The aim of this thesis is to discuss and analyse the influenceof data uncertainties with regard to the reliability of materialflow analysis (MFA) studies. MFA, as a part of environmentalsystems analysis, is a method belonging to the research field ofindustrial ecology and more specifically industrial metabolism.As such, the method strives at giving a holistic view of thecomplex world we live in, in order to reduce negativeenvironmental impact. Among other things, MFA studies have beenproposed to be useful for priority setting and following up inmunicipalities. Serving as a starting point is a local case study of flows ofnitrogen in a Swedish municipality, Västerås. The casestudy has been performed using the ComBoxmodel. The years studiedare 1995 and 1998. The main sectors in society emitting nitrogento water were identified as the agricultural and householdsectors. The dominating sectors emitting nitrogen to air wereidentified as the agricultural, transport and infrastructuresectors. As a basis for discussing data uncertainties qualitatively andquantitatively a literature survey was performed. 50 articles andbooks were identified as in some way or another dealing with datauncertainties in MFA. The literature survey showed that theuncertainties for results from a MFA study might vary between±30 % and a factor 10 depending on what kind of parameter isinvestigated. Only one method was found that dealt with datauncertainties in MFA in a complete way; a model developed byHedbrant and Sörme (HS model). When applying the HS model to the case study of nitrogen flowsin Västerås, it was found that when uncertaintyintervals were calculated the possible conclusions changed. Ofthe two pair of flows compared in relation to priority setting,none of the earlier conclusions remained. Of the three flowsanalysed in relation to following up, only the flow from onepoint source supported the same conclusion when uncertainty wasconsidered. In all, it is concluded that data uncertainties in MFAanalysis are an important aspect and that further research isneeded in order to improve input data quality estimations andframeworks for determining, calculating and presenting data, datauncertainties and results from MFA studies. However, theunderlying reality remains, e.g. that management of materialflows are important for understanding and reducing the negativeenvironmental impact. Thus, MFA is one useful tool in thiswork. <b>Keywords:</b>data uncertainties, sensitivity analysis,Material flow analysis, MFA, method to determine datauncertainties, case study, ComBox model, nitrogenflows. / NR 20140805

<div>Many two-phase flow systems might undergo flow instabilities even if the system is adiabatic but operates near the saturation conditions, especially in vertical flow conditions. Such instabilities are caused by <i>flashing</i> of the fluid in flow. Flashing is a sudden phase change in the fluid caused when local saturation enthalpy falls below the fluid enthalpy and the excess energy is used as latent heat for gas generation.</div><div> In the current analysis, a mathematical model is presented for analysis of such instability analytically. The conservation equations have been obtained by statistical averaging in time and space. Then, the concerned system is divided into various regions based on flow conditions, and these averaged equations are used to describe the flow. For flashing-based instability, two parameters are derived from constitutive relationships for the fluid. These two parameters are <i>Flashing Boundary</i> and <i>Gas Generation due to Flashing</i>. These parameters provide for the closure of the mathematical model. Some simple models for flashing have been developed and discussed.</div><div> The mathematical model is then solved analytically for <i>Uniform Heat</i> and <i>Flat Model</i> for the heater and flashing region respectively. The solution is in terms of the characteristic equation which is used to predict the onset of instability caused by flashing. The results are then plotted on the Subcooling-Phase Change number plane. It is observed that inlet and outlet restrictions in the flow does <b>not</b> affect the onset of flashing induced instability as the flow rate is coupled with the pressure drop of the system. This is important as these restrictions play a major role in other two-phase flow instabilities such as <i>Density Wave Oscillations</i></div><div> Finally, the stability boundary in the stability plane is compared to experimental data present for flashing. The comparison was made with data of S. Shi, A. Dixit, and F. Inada. The stability boundary satisfactorily agrees with the experimental data thus corroborating the present mathematical model and analysis.</div>

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第19986号 / 工博第4230号 / 新制||工||1654(附属図書館) / 33082 / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 酒井 伸一, 教授 米田 稔, 准教授 平井 康宏 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

