Cities are responsible for an increasingly large share of environmental impacts linked to their resource consumption and production of waste. Understanding how the flows of materials and energy in urban systems contribute to environmental impacts is fundamental for urban sustainability. The combination of Material and Energy Flow Analysis (MEFA) and Life Cycle Assessment (LCA) allows an in-depth evaluation of the city’s metabolism by quantifying the environmental impacts of these flows from a life cycle perspective. This method provides a global perspective on the environmental impacts of the studied system and helps avoiding unintended tradeoffs between life cycle stages or between different types of environmental impact.  This thesis aims to analyze the urban metabolism of the city of Umeå by using a simplified MEFA- LCA methodology. The simplified method aims to evaluate urban metabolism based on the available data, without requiring intensive data inventory, and thus can be a powerful tool to assess the sustainability of cities that have not previously been studied, and for which detailed data on material flows are not available, like in the case of Umeå. The MEFA method was used to identify and quantify the most important flows for 5 main sectors in Umeå’s metabolism: households, construction, transportation, wastewater and solid waste treatment. Then, the environmental impacts of these flows throughout their life cycles were quantified with the LCA methodology. Life cycle inventory data were taken from processes available on the Ecoinvent and Agri-footprint databases, and the impact assessment was done using the ReCiPe midpoint method, considering all impact categories to provide a broader view of the environmental impacts.  The results from the application of the MEFA-LCA methodology provided different but complementary information on the city’s metabolism. The households are responsible for most of the material flows, with water being the most relevant flow, while the transportation sector is responsible for most of the energy flows in the form of fuels. The LCA analysis showed that the households and the transportation sector are responsible for the largest share of the environmental impacts. The flow of manufactured materials is the most relevant for the households sector, followed by energy and foods and drinks. In the transportation sector, private passenger cars and air travel correspond to the largest share of impacts in all categories. Regarding the other three sectors, in the construction sector, concrete and cement represent the material flow with the most impact, while the solid waste and wastewater treatment have small contributions to the total environmental impacts.  The analysis performed in this thesis demonstrated that the MEFA-LCA methodology is a useful tool to evaluate the environmental sustainability of a city’s metabolism. It can assess how different sectors and flows contribute to environmental impacts, without requiring exhaustive data. Thus, it can identify key sectors and flows that should be prioritized when developing strategies or planning future research. / Städer står för en allt större del av miljöpåverkan kopplad till deras resursförbrukning och produktion av avfall. Att förstå hur flöden av material och energi i urbana system bidrar till miljöpåverkan är grundläggande för urban hållbarhet. Kombinationen av material- och energiflödesanalys (MEFA) och livscykelanalys (LCA) möjliggör en djupgående utvärdering av stadens metabolism genom att kvantifiera miljöpåverkan från dessa flöden ur ett livscykelperspektiv. Denna metod ger ett globalt perspektiv på miljöpåverkan från det studerade systemet och hjälper till att undvika oavsiktliga förskjutningar (trade-offs) mellan olika typer av miljöpåverkan eller mellan olika delar av livscykeln.  Detta examensarbete syftar till att analysera den urbana metabolismen i Umeå stad genom att använda en förenklad MEFA-LCA metod. Den förenklade metoden syftar till att utvärdera urban metabolism baserat på tillgängliga data, utan att kräva intensiv datainventering, och kan därmed vara ett kraftfullt verktyg för att bedöma hållbarheten i städer som inte tidigare har undersökts och för vilka detaljerade data om materialflöden inte finns tillgängliga, som i fallet med Umeå. MEFA-metoden användes för att identifiera och kvantifiera de viktigaste flödena för 5 huvudsektorer i Umeås urbana metabolism: hushåll, byggsektorn, transport, avloppsrening och avfallshantering. Sedan kvantifierades miljöpåverkan av dessa flöden under deras livscykel med LCA-metoden. Livscykelinventeringsdata togs från processer tillgängliga på Ecoinvent- och Agri- footprint-databaserna, och miljöpåverkansbedömningen gjordes med hjälp av ReCiPe- midpunktsmetoden, med hänsyn till alla påverkanskategorier för att ge en bredare bild av miljökonsekvenserna.  Resultaten från tillämpningen av MEFA-LCA-metoden gav olika men kompletterande information om stadens metabolism. Hushållen står för merparten av materialflödena, där vatten är det mest relevanta flödet, medan transportsektorn står för merparten av energiflödena i form av bränslen. LCA-analysen visade att hushållen och transportsektorn står för den största delen av miljöpåverkan. Flödet av tillverkat material är det mest relevanta för hushållssektorn, följt av energi samt mat och dryck. Inom transportsektorn motsvarar privata personbilar och flygresor den största andelen påverkan i alla kategorier. När det gäller de övriga tre sektorerna, inom byggsektorn representerar betong och cement det materialflöde som har störst påverkan, medan avloppsrening och avfallshantering har små bidrag till den totala miljöpåverkan.  Analysen som utfördes i denna avhandling visade att MEFA-LCA-metoden är ett användbart verktyg för att utvärdera den miljömässiga hållbarheten hos en stads metabolism. Den kan bedöma hur olika sektorer och flöden bidrar till miljöpåverkan, utan att kräva uttömmande data. Således kan den identifiera nyckelsektorer och flöden som bör prioriteras vid utveckling av strategier eller planering av framtida forskning.

