In the first part of this work a novel type of low-density, sponge-like material for the separation of mixtures of oil and water has been prepared by vapour deposition of hydrophobic silanes on ultra-porous nanocellulose aerogels. To achieve this, a highly porous (&gt; 99 %) nanocellulose aerogel with high structural flexibility and robustness is first formed by freeze-drying an aqueous dispersion of the nanocellulose. The density, pore size distribution and wetting properties of the aerogel can be tuned by selecting the concentration of the nanocellulose dispersion before freeze-drying. The hydrophobic light-weight aerogels are almost instantly filled with the oil phase when they selectively absorb oil from water, with a capacity to absorb up to 45 times their own weight. The oil can also be drained from the aerogel and the aerogel can then be subjected to a second absorption cycle.In the second part of the work a novel, lightweight and strong porous cellulose material has been prepared by drying aqueous foams stabilized with surface-modified NanoFibrillated Cellulose (NFC). Confocal microscopy and high-speed video imaging show that the long-term stability of the wet foams can be attributed to the octylamine-coated, rod-shaped NFC nanoparticles residing at the air-liquid interface which prevent the air bubbles from collapsing or coalescing. Careful removal of the water yields a porous cellulose-based material with a porosity of 98 % and a density of 30 mg cm-3. These porous cellulose materials have a higher Young’s modulus than other cellulose materials made by freeze drying and a compressive energy absorption of 56 kJ m-3 at 80 % strain. Measurements with an autoporosimeter reveal that most pores are in the range of 300 to 500 μm. / <p>QC 20121107</p>

Today, tall buildings are generally built with a central core that transfers the loads down to the ground. The central core takes up a large part of the floor space and there is less room for the actual purpose of the building, such as offices and apartments. The consequence of this is also less rental profit. At a certain height of the building, the central core will not alone manage to keep the building stable. Therefore it needs to be connected with outriggers to withstand the horizontal forces. The Tubed Mega Frame system developed by Tyréns is designed without the central core and the purpose is to transfer all the loads to the ground via the perimeter of building, making the structure more stable since the lever arm between the loads is maximized. The system has not yet been used in reality. This thesis aimed at testing the efficiency of the Tubed Mega Frame system against conventional systems for tall buildings. Two different types of the Tubed Mega Frame system were evaluated; TMF Perimeter frame and TMF Mega columns. To begin with, a pre-study was carried out with the purpose of comparing wind deflections and eigenmodes of several conventional systems and Tubed Mega Frame systems. The buildings were modeled in the finite element software ETABS. The Core, outrigger and perimeter frame system performed best compared to the other conventional systems and was therefore chosen as the conventional system to be tested in the main study. A comparison of the Core, outrigger and perimeter frame system and eight different configurations of Tubed Mega Frame systems was carried out for several different building heights as a main study, based on the tall building 432 Park Avenue, New York. The deformations due to wind and seismic loading and eigenmodes were compared. Furthermore, the models were controlled for tension at the base and Pdelta convergence. Overall the TMF Perimeter frame systems had the smallest deflections as the building height was increased and could be increased the most without reaching tension at the base. As the top story height of the buildings was increased, the Tubed Mega Frame systems outperformed the conventional system. For the TMF Perimeter frame system it could be seen that belt walls were more efficient than cross walls, and for the TMF Mega columns the smaller the distance between the belt or cross wall levels was, the less deflection was achieved. The Core, outrigger and perimeter frame system could be increased to 859 m in height before collapse and the Tubed Mega Frame system that performed best – TMF: Perimeter frame single story belt walls – was increased to 1024 m in height until divergence was achieved.

Virtual reality (VR) is a fast-growing market that an increased number of organisations are trying to enter by bringing their products into the virtual world. Although extensive research has been done on the design of VR, less research is done on how to move an existing interface into the virtual world. This study aimed to answer the question of how an existing interface can be implemented into a VR environment. In collaboration with the consultant agency Decerno this study has been looking at how an operative system used by brokers can be transitioned. Using research through design methodology, the work has featured interviews with the system’s developers, designing a VR prototype of the operating system and an evaluation of the prototype with the experts. The result generated five guidelines that can be used when attempting to move a 2D interface into the VR world: Take advantage of the volume, Rely on consistency, Use a minimum font size of 23 dmm, 0.75-3.45m between user and screen and interaction using ray-casting.

