspections are used to assess the condition of bridges. There are three types of inspection; main inspection, general inspection and special inspection. Structural Health Monitoring (SHM) is a technology that is globally more used as a method for condition assessment of bridges. SHM aims to perform automatic assessment of the state of the entire construction and individual damages in real time. SHM uses sensors placed at critical positions to collect measurement data compared to pre-defined limit values. In Sweden, SHM is used sparingly today, where knowledge is at an academic level and there is uncertainty about how SHM should be implemented in practice. By implementing SHM, damage can be detected at an early stage and minimized by quickly performing repairs on the design before the damage becomes critical. The study aims to produce a report that can be used as a guide on how SHM can be implemented and show how the SHM systems have been implemented on previous projects. The report should give the reader an overall picture of how condition assessment is performed today, which damages are common and how SHM can be used as a tool when assessing the condition. The report also aims to provide an overall explanation in Swedish of the SHM technology and what is needed for implementation. Open unstructured interviews were conducted with researchers within SHM and damages to concrete structures as well as experts in condition assessment. The interviews were used as a starting point for further studies of commonly occurring damages and SHM techniques. In the literature study, various scientific databases were used, such as Diva and ScienceDirect, as well as KTH's library to obtain earlier material on concrete damage to bridges, its damage mechanisms and about SHM technology. Furthermore, information was obtained from a number of doctoral dissertations, articles and previous degree projects. Through literature study and interviews with experts, the study concluded that reinforcement corrosion and cracks in the concrete are damages that are commonly found in concrete bridges. The damage mechanisms are described in the report. The study identified three different systems that can be used for detection and monitoring of reinforcement corrosion and cracks, those systems are acoustic emission, SOFO system (SOFO is an abbreviation for Surveillance d'Ouvrage pair of Fiber's Optics) and MuST system (MuST is a commercial name). The report gives examples of how the systems can be used for the detection and monitoring of the damages by presenting four case studies where the systems have been used. Two of the case studies present how acoustic emission has been implemented and two of the case studies present how the SOFO-system has been implemented. The study could not identify any case study for the MuST-system and how the system was implemented. The conclusion of the study is that SHM can be used as a supplement to condition assessments but cannot for the time being used for performing automated condition assessments today.

  • Brinck, Mårten
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Stigenius, Karl
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Jet grouting as a method for sealing sheet pile excavations in Swedish conditions: A probabilistic approach2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Jet grouting is a groundimprovement method that creates cemented columns in the soil. The soil isinjected with different pressurized fluids, through the monitor, to replace andcement the soil, often with water cement grout. There are three different commonsystems for ejecting the fluids, the single, double and triple fluid system.The process is performed from the ground surface by drilling to desired depthand then withdrawing the monitor while rotating and ejecting and thus creatinga column. There are many applications for this technique. However, this thesisfocus on using jet grouted columns in formation to seal sheet pile excavationsfrom water.

  • Andersson, Sophia
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Jonsén, Oscar
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Schaktfri ledningsbyggnad: En kostnadsanalys mellan styrd borrning och konventionell schaktning2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Horizontal directional drilling is a trenchless method used to install pipelines underground. This thesis is conducted in collaboration with Styrud Ingenjörsfirma AB, who perceived lacking knowledge within the industry regarding the financial aspects of directional drilling. The purpose of this thesis is to carry out a cost analysis that defines how directional drilling stands financially against traditional excavation. The study also intends to describe which factors that influence a possible economic breakpoint, in this study referring to when a certain method becomes the economically strongest alternative. This thesis has been carried out to as objectively as possible describe the topic focusing on making the methods analytically comparable. To carry out the analysis, an economic model has been created. The model and its design have been created in a manner that makes it easy to develop it in the future and aims to act as a guide for project planners to indicate which method to proceed with. From the economic model, 70 cases have been studied. The result shows that directional drilling is cheaper in 73% of the cases. In the rest of the cases, the result suggests that directional drilling as a method generally is not so expensive that consideration of using the method disappears. Through results and analysis, it is concluded that directional drilling in most cases is a strong alternative to traditional excavation from an economic standpoint.

  • Gante Lokesha Renukaradhya, Karthikesh
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Metal Filament 3D Printing of SS316L: Focusing on the printing process2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    As a cutting edge manufacturing methodology, 3D printing or additive manufacturing (AM) brings much more attention to the fabrication of complex structure, especially in the manufacturing of metal parts.A number of various metal AM techniques have been studied and commercialized. However, most of them are expensive and less available, in comparison with Selective Laser Melting manufactured stainless steel 316L component.The purpose of this Master Thesis is to introduce an innovative AM technique which focuses on material extrusion-based 3D printing process for creating a Stainless Steel 316L part using a metal-polymer composite filament. The Stainless Steel test specimen was printed using an Fused Deposition Modelling based 3D printer loaded with a metal infused filament, followed by industrial standard debinding and sintering process. Investigation was performed on the specimen to understand the material properties and their behaviour during the postprocessing method. In addition effects of debinding, sintering and comparison of the test Specimen before and after debinding stages was also carried out. Metal polymer filaments for 3D printing could be an alternative way of making metal AM parts.

  • Berndtsson, Filippa
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Suleyman Bal, Harun
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Acceleratorers påverkan för sprutbetongens tidiga hållfasthet2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    During maintenance work in trafficked tunnels, the traffic must be halted. Therefore, such efforts often take place night-time. In order to enable a quick release of traffic again, it is crucial to have an effective reinforcement work. Due to the safety risks of using shotcrete as a reinforce method, there is a chance of adding additional strength-requirement can exist due to safety risks. If the concrete achieves the strength requirements sooner than expected, the number of nights dedicated to maintenance work can be reduced. This study intends to investigate how different types of admixtures, so called accelerators, can expedite the shotcrete’s initial strength development. Furthermore, the study will include a conclusion of the suitability for the accelerators that have been applied in the shotcrete. To investigate the effects of these accelerators, extensive tests has taken place. During these tests, shotcretes with different recipes were sprinkled into test boxes. Thereafter, tests of strength development could be performed on these boxes in agreement with prevailing standards. To delimitate the study, the selected methods only show the early strength-development of shotcrete. The results from these tests will be presented in graphs. Uncertainties regarding measurement data and how separated physical parameters affect the test results will be discussed as well. By reading the data presented in the graphs, a positive development can be identified in recipes with added hardening accelerators compared to recipes containing only shotcrete accelerators within the first four hours. Following the first four hours, a significant uncertainty in measurements will be noticed. Finally, due to high irregularity in measured values, conclusions of the accelerators’ effect cannot be confirmed solely by the results from these tests. Therefore, a hypothesis trial is necessary as it would exclude if the recipes statically can be separated. Furthermore, the company recommends performing additional small-scale tests in a laboratory environment. Through laboratory tests, a more certain result can be received.

  • Brännmark, Disa
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Cano Norberg, Desirée
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Miljöpåverkan vid grundläggning i samband med vägbyggnad: En komparativ fallstudie av inblandningspelare, lättklinker, skumglas och cellplast (EPS) ur ett hållbart och ekonomiskt perspektiv2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The climate normally varies over time but never before has the climate change been so rapid and tangible. Rising temperatures, elevated sea levels and endangered ecosystems are consequences of human impact on the environment. The use of resources and emissions contributes to the increased impact on the greenhouse effect. Everyone is affected by the climate change and must take his or her responsibility to create better conditions for future generations by understanding the environmental consequences of his or her actions. Studies reveal that the construction industry accounts for almost one third of the total greenhouse gas emissions but there are still gaps in knowledge about the environ¬mental impact. The knowledge can increase through agreements on climate actions, industry-wide forums and tools such as life-cycle assessments and environmental product declarations. Several available tools with generic data have been developed for life-cycle assessments of buildings, but for the infrastructure sector the tools are still not fully developed. Today, the foundation method is mostly chosen based on the economical aspect, and the environmental aspect is not given priority. The aim of this case study is to investigate which foundation method is best suited from an environ-mentally sustainable and economical perspective in a specific soil profile of clay which is common around Uppsala. To raise awareness of environmental impact, four common foundation methods were compared: deep soil mixing with Multicem and light filling methods; expanded clay lightweight aggregate, foam glass and expanded polystyrene foam. Based on settlement calculations in the soil profile, dimensions could be made for consumption of material for each method. The consumption of material was used to make estimations of costs and calculations of climate effect, in terms of carbon dioxide equivalents, during production of the material and transport to the specific location. In addition, the assessment of the chemical content was examined through two environmental databases, BASTA and SundaHus. The result revealed that foam glass has the lowest total climate effect, where about half of the carbon dioxide emissions come from production and the remainder from transport. This indicates that the geographical location of the foundation is important for the result of the climate impact. Foam glass receives the best ratings in BASTA and SundaHus but has the highest total cost of the compared alternatives in the study. Deep soil mixing with Multicem as binder has the lowest total cost and the second lowest climate impact. Through the interview study, it was found that the choice of foundation method is mainly determined by the cost, which means that Multicem would probably be prefered. Based on chemical content the assessment is incomplete since Multicem has not been declared in SundaHus. In summary, the choice of foundation method depends on a number of factors in which companies must evaluate which factor has the highest priority.

