This study examines the subsurface infrastructure in the Swedish city of Norrköping from an urban mining perspective. Urban mining is a broadly defined term for different strategies that regard the built environment as a resource base for materials. In this study, the focus is on three base metals that exist in large quantities in infrastructure parts: iron, copper and aluminium. A special focus is given to the parts of Norrköping’s infrastructure that are not in-use and thus constitute a ”hibernating stock” that contains recyclable metals. The main results of this study are twofold. First, a quantitative assessment of the hibernating stocks of urban infrastructure gives answers to how large the stocks are and where in Norrköping they are located. This was performed using a spatially informed Material Flow Analysis to arrive at a recycling potential in terms of weight and spatial concentration. Second, a qualitative assessment was made regarding how these hibernating stocks of urban infrastructure come into existence. An infrastructure studies perspective was used to outline three patterns with their own sets of ”hibernation” logics. These logics give rise to different prerequisites for the implementation of urban mining in practice. A main argument of this study’s cover essay is that both of the above outlined kinds of knowledge are needed to engage in urban mining with confidence. Thus, the main focus of the cover essay text is to describe how the two different perspectives of Material Flow Analysis and infrastructure studies were combined into a coherent research approach.

Today’s society is increasingly moving towards a digitalized world where society is becoming more connected. In terms of industries, it´s extra important to keep up with this trend to be competitive, but also to be more effective. This work will be done in collaboration with the company Attindas. Attindas is a manufacturer of absorbent incontinence aids and delivers products worldwide. The purpose of this work is to investigate two different material flows at Attindas. These flows are raw materials in the warehouse and waste from production to recycling rooms. A deeper analysis is made of the different flows to investigate which parts can be automated and how to do this. The goal of this work is to develop a solution that can replace today’s manual material handling. The problem statements this work is based on is: • Which material flow of waste and raw material are the most valuable to automate? • How can the chosen material flow be automated? The work is carried out with a Design Thinking method that goes through the following steps. Find users’ needs, define needs and problems, come up with ideas and test the solution. The work is supported by a literature study that examines what has already been done and what is already on the market. The result of this work was that Attinda’s waste management is the material flow that should be automated if financial gain and efficiency are to be achieved. The solution that was constructed is an external lifting device that will be mounted on a platform AGV (Automated Guided Vehicle). Two AGVs will drive in the factory and pick up four waste wagons at a time. This is to cope with the waste flow that comes from the production lines. The conclusion of the work is that waste management is a step that Attindas can automate to go to a more automated factory and get one step closer to Industry 4.0. With the help of the new solution, which is a lifting device adapted to the waste bins. Attindas can replace manual work and automate the flow of waste from production to recycling room. By implementing this solution in the factory, Attindas will over time make a financial gain comparable to the current solution, while maintaining its efficiency. / Dagens samhälle går allt mer mot en digitaliserad värld där samhället blir mer uppkopplat. Vad gäller industrier är det extra viktigt att hänga med i denna trenden för att vara konkurrenskraftiga, men även för att effektivisera verksamheten. Detta arbete kommer att göras i samarbete med företaget Attindas. Attindas är en tillverkare av absorberande inkontinenshjälpmedel och de levererar produkter över hela världen. Problemformuleringen som arbetet utgår ifrån är: • Vilket materialflöde av avfall och råmaterial är det mest värdefulla att automatisera? • Hur kan det valda materialflödet automatiseras? Syftet med detta arbete är att undersöka två olika materialflöden hos Attindas. Dessa flöden är råmaterial i lagret och spill från produktion till återvinningsrum. En djupare analys görs på de olika flödena för att undersöka vilka delar som går att automatisera samt hur man kan göra detta. Målet med detta arbete är att ta fram en lösning som kan ersätta dagens manuella materialhantering. Arbetet genomförs med en Design Thinking metod som genomgår följande fem steg. Hitta användarens behov, definiera behov och problem, komma upp med ideer, ta fram ideerna och testa lösningen. Arbetet styrks upp av en litteraturstudie som undersöker vad som redan har gjorts och vad som redan finns på marknaden. Resultatet av detta arbete blev att Attindas spillhantering är det materialflöde som borde automatiseras ifall ekonomisk vinning och effektivitet vill uppnås. Lösningen som konstruerades är en extern lyftanordning som ska monteras på en plattform AGV. Två stycken AGV ska köra i fabriken och hämta upp fyra spillvagnar åt gången. Detta för att klara av det flöde av spill som kommer från produktions linjerna. Slutsatsen av arbete är att spillhantering är ett steg som Attindas kan automatisera för att gå till en mer automatiserad fabrik och komma ett steg närmre Industri 4.0. Med hjälp av den framtagna lösningen som är en lyftanordning anpassad för de spillvagnar som finns i fabriken kan Attindas ersätta manuellt arbete och automatisera flödet av spill från produktion till återvinningsrum. Genom att implementeradenna lösningen i fabriken kommer Attindas både göra en ekonomisk vinning jämfört med dagens lösning, samtidigt som arbetet bibehåller sin effektivitet.

