| 1. |
- Abaravicius, Juozas
(author)
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Load Management in Residential Buildings: Considering Techno-Economical and Environmental Aspects
- 2004
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Licentiate thesis (other academic/artistic)abstract
- Load problems in electricity markets occur both on the supply and demand side and can have technical, economic and even political causes. Commonly, such problems have been solved by expanding production and/or distribution capacity, importing electricity or by load management. Load management is a techno-economic measure for harmonizing the relations between supply and demand sides, optimizing power generation and transmission and increasing security of supply. Interest in load management differs depending on the perspective of the actors involved: from customer, utility, or producer to state policymaker. The problem of load demand and load management in residential sector is in this thesis approached from different perspectives, i.e. technical, economic, and environmental. The study does not go deep into detailed analyses of each perspective, but rather aims to establish and analyze the links between them. This trans-disciplinary approach is the key methodological moment used in the research work performed by the research group for load management in buildings at the Lund Institute of Technology. The key objective of this study is to analyze load demand variation and load management possibilities in residential sector, particularly detached and semi-detached houses, to experimentally test and analyze the conditions and potential of direct load management from customer and utility viewpoint. Techno-economic and environmental aspects are investigated. The study was performed in collaboration with one electric utility in Southern Sweden. Ten electric-heated houses were equipped with extra meters, enabling hourly load measurements for heating, hot water and total electricity use. Household heating and hot water systems were controlled by the utility using an existing remote reading and monitoring system. The residents noticed some of the control periods, although they didn’t express any larger discomfort. The experiments proved that direct load management might be a possible solution for the utility to solve their peak demand problems. Another solution, considered by the utility and analyzed in this study is a construction of diesel peak power plant. This alternative has negative environmental consequences compared to load management. The analysis of environmental aspects was extended to national level. To include an environmental perspective is a novel approach, since traditionally, load management evaluation is limited the economic and technical viewpoints. It identifies and discusses the possible environmental benefits of load management and evaluates their significance, primary focusing on CO2 emissions reduction. The results show the importance of considering the influence of site-specific or level-specific conditions on the environmental effects of load management. On the national level, load management measures can hardly provide significant environmental benefits, since hydropower is used as the demand following production source in Sweden. Emission reductions will rather be the result of energy efficiency measures, which will cut the load demand as well as the energy demand.
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| 2. |
- Abbasi, Maisam
(author)
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Themes and challenges in developing sustainable supply chains
- 2012
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Licentiate thesis (other academic/artistic)abstract
- Sustainable development is one of the greatest global challenges facing human beings in the 21st century. In order to tackle sustainability related problems, several global, European, and national targets for 2050 have been set. The transition of supply chains activities towards sustainability targets calls for designing new strategies and continuously identifying and tackling the challenges that can hinder the operationalization of such strategies. The purpose of this research was to explore and classify themes and challenges in developing sustainable supply chains activities in general, and freight transport and urban distribution in particular. Three research questions were defined followed by defining the scientific assumptions and research strategies. Three research studies were then designed and carried out to find trustworthy and authentic answers to the corresponding research questions. However, research design, data collection, and data analysis were mixed and overlapping as they were not completely sequentially carried out. Data were collected by triangulation of different research methods, namely, literature review, content analysis, and semi-structured interviews. Analysis of the data was guided by principles of content analysis, discourse analysis, analytic induction, and grounded theory. Synthesis of the analyzed data resulted in the emergence of categories of themes and challenges, the development of hypotheses, and further discussion. In total, five categories of themes were identified for making supply chains environmentally sustainable, fifteen for making freight transport sustainable, and eight for making urban freight distribution sustainable. Five categories of challenges were identified for making supply chains environmentally sustainable, five for making freight transport sustainable, and seven for making urban freight distribution sustainable. All the themes and challenges were then synthesized to determine the patterns of their association. Five major themes in developing sustainable supply chains emerged, namely, increasing sustainability awareness, closing the loop of supply chains, making supply chains energy-efficient, making supply chains environmentally responsible, and managerial issues. Five major challenges in developing sustainable supply chains emerged, namely, change of behavior, costs, implementation, corporate governance, and antagonistic effects and paradoxical conflicts. As the nature of supply chains and the challenges identified in developing them sustainably is complex, a complexity theory perspective was considered beneficial for dealing with them. Such a perspective can enable us to: take a more holistic view of available sustainability-oriented strategies and activities; analyze the antagonistic effects of strategies and activities on each other; recognize conflicts of a paradoxical character that exist in supply chains; analyze the changes influencing and influenced by the strategies and activities; appreciate enough diversity and freedom among the sub-systems rather than too much simplification of them; design and redesign the transition paths for different types of supply chains. A complexity theory perspective can also be beneficial when governing a transformative transition of supply chains towards sustainability targets. Lessons are suggested in the discussion chapter that may help policy and decision makers in designing the future strategies and in tackling the challenges. The themes identified can be beneficial for increasing the absorptive capacity of industries, practitioners, and policy makers while they design innovative strategies for transitions towards sustainability targets. The identified challenges can also be beneficial for reducing the inertia and uncertainties against operationalization of sustainable development in practice.