  • Olsson, Helena
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Making wood durable. A sustainable approachwith linseed oil2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Linseed oil has been and is used for vast number of applications, such as in food and paint industry, and wood preservation. It is a good environmental choice, as it originates from renewable sources. Linseed oil is mainly a mixture of triglyceride of fatty acids, both saturated and mono- or polyunsaturated, which allows the oil to oxidize. The oxidation occurs via an auto-oxidation mechanism with the carbon-carbon double bonds and oxygen from the air, reacts to form a polymer.

    Herein, four different linseed oils (three commercial ones and one industrially available) were analyzed to obtain a better understanding of why different oils provide different protection of wooden materials. This was done by a study of the unoxidized oil, followed by an oxidation time-resolved study of oxidized oil films. The analysis was done by nuclear magnetic resonance, gas chromatography - mass spectrometry and/or inductively coupled plasma atomic emission spectroscopy.

    This study provided the fatty acid profile of the oils, which were similar for all oils. The unoxidized oils contained some metals ions which probably originate from additives. Aluminum, cobalt, iron, manganese, and zinc was detected in some of the oils at concentrations up to 135 mg/L, but only manganese was detected in all oils and its concentration was much higher than all other metals together.

    The time-resolved oxidation study had some problems with the solubility of the formed polymers. Several solvents were examined, such as dimethylsulfoxide, alkaline alcohol solutions and toluene, before chloroform-d was chosen as solvent. Though, chloroform-d was not a perfect solvent; it was capable to solve a fraction of the sample, but the fraction decreased with oxidation time. After fifteen days of oxidation, only a few percent of the sample could be dissolved, but for short oxidation times (<48 h) the majority of the samples were dissolved.

    The oils were analyzed after thirteen different oxidation times. Some structural changes appeared, for example loss of unsaturated protons and some oxidation products arose, such as peroxides and aldyhydes. The diffusion coefficient decreased over the first 3-4 days of oxidation, as expected when the polymerization progressed. After a week of oxidation, the diffusion coefficient increased again, this could possibly be explained by the solubility problem for the large polymer formed. Contrary, at shorter oxidation times this method probably could still be used, as the majority of the sample was dissolved. However, the solubility problem made it impossible to conclude anything about the oxidation rate at longer oxidation times and thus prevented any ranking of the oils.

  • Srikanth, Sai Aswin
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Use of Electrical Coolant Pumps in Scania’s Cooling System2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The automotive industry is currently traversing through the electrification wave. Numerous manufacturers are directing focus to electrify their lineup and reduce emissions. In the frontier of heavy duty diesel trucks, electrification of auxiliary units remains an unexplored potential. An optimized cooling system functioning in sync with a controllable electric coolant pump attempts to reduce parasitic losses and emissions. The cooling flow requirements in challenging conditions may also be fulfilled. Although electric coolant pumps are found increasingly in passenger cars, the implication of independently operating them in a heavy duty diesel truck is an important objective to be explored. The purpose of this project is to generate different cooling system layouts coupled with electrical coolant pumps. The performance of these layouts is compared with the volume flows in a standard cooling system. Refined layouts which fulfill the cooling system requirements are chosen for verification. 1-D Simulation is used to correlate and verify the trends of the test rig data. The results show an adequate gain in the total volume flow across distinct layouts with the electric coolant pumps. However, numerous challenges are required to be overcome.

  • Sanchez Santiago, Pablo
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Rim-Jet - A Mechanical Design for a Shaft-less Propulsor2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    During sea rescue operations it is common for the rescue vessels to operate in water with high number of debris that can get stuck in the propulsor. In particular plastic ropes that can get tangled around the shaft and melt causing a complete stop or damage the motor. Currently rim driven shaft-less thrusters have proven to deal with debris in a better way than conventional motors, but they usually operate only at low speeds. The Swedish Sea Rescue Society along with Rolls-Royce and other partners such as Marna decided to start developing a motor combining the idea of the rim driven thrusters driven by a Permanent magnet motor and a water jet to increase the thrust. In this thesis a conceptual design for this motor is presented, in which bearings and seals have been chosen from standard components as well as the bolts and other components, and all the housing has been designed. In order to design the housing and choose the standard components, three main factors were taken into account: not using extra systems, modularity and being as compact as possible. By focusing on those three requirements different bearing and seals solutions were studied and analyzed to check their viability. Furthermore, in order to verify the design and components chosen, mathematical models through MATLAB and simulations with ANSYS were carried out. Finally the drawings of the non standard components were added including the tolerances defined by the standard components.

  • Warsame, Idil
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    Practices for co-productive planning modes: Urban development in Cape Town: A case study based on the implementation of a design and building development incubator2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Together with a steadily increasing urban population, South Africa and the city of Cape Town is facing continuously expanding informal settlements and communities with no access to basic human services or adequate housing. There’s an urgent need to design, plan and implement alternative and creative approaches to help stimulate an equal, inclusive and sustainable urban development and strategic spatial planning. Integrating methods and processes that includes participation, communication and collaboration by incorporating civil society and local community members in urban planning practices is one way of promoting sustainable and equal spatial growth. Co-production is a concept used in urban development theory that embraces this in and can be described as a communicative form of spatial planning where state, planners and citizens mutually interact in the planning process. In consideration of these challenges, this thesis aims to apprehend how marginalized, local communities in Cape Town can be included in matters regarding urban development and spatial planning practically and if co-production can be used to define and explain this form of approach. Therefore, this thesis is based on a case study research of the Better Living Challenge (BLC) incubator, a two-week long project in Cape Town, which supported 15 informal builders in improving and developing their designing, building and marketing skills. The practical implementation of this incubator and its process has been examined to determine if the theory of co-production can be used to outline the project and understand the results emerging from it. The incubator proved to be successful in several ways and was met with impressive feedback from the stakeholders. It was also followed with difficulties and restrictions like power dynamics and tension. The conclusions that were made highlights that the incubator can be defined as an alternative and unorthodox co-productive approach based on the aim and lay-out of the process.

  • Shkurenko, Liubov
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    Community water management and local governance: the case of Oaxen island2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Water has a critical role in sustaining both natural ecosystems and human livelihoods. However, nowadays intensive population growth and increasing pressure on natural resources lead to substantial issues related to water services provision. At the same time, mismanagement of water resources hinders water security and leads to escalation of water-related challenges. Thus, the research of principles for good water governance has got a substantial attention and aimed at establishing new policies and institutional frameworks for addressing those challenges. Pluralistic forms of governance, with the focus on community water governance has been advocated as a way to more sensibly tackle the complexity of issues linked to water systems. The present research aims to investigate the specifics of community water governance and analyze how community governance practices can contribute to a more sustainable management of water systems on the case of Oaxen island in Stockholm archipelago.

  • Särenfors, Matilda
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Jakobsson, Mattias
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Uppföljning av arbetssätt för precisare prognoser inom anläggningssektorn2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Economy and forecasting are a big challenge for the corporations and an important piece if the puzzle when it comes to profitability in the construction industry. Digitalization of the workplace within the construction industries has made it easier to communicate between the entrepreneur and project management. A big part of the digitalization and the pressure from other companies makes it very important to be able to make realistic forecasts. Also be able to extract the experience from the forecasts and applying it in the future endeavors of the company. Since a well thought out forecast from every project create a basis in which the future decisions will be grounded in, identifying the risks and possibilities of each project and in how they were resolved to minimize losses will be of much importance. This reports background is the need to investigate a uniform approach to forecast management. This thesis was made in collaboration with Svevia and the bulk of the information was derived from their company. The study is based on interviews conducted with employees and a survey. The respondents held different positions within the company where both members of the management were interviewed and from the production. Shortcomings in current method were made visible and investigated. Likewise issues concerning education, software and resources were discussed. The result of the survey was compiled with diagrams where the employees of the company responded to the different questions. Together with the result of the interviews and the survey the analysis and conclusion was formed. The comprehensive flaws can be attributed to the lack of a uniform practice, where the follow up and approaches are the same for all employees.