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This study has contributed to the developing concepts of circular economy by assessing circular business models and to test different approaches for circularity in a measurable way. In our current era of time, we stand against environment challenges with a warming planet and resources scarcity. To mitigate the effect of greenhouse gasemissions and to find new more circular solutions to material demand. The developing concept of circular economy is aligned with these goals. In this study the climate impact and profitability of circular business models are investigated using material flow analysis. The result is an assessment of these parameters from a sustainability perspective for product organizations and show that longer lifetime and use period a product has the lower the yearly global warming potential. For profitability the assessment is dependent on more parameters such ascurrent business models, gross margin, raw material, logistics and distribution cost an increased profit is not as strongly connected to lifetime or use. When an increasedcircularity can be accomplished as a complement to current business (withoutsignificant cost increase) there is a possible profit.The study suggests an analysis model for investigate circular strategies in theAssessment model for circular business models. The study contributed to the practical adaptation of circular economy principles providing a suggested analysis framework .By applying circular economy principles and this assessment model it is possible to contribute to a more sustainable future for the system of planet Earth. / <p>2023-06-08</p>

The aim of this study is to analyse the voltage regulation of a power grid when wind power parks are connected to an existing power grid. Secondary the project have studied the placement of these wind power parks and costs related to connecting them to the grid. The goal was to achieve this grid with a smaller than 5% voltage margin and preferably a low phase deviation. The power grid is located in the area around Lule älven. Several issues with constructing and connecting windpower parks to an electrical grid have been studied by numerical analysis of a fictive grid but with real world variables. A balanced and stable grid is achieved with wind and hydro power and is able to successfully operate without non-renewable energy sources.The data was simulated in Matlab to analyse the power grid and the modification of it when connecting the wind power parks. The method used is power flow analysis through Matlab. All required unknown voltages and phase angles are determined and whether they are within given specifications. This entails that a stable electrical grid can be constructed

In this competitive world with rapid growth of markets, the main goal of any company is to attain an edge over its competitors. In order to achieve this goal a company has to continually improve its process and eliminate the wastes in the process while not compromising on the quality of the product and customer satisfaction. Though Eco Supplies Solar AB is one of the largest producers of Photovoltaic solar modules in Scandinavia, the need for improvement is vital to match with growing requirements and to maintain its position in the market. This master thesis was done for Eco Supplies Solar AB, so as to help them identify the waste along their value stream process. The project was divided into three phases. The first phase of the project was to map and analyze the plant layout as well as analyze the worker movement. This helped to understand the various movements through the entire process of production and the associated distances and time. The second phase of the thesis was the execution of the Value Stream Mapping. For this purpose the entire production process was walked through and through several interviews the data was collected. The current state value stream map gave a one page static picture of the key areas of waste within the process and to suggest necessary changes so as to improve the efficiency. The suggested changes are implemented and the future state map is drawn. The results from the current state and future state map are calculated theoretically and analyzed. The third phase is the use of Simulation to understand the behavioral effects of each the processes and to determine the overall change in productivity if the changes are implemented. It is difficult to implement changes in a production plant that works continuously for 24 hours. That would interrupt production and also lead to large costs. The easier and most optimal solution to implement changes, understand the behavior of each process before and after the changes and to analyze the changes is to run a simulation model of the current and future state. The simulation is done using Extend Sim software and the results are analyzed further. The main aim of the thesis was to analyze the current plant layout and the product process and develop a methodology to identify visualize and measure the wastes in the production process of Photovoltaic solar modules.