This thesis reports on the research undertaken to minimise energy consumption within the production phase of a product lifecycle through modelling, monitoring and improved control of energy use within manufacturing facilities. The principle objective of this research is to develop a framework which integrates energy data at plant and process levels within a manufacturing system so as to establish how much energy is required to manufacture a unit product. The research contributions are divided into four major parts. The first reviews relevant literature in energy trends, related governmental policies, and energy tools and software. The second introduces an Embodied Product Energy framework which categorises energy consumption within a production facility into direct and indirect energy required to manufacture a product. The third describes the design and implementation of a simulation model based on this framework to support manufacturing and design decisions for improved energy efficiency through the use of what-if scenario planning. The final part outlines the utilisation of this energy simulation model to support a Design for Energy Minimisation methodology which incorporates energy considerations within the design process. The applicability of the research concepts have been demonstrated via two case studies. The detailed analysis of energy consumption from a product viewpoint provides greater insight into inefficiencies of processes and associated supporting activities, thereby highlighting opportunities for optimisation of energy consumption via operational or design improvements. Although the research domain for this thesis is limited to the production phase, the flexibility offered by the energy modelling framework and associated simulation tool allow for their employment other product lifecycle phases. In summary, the research has concluded that investment in green sources of power generation alone is insufficient to deal with the rapid rise in energy demand, and has highlighted the paramount importance of energy rationalisation and optimisation within the manufacturing industry.

Στην παρούσα διατριβή αναπτύσσονται κατάλληλα μοντέλα για τις επιμέρους μονάδες φωτοβολταϊκού (ΦΒ) συστήματος συνδεδεμένου στο δίκτυο. Στόχος είναι να αντιμετωπιστούν ταυτόχρονα και αποτελεσματικά οι ιδιαιτερότητές του, που οφείλονται στη συμπεριφορά των διακοπτικών στοιχείων και στα μη γραμμικά χαρακτηριστικά της ΦΒ γεννήτριας και του μετασχηματιστή απομόνωσης. Αναπτύσσονται μέθοδοι που αυξάνουν την ταχύτητα εξομοίωσης. Αυτό επιτυγχάνεται με χρήση αυξητικών μοντέλων για τα μη γραμμικά στοιχεία και αποτελεσματικών αλγορίθμων για την αντιμετώπιση της μεταβλητής τοπολογίας. Τα μοντέλα που παρουσιάζονται μπορούν να χρησιμοποιηθούν για συνδεδεμένα στο δίκτυο ΦΒ συστήματα οποιασδήποτε διάταξης. Μέσω εξομοιώσεων της λειτουργίας ενός οικιακού ΦΒ συστήματος συνδεδεμένου στο δίκτυο διερευνάται η ευαισθησία της αρμονικής παραμόρφωσης τάσεων και ρευμάτων σε μεταβολές παραμέτρων του συστήματος. Στη συνέχεια παρουσιάζεται ένα νέο μοντέλο για τη ροή ενέργειας σε κυκλώματα με μη ημιτονοειδείς κυματομορφές. Το μοντέλο παρέχει μαθηματική περιγραφή μέσω του πολυδιανύσματος της ισχύος, το οποίο γεφυρώνει το χάσμα μεταξύ στιγμιαίας και φαινομένης ισχύος, όπως η μιγαδική ισχύς υπό ημιτονοειδείς συνθήκες. Το πολυδιάνυσμα της ισχύος επιτρέπει συστηματική και ενιαία αντιμετώπιση όλων των περιπτώσεων. Το μοντέλο ροής ενέργειας που παρουσιάζεται περιγράφει τις συνιστώσες ισχύος όχι μόνο ποσοτικά, αλλά και ποιοτικά. Από φυσικής πλευράς βασίζεται στη γενίκευση της έννοιας της αμοιβαίας σύζευξης. Η προσέγγιση που ακολουθείται επιτρέπει την φυσική ερμηνεία