  • Calderon Salmeron, Gabriel Benjamin
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Enabling More Efficient E-Mobility: Grease Development by a Novel Bearing-Grease Test Machine2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The inclusion of electric vehicles in the automotive industry represents an opportunity for lubricating grease producers. Different speed, loads, and electric conditions are present in the bearings of the electric vehicles when compared with the conditions in a traditional internal combustion engine vehicle. Therefore, the development of new grease formulations is desired to overcome these, and other challenges introduced by this new technology. This project aims to compare two grease-thickener technologies through the installation, development, and validation of a novel high-speed bearing-grease test HSBT machine. This rig allows emulating the conditions present in the bearings of an electric vehicle. In this thesis, 6208 deep groove ball bearings were used to compare the mechanical performance of the greases. The comparative study of lithium complex and polypropylene greases was performed through the analysis of the frictional moment and self-induced temperature of the tested grease-bearing combinations. The results present the energy-saving potential of both greases and show the feasibility of using the HSBT machine as a grease testing machine. This project is the first step in an ambitious plan of enhancing e-mobility through grease research. It gives the input for future development of the machine and the creation of new standards for testing electric vehicle greases.

  • Schmied, August
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Strömberg, Moa
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Armering i pålfundament: Effektivare byggprojektering med grafisk programmering2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Most of the time spent on project planning is dedicated to the development of construction documents, mainly 2D-drawings. A more modern method is to gather all information about a building project in a coordinated 3D-model, so called BIM-model. Building information modelling (BIM) is a well-known design method based on a digital 3D model having enough information to enable procurement work and actual production. The model consists of parameters that represent different properties and when a parameter is changed, the model is updated automatically. These parameters can be accessed and modified through external programs, so called plug-ins that extend the original software’s functionality using program code. Visual programming is a modern programming method which utilizes a visual interface that favours users with little or no experience. Using visual programming, parameter control can be made more efficient and save valuable time. For this reason, Dynamo (a plugin developed by the company Autodesk for Revit), has been studied to create a so-called script that automates 3D modelling processes in Revit linked to placement of reinforcement in pile caps. In addition, possibilities for standardization have been investigated, as well as the advantages and disadvantages of the method. With this project, the potential of Dynamo and the scripts created through an empirical study is described, where a relatively simple case study is carried out in order to illustrate the amount of time saved through visual programming compared to corresponding work manually done in Revit. Furthermore, calculation templates were created, according to the strut and tie model and Eurocode 2, to provide the script in Dynamo with the correct inputs. The result shows that Dynamo and visual programming can make placement of reinforcement in pile caps more efficient. While the degree of efficiency is case dependent, the case study showed an overall 85-90% time saving. A general conclusion suggests that the more complicated rebar designs, the more time there is to be saved. Since visual programming is based on the automation of repetitive processes, there is great potential to standardize structural design with the help of Dynamo scripts. Companies can thus create routines that increase continuity and quality in their projects. The automation also leads to fewer human errors and a more efficient execution. The client is advised to further develop this method by implementing explicit routines regarding 3D modelling with visual programming and investigate the possibilities of automation of reinforcement design in other load-bearing structures.

  • Gustafson, Anna
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Krogh, Jenny
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Underlag för projektering av sockelkonstruktioner: En kvalitativ analys av sockelkonstruktionen utifrån kriterierna funktion, byggbarhet, beständighet och utformning2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The base of the construction where the outer wall is connected to the ground plate is the connection dealt with in this report. We refer to it as the base. The base leads the loads from the building down to the ground and is supposed to protect the building from outer impact. This part of the building shell is well exposed with the Swedish climate and in constant contact with wet ground. Forming a base is difficult in many ways and demands knowledge in many different areas. It takes a great amount of time and it is hard to be sure that you fulfill the specific demand of each construction in each project. The aim of this report is to make the process of forming a base easier and better for the sponsoring company Kåver & Mellin. The report is supposed to lead to a written report that could be used as a guide when forming bases. The report is based on the four criterias: function, constructability, constancy and shaping. The result came from studying literature, interviewing experts in the branch of building construction combined with sorting drawings of bases from former projects at Kåver & Mellin. The result has been analyzed and lead to several wide and narrow conclusions about bases. The result showed that there are many ways of forming a base to reach the demand of each project. Aspects to think about when forming a base is the demands of each project and the materials and connections in the base. The result also showed that there are no clear directions of how to form a base in a building. Different laws and rules can be read in different ways depending on who is reading which shows that the guidelines could be clearer. This report is a guide of how to think when forming a base in a building.

  • Public defence: 2019-10-24 10:00 sal F3, Stockholm
    Josefsson, Leila
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Bioanalysis using capillary electrophoresis and mass spectrometry: Applied on proteins, protein nanofibrils and polyvinyl alcohol microbubbles2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The sequencing of the genome of various species, including the human species, have led to increased understanding about how a protein structure is generated, and how specific structures are related to the proteins’ functionality. In paper I and II of this thesis, the folding of proteins in vitro to form hierarchical nanostructures, which in vivo often have a pathological effect, have been studied. Protein isolates from soybean and potato, that are byproducts from oil and starch production, respectively, were used as a starting material for protein nanofibril (PNF) formation, and mass spectrometry was used to identify the building blocks that are included in the formed PNF. The five peptides identified in soybean PNF and the six peptides identified in potato PNF originated from the major seed storage proteins for the respective crop.

    The use of ionic liquids has increased for improvement of the performance of different separation techniques due to their adjustable properties, and good solvating ability. In paper III, an ionic liquid and water mixture was used as background electrolyte in capillary electrophoresis for protein separation. The system showed high reproducibility at basic conditions, and could potentially be used for routine control analysis.

    Many diseases and injuries require clinical diagnosis techniques e.g. ultrasound imaging, to be detected, and for the physician to be able to decide the correct therapy. To increase the resolution of such imaging techniques, contrast agents can be used. In paper IV-VI, a newly developed contrast agent consisting of air-filled microbubbles stabilized with a shell of polyvinyl alcohol (PVA-MBs) was studied. Development of a capillary electrophoretic method for analysis of the PVA-MBs with the intentions to be used for clinical diagnosis is performed, where different detectors such as a UV detector, a UV area imaging detector and an in-house constructed microscope are used to increase the sensitivity of detection for the PVA-MBs. The developed method could be used for quantification of the contrast agent, since individual PVA-MBs were visible using the imaging detectors. Findings regarding the mobility of the PVA-MBs in human blood plasma and in water implies that a protein corona was formed around the MBs.

  • Lazaris, Angelos
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Seismic evaluation and retrofitting of an existing building in Athens using pushover analysis2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Earthquakes are one of the biggest problems in civil engineering all over the world. Due to earthquakes, great disasters in cities with collapsed structures and human losses have been caused. More specific, old buildings that have been built based on old regulations and design building codes do not fulfil anymore the new criteria of seismic designing.In this study, an old building has been evaluated for the seismic load in order to decide if there is a need for strengthening it using retrofitting methods. The seismic evaluation is based on Eurocode 8 and after the application of retrofitting techniques the building fulfilled its seismic design criteria. The existing building is a four-storey, concrete structure that has been built in 1970 and is located in Athens (the capital city of Greece). The seismic evaluation is conducted by using the software Seismostruct.Two analyses are performed in order to evaluate the seismic behavior of the building. First, an eigenvalue analysis is conducted before and after retrofitting. By using this analysis the torsional sensitivity of the building has been checked. Then, using pushover analysis, the comparison of the target displacement (expected displacement of the building for the design seismic action) for each limit state and the displacement of the building when the first member of the building reached the corresponding limit state, is presented. Target displacement must not be greater than this displacement in order to ensure the safety of the building. If the comparison shows that target displacement is greater, the weak links in the facility should be identified and the proper retrofitting method should be applied for the improvement of the seismic behavior of the building. Pushover analysis is conducted before and after the application of retrofitting methods.After performing the eigenvalue and pushover analysis of the existing building it was found that the building was torsional sensitive and shear failures occurred in many beams of the structure. Regarding the bending failures, the target displacement was not greater than the displacement of the building when the first member of the building reached any of the corresponding limit states. Therefore the building was safe against bending failures. With the application of X-shaped steel braces in selected frames, the building had higher stiffness and it was not torsional sensitive but shear failures occurred again in many beams. Furthermore, compressive failures occurred in columns that were connected with the steel braces. Finally, with the application of fibre reinforced plastic jacketing in the members that failed in the previous pushover analysis there were no shear or compressive failures. Finally the structure was safe against seismic actions.The application of retrofitting methods improved the seismic behavior of the building and the structure fulfilled the updated regulations of Eurocode 8 regarding seismic design. This project thesis may give rise to further studies and researches concerning seismic retrofitting and seismic damage prevention.