Idag står byggbranschen för 20% av Sveriges konsumtionsbaserade koldioxidutsläpp, och har blivit uppmärksammad i Sveriges strategi för cirkulär ekonomi som en nyckelbransch i omställningen till en cirkulär ekonomi. Detta då byggbranschen till stor del har linjära flöden idag, men det pågår arbete från både myndigheter och branschaktörer för att öka cirkulariteten av dessa flöden. Idag fokuserar dessa åtgärder och studier dock främst på husbyggnation och avfallsminimering. Det finns alltså en kunskapslucka kring cirkularitet för infrastrukturprojekt med ett perspektiv som sträcker sig bortom avfallsminimering och hantering. Genom att kartlägga materialflöden för ett infrastrukturprojekt inom markläggning med en materialflödesanalys och analysera den tillhörande värdekedjan med en SWOT-analys utökar den här studien kunskapen kring cirkularitet för infrastrukturprojekt. Mer specifikt används Skanska och ett av deras infrastrukturprojekt i Stockholm som en fallstudie för att undersöka hur materialanvändningen för Skanska väg och anläggning kan bli cirkulär och öka förståelsen för vilka processer och aktörer som är relevanta för att uppnå detta.  Resultaten visar att viktiga avfallsflöden att minimera för ett cirkulärt projekt är byggpallar, plaströr och brännbart avfall. De visar även att det mesta avfallet inte bildas från byggmaterial utan från emballage. Från materialflödesanalysen är det dock tydligt att överbeställningen av material som idag är mellan 5-10% har potential att utgöra den största orsaken till avfall under andra projektförhållanden. Från SWOT-analysen framkom att samarbete över hela värdekedjan är nödvändigt för att kunna implementera cirkulära lösningar. Styrkor, svagheter, hot och möjligheter för cirkulärt agerande identifierades för alla aktörer och visade bland annat att projektbeställaren är en nyckelaktör för att skapa förutsättningar för en cirkulär materialhantering.  I studien genomfördes även en djupare analys av hur relevanta de i värdekedjan identifierade processer och verktyg är för Skanskas arbete med cirkularitet. Där framkom bland annat att certifieringar som CEEQUAL och Byggvarubedömningen kan vara viktiga utgångspunkter. Det visades även att utformningen av projektet och Skanskas interna hållbarhetsverktyg kan vara nycklar för att skapa förutsättningar, konkreta mål, och arbetssätt för en cirkulär materialhantering. Studien identifierade även en viss diskrepans mellan den gällande avfallslagstiftningen som förespråkar återvinning och den möjlighet och ekonomi som idag finns i materialåtervinning, framför allt för plast. Här kan Skanska och andra byggentreprenörer ha en viktig roll att spela för att skapa efterfrågan på återvunnet material och på så sätt sluta idag linjära flöden. / Today, the construction industry accounts for 20 % of Sweden’s consumption-based carbon emissions, and has been recognized in Sweden’s strategy for the circular economy as a key industry in the transition to a circular economy. One reasoning behind this is the largely linear flows in the construction industry today, but work is underway from both authorities and industry players to increase the circularity of these flows. However, these measures and studies currently focus mainly on house construction and waste minimization. This leaves a knowledge gap for circularity for infrastructure projects with a perspective that extends beyond waste minimization and management. By mapping material flows for an infrastructure project through a material flow analysis and analyzing the associated value chain through a SWOT analysis, this study expands the knowledge about circularity for infrastructure projects. More specifically, a case study of one of Skanska’s infrastructure projects in Stockholm was made to investigate how the use of materials for Skanska can become circular and increase the understanding of which processes and actors are relevant to achieve this.  The results show that important waste flows to minimize for a circular project are construction pallets, plastic pipes and combustible waste. They also show that most waste is not formed from building materials but from packaging. From the material flow analysis, however, the over-ordering of materials that today is between 5-10 % has the potential to be the biggest cause of waste for projects with other conditions than the studied project. The SWOT analysis showed that collaboration across the entire value chain is necessary to be able to implement circular solutions. Strengths, weaknesses, threats and opportunities for circular action were identified for all actors and showed, among other things, that the project client is a key actor in creating the right conditions for circular material handling.  The study also carried out a deeper analysis of how relevant the processes and tools identified in the value chain are for Skanska’s work with circularity. Among other things, it emerged that certifications such as CEEQUAL and Byggvarubedömningen can be important starting points. It was also shown that the design of the project and Skanska’s internal sustainability tools can be keys to create conditions, tangible goals, and strategies for working with circular material handling. The study also identified a certain discrepancy between the current waste legislation that advocates recycling and the opportunity and economy that currently exists in material recycling, especially for plastic. Here, Skanska and other construction contractors can have an important role to play in creating demand for recycled materials and thus increase the circularity of flows.