The construction and real estate sector were in 2019 responsible for a fifth of Sweden's totalemissions and a third of its total energy consumption. With new rules and regulationsconcerning the environment, industry participants have a large potential to influence theimplementation of this legislation in practice.Today there are two main approaches in the construction of new buildings, traditionalconstruction and industrial construction. The traditional, often referred to as project based,gives the constructors much freedom concerning the building's architectural expressionsince every project is considered unique. The industrial, on the other hand, entails a fasterand more structured construction process. Through the implementation of the IHB-model, aframework for industrial construction, there is a continuous pursuit of improvements in theoperating efficiency throughout the entire construction process. The IHB-model ranks acompany’s degree of industrialization on the basis of eight categories, which allows for anefficient process of discovering potential areas of improvements.The purpose of this report is to evaluate the possibilities of improving Skanska’s currentoperations through the implementation of a more industrialized mindset. This is donethrough a description of one of Skanska's ongoing construction of apartment buildings inUmeå. Through the data collection process, which consists of observations around theconstruction and interviews, the degree of the project's industrialization is then determinedthrough the use of the IHB-model. The results are then analyzed and potentialimprovements in their operations and mindset is suggested. Skanska is the front runner insustainable construction and with rigid regulations regarding the sustainability of the projectthe implementation of industrial methods might help them achieve their goals.The findings suggest that Skanska has achieved a relatively high degree of industrialization,but there is still room for improvements. Because the project consists of different phases,Skanska will have great potential to improve the efficiency of their processes for thebuildings that are not yet erected. Through increased application of prefabricated materialsit is possible to achieve a better working environment, minimize risks and improvedefficiency. This would then result in fewer errors, shorter time of production and decreasethe waste associated with the project.Increased usage of ICT-tools during the production might lead to both increased usage ofexperience and better control of the construction process. This results in improvedoperating efficiency, fewer errors and provides the optimal conditions for further projects.Through the implementation of the Last Planner framework, only the necessary and good togo parts of the project will be built, thus eliminating the necessity for corrections andreducing the waste associated with the project. The JIT-principle can be applied to improvesupply chain management which allows for material to be delivered to the right place at theright time. Through long-term relationships with their suppliers an efficient work flow isestablished which results in increased productivity and the alignment of the interestsregarding increased operating efficiency and sustainable construction. / Bygg- och fastighetssektorn stod år 2019 för en femtedel av Sveriges totala utsläpp avväxthusgaser och en tredjedel av den totala energianvändningen. Med nya krav och reglerpå energisnålare byggnader och mer hållbart tänkande har medverkande i byggbranschenstor potential att påverka detta i praktiken, genom en effektivare styrning under helabyggprocessen.Idag finns två huvudsakliga metoder för uppförandet av en byggnad, traditionellt byggandeoch industriellt byggande. Där det traditionella, även kallat projektbaserat byggande medförstor frihet till byggnadens arkitektoniska uttryck då varje projekt är ett enskilt unikt projekt.Det s.k. industriella byggandet kan innebära ett snabbare och mer kontrollerat sätt att byggapå. Genom IHB-modellen, en affärsmodell för industriellt husbyggande, eftersträvas alltidständiga förbättringar under hela byggprocessen. Ett företags industrialiseringsgrad kanbestämmas genom IHB-modellens åtta delområden, för att sedan hittaförbättringsmöjligheter inom områdena.Syftet med detta arbete är att utvärdera möjligheterna till mer industriella metoder ochtankesätt hos Skanska vid nybyggnation av ett flerbostadshus. Detta har gjorts genom ennulägesbeskrivning på ett av Skanskas pågående projekt i Umeå. Genom en datainsamlingsom innefattar observationer på byggarbetsplatsen och kvalitativa intervjuer har dennuvarande industrialiseringsgraden satts för projektet. Därefter har förslag till förbättringarav industriella metoder och tankesätt analyserats. Skanska är ett ledande byggföretag inomhållbart byggande och med höga miljökrav på byggprojekten kan industriella metoder ochtankesätt vara ett sätt att nå satta mål.Det har för det studerade projektet framgått att Skanska är relativt industrialiserade, men pånågra av IHB-modellens delområden finns tillgängliga förbättrings- ochutvecklingsmöjligheter. Eftersom projektet består av olika etapper har Skanska stor potentialatt effektivisera processerna för de byggnader som inte upprättats ännu.Studien tyder på att en högre prefabriceringsgrad under ett projekt exempelvis kan ge bättrearbetsmiljö, mindre riskmoment på byggarbetsplatsen och effektivare processer. Dettaresulterar i mindre byggfel, kortare produktionstid och att mindre avfall påbyggarbetsplatsen kan genereras. En högre användning av s.k. ICT-verktyg underproduktionen kan leda till att både erfarenhetsåterföring och bättre kontroll av processernabli möjligt, vilket resulterar i effektivare processer, mindre byggfel och bättre möjligheter förframtida projekt. Med användning av planeringsmetoden Last Planner är det endast demoment som är startklara och bör göras som byggs, vilket resulterar i att mindrekorrigeringar behöver göras vilket därmed medför mindre restprodukter påbyggarbetsplatsen. JIT-principen (just-in-time) kan användas för att påverka logistiken somleder till att material levereras till rätt plats i rätt tid. Genom långsiktiga relationer medunderentreprenörer säkerställs effektivare flöden och en ökad produktivitet, som kanresultera i förbättrade arbetsmetoder och att företagsmål som hållbart byggande blir ettgemensamt mål.

