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Blockchain is described as having endless theoretical potential. In reality however, it is hard toestablish how blockchain can be utilized and what opportunities blockchain may create. Theunclear future of blockchain constitutes a challenge for many companies. Many large incumbentsare uncertain of how to implement blockchain technology in their organization and are anxiousabout the consequences of the new technology. The purpose of this exploratory study is to evaluateblockchain applications for a district heating company in Stockholm to understand favorable areas,necessary criteria for successful implementation and how blockchain could enable new businessopportunities in the district heating market. To be able to reach the purpose of the thesis aliterature study and an empirical study were performed. The literature study is in the form of anextensive investigation about the areas of blockchain and district heating. The empirical studyincludes 17 interviews, both internal interviews with employees at Stockholm Exergi and externalinterviews conducted with professionals with knowledge about blockchain, district heating and theenergy sector. Furthermore, two workshops, in collaboration with Stockholm Exergi, wereperformed at the end of the thesis to evaluate and prioritize the developed blockchain applications.This thesis proposes 32 blockchain applications within 10 areas in the district heating industry.The applications are categorized after their potential, in three categories; green for the blockchainapplications that are valuable to investigate further, orange for the applications that potentiallycould be interesting to investigate further, and red for the applications that are not interesting toinvestigate further. Some applications focus on solving inefficiencies within district heating andsome on exploiting the benefits of blockchain. Eight applications are categorized with greenprioritization, and thus presented in more detail. To take into account that blockchain probablywill have a greater impact in the future, a future scenario was developed and used in the situationalanalysis for the applications. Furthermore, a framework was developed with the aim to be a toolfor a district heating company to utilize while considering if a blockchain implementation wouldbe beneficial, and if so, in what way. The framework is focused on district heating companies butcan be utilized by other actors as well.Our recommendation for a district heating company in Stockholm is to wait one or two yearswhile staying updated. Especially important for the companies are to stay updated on whether newblockchain standardizations will emerge in the energy sector. However, if a district heatingcompany want to initialize a blockchain project we advise the companies to start a pilot projectthat does not affect the current business model but has the potential to be scaled. Since theblockchain technology enhances collaboration, it is important to consider which partners shouldbe included and how the application can create value for all involved parties. However, due to theuncertainty of the technology, companies need to be well aware of that assumed created value maynot be reached as expected. Furthermore, district heating companies also need to bear in mindthat other parameters, for example additional technologies, policies or infrastructure systems, maybe necessary to implement in order to create value from a blockchain solution. Blockchain beskrivs ofta som något med ändlös teoretisk potential. I verkligheten är det dock svårtatt fastställa hur blockchain kan användas och vilka möjligheter blockchain kan skapa. Den osäkraframtiden för blockchain är en utmaning för många företag att förhålla sig till. Inte minst för storaetablerade företag då blockchain kan användas för att decentralisera en centraliseradmarknadsstruktur. Syftet med denna undersökande studie är att utvärdera blockchainapplikationerför ett fjärrvärmeföretag i Stockholm, för att förstå gynnsamma områden,nödvändiga kriterier vid genomförande och hur blockchain skulle kunna möjliggöra nyaaffärsmöjligheter på fjärrvärmemarknaden. För att uppfylla uppsatsens syfte genomfördes enlitteraturstudie och en empirisk studie. Inom litteraturstudien genomfördes en omfattandeundersökning av blockchain och fjärrvärme. Den empiriska studien bestod av 17 intervjuer, bådeinterna intervjuer med anställda från Stockholm Exergi och externa intervjuer med experter inomblockchain, fjärrvärme och energisektorn. Vidare genomfördes under slutfasen två workshops isamarbete med Stockholm Exergi, för att utvärdera och prioritera de skapade blockchainapplikationerna.Rapporten presenterar 32 blockchain-applikationer inom 10 olika områden inomfjärrvärmeindustrin. Applikationerna är kategoriserade efter sin potential i tre grupper, grön för deapplikationer som kan vara fördelaktiga för ett fjärrvärmeföretag och bör fortsätta undersökas,orange för de applikationer som sannolikt inte skulle vara fördelaktiga och röd för de applikationersom inte är intressanta för ett fjärrvärmeföretag att fortsätta undersöka. Vissa applikationerfokuserar på att lösa de ineffektiviteter som finns för fjärrvärme och vissa på att utnyttja fördelarnamed blockchain. Det åtta applikationer med grön prioritering presenteras mer detaljerat. Ettframtida scenario togs fram för att ta hänsyn till att blockchain sannolikt kommer att ha störrepåverkan i framtiden. Detta används som hjälpmedel när situationsanalysen för applikationernagenomförs. Dessutom utvecklades ett ramverk som har som syfte att vara ett verktyg för ettfjärrvärmeföretag att utnyttja när en blockchain implementering övervägs. Ramverket är inriktatpå fjärrvärmeföretag men kan även användas av andra aktörer.Vår rekommendation till ett fjärrvärmeföretag i Stockholm är att vänta ett eller två år, samtidigtsom de håller sig uppdaterade om marknadsförändringar för blockchain. Särskilt viktigt för ettfjärrvärmeföretag är att hålla sig uppdaterad om huruvida nya blockchain-standardiseringar uppstårinom energisektorn. Om ett fjärrvärmeföretag vill initiera ett blockchain-projekt, rekommenderarvi att starta med ett pilotprojekt som inte påverkar den nuvarande affärsmodellen, men harpotential att skalas. Eftersom blockchain-teknologin möjliggör samarbete är det viktigt attöverväga vilka partners som kan ingå i lösningen och hur applikationen kan skapa värde för allaberörda parter. Företag måste emellertid vara väl medvetna om att det förväntade värdet kanskeinte uppnås på grund av teknologins osäkerhet. Dessutom måste företagen också överväga attandra parametrar, till exempel andra teknologier, politik eller infrastruktur, är nödvändiga, för atten blockchain implementering ska skapa värde.