όλων των συνιστωσών της ισχύος, οι οποίες συνδέονται με μια αναπαράσταση μέσω ισοδυνάμου κυκλώματος. Οι προϋπάρχουσες μέθοδοι μπορούν να προκύψουν ως ειδικές περιπτώσεις του μοντέλου. Η βαθύτερη κατανόηση των φαινομένων ισχύος που παρέχει θέτει το θεωρητικό υπόβαθρο για την επίλυση πρακτικών προβλημάτων, όπως η αντιστάθμιση. Ακολούθως εξετάζεται η επιλογή του βέλτιστου μεγέθους παθητικών φίλτρων με παράλληλους συντονιζόμενους κλάδους. Η διερεύνηση λαμβάνει υπόψη όχι μόνο πηγές αρμονικών ρευμάτων λόγω μη γραμμικών φορτίων αλλά και την παρουσία προϋπάρχουσας αρμονικής παραμόρφωσης της τάσης. Μέσω αναλυτικής μεθόδου προκύπτουν εκφράσεις κλειστής μορφής για απλοποιημένες περιπτώσεις. Αυτές μπορούν να βοηθήσουν στην κατανόηση της επίδρασης διαφόρων παραμέτρων. Επίσης διαμορφώνεται η γενικότερη περίπτωση του προβλήματος και αντιμετωπίζεται με Γενετικούς Αλγόριθμους. Μέσα από εκτεταμένες εξομοιώσεις για διάφορα επίπεδα αρμονικών τάσης και ρεύματος, διερευνώνται διεξοδικά οι δυνατότητες των παθητικών φίλτρων. Τα πρακτικά συμπεράσματα που προκύπτουν μπορούν να βοηθήσουν στη λήψη αποφάσεων για τον έλεγχο των αρμονικών σε διάφορες εφαρμογές. / In this thesis, appropriate models for the individual components of a grid-connected photovoltaic (PV) system are developed. The aim is to simultaneously and efficiently handle its peculiarities, which are due to the switching action of the switching devices and the nonlinear characteristics of the PV generator and the isolation transformer. Methods that increase simulation speed are developed. This is accomplished by using incremental models for the nonlinear components and efficient algorithms to handle the variable topology. The presented models can be used for grid-connected PV systems of any configuration. Through simulations of the performance of a residential grid-connected PV system the sensitivity of the harmonic distortion of voltages and currents to variations in system parameters is investigated. Next, a novel model for the energy flow in circuits with nonsinusoidal waveforms is presented. This model provides a mathematical description through the power multivector, which bridges the gap between the instantaneous and apparent power, like the complex power does under sinusoidal conditions. The power multivector permits a systematic and uniform treatment of all cases. The presented energy flow model describes power components not only quantitatively but also qualitatively. From a physical perspective it is based on the generalization of the concept of mutual coupling. The approach that is followed permits the physical interpretation of all power components, which are associated with an equivalent circuit representation. Pre-existing methods can be derived as special cases of the model. The deeper understanding of power phenomena it provides sets the theoretical foundation for the solution of practical problems, such as compensation. Next, the optimal sizing of shunt, passive, single-tuned filters is examined. The investigation takes into account not only harmonic current sources due to nonlinear loads but also the presence of background voltage harmonic distortion. Through an analytical approach closed-form expressions are derived for simplified cases. These can help in the comprehension of the influence of various parameters. Moreover, the general case of this problem is formulated and solved using Genetic Algorithms. Through extensive simulations for various current and voltage harmonic levels, the potentialities of these filters are thoroughly investigated. The practical conclusions that are drawn can facilitate decisions regarding harmonic control in various applications.

