| 346521. |
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Multimodal interaktionsanalys
- 2020
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Samlingsverk (redaktörskap) (övrigt vetenskapligt/konstnärligt)abstract
- När vi kommunicerar och deltar i olika aktiviteter tolkar vi inte bara det som sägs, utan vi läser också av blickriktningar, kroppsposition och mycket annat som finns närvarande i situationen. Ömsesidig förståelse åstadkoms alltså i flera dimensioner, eller modaliteter. Denna bok är den första på svenska som introducerar det mångfacetterade forskningsområde som kallas multimodal interaktionsanalys. Detta fält intresserar sig för hur människor tillsammans utför handlingar med hjälp av språkliga, kroppsliga och materiella resurser. Bokens första del presenterar perspektivets teoretiska grunder och förklarar hur en interaktionsanalytisk studie kan genomföras ”från ax till limpa”. Bokens andra del introducerar ett antal centrala kommunikativa resurser, från röst och gester till objekt och teknologier. I den tredje och mest omfångsrika delen ges en lång rad exempel på hur man genom multimodal interaktionsanalys kan nå nya insikter inom olika forskningsområden. Multimodal interaktionsanalys vänder sig till studenter och forskare som vill förstå hur det egentligen går till när människor agerar och skapar mening tillsammans.
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| 346522. |
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Multimodality: Disciplinary thoughts and the challenge of diversity
- 2019
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Samlingsverk (redaktörskap) (övrigt vetenskapligt/konstnärligt)abstract
- Multimodality’s popularity as a semiotic approach has not resulted in a common voice yet. Its conceptual anchoring as well as its empirical applications often remain localized and disparate, and ideas of a theory of multimodality are heterogeneous and uncoordinated. For the field to move ahead, it must achieve a more mature status of reflection, mutual support, and interaction with regard to both past and future directions. The red thread across the disciplines reflected in this book is a common goal of capturing the mechanisms of synergetic knowledge construction and transmission using diverse forms of expressions, i.e., multimodality. The collection of chapters brought together in the book reflects both a diversity of disciplines and common interests and challenges, thereby establishing an excellent roadmap for the future. The contributions revisit and redefine theoretical concepts or empirical analyses, which are crucial to the study of multimodality from various perspectives, with a view towards evolving issues of multimodal analysis. With this, the book aims at repositioning the field as a well-grounded scientific discipline with significant implications for future communication research in many fields of study.
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| 346523. |
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| 346524. |
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Multiple Contexts Engender Multiple Rationalities: An Ecological Rationality Approach to Capability Imitation
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Proceedings (redaktörskap) (övrigt vetenskapligt/konstnärligt)abstract
- If behavioral strategy is set out to bring in “realistic assumptions about human cognition, emotions, and social behavior” (Powell et al., 2011: 1371), research in this emerging stream needs to go beyond conventional rational vs. bounded rational debate. It is not anymore novel to claim that managers are hardwired with cognitive biases. Nor do we see any added value in examining the battery of factors that can explain variance in a uniformly defined type of ‘rationality’. Instead, there is a need for an integrative perspective that can yield a more realistic picture of executive decision makers who interact in different social, political and historical contexts and, accordingly, develop their own heuristics and rules of thumb in order to arrive at their own ‘rational decisions’ attuned to their idiosyncratic ecologies. In this paper, we aim to fulfill this need.
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| 346525. |
- Mulu, Berhanu
(författare)
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An experimental and numerical investigation of a Kaplan turbine model
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Hydropower is a renewable, reliable and highly efficient source of energy. Hydropower has the ability to run as a base load and to adjust load rapidly. This makes hydropower suitable for coupling with other renewable energy sources to stabilize frequency fluctuations. This ability has been used increasingly over the last decade due to the deregulation of the electricity markets and the introduction of other renewable energy sources, such as wind power. These changes have involved a substantial increase in the load variations and frequent start-stops. Such operating conditions may lead to unnecessary stresses and losses in turbines. Throughout the world, hydropower is the largest renewable source of energy. Currently, there is a need for refurbishment of old hydropower plants because most of them have reached the end of their design period. Efficiency may be improved by upgrading these older turbines. During the design or refurbishment phase of turbines, model testing and computational fluid dynamics (CFD) are the main tools available to predict, test and verify the performance as well as to investigate the flow characteristics.The use of CFD in the design and refurbishment process is becoming increasingly popular due to its flexibility, detailed flow description and cost effectiveness compared to model testing, which has been used over the last century of turbines development. However, issues still must be resolved due to the combined flow physics involved in hydropower machines, such as flow turbulence, separation, vortices, unsteadiness, swirl flow, strong adverse pressure gradients, convoluted geometry and numerical artifacts. Therefore, experimental data in such complicated systems are required to validate the numerical simulations and develop more accurate models.This thesis presents an experimental and numerical investigation performed on a reaction type axial water turbine. The investigation was performed on a model known as the Porjus U9. It is a geometrically similar model of the prototype turbine produced on a 1:3.1 scale. The main objectives were to characterize the flow phenomena in this modern Kaplan turbine model, to build a data bank for the validation of the CFD tools and to study the scale-up between the model and prototype, because the corresponding prototype is available for similar experiments. The investigation was performed at three different operating points: part load, best efficiency point (BEP) and high load. The technique used to investigate the flow was laser Doppler anemometry. The investigation was performed with time- and phase-averaged velocity measurements in several sections of the turbine where different periodic and non-periodic flow phenomena were captured. Some engineering quantities were also calculated to describe the turbine characteristics, such as the pressure recovery factor and the swirl number. At off-design operations, vortex breakdown was present.The numerical analysis of the model is also presented, where several RANS turbulence models were tested. The aim was to evaluate the capability of the turbulence models to predict the flow physics in the water turbines at the BEP. Validation was made with the experimental results in order to extend the range of confidence in the CFD results.