Life cycle analysis is an appropriate way to clear obscure facts about an element. Gallium is a critical element which is used in many technologies these days and therefore quantification of main global cycles of gallium, production, consumption and end of life products, also investigation about recycled gallium content and potential recycling possibilities are investigated in this paper. First a qualitative substance flow for gallium is designed similar to other metal cycles with regards to exclusive characteristics of gallium flows itself. USGS and World Mining Data are mainly used to get information about gallium production, main gallium consumptions and end of life products. Subsequently a quantitative model in STAN should unlock many uncertainties. Substance flow analysis and material flow analysis give a better understanding of unknown gallium flows with their uncertainties and meanwhile major applications, concentration of gallium in different products, waste flows, landfills and present recycling technologies are detailed. Consequently STAN model asserts that main gallium flows are primary gallium production and refined gallium production in production process, Integrated Circuit board fabrication, Light Emitting Diodes, Photovoltaic and recycled new scrap flow in manufacturing process. A significant amount of gallium is collected as stock in consumption process. Also current gallium recycling facilities are limited as recycling is not economically justified. Moreover main part of recycled gallium content is collected from new scrap which is formed through manufacturing process. Finally gallium consumption in Photovoltaic and Light Emitting Diodes industry increases rapidly and sustainability demand cost efficient methods for gallium recycling from solar cells, diodes and other end of life products.

In today’s competitive global market every companies strive to overcome challenges that occur during manufacturing in order to gain profits and stay in competition. Overcoming challenges include elimination or reduction of non-value adding activities that are happening in production. To eliminate non-value adding activities and achieve desired workflow it is important to follow set of successful strategies which suits production system. In this current research framework has been proposed which aids reduction of non-value adding activities and also plays an important role in achieving efficient material flow. Current research is carried out in a single case study at a Swedish manufacturing firm where identification of effects of existing non-value-added activities in major aspects of material flow was carried out. By analysing the findings from case company along with data from literature review effects of NVA on material flow were identified in production facility and solution has been recommended in the form of framework to overcome these problems. In the conclusion a set of strategies were developed into a framework by analysing the effects of existing NVA in production facility has been further recommended for implementation at case company to check for generalisability of developed framework. This framework aids in overcoming common problems associated with material flow along with eliminating effects of NVA activities and also helps improving productivity which enhances proper flow of materials into line.

The aim of the PhD thesis is to design a methodology for generating a material flow using a simulation meta-model of a mass production process. This methodology is in principle based on the relationship between selected material flow characteristics. Simulation of production and logistics processes has been increasingly used in planning, commissioning and subsequent operational management and optimization of the respective technological operations, in particular in mass production. The first part of the PhD thesis summarizes up-to-date findings in the field of discrete event simulation of material flow, related statistical and mathematical disciplines, but also information technology which enables effective realization of simulation studies. Attention is also paid to significant domestic and international conferences, symposia and interest associations related to simulation of manufacturing processes. The next part of the PhD thesis presents the methodology of reconstruction and generation of material flow using simulation meta-models developed for this purpose. Principles of algorithms used by these meta-models and their possible range of use are demonstrated by simulation experiments carried out. Their description and results are also commented. Special focus is put on the selection of significant material flow characteristics and their mutual relationship. For its evaluation a series of simulation experiments was conducted using a simulation model of a closed queuing system with variable parameters. Revealed interdependence between the selected material flow characteristics is experimentally verified using a detailed simulation model of particular selected mass production system. The conclusion of the PhD thesis summarizes provided findings and, with regard to the designed methodology of reconstruction and generating of material flow, it outlines possible further steps both in research and their practical application.