The advent of services such as cloud computing, social networks and e-commerce has led to an increased demand for computer resources from data centers. Prominent issues for data center designers are sustainability, cost, and dependability, which are significantly affected by the redundant architectures required to support these services. Within this context, models are important tools for designers when attempting to quantify these issues before implementing the final architecture. This thesis proposes a set of models for the integrated quantification of the sustainability impact, cost, and dependability of data center power and cooling infrastructures. This is achieved with the support of an evaluation environment which is composed of ASTRO, Mercury and Optimization tools. The approach taken to perform the system dependability evaluation employs a hybrid modeling strategy which recognizes the advantages of both stochastic Petri nets and reliability block diagrams. Besides that, a model is proposed to verify that the energy flow does not exceed the maximum power capacity that each component can provide (considering electrical devices) or extract (assuming cooling equipment). Additionally, an optimization method is proposed for improving the results obtained by Reliability Block Diagrams, Stochastic Petri nets and Energy Flow models through the automatic selection of the appropriate devices from a list of candidate components. This list corresponds to a set of alternative components that may compose the data center architecture. Several case studies are presented that analyze the environmental impact and dependability metrics as well as the operational energy cost of real-world data center power and cooling architectures. / Submitted by João Arthur Martins (joao.arthur@ufpe.br) on 2015-03-12T18:54:10Z No. of bitstreams: 2 Tese Gustavo Callou.pdf: 4626749 bytes, checksum: 336a34ffc39f6ac623fa1144de2a66bf (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) / Made available in DSpace on 2015-03-12T18:54:10Z (GMT). No. of bitstreams: 2 Tese Gustavo Callou.pdf: 4626749 bytes, checksum: 336a34ffc39f6ac623fa1144de2a66bf (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Previous issue date: 2013-11-12 / O surgimento de servi¸cos como computa¸c˜ao nas nuvens, redes sociais e com´ercio eletrˆonico tem aumentado a demanda por recursos computacionais dos data centers. Preocupa¸c˜oes decorrentes para os projetistas de data center s˜ao sustentabilidade, custo, e dependabilidade, os quais s˜ao significativamente afetados pelas arquiteturas redundantes requeridas para suportar tais servi¸cos. Nesse contexto, modelos s˜ao ferramentas importantes para projetistas quanto a tentativa de quantificar esses problemas antes mesmo de implementar a arquitetura final. Nessa tese, um conjunto de modelos ´e proposto para a quantifica¸c˜ao integrada do impacto na sustentabilidade, custo e dependabilidade das infraestruturas de refrigeramento e potˆencia de data centers. Isso ´e obtido com o suporte do ambiente de avalia¸c˜ao que ´e composto pelas ferramentas ASTRO, Mercury e o m´odulo de otimiza¸c˜ao. A avalia¸c˜ao de dependabilidade faz uso de uma estrat´egia de modelagem h´ıbrida que usa as vantagens tanto das redes de Petri estoc´asticas como dos diagramas de blocos de confiabilidade. Al´em disso, um modelo ´e proposto para realizar a verifica¸c˜ao se fluxo de energia n˜ao excede a capacidade m´axima de potˆencia que cada equipamento pode prover (considerando dispositivos el´etricos) ou extrair (assumindo equipamentos de refrigera¸c˜ao). Adicionalmente, um m´etodo de otimiza¸c˜ao ´e proposto para melhorar os resultados obtidos atrav´es dos diagramas de blocos de confiabilidade, das redes de Petri estoc´asticas e do modelo de fluxo de energia pela sele¸c˜ao autom´atica dos dispositivos apropriados a partir da lista de componentes candidatos. Essa lista corrresponde a um conjunto de componentes que podem ser utilizados para compor a arquitetura de data center. V´arios estudos de casos s˜ao apresentados para analisar o impacto ambiental, a dependabilidade e o custo operacional de energia el´etrica de arquiteturas reais de potˆencia e refrigera¸c˜ao de data centers.

