1. |
- Averfalk, Helge, 1988-
(författare)
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Enhanced District Heating Technology : Maintaining Future System Feasibility
- 2017
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- When heat demand and high temperature heat supply gradually decreases in the future, then it will effect district heating systems ability to compete on the heat market. A good way to mitigate less district heating feasibility is to operate systems with lower temperature levels and the most conceivable way to achieve lower temperature levels is to decrease return temperatures.Thus, this thesis emphasise temperature errors embedded in district heating systems. Only a selection of temperature errors are analysed in this thesis. First, the temperature error that occurs due to recirculation in distribution networks at low heat demands. Second, the temperature error that occurs due to hot water circulation in multi-family buildings. Third, the temperature error that occurs due to less than possible heat transfer in heat exchangers, i.e. too short thermal lengths.In order to address these temperature errors three technology changes have been proposed (i) three-pipe distribution network to separate the recirculation return flow from the delivery return flow, (ii) apartment substations to eliminate hot water circulation utilisation, and (iii) improved heat exchangers for lower return temperatures at a constant scenario. Analysis of proposed changes has resulted in annual average return temperatures between 17-21 °C.Furthermore, rapid introduction of intermittent renewable electricity supply in the energy system has prompted an increased necessity of power system balancing capacities. Large-scale conversion of power-to-heat in electric boilers and heat pumps is a feasible alternative to achieve such balancing capacities. Analysis of the unique Swedish experience with utilisation of large heat pumps installations connected to district heating systems show that since the 1980s 1527 MW of heat power has been installed, about 80 % of the capacity was still in use by 2013. Thus, a cumulative value of over three decades of operation and maintenance exists within Swedish district heating systems.The two papers presented in this thesis are related to future district heating systems through the five abilities of fourth generation district heating (4GDH), which are documented in the definition paper of 4GDH.
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2. |
- Johansson, Stefan, 1963-
(författare)
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Design for Participation and Inclusion will Follow : Disabled People and the Digital Society
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Digitalization is rapidly taking over all aspects of society, but still there are parts of the population who have to struggle for access to, and to be able to use, the digital resources. Design processes and outcomes in the form of artefacts, that takes accessibility into account, is key to participation. This gives the designer a central role in providing for a more equal participation of all, in the digital society. The work in this thesis contributes to a better understanding of the prerequisites for participation in the digital society, and in the design processes to accomplish this, by presenting research done together with three communities: people with cognitive impairments, people with mental health issues and homeless people.The overall question has been How can participation in the digital society be understood? We have investigated the nature of difficulties or enabling factors for people with impairments, people with mental health issues and homeless people, when using the internet. We have also investigated possible digital divides within the groups, and how they can be explained.Ontologically, the work is based on an assumption that knowledge is to be found in a dialectic interplay between the material world and how we interpret what is going on in this world. The underlying epistemological assumption is that data has to be empiric, and critically interpreted in dialogue between members of the communities, which are being researched, and other stakeholders. This work draws on the idea of emancipation and that research can be liberating.The work also takes on a pragmatic stance. We have used adapted versions of Emancipatory Participatory Research, and of Participatory and Value Sensitive Design, thus making them accessible to people with cognitive impairments, people with mental health issues or homeless people. We have tested and adapted methods for sampling of rare populations, to enhance the quality of quantitative studies of how people with impairments and people with mental health issues have access to, and are using, the internet.In our research, we have found fourteen prerequisites, all of which need to be in place to provide for participation. To promote participation, we need a toolbox of methods and accessible tools. Finally, to analyse what is going on we need an analytical model which allows for analysis on multiple levels and from multiple perspectives.As a result, I here propose, define and position a framework for researching and understanding participation in the digital society, based on three parts: Guidelines, Ethics and Statistics. Guidelines can be understood as the theories, the regulations, the standards, etc. that inform our thinking. Ethics guide us in the right direction. Statistics make progress or lack of progress visible.The conclusion is: if we plan for participation - by improved statistic survey sampling methods, a participatory approach to collaborative research and in using research methods in an accessible and emancipatory way – inclusion will follow.
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3. |
- Andersson K, Pernille
(författare)
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Changing the servicescape : The influence of music, self-disclosure and eye gaze on service encounter experience and approach-avoidance behavior
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The purpose of this thesis is to investigate and understand the effect of a servicescape’s ambient and social conditions on consumers’ service encounter experience and their approach/avoidance behavior in a retail context. In three papers, with a total sample of over 1600 participants (including 550 actual consumers) and seven experiments, the author investigates the effect of music (ambient stimuli), employees’ self-disclosure (verbal social stimuli) and employees’ gazing behavior (nonverbal social stimuli) on consumers’ service encounter experience and approach/avoidance behavior in a retail store.Paper I comprised two experiments, and the aim was to investigate the influence of music on emotions, approach/avoidance behavior. Paper II comprised two experiments, and the aim was to investigate the effect of frontline employees’ personal self-disclosure on consumers’ reciprocal behavior. Paper III comprised three experiments, and the aim was to investigate the influence of employee’s direct eye gaze/ averted eye gaze on consumer emotions, social impression of the frontline employee and encounter satisfaction in different purchase situations.The results in this thesis show that music affects consumers in both positive and negative ways (Paper I). Self-disclosure affects consumers negatively, in such a way that it decreases encounter satisfaction (Paper II) and, finally, eye gaze affects consumers by regulating both positively – and in some cases also negatively – consumers’ social impression of the frontline employee and their encounter satisfaction (Paper III).The conclusions of this thesis are that both ambient and social stimuli in a servicescape affect consumers’ internal responses, which in turn affect their behavior. Depending on the purchase situation, type of retail, and stimuli, the internal and behavioral responses are different.