     

  • Guðjónsdóttir, Auður
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Harðarson, Benedikt Árni
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Investigation of leakage contribution from different air seal components2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Mountain biking is a sport where riders bike on trails, varying in slope and difficulty. Mountain bikes are generally equipped with suspension on the front wheel and often also on the rear. Some types of rear shocks use pressurized air for a spring action instead of the traditional metal coil. Air is sealed inside the shock’s air can by means of X-ring seals, providing a spring force on the wheel. It is of great importance that the sealing system performs as intended so the air spring does not quickly lose pressure during use. An experimental plan is conducted in an attempt to estimate the effects of seal dimension, lubrication and surface roughness on air leakage for more robust shocks. Accelerated tests were performed in a dynamometer, believed to repeatedly cause significant wear on the shock’s air seal within 24 hours. Nineteen tests were carried out, for a duration up to 72 hours, with variations to test parameters such as stroke length and frequency. The expected failure modes did not occur in any of them. Eleven tests showed no signs of failure while the other eight failed due to unexpected components breaking or wearing out. The shock’s main seal was found to wear out faster than the air seal, causing leakage within the air spring, between its positive and negative air chambers. This unforeseen failure needs further examination with tests conducted on more shock types.

  • Gustafson, Anders
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Performance monitoring of systems for airpuricationAuthor:Anders2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Wastewater treatment plants (WWTP) are often the cause of malodor. The compounds which are the main causes of the odor is hydrogen sulfide (H2S), ammonia(NH3), mercaptans (RSH) and volatile organic compounds (V OC) [1]. The odorous air can be analyzed to determine the concentration of the odorants. The odorous can also be analyzed by measuring the odor. The odor is measured, a test panel of people smells the odorous air and determines how many times greater the concentration of the odorants is compared to the odor threshold which is the concentration at which a compound or a mixture is detectable by smell [3].

    Measurements were done at three systems for air purication at three different locations, the Vimmerby WWTP, the Alvim WWTP and Renova's biological waste treatment facility in Gothenburg. The odor was measured at the inlet and the outlet and the concentration of H2S and ozone (O3) were measured at all the sampling points of the systems. The system at Vimmerby consisted of three CIFs followed by an UV-reactor and an AC-reactor. In Alvim there were two system which used UV and AC. The system at Renova consisted of a barrier filter followed by UV and AC.

    The system at the Vimmerby WWTP had a conversion rate between 87-97% of H2.S The CIFs had conversions between 50-64% of the H2S. H2S was not detected at any of the other systems. O3 was only detected at Renova where ground level O3 was present at the inlet, 0.16 ppm. The concentration increased to 0.20 ppm after the UV-reactor. The activated carbon could adsorb all the incoming O3.

    The odor at the Vimmerby WWTP was determined to 27500 Ou/m3 at the inlet and 19071 Ou/m3 at the outlet. The odor conversion over the system was 31%. The odor conversion at the Alvim WWTP was 99.8%. With an odor of 5490 Ou/m3 atthe inlet and 11 Ou/m3 at the outlet. The ingoing air at the system at Renova had an odor of 434 Ou/m3 and was reduced to 36 Ou/m3 at outlet. The odor conversion at Renova was 92%.

    To increase the accuracy of the measurements the time between the sampling and measurements should have been minimized. The test panels should also have been larger and the panelists should have been screened in advance, so results from panelists which were over and under sensitive to odors were not included in the final results.

  • Osterman, Fredrik
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    The Impact of Fracture Orientation on the Choice of Grout Fan Geometry - a Statistical Analysis2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Water ingress into rock tunnels is a problematic phenomenon – especially in urban areas – as a lowered groundwater table may cause harmful settlements. Furthermore, too much ingress can be an incentive for the environmental court to halt the tunnel process, in order to protect the nature as part of a national interest.Water ingress is normally lowered by injecting a water and cement mixture into boreholes in the rock mass – a process called rock grouting – thus sealing the rock fractures. Very little information and research has been on the subject of how the rock fracture orientation interact with the orientation and geometry of the grouting holes. The purpose of this thesis is to investigate whether or not it is possible and feasible to select a grout fan geometry that will have the most intersections with the rock fractures, based on fracture information gained in an early pre-investigation stage. The suitability of different grout fan geometries will be determined by analyzing the amount of fracture intersections that each geometry has in a discrete fracture network, generated based on data obtained from rock cores in the Stockholm Bypass project. The assumption is that more fracture intersections means a higher chance of sealing the rock mass. The results show that there is no clear difference in number of intersections between the analyzed grout fan geometries, indicating that focus should not be on analyzing the grout fans as whole units, but rather on the scale of individual grouting holes and fractures. This thesis also highlights the importance of monitoring according to the observational method.

     

  • Public defence: 2019-10-11 09:30 T2, Huddinge
    Shreenath, Vinutha Magal
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Creating Knowledge with Data Science for Design in Systems2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Designing in large-scale engineering systems is a difficult cognitive task undertakenby experts. Knowledge of experts continually changes as they are confrontedwith similar by different problems in designing in such systems. However, it is alsoimportant that designers are presented information that is representative of the system,and that they are cognizant of activities on a system scale so they can create diversechoices for designs in early phase of design process.Data Science has been proven to be effective at informing people for decisions atimmediate horizons. But the use of data science to drive long terms designs whereexperts have to make the right series of decisions i.e. designs is yet unknown. The useof data science is to inform decision makers of activities at system scale.In this thesis, I have looked at how data science can be used to create knowledge indesigners for designing in large scale systems. I have also investigated further questionsregarding imitation of expertise using AI, and in generating similar knowledge bycreating diverse options in design.The results point out that data science can indeed inform designers, change theirdesigns and hence create knowledge. They also point out that design cognition inexperts can be partly imitated in data science itself, through careful modeling of theill-defined problem in design. This therefore points to a promising future directionwhere data can be used as an interface between human thinking and machine learning,by translation of conceptual forms such as differential diagnoses and cognitive artefactsusing data.

  • Arsana, Komang Gede Yudi
    KTH, School of Engineering Sciences (SCI), Applied Physics.
    Improving the resolution of the Stockholm laboratory x-ray microscope by analyzing and reducing vibrations2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • Rydefalk, Cecilia
    KTH, School of Engineering Sciences (SCI), Mechanics.
    Optical Coherence Tomography measurements of biofibril dispersions in flow-focusing2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Microfluidic spinning techniques have been used as a successful assembly process for biofibrils dispersed in a fluid. The dispersion flows through a microchannel and is focused by a sheath flow. In this way the topology and velocity of the dispersion in the core can be manipulated. By using Optical Coherence Tomography this topological development and velocities in the channel can be investigated and visualized. This is done for two different biofibrils: cellulose nano-fibrils and protein nano-fibrils. In both cases the geometry of the channel has been varied to investigate how this affects the flow of the dispersion. In the case of cellulose nano-fibrils the inlet angle of the side channels in the focus-section is varied. There is a thread forming for all angles tested, but with variations in shape. The velocity measurements also show differences in acceleration and deceleration behavior; indicating differences in inner morphology. For the protein nano-fibrils the distance between the side-channel inlets, in a device with two focus-sections, is shown to affect the wetting behavior of the dispersion.