Les changements d'intensité dans l'utilisation des sols et la dégradation de l'environnement en raison de activités humaines ont entraîné une forte altération des écosystèmes tropicaux, en particulier dans les cours d'eau de tête de bassin de la savane néotropicale. Les pressions humaines liées à l'expansion agricole et à l'urbanisation ont conduit à une réduction drastique de la couverture végétale indigène, affectant les zones riveraines et altérant le fonctionnement des écosystèmes aquatiques. Il est urgent de quantifier et de prévoir comment les communautés aquatiques répondent aux changements de l'utilisation des sols pour guider les efforts de conservation et de gestion des ressources naturelles. Dans ce contexte, cette thèse visait à évaluer à quelles échelles spatiales la relation entre habitat et communautés de macroinvertébrés benthiques s'exprimait le plus fortement et comment l'intensité d'utilisation des sols affectait les relations trophiques et la composition en traits biologiques des communautés de macroinvertébrés benthiques. Dans le chapitre 1, j'évalue comment l'intensité d'utilisation des sols (représentée par un gradient depuis la végétation autochtone, au pâturage, et à la plantation de canne à sucre et la végétation indigène) influe sur les flux d'énergie et les niches trophiques des macroinvertébrés benthiques. Ensuite, j'ai évalué à quelle échelle spatiale (bassin versant, localité) et pour quelles variables, le lien entre la composition taxonomique et fonctionnelle des assemblages de macroinvertébrés benthiques était le mieux exprimé (chapitre 2). Enfin, j'ai montré que les perturbations anthropiques avait unj impact sur la diversité fonctionnelle des assemblages de macroinvertébrés benthiques (chapitre 3). Les résultats présentés ici montrent que les changements d'intensité de l'utilisation des sols conduisent les assemblages de macroinvertébrés benthiques vers des comportements d'alimentation plus généralistes avec un chevauchement des niches trophiques (chapitre 1). De plus, les variables environnementales à l'échelle locale et du bassin versant expliquent de façon significative les variations de la composition taxonomique et fonctionnelle des assemblages d'Ephéméroptères, Plécoptères et Trichoptères, mais les variables décrivant l'intensité d'utilisation des sols expliquent le mieux les différences de composition fonctionnelle entre les différents sites (chapitre 2). Enfin, J'ai montré que les sites quasi-naturels (dans des conditions de référence) ont des assemblages de macroinvertébrés plus spécialisés comparés aux sites perturbés (chapitre 3). Les résultats corroborent le fait que la biodiversité doit être évaluée en tenant compte de variables agissant à de multiples échelles spatiales et que les éléments fonctionnels des communautés biologiques doivent être considérés, en vue de la conservation et du développement d'outils prédictifs. Cette étude contribue à une meilleure compréhension de la structure et du fonctionnement des cours d'eau dans la savane néotropicale dans le contexte du développement d'outils d'évaluation environnementale. Ces approches contribueront à l'élaboration de mesures de gestion et de conservation plus appropriées et permettront d'examiner les conséquences futures d'une poursuite de la dégradation des conditions écologiques dans les cours d'eau tropicaux / Changes in land cover and use and the associated environmental degradation due to human activities have resulted in extreme alterations of tropical ecosystems, especially in headwater streams and their watersheds in the neotropical savanna. Human pressures related to agricultural expansion and urbanization have led to drastic reductions in native vegetation cover, affecting riparian zones and degrading aquatic ecosystem functioning. There is an urgent need to quantify and predict how aquatic communities respond to different intensities of land use to guide conservation and natural resource management efforts. This thesis aims to evaluate how spatial scales influence the relationship between habitat and benthic macroinvertebrate communities and how land use intensity affects the trophic relationships and biological traits of macroinvertebrates. In Chapter 1, we evaluated how the intensity of land use (represented by a gradient moving from native vegetation toward pasture and sugar cane plantations) influences the energy flow and trophic niches of macroinvertebrates. In Chapter 2, we investigated the spatial scales (e.g., catchment, local) that most influence the taxonomic and functional composition of macroinvertebrate assemblages. Finally, in Chapter 3, we examined the impacts of human pressures on the functional diversity of macroinvertebrate assemblages. we showed that the intensity of land use affects benthic macroinvertebrate assemblages, yielding more generalist feeding behaviors with greater overlap of trophic niches (Chapter 1). In addition, environmental variables at the local and catchment scales significantly explained the variations in the taxonomic and functional composition of Ephemeroptera, Plecoptera and Trichoptera assemblages, but land use variables best explained the differences in functional composition among sites (Chapter 2). Finally, we showed that less impacted sites (under reference conditions) had more specialized and more functional diverse macroinvertebrate assemblages compared to disturbed sites (Chapter 3). These results corroborate the idea that biodiversity should be evaluated at multiple spatial scales and that the functional elements of biological communities should be considered when aiming for conservation and the development of predictive tools. This study contributes to a better understanding of the structure and functioning of streams in the neotropical savanna by subsidizing the development of environmental assessment tools. Such approaches will contribute to the development of more appropriate management and conservation measures that will allow for evaluation of the impacts on biota of further degradation of the ecological conditions in tropical streams

The aim of this study is to assess the current situation of energy and carbon flows through the waste sector in Jämtland. An energy flow analysis is performed by balancing the inflows and outflows of the lower heating value and embodied energy. A carbon flow analysis was made on the same principles although with the carbon content and embodied CO2eq.  The results are showing that over a period of one year, 75 000 tons of waste flows through the waste sector in Jämtland. Approximately 60 % of all the waste is incinerated. The energy analysis shows that 970TJ flows through the waste sector every year. Household waste is the category with most energy consumption and emissions in total. However, other materials like metal and electronics have higher energy and carbon content per ton than the household category. The results of the analyses can further be implemented in the Sustainable Jämtland model and it can then be used as a base when making strategies for a sustainable waste treatment.