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4. |
- Carlbom, Lina
(författare)
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Positron Emission Tomography and Magnetic Resonance Techniques in Diabetes
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In order to further advance the field of diabetes research there is a great need for establishing validated non-invasive quantitative techniques to study the pancreas and other tissues of importance for blood glucose regulation. The general aim of this thesis was to explore magnetic resonance techniques and positron emission tomography as such tools.In paper I pancreatic perfusion under basal conditions and in response to glucose in nondiabetic and type 1 diabetic individuals was studied with [15O]H2O PET/CT. Individuals with type 1 diabetes were found to have reduced basal pancreatic perfusion and a severely impaired pancreatic and splanchnic perfusion response to intravenous glucose stimulation.In paper II four groups of subjects at different stages of type 2 diabetes development and a control group of individuals without diabetes were examined with PET/CT and MRI. The [11C]5-HTP uptake in pancreas was hypothesized to correlate with remaining functional capacity of the β-cells. The progressive loss of β-cell function indicated by metabolic testing was not mirrored by a decrease in [11C]5-HTP tracer accumulation in the pancreas. This provides evidence of retained islet mass despite decreased β-cell function, indicating that β-cell dysfunction or dedifferentiation, and not necessarily endocrine cell loss, constitutes a major cause of β-cell failure in type 2 diabetes.In paper III the feasibility of using ex-vivo MR spectroscopy for assessment of viability of human pancreas grafts prior to transplantation was studied. It was found that 31P-MRS may provide quantitative parameters for evaluating graft viability ex vivo, and is a promising tool for objective non-invasive assessment of the quality of human pancreas grafts.In paper IV the Imiomics method for automatic image analysis was validated in whole-body [18F]-FDG PET/MR images in subjects with varying degree of insulin resistance. Imiomics was found to provide association screening and timesaving analysis of whole-body data and detected differences in glucose uptake and tissue composition between subjects on voxel-level. However, it did not show complete correlation with traditional volume of interest based tissue analysis in a small cohort.
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5. |
- Westerlund, Stina, 1968-
(författare)
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Lust och olust : elevers erfarenheter i textilslöjd
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of the thesis is to investigate and analyse students’ expressions of pleasure and displeasure and how these are manifested in actions in the teaching of textile sloyd in lower secondary education. The study’s focus is on students’ expressions of pleasure and displeasure in social action in the working processes of textile sloyd and on how these expressions can be related to learning. The empirical material consists of observations, video and audio recordings, individual interviews and focus group interviews, where video and audio recordings were used as stimulated recall. In all, 32 lessons in textile sloyd and 49 students aged 14-15 years were observed at four different schools. Theoretically, the thesis is based on Mead’s practical intersubjectivity and on Dewey’s theory of experience-based learning and dependence on emotions and actions. Pleasure and displeasure constitute valuating partial aspects of emotions. Based on a socio-cultural perspective, emotions are regarded as practices which arise from different predispositions’ dependence on the social context. The study’s analytical approach is hermeneutical. Critical incidents regarding students’ expressions of pleasure and displeasure in social action found in observations and video and audio recordings were analysed in terms of Mead’s concept of gestures. The events were combined with what the students describe as critical incidents of pleasure and displeasure in the interviews and focus group talks. The material was then thematised. Several situations were then subjected to deeper analysis based on sociality and a change in perspective and related to different concepts of learning. The result of the thesis shows a tripartite semantic structure where students’ pleasure and displeasure in textile sloyd are mainly based on textile sloyd’s specific educational community, students’ relationship to the sloyd object and their experience of the working process. Social interaction, humour and mutual acknowledgement proved to be of importance for the function of pleasure and displeasure in the students’ working processes. The students’ experience of pleasure and displeasure depended on their control of the work, the characteristics of different craft techniques and their awareness of time. Pleasure and displeasure in textile sloyd found an expression in four overarching emotional practices with decisive importance for the students’ opportunities for learning: the repudiating, insecure, accepting and incorporating emotional practice. The study also provides an insight into how different cultural factors enable a certain scope for pleasure and displeasure. In this connection, social changes in relation to objects are discussed, as are changes in sociality and emotionality. Based on the pair of concepts of authenticity and ephemerality and closeness and intensity, cultural changes are visualised that are conceivably important for the students’ experiences of pleasure and displeasure in textile sloyd.
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6. |
- Galván, Ignacio Fdez., et al.