京都大学 / 0048 / 新制・課程博士 / 博士(地球環境学) / 甲第19159号 / 地環博第134号 / 新制||地環||27(附属図書館) / 32110 / 京都大学大学院地球環境学舎環境マネジメント専攻 / (主査)教授 藤井 滋穂, 准教授 田中 周平, 准教授 西前 出 / 学位規則第4条第1項該当 / Doctor of Global Environmental Studies / Kyoto University / DFAM

Hydroscand in Örebro is part of the Hydroscand Group, which is the market leader in the Nordic region for customized hydraulic solutions. Hydroscand's main products consist of adapters, couplings, hydraulic hoses, pipes, and hose clamps. Due to the wide range of products offered by Hydroscand, the company's facility in Örebro has experienced recurring production stops linked to material shortages. The Örebro facility comprises three buildings: a production house, a warehouse, and Spendrup, where a large quantity of hoses is stored. This leads to long waiting times in the form of production stops because the transportation time between the buildings is lengthy.Through a systematic approach involving a current state analysis, it was confirmed that production stops related to material shortages should be prevented to streamline production. Following the current state analysis, a root cause analysis was conducted, identifying the root causes of material shortages in production. These root causes included an inadequate material supply strategy that was not tailored to the product flow, a lack of a visual system clarifying empty shelves for material suppliers, improper prioritization of hoses in the hose tower near the production lines, and material suppliers' position in the information flow, which hinderedpreventive actions against material shortages.The proposed solution consisted of four sub-solutions to prevent these root causes, including a shift from a push to a pull material supply strategy. This involved following a material list to ensure the availability of the correct materials in the production house. Implementation of a Kanban system was one of the sub-solutions to simplify the detection of empty shelves. The change in strategy led to a modification in the information flow, resulting in improved communication between production and material suppliers. The final sub-solution was to replace the hoses in the hose tower with the ones that are frequently sold, as the hoses in the highest demand will also be the most needed in production.The proposed solution will result in increased production productivity and the elimination of production stops associated with material shortages, which was the objective of the work. / Hydroscand i Örebro tillhör företagsgruppen Hydroscand Group som är marknadsledande iNorden gällande kundanpassade hydrauliklösningar. Hydroscands huvudsakliga produkter består av adapters, kopplingar, hydraulslangar, rör och slangklämmor. På grund av Hydroscands stora produktvariation så har företagets anläggning i Örebro haft återkommande produktionsstopp som har kopplats till materialbrist i produktionen. Örebros anläggning består av tre byggnader ett produktionshus, ett lagerhus och Spendrup där stora slangkvantitet lagras. Detta medför att materialbristen kan orsaka långa väntetider i form av produktionsstopp, eftersom transporttiden mellan byggnaderna tar lång tid.Genom ett metodiskt arbete där en nulägesanalys genomfördes bekräftades bilden av att produktionsstoppen kopplade till materialbrist bör förebyggas för att effektivisera produktionen. Efter nulägesanalysen genomfördes en rotorsaksanalys som fann rotorsakerna till att materialbrist förekom i produktionen. Dessa rotorsaker var felaktig materialförsörjningsstrategi som inte var anpassad till produktflödet, en avsaknad av ett visuellt system som förtydligar tomma hyllor för materialförsörjare, fel prioritering av slang i slangtornet nära anslutning till produktionslinorna och materialförsörjares position i informationsflödet som försvårade det förebyggande arbetet mot materialbrister.Lösningförslaget bestod av fyra dellösningar som skulle förebygga dessa rotorsaker, lösningen bestod av att förändra materialförsörjnings strategi från push till pull. Detta genom att följa en materiallista för att säkerställa att rätt material finns tillgängligt i produktionshuset. En implementering av ett Kanbansystem var en av dellösningar, detta för att förenkla upptäckten av tomma hyllor. Bytet av strategin ledde till en förändring av informationsflödet, vilket kommer resultera i en förbättrad kommunikation mellan produktion och materialförsörjare. Sista dellösningen var att byta de slang som låg i slangtornet mot de slang som oftast säljs, eftersom slang som har mest efterfrågan kommer även att behövas mest i produktionen.Lösningsförslaget kommer att resultera i ökad produktionsproduktivitet samt en eliminering av produktionsstopp kopplade till materialbrist, vilket var syftet med arbetet.