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| 3. |
- Abdelmassih Waller, Peter
(author)
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Den utsträckta TV:n - Ett exempel ur praktiken
- 2007
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Licentiate thesis (other academic/artistic)abstract
- The aim of this licentiate thesis is twofold: 1) to describe old people’s interest in and prospects of using the television for something other than traditional TV viewing, and 2) to describe the nonlinearities in the design process in which this research was performed. A concept called The Extended TV was developed and tested (by old people, their relatives and care workers) in a new nursing home in the process of moving in, hiring employees, making final adjustments on the premises and in the technology. A total of thirty old people, between 60 and 100 years old, were included in the process which was carried out between June 2006 and February 2007. A pivotal background factor was that the initial resistance to the technology itself was low when it came to such a frequently used product as the television set. This proved to also be the case in this study when it came to TVs with flat screens (installed in all rooms and entirely independent of this project). The functions in The Extended TV included both personal ones and ones in common with other residents. The common functions consisted of an internal TV channel and two media centres with the necessary equipment to view common internal productions, other programmes of general interest and material that relatives supplied. The personal function dealt with communication based on one individual’s photo album presented on her own TV. The function and usage of The Extended TV were developed in and through an interweaving of visions, expertise, relationships, responsibilities and logistical prerequisites. The results deal with the interface, the people themselves in action (the old people, their relatives, the staff, IT consultants, technology providers, myself and many others), our tools and the scope of our action. What undoubtedly took the most time was the nonlinear design process. It was complex and by no means followed the initial plans. This is indeed more the rule than the exception in situated human design processes, but is documented all too seldom. I hope that the lessons from the usage of The Extended TV will contribute to innovative ideas concerning old people’s TV viewing.
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| 4. |
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| 5. |
- Abdul Hamid, Akram
(author)
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Method for evaluation of renovation measures with regards to moisture and emission loads : Based on risk assessments
- 2017
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Licentiate thesis (other academic/artistic)abstract
- Renovating the European building stock has for almost two decades been a matter of importance. For Sweden, it is important to renovate its multifamily buildings in order to achieve a reduced energy use, but also because renovation is needed due to building materials and services reaching (or having passed) the end of their life span. In order to renovate properly, renovation measures must be implemented correctly to avoid negative impact on the building materials and the indoor environment. For this purpose, renovation measures need to be evaluated with regards to moisture and emission loads, and the risks related to these. This thesis has developed a realistically applicable method for this type of evaluation, called RememberL, and tests RememberL on two renovation measures as case studies. Through laboratory tests, in-field measurements, building performance simulations, hygrothermal simulations and surveys, the renovation measures are evaluated according to the methodology. RememberL thereby yields useful results for understanding the impact that these methods have on building materials and the indoor environment and vice versa. Furthermore, through the application of RememberL on these case studies, it is further developed to a method that proves flexible through several alternatives.
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| 6. |
- Abrahamsson, Cristian
(author)
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Elevengagemang ur ett NO-lärarperspektiv : Hur lärare uppfattar elevers engagemang och dess betydelse för lärarrollen och undervisningen
- 2019
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Licentiate thesis (other academic/artistic)abstract
- AbstractThis essay focuses on teachers' perspective on student engagement and aims to highlight the connection between student engagement, teaching and content matter. It investigates how teachers interpret the concept of student engagement and what consequences their interpretation have for themselves, their teaching and their students. It also examines how teachers perceive the relationship between student engagement and the content of science teaching. The study is based on a theoretical view on engagement as a context-dependent, multi-dimensional concept that includes other concepts such as interest and motivation. Engagement is a concept often used when describing a desirable quality of school students. In research, the concept has been linked to students' outcome and lack of engagment as a precursor for drop-out from school behaviour. Many studies about engagement focus on how the concept is to be defined and measured and how engagement is influenced by its context, often described with other concepts such as attitude, interest and motivation. These studies often have a student-oriented perspective with questionnaires or self-assessments.Two methods for data collecting has been used. First, a three-stage Delphi survey distributed to 39 Swedish expert science teachers and second, four focus group interviews with a total of 21 science teachers teaching in Swedish upper primary school. The results show that teachers in the studies had no problem to use the concept of engagement even though they did not have a clear definition of what it stands for. They link engagement to motivation and interest and often interpret students’ feelings or behaviours as engagement, whereas evidence of cognitive strategies often go unnoticed. The teachers emphasize that their teaching in terms of strategies, methods and relations to studens is of great importance to students' engagement rather than content matter, itself. The major conclusions concern the relation between teaching and student engagement. Teachers can create engagement by using interesting aspects of the content or by linking it to students' own experiences. They see students' engagement as a confirmation of their own ability and the quality of their work. Their interpretation of the students' responses will then influence the form and content of teaching as student engagement is considered important. The results imply that engagement has a role to play as a concept teachers can use when they want to discuss science teaching and students' learning. This requires that teachers gain a deeper understanding of all dimensions of student engagement in view of the major influence student engagement has on the teacher and thereby the teaching. Then teachers’ knowledge about how to create engagement in science can be used as a means of increasing students’ learning, not for engagement as a goal for the teaching itself.