(författare)
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OpenMolcas : From Source Code to Insight
- 2019
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Ingår i: Journal of Chemical Theory and Computation. - : American Chemical Society (ACS). - 1549-9618 .- 1549-9626. ; 15:11, s. 5925-5964
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Tidskriftsartikel (refereegranskat)abstract
- In this Article we describe the OpenMolcas environment and invite the computational chemistry community to collaborate. The open-source project already includes a large number of new developments realized during the transition from the commercial MOLCAS product to the open-source platform. The paper initially describes the technical details of the new software development platform. This is followed by brief presentations of many new methods, implementations, and features of the OpenMolcas program suite. These developments include novel wave function methods such as stochastic complete active space self-consistent field, density matrix renormalization group (DMRG) methods, and hybrid multiconfigurational wave function and density functional theory models. Some of these implementations include an array of additional options and functionalities. The paper proceeds and describes developments related to explorations of potential energy surfaces. Here we present methods for the optimization of conical intersections, the simulation of adiabatic and nonadiabatic molecular dynamics, and interfaces to tools for semiclassical and quantum mechanical nuclear dynamics. Furthermore, the Article describes features unique to simulations of spectroscopic and magnetic phenomena such as the exact semiclassical description of the interaction between light and matter, various X-ray processes, magnetic circular dichroism, and properties. Finally, the paper describes a number of built-in and add-on features to support the OpenMolcas platform with postcalculation analysis and visualization, a multiscale simulation option using frozen-density embedding theory, and new electronic and muonic basis sets.
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7. |
- Selvaraju, Ram kumar, 1987-
(författare)
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[68Ga]Exendin-4: Bench-to-Bedside : PET molecular imaging of the GLP-1 receptor for diabetes and cancer
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Diabetes epidemic is underway. Beta cell dysfunction (BCF) and loss of beta cell mass (BCM) are known to be key events in its progression. Currently, there are no reliable techniques to estimate or follow the loss of BCM, in vivo. Non-invasive imaging and quantification of the whole BCM in the pancreas, therefore, has a great potential for understanding the progression of diabetes and the scope for early diagnosis for Type 2 diabetes.Glucagon-like peptide-1 receptor (GLP-1R) is known to be selectively expressed on the pancreatic beta cells and overexpressed on the insulinoma, a pancreatic neuroendocrine tumor (PNET). Therefore, this receptor is considered to be a selective imaging biomarker for the beta cells and the insulinoma. Exendin-4 is a naturally occurring analog of GLP-1 peptide. It binds and activates GLP-1R with same the potency and engages in the insulin synthesis, with a longer biological half-life. In this thesis, Exendin-4 precursor, DO3A-VS-Cys40-Exendin-4 labeled with [68Ga], [68Ga]Ga-DO3A-VS-Cys40-Exendin-4 ([68Ga]Exendin-4), was evaluated in different species models, namely, immune deficient nude mice, rats, pigs, non-human primate (NHP), and clinically in one insulinoma patient by positron emission tomography (PET), for its potential in beta cell imaging and its quantification as well as for visualizing the insulinoma. From internal dosimetry, the possible number of repetitive [68Ga]Exendin-4-PET/CT scans was estimated.Pancreatic uptake and insulinoma tumor uptake of [68Ga]Exendin-4 were confirmed to be mediated by the specific binding to the GLP-1R. Pancreatic GLP-1R could be visualized and semi-quantified, for diabetic studies, except in rats. Nonetheless, we found conflicting results regarding the GLP-1R being a selective imaging biomarker for the beta cells. PET/CT scan of the patient with [68Ga]Exendin-4 has proven to be more sensitive than the clinical neuroendocrine tracer, [11C]5-HTP, as it could reveal small metastatic tumors in liver. The kidney was the dose-limiting organ in the entire species model, from absorbed dose estimation. Before reaching a yearly kidney limiting dose of 150 mGy and a whole body effective dose of 10 mSv, 2–4 [68Ga]Exendin-4 PET/CT scans be performed in an adult human, which enables longitudinal clinical PET imaging studies of the GLP-1R in the pancreas, transplanted islets, or insulinoma, as well as in healthy volunteers enrolled in the early phase of anti-diabetic drug development studies.
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8. |
- Sundström, Johan, Professor, 1971-, et al.
(författare)
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Rationale for a Swedish cohort consortium
- 2019
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Ingår i: Upsala Journal of Medical Sciences. - : Taylor & Francis Group. - 0300-9734 .- 2000-1967. ; 124:1, s. 21-28
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Tidskriftsartikel (refereegranskat)abstract
- We herein outline the rationale for a Swedish cohort consortium, aiming to facilitate greater use of Swedish cohorts for world-class research. Coordination of all Swedish prospective population-based cohorts in a common infrastructure would enable more precise research findings and facilitate research on rare exposures and outcomes, leading to better utilization of study participants' data, better return of funders' investments, and higher benefit to patients and populations. We motivate the proposed infrastructure partly by lessons learned from a pilot study encompassing data from 21 cohorts. We envisage a standing Swedish cohort consortium that would drive development of epidemiological research methods and strengthen the Swedish as well as international epidemiological competence, community, and competitiveness.
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