Upcycling is the process of repurposing discarded materials into new products of higher value, and holds significant potential for sustainable waste management. This thesis explores the challenges and opportunities involved in expanding upcycling practices in the city of Stockholm, with a specific focus on craft classes in public schools. The goal of the study is to identify key success factors and propose strategies for scaling up upcycling initiatives. A mixed method approach, including literature review, semi-structured stakeholder interviews, attitude surveys, and material flow analysis, was employed to gather insights and data. The findings reveal various challenges within the upcycling value chain, such as the need for efficient collecting processes, limited storage space, and financial feasibility. Despite the sechallenges, the research identifies several success factors, including cost-effectiveness, regulatory support, and the availability of discarded materials. Overall, this research contributes to the understanding of upcycling practices in public schools’ craft class and provides valuable insights for policymakers, educators, and practitioners seeking to implement and expand sustainable waste management strategies. By addressing the identified challenges and leveraging the opportunities, upcycling practices can be effectively integrated into public school curricula, fostering environmental consciousness and promoting a circular economy mindset among students. / Upcycling är förädlingsprocessen att återanvända avfall för att skapa mer värdefulla produkter. Det har en betydande potential för hållbar avfallshantering. Detta examensarbete undersöker svårigheterna och möjligheterna med att bredda metoderna för upcycling i Stockholms stad, med särskild uppmärksamhet på hantverkskurser som erbjuds av offentliga skolor. Målet med studien är att identifiera avgörande faktorer för framgång och ge förslag på metoder för att öka storleken på ett upcycling-projekt. För att inhämta information och data användes en blandning av tekniker, som inkluderade litteraturgenomgångar, semistrukturerade intervjuer av intressenter, attitydundersökningar och materialflödesanalyser. Resultatet visar på flera utmaningar inom värdekedjan för upcycling, inklusive krävande insamlingsprocedurer, begränsat lagringsutrymme samt villkoren för ekonomisk genomförbarhet. Trots dessa brister och utmaningar avslöjar denna studie även flera framgångsfaktorer. Dessa inkluderar kostnadseffektivitet, kommunalt stöd samt tillgången till avfall. Sammantaget bidrar denna studie till förståelsen av återanvändningsmetoder i offentliga skolorshantverkskurser och ger värdefulla insikter för beslutsfattare, utbildare samt andra praktiserande som vill implementera och utöka strategier för hållbar avfallshantering. Genom att ta itu med de påvisade utmaningarna och utnyttja möjligheterna kan praxis för upcycling effektivt integreras i den offentliga skolans läroplaner, öka miljömedvetenheten och slutligen främja ett tankesätt för cirkulärekonomi bland skoleleverna.

The purpose of this research was to use the Transvalor S.A. product, Forge3, to develop a finite element simulation of the friction stir welding process that improves the predictability of temperature evolution and material flow within the plunge portion of the process. Previous modeling created more heating within the billet than experimental results, probably due to the simplification of the simulation with adiabatic boundary conditions. More realistic tooling temperatures were included in this model as these affect heat evolution which is a determining factor in microcrystalline growth. These results were validated by experimental efforts using a billet and tooling instrumented with thermocouples used to evaluate the temperatures at specific locations over time. Simulation results were compared with previous experiments to validate the predicted material flow.

Material flow in friction stir welding is largely uncharacterized due to the difficulty in material flow measurement and visualization in metals. This study investigates plasticine for use as an analog for modeling material flow in friction stir welding (FSW) of metals. Qualitative comparisons between welded plasticine and metal sections exhibit many similarities. The transient temperature response of the plasticine also shows the same qualitative behavior as welds conducted in metal. To quantify its similarity to metal, the plasticine is further analyzed through compression tests to characterize its strain, strain-rate, and temperature sensitivities. A detailed analysis is presented which defines the criteria for rigorous mechanical and thermal similarity between metals and analog materials. The mechanical response of the plasticine is quantitatively similar to many aluminum and steel alloys. In addition to the mechanical properties of the plasticine, thermal properties are measured and thermal similarity is investigated. Generally, complete thermal similarity cannot be achieved in FSW. However, given the similarities between other critical parameters, and observed qualitatively similarity, it is possible to satisfy similarity approximately, such that information can be obtained from the physical model and extrapolated to metals. Using plasticine, material flow behavior in FSW is investigated under various operating conditions. The physical model permits visualization and characterization of material flow around a suspended welding tool. Depending on operating conditions, several material flow regimes are observed, including simple extrusion with substantial tool/material slip, defect formation, a region of rotating material adjacent to the tool, and vertical deformation. Material flow and frictional heating in FSW are also investigated using a three-dimensional numerical model. Two mechanical boundary conditions are investigated, including 1) a sticking constant velocity, and 2) a slipping variable shear stress model. The constant velocity model generally over-predicts the extent of material flow in the weld region. The variable shear model predicts simple extrusion of material around the tool, and substantial tool/material slip. Additionally, the variable shear model exhibits a region of diminishing shear stress, velocity, and pressure at the back advancing side of the pin, suggesting formation of an internal void. The limited deformation, low velocities, and indication of void formation agree well with flow visualization studies using plasticine under identical operating parameters.