If we have a program with strict control flow security requirements and want to ensure system requirements by verifying properties of said program, but part of the code base is in the form of a plug-in or third party library which we do not have access to at the time of verification, the procedure presented in this thesis can be used to generate the requirements needed for the plug-ins or third party libraries that they would have to fulfil in order for the final product to pass the given system requirements. This thesis builds upon a transformation procedure that turns control flow properties of a behavioural form into a structural form. The control flow properties focus purely on control flow in the sense that they abstract away any kind of program data and target only call and return events. By behavioural properties we refer to properties regarding execution behaviour and by structural properties to properties regarding sequences of instructions in the source code or object code. The result presented in this thesis takes this transformation procedure one step further and assume that some methods (or functions or procedures, depending on the programming language) are given in the form of models called flow graph, while the remaining methods are left unspecified. The output then becomes a set of structural constraints for the unspecified methods, which they must adhere to in order for any completion of the partial flow graph to satisfy the behavioural formula. / Om vi har ett program med strikta kontrollflödeskrav och vill garantera att vissa systemkrav uppfylls genom att verifiera formella egenskaper av detta program, samtidigt som en del av kodbasen är i form av ett plug-in eller tredjeparts-bibliotek som vi inte har tillgång till vid verifieringen, så kan proceduren som presenteras i detta examensarbete användas för att generera de systemkrav som de plug-in eller tredjeparts-bibliotek behöver uppfylla för att slutprodukten ska passera de givna systemkraven. Detta examensarbete bygger på en transformationsprocedur som omvandlar kontrollflödesegenskaper på en beteendemässig form till en strukturell form. Kontrollflödes-egenskaperna fokuserar uteslutande på kontrollflöden i den meningen att de abstraherar bort all form av programdata och berör enbart anrop- och retur-händelser. Med beteendemässiga egenskaper syftar vi på egenskaper som berör exekverings-beteende och med strukturella egenskaper syftar vi på egenskaper som berör ordningen på instruktionerna i källkoden eller objektkoden. Resultatet i detta examensarbete tar denna transformationsprocedur ett steg längre och antar att vissa metoder (eller funktioner eller procedurer beroende på programmeringsspråk) är redan givna i formen av modeller som kallas flödesgrafer, medan resten av metoderna fortfarande är ospecificerade. Utdata blir då en mängd av strukturella restriktioner för de ospecificerade metoderna, som de måste följa för att en fulländning av den partiella flödesgrafen ska satisfiera den beteendemässiga formeln.

Detta är en studie om hur en framtagning utav en transportlåda på företaget AstraZeneca utfördes. Syftet med studien var att transportlådan skulle ersätta tre olika transportlådor som användes för att paketera tre olika storlekar på en förpackning som innehåller samma produkt. Förpackningarna har samma höjd och bredd men har olika längdmått beroende på hur många produkter som ska in i samma förpackning. Den första förpackningen har 1 produkt i sig, den andra förpackningen har 2 produkter i sig och den tredje förpackningen har 3 produkter i sig. För att ta sig an problemet användes linjärprogrammering för att hitta största gemensamma längdmått som ligger inom dimensionerna för en standardiserad EUR-pall. Utöver framtagningen utav lådan utfördes en flödesanalys samt en kostnadsanalys för att hitta förbättringsområden och kostnadsreduceringar i flödet. Studien lyckades att ta fram en låda där all tre olika förpackningar fick plats i och utöver det medförde den framtagna lådan att antalet produkter på pall ökade med 20% för förpackningen med 1 produkt i sig, 12 % för förpackningen med 2 produkter i sig och den sista förpackningen har samma antal produkter på pall jämfört med föregående låda. Kostnadsanalysen visade en kostnadsreducering på 1,96 mkr per år på inköpspriset jämfört med inköpskostnader för de tre tidigare transportlådorna. Slutsatsen för denna studie blev därför att det är en förbättring att införa den framtagna lådan istället för att ha tre separata transportlådor för respektive förpackning. / This is a study to display the process of developing a transportation box for the pharmaceutical company AstraZeneca. The purpose of study is to develop a transportation box in such a way so it could replace three already existing transportation boxes and enable these products to use the same transportation box. The products contain the same pharmaceutical product but has different dimensions for their respective containers where the height and the width is the same on all containers but has different length measurements depending on the number of pharmaceutical products in them. The first container contains 1 product, the second container contains 2 products and the third container contains 3 products. The solution to this problem was to use linear programming to establish a common length that the three containers share but is not larger than the dimensions on a standard EUR-pallet. Furthermore, the study was using a valueflow analysis and a cost analysis to determine which areas this transportation box can improve different processes within the company’s material flow. The linear programming succeeded in finding a common length for the three containers and a prototype was constructed in collaboration with the supplier. With the developed transportation box the study managed to increase the quantity on each pallet for 2 out of the 3 containers. The first container increased the quantity for each pallet with 20% and the increased the quantity for the second container with 12%. The quantity for the third container on each pallet remained the same as before. Furthermore, the cost analysis showed a reduced cost for purchasing the transportation box by 1,96 million SEK. This number is a comparison of the cost for the three already existing transportation boxes and an estimated prize on the developed transportation box. The verdict for this study is to implement the developed box because of the reduced costs and the improvements in the material flow that the box provides.