  • Ramakrishnan, Siddharth
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Proving Ground Durability Simulations2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Virtual durability simulations have been explored in the automotive industry to complement physical testing in designing durable vehicles. Simulations are useful to check the validity of the design before even building the prototype of the vehicle. They are also useful in checking the effect of changes in vehicle design to the durability of the vehicle. Buses are designed and tested for durability before they are sold to customers. Bus manufacturers use special test tracks consisting of different kinds of maneuvers/obstacles to test the buses for durability. Proving ground durability test schedules defines the combination of different test track maneuvers/obstacles at which the bus is to be run. The test schedules are created to achieve accelerated fatigue damage in the bus comparable with the fatigue damage occurring in typical customer usage. This thesis is an attempt to check if a proving ground durability test schedule can be simulated in a computer. A Multibody dynamic model of the bus with its constituent subsystems is modeled in a multibody simulation software MSC ADAMS. Sub-systems like bus chassis frame and axle are modeled as flexible as their dynamic properties are assumed to influence the simulation results. The virtual bus is run on the virtual version of the test tracks. Loads at suspension torque rods, anti-roll bars, axles and displacement of dampers are extracted from the simulation. The load signals are post-processed to derive fatigue damage. The simulation model is compared with the test results of a single standard test track maneuver. The simulation model is tuned by adjusting the parameters to match with the test results of the given maneuver. Finally, the tuned model is used to run the bus in a test schedule.

    Results achieved at the end of the thesis shows that well-tuned simulation model is necessary for simulating test schedules with enough accuracy. Comparison with test results are to be treated with caution as the conditions of the test bus should be exactly same as the simulation model; which is difficult to achieve. Future extension of the work involves improving the accuracy of simulations and using simulations to iterate new kinds of maneuvers/obstacles to improve existing test schedules.

  • Polanco Olsen, Maria Nicte
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Characterization of the Electrical Resistivity and Water Sorption Properties of a Semiconducting Swelling Tape2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In presence of moisture and localized field enhancements water trees might develop within the polymeric insulation of HV subsea power cables. Water trees tend to grow unnoticeable and deteriorate the insulation properties with time. The humidity within the insulation can efficiently be reduced through the application of semiconducting swelling tapes. Semi conducting swelling tapes provide a unique combination of electrical conductivity and a large water retention capacity. This is attributed to the presence of conductive carbon black (CB) and superabsorbent polymer (SAP) particles, respectively.

    To understand the mass transport properties of water vapor within a swelling tape, transport coefficients were determined. The sorption of water vapor revealed concentration dependent transport coefficients and a general increase in diffusion and solubility with increasing water activity. This was attributed to the hygroscopic and polyelectrolyte properties of the SAP components and resulted in an increase in diffusivity by a factor of 100, when increasing the relative humidity (RH) from 7 to 65 %. At higher water activity, it was assumed that the formation of immobile water clusters reduced the diffusion of water vapor. Several sorption modes were suggested for the sorption behaviour of the tape between 10 to 80 % RH.

    The introduction of conductivity within the tape reduces potential differences throughout several cable layers and subsequent field enhancements. However, conductivity and water sorption properties of the semi-conductive swelling tape can be altered by mechanical compressions, exerted by surrounding cable components. The electrical resistivity of a humid swelling tape under load was therefore determined. Due to the anisotropy of the tape, electrical resistivity measurements were performed across (radial direction) and along with (axial direction) the tape. The radial and axial directions of the tape were dominated by the presence of SAPs and CBs, respectively. A significant reduction in radial resistivity of the tape was observed when increasing the humidity from 40 % to 60 % RH. The resistivity decreased by a factor of 100. No significant effect of compression was observed, but the tape showed a decreasing trend in resistivity with increasing compression. At 60 % RH radial resistivity approached axial resistivity, and the influence of SAPs is reduced. The axial resistivity was around 18 Ωcm. The axial resistivity of the tape was less affected by humidity and compression than the radial resistivity.

    Ageing reveal deterioration of swelling height, but had no influence on tape resistivity.

  • Paro, Michaela
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Tikhonova, Irina
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Den förändrade förmedlingsprocessen: Sålt innan visning2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Our study is obtained to see how the phenomenon sold before viewing in the housing market

    has changed in recent years. In this study we show how the new housing market affects

    brokers, sellers and buyers and what are the real factors behind it all.

    In order to get as fresh data as possible we have chosen to use a qualitative method. Our

    study is based on a group interview, moreover, to cover other perspectives regarding this

    phenomenon by posting an interview questionnaire to franchisees and registered real estate

    brokers from various offices downtown.

    As the market has fluctuated slightly over the past year and similar phenomena have been

    studied in previous years, 2016 and 2017, it was interesting to see how much has changed

    from these years and if we could come up with a more recent study for the changed housing

    market process.

    Our study has resulted in the process sold before viewing and pre-bids has decreased in the

    past year compared with previous years. When the market has changed, we also see the prebids

    from a different point of view, today it is more positive reactions if you get at pre-bid

    before the ordinary viewing than 1-2 years ago. In the ordinary process with viewing, you have the opportunity to meet several speculators

    and strengthen your personal brand while in the changing the process, you lose this chance as

    the process is shortened and the ordinary viewing is removed. In the latter process, however,

    we can see that customers who want to make business quickly appreciate the opportunity to

    buy before viewing but the consequence will be that other speculators miss the chance to buy

    and are more likely to be disappointed. This is something that the broker needs to try to deal

    with afterwards in a smooth manner.

  • Forsberg, Isabelle
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Edlund Asfour, Fanny
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Bindande bud vid bostadsköp: En studie om hur den svenska bostadsmarknaden skulle påverkas av att införa bindande bud2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The housing market in Sweden has been a central debate topic in media during the past few years. The increase of prices in the big cities has caused hectic auctions that leaves the bidders to question whether the process really passed as it should. The bidding process has today no regulation by law and it is therefore up to the seller to decide how he wants it to proceed. This brings consequences in form of unhappy customers that does not know what to expect of this process.One solution, that has been discussed in media already, is to make the bidding process more safe by making the bids legally binding. This thesis is written in order to find out how this kind of regulation would change the swedish housing market. To do so we will investigate the system in Norway to see how they handle the binding bids.The investigation is based on interviews with industry professionals that has knowledge of the subject. The interviews showed that there is split opinions about whether binding bids in the housing market would be a good regulation since both advantages and disadvantages were discussed. The regulation of the law is comprehensive and it would take many years to process before it would be applied. Thus the result of the investigation is that both the real estate industry as well as the customers will need time to adapt to the new law, since it is a major change. On the other hand, binding bids would contribute to a safer bidding process in the sense that the risk of false bids probably would be eliminated. That in combination with a slower and more serious bidding process makes the regulation reasonable in the long run.

  • Bergvall, Olof
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Hämquist, Linnéa
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Gröna obligationer: Trender inom fastighetfinansiering2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The Capital Market for Real Estate is ever changing. Companies continuously try to find new ways to obtain financing and for the past years the trend has been for companies to go to the capital market and finance their projects with bonds. Furthermore, the climate-question has been intensified lately and companies are taking more responsibility when it comes to working towards a sustainable future. In view of this, this research paper aims to examine financing trends on the Swedish Real Estate Market with special focus on green bonds.The benefits that real estate companies can enjoy from being more environmentally sustainable are many, but the main benefits are that more sustainable buildings often result in lower operating and maintenance costs which in turn has a positive effect on the net operating income. Furthermore, companies that issue green bonds can enjoy a lower interest rate compared to those issuing regular bonds. Issuing a green bond also allows the company to communicate their sustainability work in a more natural way which in turn gives the company some good-will. Though some companies worry that there are other firms out there trying to capitalise on this green trend thus taking advantage of the work of others and attracting investors for the wrong reasons.The research has been conducted by interviewing representatives from five large Swedish real estate companies in addition to Svensk Fastighetsfinansiering, a bond issuer co-owned by five real estate companies, one which we have interviewed. Moreover, we have collected historical data of 26 Swedish real estate companies aggregated capital structure since 2012.

  • Public defence: 2019-10-21 09:30 F3, Stockholm
    Teng, Penghua
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    CFD MODELLING AND EXPERIMENTS ON AERATOR FLOW IN CHUTE SPILLWAYS2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    A chute spillway is a typical component of large dams for discharging floods. Because of the high water head, the flow velocity in the chute is often in excess of 20 m/s. Consequently, the structure is usually prone to cavitation damages. Flow aeration is evidenced to efficiently eliminate or to mitigate the damages. An aerator is a device that entrains air into the water flows and is an effective technical measure to counter the cavitation damages.