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| 7. |
- Abrahamsson, Marcus
(author)
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Uncertainty in Quantitative Risk Analysis - Characterisation and Methods of Treatment
- 2002
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Licentiate thesis (other academic/artistic)abstract
- The fundamental problems related to uncertainty in quantitative risk analyses, used in decision making in safety-related issues (for instance, in land use planning and licensing procedures for hazardous establishments and activities) are presented and discussed, together with the different types of uncertainty that are introduced in the various stages of an analysis. A survey of methods for the practical treatment of uncertainty, with emphasis on the kind of information that is needed for the different methods, and the kind of results they produce, is also presented. Furthermore, a thorough discussion of the arguments for and against each of the methods is given, and of different levels of treatment based on the problem under consideration. Recommendations for future research and standardisation efforts are proposed.
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| 8. |
- Abugabbara, Marwan
(author)
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Modelling and Simulation of the Fifth-Generation District Heating and Cooling
- 2021
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Licentiate thesis (other academic/artistic)abstract
- District heating and cooling are efficient systems for distributing heat and cold in urban areas. They are a key solution for planning future urban energy-efficient systems due to their high potential for integrating renewable energy sources. The systems also play an important role in community resilience, which makes them a multidisciplinary research topic. The continuous development of these systems has now reached the fifth-generation whereby end-customers can benefit from the intrinsic synergies this generation offers. A typical Fifth-Generation District Heating and Cooling (5GDHC) system consists of connected buildings that together have simultaneous heating and cooling demands. Local heat pumps and chillers in decentralised substations modulate the low network temperature to the desired building supply temperatures. The demands are potentially balanced by the means of recovering local waste heat from chillers, while also utilising heat pumps to provide direct cooling. The heat carrier fluid in the distribution pipes can therefore flow in either direction in the so-called bidirectional low-temperature network. A balancing unit is incorporated to compensate for network energy imbalances. The exchange of energy flows is realised at different stages within the individual building and across connected buildings. Numerous factors influence the quantity and quality of the exchanged energy flows. Demand profiles in each building, the efficiency of building energy systems, and control logics of system components are some examples of these factors. Investigating this generation using traditional computational tools developed using imperative programming languages is no longer suitable due to system complexity, size variability, and changes adopted in different use cases. Modelica is a free open-source equation-based object-oriented language used for the modelling and simulation of multi-domain physical systems. Models are described by differential-algebraic and discrete equations. The mathematical relations between model variables are encapsulated inside an icon that represents the model. Different component models interface variables through standardised interfaces and connection lines. Large complex systems are composed by the visual assembly of components in a Lego-like approach. Models developed in Modelica can be easily inherited for rapid virtual prototyping and/or edited to adopt changes in the model use. This dissertation has a fourfold objective. Firstly, it demonstrates the development of a simulation model for an installed 5GDHC system located in Lund, Sweden. Secondly, it characterises the components that constitute a 5GDHC system. Thirdly, it unravels the exchange of energy flows at different system levels and describes, in a logical progression, the modelling of 5GDHC with Modelica. Fourthly, it presents ethical risk analyses of the different role-combinations that may arise in 5GDHC business models. The developed model is used in performing annual simulations and to evaluate the system performance under two different substation design cases. The results indicate that adding a direct cooling heat exchanger in each substation can reduce the electric energy consumption at both substation and system levels by about 10 and 7 %, respectively. Moreover, the annual waste heat to ambient air can be decreased by about 17 %. The dissertation fosters an ethical discourse that engages the public and all who take part in the multidisciplinary research on 5GDHC to guarantee safe operation and appropriate services. Future research will build on the models presented in this dissertation to investigate different network temperature and pressure control strategies, in addition to adopting several design concepts for balancing units and thermal energy storage systems.
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| 9. |
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| 10. |
- Adalberth, Karin
(author)
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Bygga - Bruka - Riva : Energianvändning i småhus ur ett kretsloppsperspektiv
- 1995
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Licentiate thesis (other academic/artistic)abstract
- This report deals with single-unit dwellings built in 1991 and 1992 in a city called Orebro, Sweden.The houses are prefabricated and the frameworks are made of wood. The aim of the essay is to present the total use of energy during the life-cycle of single-unit dwellings, taking their mode of construction into account. The life-cycle of a house is divided into the following periods: production (manufacturing of the building materials, transportation of the materials and erection of the single-unit dwellings);· management (occupation and renovation); and, finally, destruction (demolition and removal of debris). The management period is assumed to be 50 years.
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