The use of concrete in the construction industry goes back a long way, which in itself creates a huge amount of information that can be used to understand its properties and components. Through the many different calculation-methods that have been used over the years, new solutions have come and gone [1]. With many years of constructing different elements in concrete, a number of different standards have also been developed. Before the introduction of the Eurocode, there was a large number of documents that were applied for the same construction. One of these was ”betongelementföreningens handbok”. This book is based on several years of experience around a more specific niche in concrete, prefabricated industrialized building. As today's guideline means that the principles of the Eurocode are what today's standards should be built on, it is interesting to discuss which calculation method is best for prefabricated concrete elements. One of the corner stones of the Eurocode is that it should be versatile and suit the demand of all countries, while at the same time being sustainable and functional [2]. Differences in demand between the calculation methods mean that different things are taken into account. The purpose of the project is to provide Prefabmästarna AB with a basis for method change from the current dimensioning method to Eurocode. The aim of the report was to shed light on the calculation methods' difference in loads and moments that affect an example building. The frame consists of prefabricated concrete based on the company's requirements. The impact of the skew load differs between the calculation methods in that Eurocode uses reduction in connection with the building's number of stabilizing units and a reduction of the angle of incidence depending on the height of the building. According to "bygga med prefab", only a reduction factor is used that is affected by the number of stabilizing units in the building. The roof will have, for example, a skewload of 27,1 kn according to Eurokod and 56,6 kN according to ”bygga med prefab”. The moment of inertia was calculated in a similar way between the calculation methods, except that "building with prefab" takes into account the lateral stiffness that occurs in certain cross-sections. In this way, a fictitious reduction of the moment of inertia is applied, which depends on the height and width of the wall panel. The coordinates of the rotation center also differ. Eurokod had the same rotation center for all floors at the same time as the "bygga med prefab" rotation center separates the floor plans. The conclusion was that the total skew load and the calculation model of the moment of inertia differed between Eurocode and "building with prefab". This meant that the overturning load and torque that affected the building showed a difference in the resulting calculations. Eurocode calculations showed a reduction in loads and torque compared to "build with prefab" calculations. The load distribution of the calculation methods was equally designed where the percentage impact on each wall panel was the same. The calculations of loads and torques meant that a reduction in material use and oversizing was the basis for motivating the company to change the calculation method. The attachment was calculated on the basis of a model that corresponds to an arbitrary example of how the board is affected by the moment, but in addition to this, there are equivalent methods that lead to an even more favorable answer for the dimensioning.