    Aerator flow includes intense air-water exchange and involves a process of air entrainment, transport, and detrainment. Because of the complex phenomena, it is still a challenge to investigate the behaviors of interaction between air and water. It is fundamental to understand the flow behaviors downstream of the aerator. This thesis investigates the aerator flow features using both the Computational Fluid Dynamics (CFD) and advanced measurement techniques.

    The CFD method presents three two-phase flow models to describe the aerator flows, namely, the Volume of Fluid Model, the Mixture Model, and the Two-Fluid Model. They are applied and evaluated via practical engineering projects and experimental data. The Volume of Fluid model leads to reasonable results regarding the water flow discharge and flow fields. For predicting the air concentration distribution and air bubble transport processes, the Two-Fluid Model is superior to others because it includes forces acting on the air bubbles. However, the model still overestimates the air content near the chute bottom. Based on the aerator flow from a chute spillway in Sweden, three two-phase flow models are applied and compared.

    Physical model tests are commonly conducted to investigate aerator flow features. Because of the scale effects, the results may lead to a discrepancy in the flow behaviors compared with the prototype. Thus, CFD modeling becomes an alternative tool when seeking the reason for the difference. Based on the aerator flow in a real spillway, CFD is applied to reproduce the flow; the discrepancy between the model tests and prototype observations is evidenced. The results show similar flow features with the prototype but differ from those of the model tests. An explanation for the discrepancy is discussed in terms of flow features, effect of surface tension in model tests, and the prerequisite for air entrainment of the free-surface flow.

    Laboratory experiments are conducted to study the aerator flow in a chute. Four image-based measurement techniques-i.e., high-speed particle image velocimetry (HSPIV), shadowgraphic image method (SIM), bubble tracking method (BTM), and bubble image velocimetry (BIV)-are employed. The study focuses on issues of exploring characteristic positions of water-air interfaces, interpreting the evaluation process of air bubbles shed from the tip of the air cavity, identifying the probabilistic means for characteristic positions near the fluctuating free surface, and obtaining the flow field both water flow and air bubbles features of the aerator flow. The application of these techniques leads to a better understanding of two-phase flow characteristics of the chute aerator.

  • Björling, Linnéa
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Diaz Gardell, Alicia
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Reparation av inbyggda stålbalkar: Ekonomiska och tidseffektiva förstärkningsmetoder med låg klimatpåverkan2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    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.

  • Mohammed, Mostafa
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Hagi Omar, Hassan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Effektivisering av FEM-Design för brodimensionering: Trafiklaster på broar2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    FEM-Design is generally used for structural design of buildings. This work aims to make the program more adaptable to bridge design. It is possible in this way that loads of military vehicles are modeled in FEM-Design. In this work Wheeled vehicles, tire vehicles, convoys have been modeled. A previous degree project on modeling of special vehicles and load modeling was checked in this work. It was made to ensure that they were modeled correctly. The loads were analyzed by inserting the modeled loads on a plate or a beam where the moment diagram would give the same result as if it had been made by hand. The military vehicle loads were calculated according to the Swedish transportation administration requirements and the result was defined in FEM-Design so that the result can be used for load modelling. The work together with Strusoft AB resulted in 128 new loads being modeled in FEM-Design. In addition, 30 already modeled special vehicle loads of load models 1-3 were checked. The result shows a large number of new vehicle loads that are defined in FEM-Design according to the Swedish Transport Administration's standards. If the program also manages to apply more functions that are more adapted to define loads, through further studies, FEM design in the future can be more competitive with the other bridge design programs.

  • Lindman, Daniel
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Berlin Lindberg, Jonas
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Utmattning vid svetsad anslutning mellan tväravstyvning och fläns i samverkansbro2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    For composite bridges, transverse bracings are attached between main girders with the function of distributing loads between the main girders. These can be attached via so-called web stiffeners against the main girders web and flanges. This attachment can be done via welded joints. In the event of emergence, fatigue cracks have arisen in the welding connection between the web stiffener and the top flange of the main girder. Clear guidelines do not exist at present for the type of welded joints that should be used in the construction of the termed design connection. Here, a comparative study is carried out between fillet welded joints and butt welded joints, with flat and inclined welds. When the risk of crack initiation as a result of fatigue in the fillet weld was studied, the risk of breakage in both toe and root was considered. The current study intended to provide answers as to whether a correlation between geometric parameters such as distance between main girders and cantilever length of the deck slab could be linked to recommendation regarding which welding design should be used at different dimensions of these two properties. Furthermore, the study intended to determine whether any limit values for the selection of welding connections could be determined. For the production of data, BRIGADE PLUS, a calculation program that utilizes FEM modeling, was used. Here, a constructed project, Viadukt Söder, situated in Östersund, was used as the basic model for the parameter study in BRIGADE PLUS. This was designed by ELU Konsult, on behalf of the Swedish Transport Administration. The calculation model consisted of a limited part of the current bridge, where Fatigue Load Vehicle 3 in SS EN 1993-2 was used to reflect traffic loads on the bridge via influenza lines and thereby find the worst load positions. These positions were subsequently used for calculating the influence of Fatigue Load Vehicle 3 on the studied part in the form of stress amplitude. Analysis of these stress amplitudes was subsequently recalculated to a number of load cycles to offenses that were then set against the guidelines found in SS EN 1993-1-9: 2005. Here, the fatigue resistance values were used which according to national standards are regarded as valid. The result showed an exponential decrease in the number of load cycles to fracture, with respect to fatigue, as the bridge geometry was increased. The characteristic feature here was that the risk of breakage in the web stiffener clearly exceeded the risk of breakage in the upper flange, which in turn could almost be disregarded. The geometric parameter that became guiding was cantilever length on the deck. Clear difference in service life measured in number of cycles could be read out for the different welded joints, where the controlling factor became the respective fatigue resistance values when analyzing crack initiation. Limit values for when the number of cycles to break below the limit values according to SS EN 1993-1-9:2005 linked to the geometric parameters, could be determined for each welded joint. The capacity of the fillet weld with respect to fatigue is far below the capacity of the butt weld.

  • Public defence: 2019-10-10 10:00 F11
    Berglund, Daniel
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Mathematical Statistics.
    Models for Additive and Sufficient Cause Interaction2019Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The aim of this thesis is to develop and explore models in, and related to, the sufficient cause framework, and additive interaction. Additive interaction is closely connected with public health interventions and can be used to make inferences about the sufficient causes in order to find the mechanisms behind an outcome, for instance a disease.

    In paper A we extend the additive interaction, and interventions, to include continuous exposures. We show that there does not exist a model that does not lead to inconsistent conclusions about the interaction.

    The sufficient cause framework can also be expressed using Boolean functions, which is expanded upon in paper B. In this paper we define a new model based on the multifactor potential outcome model (MFPO) and independence of causal influence models (ICI).

    In paper C we discuss the modeling and estimation of additive interaction in relation to if the exposures are harmful or protective conditioned on some other exposure. If there is uncertainty about the effects direction there can be errors in the testing of the interaction effect.

  • Svedenkrans, Christian
    KTH, School of Industrial Engineering and Management (ITM), Learning.
    En analys av elevernas attityder och strategier vid problemlösning i matematik2019Independent thesis Advanced level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this study is to better understand the attitudes and strategies that emergewhen students solve mathematical problems and to test whether it is possible todemonstrate any connection between students' attitudes to mathematical problem solvingand their problem solving ability.The survey was conducted with the help of a qualitative study of four students at the end ofyear 8. The data collection consisted of two parts, one observation part and one interviewpart. The empiri was analyzed by thematic analysis and a theoretical framework. Theframework consists of three attitude components which in total have seven subcategories,these are followed by the problem-solving strategy and the method and procedurecategories. The attitude components are: Cognitive beliefs, Affective states and Perceivedcontrol. The subcategories are: Perceived relevance, Perceived difficulty, Gender beliefs,Pleasure and delight, Worry, dissatisfaction and unease, Self-efficacy and Contextdependency. The analysis result consists of four attitude profiles, one of each participant.