Orchideoid mycorrhizal symbiosis (OM) can be found in nearly one tenth of higher plant species. This symbiosis is absolutely critical for orchids as they are unable to grow from seeds without external energy which is in nature provided by symbiotic fungi. The mechanism of transport between symbionts remains unknown. It is supposed that trehalose is one of the substances transported from fungi to plants as the source of energy. This thesis mainly aims to find out which other fungal saccharides could contribute to the process. The ability to utilize selected compounds was tested on protocorms of the common marsh orchid, Dactylorhiza majalis. The results showed that arabitol, erythritol, mannitol and sucralose are not utilized, while xylitol, sorbitol, glycerol and mannose are. Glutamin, an amino acid also suspected of participation in the OM transport, does not suffice as a source of energy. In orchids there were identified three groups of sequences coding for manitol dehydrogenase and two groups of sequences coding for sorbitol dehydrogenase. Key words: orchideoid mycorrhizal symbiosis, sugar alcohols, mannose, glutamine, carbon flow, energy flow, sorbitol dehydrogenase, in vitro

Värmevärden AB is an energy company that distributes district heating. One of their challenges today is to reduce the energy losses and wear that occur in the plant's scrapper conveyor unit. The conveyor belt is in constant motion whether it is transporting fuel or going unloaded at idle. An understanding of the module's energy flow needs to be mapped. An energy flow behavior model for the scrapper conveyor unit is presented. The energy flow in the startup sequence when the belt runs at idle and at full load is simulated. The simulations visualize the velocity and acceleration of the belt as a function of time and the current flow in the engine when getting started. The model allows changes on various parameters such as engine velocity, current limitations, work efficiency and enables the calculation of necessary material to achieve a desired power delivery. With a current-limited engine of 140 [A], a lower acceleration is obtained as the belt transports the fuel masses. Energy losses are also reduced as the belt is started by their own mass when transportation is needed. This means that the wear on the components of the plant decreases as transportation takes a more controlled form. / Värmevärden AB är ett energibolag som distribuerar fjärrvärme. En av deras utmaningar idag är att minska energiförlusterna och slitaget som uppstår i anläggningens skrapstransportörs modul. Transportbandet är i konstant rörelse vare sig det transporterar bränsle eller går olastad i tomgång. Förståelse för modulens energiflöde behöver kartläggas. En beteendemodell för skraptransportörens modul presenteras. Genom analys av energiflödet i systemet simuleras startförloppet när bandet körs i tomgång och vid full last. Simuleringarna visualiserar bandets hastighet och acceleration som funktion av tid och även motorns strömförlopp under uppstartsfasen. Modellen tillåter ändringar på diverse parametrar såsom motorns varvtal, strömbegränsning, verkningsgrad och möjliggör även framräkningen av nödvändigt material för att uppnå en viss leverans uteffekt. Med en strömbegränsad motor på 140 [A] fås en lägre acceleration när bandet transporterar bränslemassorna. Energiförlusterna minskar också eftersom bandet sätts igång av massornas egenvikt när transporteringen behövs. Detta medför att slitaget på anläggningens komponenter minskar i och med att transporten sker i mera kontrollerade former.