A successful rice production on swampland would require a planting material from high yielding varieties adaptated to the swampy ecosystem. This study was carried out to compare the growth and yield characteristics of five rice lines and a check variety as grown on non-tidal swampland. The lines were F4 generation of bulk selection from the crosses involving Bengkulu swamp rice landraces (Hanafi Putih, Tigo-tigo, Harum Curup, and Lubuk Durian) and high yielding varieties for the irrigated field (Sidenuk and Bestari). The trial was conducted on a shallow non-tidal swampland with stagnant inundation no more than 50 cm in depth often occurred during the plant life cycle. The lines and the check variety (Inpara 4) were arranged in a randomized complete block design with three replications. Observations were made for the agronomic performances of the plant, including plant height, total tiller number clump-1, effective tiller number clump-1, heading date, maturity date, panicle length, grain number panicle-1, 100-grain weight, and grain yield clump-1. Significant variation among the genotypes was found for all observed traits. On average, the evaluated lines showed comparable growth and yield performances to the check variety. Tigo-tigo × Bestari was the tallest line and potential for medium depth swampland. This line showed good overall agronomic performances and yielded relatively higher than the check variety, but delayed in attaining maturity. For shallow swampland, Hanafi Putih x Sidenuk exhibited the most potent line by having good overall agronomic and yield performances, except late in maturity. For early maturing line, Lubuk Durian x Hanafi Putih showed its potential for shallow swampland. Although this line was not the best, it showed better overall agronomic performances than the check variety. Keywords: F4 lines, growth and yield performance, rice landrace, swampland, plant maturity

Using phase detection in Surface Plasmon Resonance (SPR) sensing has potential improvements to the conventional intensity detection based SPR. Other than the phase detection and intensity detection based SPR in the visible range of the spectrum, employing SPR sensing principles in the infrared range by the use of silicon has also some promising advantages. Combining these two, in this paper, phase detection-based SPR sensing in the infrared range is studied using a mathematical model and numerical simulations. The results are compared with the results obtained by the simulations in the visible range. Performance improvements are noted by the use phase detection in the infrared range.