    The study contributes with a better understanding of attitudes and strategies inmathematical problem solving. The result indicates that a more positive attitude can mean amore developed problem-solving ability. Further outcome of the study is that students’metacognition (thinking about your own thinking) benefit their problem solving ability.Implications and further research are discussed.

  • Public defence: 2019-10-17 10:00 FB42, Stockholm
    Pernow, Marcus
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Phenomenology of SO(10) Grand Unified Theories2019Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Although the Standard Model (SM) of particle physics describes observations well, there are several shortcomings of it. The most crucial of these are that the SM cannot explain the origin of neutrino masses and the existence of dark matter. Furthermore, there are several aspects of it that are seemingly ad hoc, such as the choice of gauge group and the cancellation of gauge anomalies.

    These shortcomings point to a theory beyond the SM. Although there are many proposed models for physics beyond the SM, in this thesis, we focus on grand unified theories based on the SO(10) gauge group. It predicts that the three gauge groups in the SM unify at a higher energy into one, which contains the SM as a subgroup. We focus on the Yukawa sector of these models and investigate the extent to which the observables such as fermion masses and mixing parameters can be accommodated into different models based on the SO(10) gauge group. Neutrino masses and leptonic mixing parameters are particularly interesting, since SO(10) models naturally embed the seesaw mechanism.

    The difference in energy scale between the electroweak scale and the scale of unification spans around 14 orders of magnitude. Therefore, one must relate the parameters of the SO(10) model to those of the SM through renormalization group equations. We investigate this for several different models by performing fits of SO(10) models to fermion masses and mixing parameters, taking into account thresholds at which heavy right-handed neutrinos are integrated out of the theory. Although the results are in general dependent on the particular model under consideration, there are some general results that appear to hold true. The observ- ables of the Yukawa sector can in general be accommodated into SO(10) models only if the neutrino masses are normally ordered and that inverted ordering is strongly disfavored. We find that the observable that provides the most tension in the fits is the leptonic mixing angle θ2l3, whose value is consistently favored to be lower in the fits than the actual value. Furthermore, we find that numerical fits to the data favor type-I seesaw over type-II seesaw for the generation of neutrino masses.

  • Waller, Victor
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Wilsby, Astrid
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Abaca in the Philippines, an overview of a potential important resource for the country: Relating the tensile strength of the single fiber to the microfibrilar angle2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Due to environmental concerns and to the limited amount of fossil fuel in the world theinterest in using renewable material has been and will continue to be on the rise. With theincreasing demand for renewable materials such as bio-based fibers, the research aroundnatural fibers is intensifying. Abaca (Musa Texitilis Nee) is a plant endemic to the Philippineswhich is claimed to contain the strongest natural fiber in the world 1. However, no thoroughresearch on performing tensile strength test on single abaca fibers/cells has been found. Byperforming tensile strength test on the single abaca fibers and relate this will provide freshdata about the single abaca fiber strength that can be compared with other natural fibers.This can later be a reference tool in order to find the optimal fiber for the product to be made.

    The purpose of this study is to develop a methodology for performing tensile strength testson single abaca fibers with the major objective to relate the tensile strength and E-modulusof the fibers with their microfibrillar angle (MFA). The research was done by using Abaca(grade S2) from Camarines Sur (Philippines) that was chemically disintegrated in order toobtain single fibers. The single fibers were mounted to a custom made paper frame for thetensile strength test performed by an Instron 5944. The MFA of each fiber was also retrievedusing an optical microscope with a polarized filter. The research showed an indication of aninversely proportional relation between MFA and tensile strength of the fibers. According tothe results, the E-modulus of the single abaca fiber was almost constant, independently onthe MFA of the fiber.

  • De Barros Cruz, Julio Cesar
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Paunovic, Marijana
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Vattentäta betongkonstruktioner utsatta för tvångskrafter: Finit elementanalys av tvångsfördelning för vanliga typfall2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Concrete is one of the most widely used building materials in society today. Some of the reasons for this are that it has a long life, is a natural material that is 100% recyclable and non-flammable material. It has many advantages, but it is not entirely ideal due to its low tensile strength. A concrete structure may crack due to restrained movements which creates tensile stresses. Restrained movements are called restraint which can be described in the form of restraint factor. In this thesis, restraint factor is defined as a ratio between the actual imposed stress and the imposed stress at full restraint. The degree of fixity, movement possibility and stiffness relation between the newly casted element and the adjacent old structure are crucial parameters in the calculation of restraint and a typical case is, for example, a wall-on-slab cast. A completely restrained construction has a restraint factor equal to 1, while a structure that can move freely has a restraint factor equal to 0. However, a relative lower restraint factor is obtained if the creep effect is considered, since it has a positive influence on the restraint. The concrete may crack due to the restraint and if the crack is not expected or is larger than the expected for the dimensioned load then it is considered as damage. Preventing water penetration or leakage also means that through cracks in waterproof concrete structures should be avoided. Therefore, it is important to consider the restraint on fracture risk analyzes of waterproof concrete structures. The purpose of this thesis was to investigate the restraint based on several aspects, which meant that the work was divided into 3 analyses. Analysis 1 had as purpose to confirm typical cases specified in Eurocode SS-EN 1992–3 and to evaluate the stated restraint factors that the Eurocode proposes should be used in calculations of restraint deformations. For that matter, finite element program was used for modeling the cases from the Eurocode and at the same time hand calculations were made to supplement the analysis. Analysis 2 consisted of examining how the restraint between structural parts is affected by changing dimensions of the structure. The construction being studied was wall-on-slab cast. Variable parameters were the width and thickness of the slab, as well as the height and thickness of the wall. At the same time, changing the length of the construction was taken as an affecting factor. Lastly, crack width calculations for bending moments and shrinkage were made in analysis 3 to obtain the amount of reinforcement that meet the crack width requirement for waterproof concrete structures. This was done according to two different calculation methods: Eurocodes and Engström’s (2014). These calculations also showed a comparison in the amount of reinforcement when using restraint factors derived from Eurocode and restraint factors calculated according to the FE analyses. The results from analysis 1 showed that the variation of restraint factors calculated did not completely correspond to the variation stated in SS-EN 1992–3 but did not deviate too much. However, there were a few cases where deviations were noticeable and therefore a more detailed examination is required. Analysis 2 showed that increasing the volume of the wall reduces the restraint against the slab, but an opposite effect was obtained by increasing the volume of the slab. At the same time, it was found that a longer construction causes greater restraint between the actual components. The conclusion from analysis 3 was that the difference in generated amount of reinforcement was almost proportional in percentage to the difference in restraint factor. However, using different calculation methods resulted in amounts of reinforcement that were not comparable. Comparison between the two calculation methods was not the purpose of this thesis, but merely an attempt to gain an insight into how the different methods are structured.

  • Ayan, Hilal
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Industrial Biotechnology.
    Identify synthetic polymers used in cosmetics and further test their biodegradation in aqueous setup in order to assess their impact on the environment2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Plastics have a wide application field, where cosmetic products are one of them. Polymers which are building blocks to plastics exists in many variants, overall they can be categorized into two groups; microplastics and water soluble polymers. Both polymer types are important to study and understand since polymers in general are not covered by any legislation. To gain a more profound understanding of their impact on environment this study was conducted. In collaboration with SSNC (Naturskyddsföreningen), a database containing hundreds cosmetic products was processed. The most occurring polymers were quantified and prevalent ingredients having “poly” in their name were selected for further investigation namely Nylon 12-20 (microplast) and Acrylates C/10-30 Alkyl-crosspolymer (water soluble). A standardized analysis method OECD 301 F was performed to test the polymers biodegrading ability. Results from biodegradation method showed that, neither of the two polymers is readily biodegradable in aqueous environment, despite their different properties. In connection with the obtained results, a filtration analysis was performed, with the purpose to determine the possibility to capture the polymers using microfilters. Results mainly showed flowthrough of both polymers. Relating the results to reality implies that these polymers are not captured in waste water treatment plant due to inefficient filtration and thereby spread to the environment. In addition more research should be devoted to water-soluble polymers and their impact on nature. Based on all compiled results, it is proposed that legislation addressing microplastics should be edited and revised in such a way that water soluble polymers are included in future prohibitions (against microplastics).