This dissertation describes the development of an intelligent non-invasive thermal energy flow rate sensor for laminar and turbulent pipe flows. Energy flow rate is the thermal energy that is carried by a fluid, for example, in a pipe to heat or cool a space in a building. It can be measured by an energy flow rate sensor which consists of a volume flow rate meter and supply and return fluid temperature sensors to bill the users for their energy usage. A non-invasive, low-cost, and easy to install thermal energy flow rate sensor based on thermal interrogation transient heat flux and temperature measurements has been developed to measure fluid velocity and fluid temperature in pipes. This sensor can be used for different pipe diameters, different pipe materials, and different viscous fluids. The transient measurements are made on the outer surface of a pipe by using a heat flux sensor and a thin-film thermocouple which are covered by a thin-film heater. A one-dimensional transient thermal model is applied before and during activation of the external heater along with a parameter estimation code to provide estimates of the fluid heat transfer coefficient and apparent thermal resistance between the thermocouple and the pipe surface. This dissertation contributes to the sensor's development in three ways. First, a new design is developed by using a single layer of Kapton tape with an adhesive (dielectric material) between the thermocouple foils and the pipe wall to isolate the thermocouple electrically from the pipe surface. This new design gives accurate and reliable estimates of the internal mean fluid temperature without environmental interference. Second, this new sensor design is tested for turbulent pipe flows with two different pipe diameters ( = 25.4 mm and = 12.7 mm) and two different viscous fluids (diesel oil and water). Experiments are completed over a large range of fluid velocity from 0.2 m/s to 5.5 m/s and a range of fluid temperature from 20 ℃ to 50 ℃. The estimated parameters, heat transfer coefficient and apparent thermal resistance, are correlated with the fluid velocity and fluid temperature. This sensor gives a good correlation, repeatability, and sensitivity between the estimated parameters and the fluid velocities with an accurate estimation of the fluid temperatures without environmental interference. Third, this sensor is tested for laminar flow in pipes over a range of fluid velocity from 0.049 m/s to 0.45 m/s and a range of fluid temperature from 20 ℃ to 50 ℃. A new empirical correlation between the estimated parameters and the laminar fluid velocity has been developed. The results show that this sensor gives lower sensitivity and accuracy between the estimated parameters and the fluid velocity and fluid temperature for the laminar flow. / Doctor of Philosophy / Heating or cooling is responsible for approximately 50% of the total energy consumption in a building. Budlings' energy consumption can be measured by energy flow rate sensors (measuring both fluid velocity and fluid temperature). Current energy flow rate sensors are invasive (requiring installation inside the system and disturbing the flow) which create unacceptable risks, such as fluid leaks and damage the equipment. Other energy flow rate sensors based on ultrasonic and electromagnetic technologies are non-invasive which can be installed on the outside of the pipe without disturbing the flow, however, they are expensive to buy, difficult to install, and hard to calibrate. Therefore, developing new sensor techniques is necessary, preferably non-invasive, low-cost, and easy to install. In this dissertation, a new non-invasive, low-cost, and easy to install thermal energy flow rate sensor has been designed, developed, and tested. This thermal sensor is based on transient heat flux and temperature measurements which are made on the outside of a copper pipe surface by using a heat flux sensor and a thermocouple. This sensor is used to estimate the energy consumption by measuring a fluid velocity and a fluid temperature in heating and cooling pipe applications for different pipe diameters, different fluids, and different pipe materials. A parameter estimation code is developed to match the analytical and experimental sensor temperature values and to estimate the unknown system parameters. These parameters are correlated with the fluid velocity and fluid temperature. Experiments are completed over a large range of fluid velocity from 0.049 m/s to 5.5 m/s and a range of fluid temperature from 20℃ to 50℃. The encouraging measurement results show that this sensor gives a good correlation, repeatability, accuracy, and sensitivity between the estimated parameters and the fluid velocities with an accurate estimation of the fluid temperatures to allow calculation of the thermal energy consumption.

This dissertation is based on the conceptual framework of social metabolism and it applies methods of Material and Energy Flow Analysis and Ecological Footprint. It studies interactions between human activities and natural environment in Czech/Czechoslovak territory from the historical perspective (after the division of Czechoslovakia for Czechia and Slovakia together). The term of social metabolism is a metaphor inspired by biology. Society or human economy similarly to a living organism which extracts materials from the earth, processes biophysical materials to maintain itself and emits its wastes back. So the economic system functions in an analogy to a living organism and those processes are called "social" or "industrial" metabolism. This dissertation comprises seven individual empirical studies: (I) An introduction to a research topic covered in following articles. It is based on the work of leading world environmental historian and it interprets selected Czech realities within the context of the world environmental history. (II) The historical series of MEFA indicators together with ecological footprint. (III) An article which applies the ecological footprint method on the ecological farm in comparison to conventional agriculture in the context of more foreign studies on this topic. (IV) An...