Abstract The analysis and optimization of flat plate fins of constant thickness and straight base has been conducted for different fin’s shapes. Performance of the fins is quantified through effectiveness and expressed as a function of fin’s shape, width, and area. A linear piecewise function with varying number of evenly spaced sections is used to generate shapes with different number of degrees of freedom, which are classified as constrained- or unconstrained-base depending on the width of the fin at the constant temperature base location. For one- and two-degrees of freedom shapes, a variety of rectangular, triangular, trapezoidal, and rhomboidal geometries are considered and optimized. For more than two-degrees of freedom, more complex resulting shapes are also considered. By adjusting the value of the corresponding shape parameters, the best possible distributions of available area to maximize heat transfer are obtained, which produce significant improvements favored by smaller width and larger area. Unconstrained-base performs better than constrained-base configurations as they allow the distribution of a larger area close to the high-temperature base. Optimal shape of unconstrained-base fins is in general convergent with non-zero wide tip, while, for constrained-base fins, it is divergent in the first linear section from the base and convergent in the remaining ones. For increasing number of degrees of freedom the optimized shapes tend to resemble natural structures while effectiveness increases asymptotically to a limit for constant width and area. Besides determining the optimal configurations, consideration has been made about the optimal regions where a variety of shapes produce virtually the same effectiveness of the absolute maximum, which can be used to design fins with almost maximum performance but having simpler shapes or being functional under possible space restrictions. The dimensionless model and the systematic analysis proposed in this work are not only appropriate to study a wide range of flat plate fins but also can be implemented to analyze and perform optimization over other type of fins and fins configurations.

Abstract Levee systems are an important part of California’s water infrastructure, engineered to provide resilience against flooding and reduce flood losses. The growth in California is partly associated with costly infrastructure developments that led to population expansion in the levee protected areas. Therefore, potential changes in the flood hazard could have significant socioeconomic consequences over levee protected areas, especially in the face of a changing climate. In this study, we examine the possible impacts of a warming climate on flood hazard over levee protected land in California. We use gridded maximum daily runoff from global circulation models (GCMs) that represent a wide range of variability among the climate projections, and are recommended by the California’s Fourth Climate Change Assessment Report, to investigate possible climate-induced changes. We also quantify the exposure of several critical infrastructure protected by the levee systems (e.g. roads, electric power transmission lines, natural gas pipelines, petroleum pipelines, and railroads) to flooding. Our results provide a detailed picture of change in flood risk for different levees and the potential societal consequences (e.g. exposure of people and critical infrastructure). Levee systems in the northern part of the Central Valley and coastal counties of Southern California are likely to observe the highest increase in flood hazard relative to the past. The most evident change is projected for the northern region of the Central Valley, including Butte, Glenn, Yuba, Sutter, Sacramento, and San Joaquin counties. In the leveed regions of these counties, based on the model simulations of the future, the historical 100-year runoff can potentially increase up to threefold under RCP8.5. We argue that levee operation and maintenance along with emergency preparation plans should take into account the changes in frequencies and intensities of flood hazard in a changing climate to ensure safety of levee systems and their protected infrastructure.

This experimental study explores the possibility of using an existing Trombe wall as a space for year-round cultivation to increase building resource efficiency. To do so with the least cost to the building, a small 0.75 m2/5.45 m3 Trombe wall cavity space was retrofitted with shelves placed behind the glazing, additional ventilation, and a watering network to be able to grow 400 hydroponic Kratky basil plants in individual glass jars. Historical thermal observations made at the site over a year-long timespan were contrasted with the experimental readings. When fully equipped, the Trombe wall’s thermal mass increased by 51%, which had a balancing effect on the system, lowering the average daily thermal oscillations from 35.41 °C to 17.88 °C. The living plants and water have also had significant cooling (26.99 °C to 22.91 °C) and humidifying (39.88 to 47.74%) effects. The system’s energy efficiency, however, decreased from 26 to 18% (absorption) and from 85 to 46 (dissipation), lowering its energy contribution to the building by about 30%. The average plant’s lifespan within the Trombe wall was 46 days, with 15% of the specimens surpassing the 100-day mark. Over the course of a year, 20.55 kg of edible greens were grown in the Trombe wall. The experiment has shown that it is possible to grow the plants inside the Trombe wall cavity during the warmer half of the year, revealing many possible ways to improve the space’s comfort, yields, and energy efficiency.