Den svenska bygg och fastighetssektorn står för en betydande del av de totala utsläppen av växthusgaser i Sverige. För att minska denna sektors klimatavtryck är det viktigt att identifiera vilka delar som står för en stor del av bidragen av växthusgaser. En klimatkalkyl eller livscykelanalys är en metod för att identifiera dessa och på så sätt skapa möjligheter att hitta andra alternativ för de största bidragen.   Upprättande av klimatdeklaration är sedan 1 januari 2022 lagkrav och består av en livscykelanalys för byggskedet. Detta bidrar till att nå Sveriges miljömål genom att identifiera de delar i byggskedet som ger stora bidrag till växthuseffekten och på så sätt främja alternativa lösningar och material.   Denna studie jämför med hjälp av en klimatkalkyl en traditionell stomme i stål och betong med en stomme av lim- och KL-trä för att identifiera skillnader i klimatpåverkan avseende dessa konstruktionslösningar. Peab Sverige har tillhandahållit underlag för att kunna genomföra denna studie på deras NärBo punkthus. Specifika data hämtade från EPD:er har använts för att jämföra med de generiska, även specifika avstånd och olika leverantörer av liknade material har jämförts med hjälp av BMpro. Syftet med denna studie är att skapa en djupare förståelse och att bidra med kunskap till det pågående miljöarbete inom byggsektorn. Vidare är studiens mål till att undersöka skillnaden av den beräknade klimatpåverkan i tre olika fall för stommen i ett NärBo punkthus på åtta våningar för att kunna användas som underlag för framtida val av stomme. Även praktiska svårigheter med att utföra och hålla en klimatkalkyl med specifika data uppdaterad under produktions skedet undersöks i studien.   Resultatet från denna studie visar att en stomme lim- och KL-trä bidrar med ca 15–25% av de utsläpp av växthusgaser som en stomme i betong och stål för en likvärdig byggnad. Det är dock stora osäkerheter i resultatet då lim- och KL-trästommen inte har dimensionerats speciellt för denna byggnad. Den ekonomiska kostnaden för endast materialet är ca 50–60% högre för trästommen vilket kan vara en bidragande faktor till att den inte är mer vanligt förekommande.  Svårigheter med att följa upp klimatkalkylen kan underlättas och förenklas med sammanlänkade system och bra kommunikation mellan ansvarig för klimatkalkyl och ansvarig för produktion. Vidare visar studien att användandet av produktspecifika EPD och transportavstånd kan både hjälpa till att sänka och riskera att höja bidragen med växthusgaser i klimatkalkylen beroende på val av leverantörer.

The composition will focus on valuations of energy during production, the construction process and the building's operation and with regards to climate impact and resource use.  In addition, energy performance in different buildings will be examined.  Another important factor that the work will focus on is energy consumption.  There is already a lot of research on energy efficiency in buildings and our work should be based on the latest research and new findings in this area. The first step in the work was to contact HFAB through telephone calls and email interviews. Furthermore, the energy efficiency has been calculated for the simulated villa. Later, climate calculations were made for Nerven 1, which is an apartment building. Data coming from HFAB applies to apartment buildings. Subsequently, environmental calculations have been made for the simulated villa, which showed a result that the villa is more environmentally friendly compared to apartment buildings. The main reason for this is the poor impact of concrete on the environment. Apartment buildings use significantly more concrete than the villa, which gives a bad environmental impact and results in the villa being friendlier.

An estimated 450 million people globally do not have access to a fixed or mobile broadband signal. Recently satellite communication companies announced the concept of Megaconstellations which are large networks of inexpensive low Earth-orbiting satellites. These constellations aim to provide internet access across the planet. Many people believe these constellations will offer an opportunity to bridge the digital divide between developed and developing countries. However, according to the UN development agenda, it is crucial to harmonize three core elements: economic growth, social inclusion, and environmental protection, while achieving the Sustainable Development Goals (SDGs). Although many are enthusiastic about the possibility of closing the digital gap, some researchers have concerns about the environmental impacts of these mega-constellations. Some studies explored howsatellites’ mega-constellations would increase the collision rate among space objects. This by increased amount of space debris which would negatively impact the Low Earth Orbit and the planet and thereby would be inconsistent with environmental sustainability. This study aims to investigate this claim by examining the impacts of future capabilities of satellites on offering inclusive healthcare and education systems while investigating their environmental impacts.

No description available.

This study discusses the behavior of people towards natural language interfaces. It draws parallels to the behavior of people towards other people, and discusses how far these parallels can be stretched. A small experimental study of users performing tasks using a natural language interface to a database is presented, and the results related to the discussion. The main points made are 1) that new modalities like the one used in typical human computer interaction - written interactive communication - are problematic for new users, from lack of conventions; and 2) that users' attitudes towards computers and of the system's linguistic and other competence shape much of the interaction, and that these attitudes change, and that thus the important factor to take into account in system design is not what the initial attitudes are but rather what the process of changing them is and how to utilize the process of change to teach the user the system language and interaction modality. / <p>QC 20160530</p>