  • Linder, Andreas
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Lundberg, Emil
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Automatisering av LCA - och LCC - beräkningar för anläggningskonstruktioner: Ett verktyg för hänsynstagande av miljö och kostnad i tidigt projekteringsskede2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    While carrying out structural design work, it is important to take into consideration the environmental impacts and costs throughout the life time of the structure. This is done through life cycle assessment (LCA) and life cycle cost analysis (LCC analysis), respectively. LCA addresses the environmental aspects and potential environmental impacts throughout a product’s life cycle i.e. from cradle to grave. An LCC analysis summarizes the investment cost and costs for operation and maintenance during the life time of the product. BIM 3D modeling tool are used for modeling several different types of buildings and civil works. Ideally, digital information readily available through these powerful BIM tools, should be reused to perform LCA and LCC analyses. It would also be beneficial if it was possible to connect it to a company’s internal systems for instance in this study, the Swedish Transport Administration's “Klimatkalkyl” (a tool based on the method for LCA). The purpose of the thesis project is to integrate cost and environmental impact into the early design phase through an automated connection between BIM programs and LCA / LCC tools. By automating this process, optimization of structures can be made more efficient. An Excel sheet has been created through programming in Visual Basic for Applications (VBA) which retrieves quantities from either Tekla Structures, Excel or manual input and then generates LCA and LCC reports. These have then been compared with existing LCA and LCC analyses to ensure the program's quality. The result of the work shows that produced LCA and LCC reports can contribute to a more efficient structural design process for optimizing structures regarding environmental impacts and investment cost. The Excel sheet's user-friendly structure also enables people with limited knowledge in LCA and LCC to make more sustainable choices when undertaking structural design tasks. This helps to promote sustainable thinking in companies and encourages employees to work towards a common goal of a carbon-neutral infrastructure sector.

  • Phongsawat, Chonticha
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Industrial Biotechnology.
    Effect of nutrient limitation in chemostat cultures on amino acid excretion in Clostridium thermocellum2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Introduction: Clostridium thermocellum is considered a model organism forconsolidated bioprocessing, due to its ability to hydrolyze lignocellulosicbiomass more efficiently than many other organisms and to produce ethanol.In order to meet the industrial requirements of ethanol yield and titer, metabolicengineering efforts have been made resulting in a strain that successfullydisplays increased ethanol yield with reduced amount of some byproducts.However, the ethanol yield in this engineered strain still does not meet theindustrial requirements and significant amounts of amino acids are stillproduced. To attempt to decrease the level of amino acid excretion intended toimprove the ethanol yield in C. thermocellum, it is essential to understand itsmetabolism and how it is affected by different cultivation conditions and mediumcompositions. This study aimed to gain an insight in how carbon- and nitrogenlimitation affect amino acid excretion in C. thermocellum, with the hypothesisthat excess of carbon and nitrogen yields more amino acid excretion.

    Methods: Mass-balance based calculations of rates and yields were used toanalyze the metabolism of a wild-type of C. thermocellum (DSM 1313) grownanaerobically in carbon- or nitrogen-limiting chemostats. For this, Low-Carbonmedium containing, respectively, cellobiose (5 g/L) and urea (0.15 g/L) as thelimiting nutrient was used. Both cultivations were performed at 55 °C, pH 7.0and 400 RPM shaking at a dilution rate of 0.1 h-1.

    Conclusion:  Considering yields of total amino acids excreted in bothlimitations, it was hypothesized that C. thermocellum exploited the amino acidexcretion to maintain carbon balance around the pyruvate node caused byexcess of the carbon. Based on yield of valine excreted in particular, it washypothesized that amino acid excretion was used to maintain redox balance inthe metabolism of C. thermocellum, where malate shunt could play a major role.However, results of the Carbon-limitation did not allow any conclusion ofnitrogen excess having an effect on amino acid excretion in C. thermocellum.

  • Behaderovic, Irfan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Khaled, Nora
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Temperaturmätningar i inklädnadssystem och sprutbetong inom Norra länken2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Trafiverket strives to divert the traffic in Stockholm from the city center. In order to accomplish this, large construction projects are currently being planned and processed. One of them is a tunnel construction called Norra länken. The tunnel construction in Norra länken consists of a cladding system and rock reinforcement consisting of shotcrete. Currently there is not enough information on which temperatures that will occur in the tunnel construction and therefore Trafikverket’s general assumption is applied of when designing road tunnels. This means that the shotcrete needs to be frost resistant and that XF2 and XF4 is applied. In order to understand the temperature conditions in the tunnel construction Trafikverket decided to measure the temperatures in Norra länken. With an increased understanding of the temperature conditions it would be a possibility to alter the exposure classes that are currently applied. The purpose of this report is to investigate whether the resulting measurements could be used to design a basis for future selection of exposure class in coming road tunnel projects with similar cladding systems. For this report literature studies, field trips and analyzes of the measurements in Excel were used as a method to answer these research questions. The result showed that the temperature in the rock reinforcement never fell below 0℃ but that the cladding system did show temperatures below 0℃. Therefor it was only a risk for frostbite in the cladding system. However, when analyzing the data, it was noted that two out of three measuring stations were water damaged which caused a lot of incorrect data. The data was also only obtained from mild winters which makes it difficult to draw general conclusions from it. This contributed to uncertainties about how reliable the measured data was. From the analysis the conclusion was made that there was not enough information to support a decision that would alter the choice of exposure class in future tunnel projects. Thereby Trafikverket was recommended to continue with the measurements until the planed end date 2025 and by doing so they can obtain a sufficient amount of information to evaluate the exposure classes once again.

  • Bladholm, Viktor
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Organic Fillers for Solid Rocket Fuel2018Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Liquid propellant and solid propellant rockets are the most commonly used rockets

    Liquid propellant rockets have the advantage of being manoeuvrable with a high specific performance while they exhibit problems with storage and a complex design. Solid propellant rockets offer simplicity and are storable while they have a large environmental impact and could be difficult to handle. A third type of rocket, hybrid propellant rocket has the potential to combine the simplicity of solid propellant rocket with the manoeuvrability of liquid propellant rockets. While the hybrid propellant rocket offers advantages over liquid propellant and solid propellant rocket it have problems with its fuel which have a low regression rate and low density. Organic fillers were evaluated since they may increase in the regression rate and the density of the solid fuel. 50 organic fillers were assessed with regards to their specific impulse, density, cost and handling properties. The organic fillers with the most promising properties were then experimentally evaluated. Thermogravimetric analysis (TGA), isothermal weight loss test, compatibility test and differential scanning calorimetry analysis were conducted. The results indicate that hexamine, fluorene, anthracene and 1,4-dicyanobenzene are the most suitable organic fillers of those evaluated..

  • Emilsson, Arvid
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Buhrgard, Andreas
    KTH, School of Industrial Engineering and Management (ITM).
    Towards a prototype of a modular biogas system2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    As of today, large unused potential for biogas production exist within the Swedish agriculturesector. The biogas production within this sector is, however, associated with several problems such as poor energy efficiency and non-profitable systems. This is to some degree due to lack of standardized technical solutions. International Micro BioGas AB (IMB AB) has been aided by KTH since 2014. This project investigates several innovations from IMB AB in regards to biogas production:

    - A mixing device- A building capturing waste heat from the digesters (building concept)- Insulation of the digester (cover concept)- Small-scale and modular package systems

    The innovations listed above are evaluated from energy, economic and environmental perspectives by doing a case study on the dairy farm Ogestad close to Gamleby, Sweden. Two cases are considered. In Case 1, the raw biogas is burned in a combined heat and power-unit (CHP) in order to produce electricity. In Case 2, raw biogas is upgraded in a small-scale upgrading unit to vehicle gas standards which is sold to the market. The results show that the mixing device is promising in terms of energy use. It is therefore recommended to move on with testing of the equipment. The cover concept and the building concept show similar performance from energy and environmental standpoints. The building concept is concluded not to be economically viable. The cost reduction by applying a modular concept where one product can be used on different sized farms is significant. However, the needed investment from the company is large. The goal of achieving a modular system is therefore concluded desirable. The subsidy from the Swedish board of agriculture covering 40 % of the investment cost, has a major impact on the profitability of the systems. Without this subsidy, the systems are not viable in terms of economy. In Sweden, the small-scale vehicle gasproduction (Case 2) was concluded the most profitable as well as the best-performing from energy and environmental standpoints.