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| 346526. |
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| 346527. |
- Mulu, Berhanu
(författare)
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Experimental and numerical investigation of axial turbine models
- 2009
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Hydropower is a versatile renewable source of power generation able to change rapidly operating conditions. Hydropower plants may today work over a larger operating range than designed for due to the introduction of renewable sources of energy and the deregulation of the electricity market. Such operating conditions may involve large stresses and losses due to complex unsteady and transient flow phenomena, which have to be taken into account under design or refurbishment phase. The use of computational fluid dynamics (CFD) in the design and refurbishment process is becoming increasingly popular due to its flexibility, detailed flow description and cost-effectiveness comparing to model testing used since a century in the development of turbines. However, issues have still to be resolved due to the combined flow physics involved in hydropower machines such as partly separated flow at curved surfaces, vortices, unsteadiness, swirl flow, strong adverse pressure gradients, convoluted geometry as well as numerical artefacts. Therefore, experimental data in such complicated systems are required to validate numerical simulations and develop more accurate models.The first part of this thesis is a numerical investigation of the three-dimensional flow of the axial Hölleforsen model spiral casing and distributor, where the influence of the penstock on the flow is analysed using different turbulence models and inlet boundary conditions. Comparisons with experimental results indicate the importance of the penstock to perform accurate simulation in the present case. Therefore, detailed inlet boundary conditions are necessary to simulate accurately the spiral casing flows if the penstock is not included in the simulation.The second part of the thesis focuses on an experimental investigation of an axial hydropower turbine model known as Porjus U9. The measurements are part of a project aiming to investigate experimentally the flow in different regions of the machine to build a data bank in order to validate numerical simulations and study scale-up efficiency between model and prototype, since the corresponding prototype is available for similar experiments. The investigation was performed at 3 different working points: part load, best efficiency point and high load. The inlet flow of the spiral casing as well as some sections in the spiral casing and draft tube are investigated with a two components laser Doppler anemometer (LDA). To improve the signal quality and measurement accuracy refractive index matching optical box was mounted on the circular pipe of the spiral casing inlet. LDA result of the mean velocities and corresponding RMS are presented to investigate the flow before the runner and at the inlet of the spiral casing, since the flow is influenced by the existence of a bend before the inlet. The results of the draft tube measurements are also presented. Good quality data are obtained for initial boundary conditions at the inlet of the casing and drafttube cone to perform numerical simulations.
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| 346528. |
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| 346529. |
- Mulubwa, Chama, et al.
(författare)
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What should I do? Navigating the complexities of comprehensive sexuality education in Zambia : a realist-informed study
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Although the outcomes of comprehensive sexuality education are generally promising and positive, there has been limited research on how and under what conditions these outcomes are achieved. This article analyses the contextual factors and underpinning mechanisms that influence the implementation and outcomes of comprehensive sexuality education. Using the realist evaluation approach, data collection and analysis were conducted concurrently, beginning with an existing programme theory, followed by a literature review and then primary data collection through four realist workshops with 50 stakeholders and 60 learners. Thematic analysis, informed by the realist evaluation of demi-regularities, identified three key demi-regularities centred on the mechanisms of autonomy, curiosity, fear and juggling. These are the ‘autonomy to make the right decision’, ‘curiosity to learn and explore adolescents’ sexuality’, and the ‘role of fear in adolescents and young people’s sexual health education’. The study highlights that while comprehensive sexuality education seeks to empower learners, this empowerment is often selectively applied – particularly in more contentious areas like condom and contraception use, topics related to abortion and sexual and gender minorities – due to broader societal and cultural influences. To realise the benefits of comprehensive sexuality education to the full, a more inclusive and culturally sensitive approach is necessary that enables adolescents and young people to explore all aspects of sexual and reproductive health and rights and make informed decisions without undue pressure or fear.
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| 346530. |
- Mulugeta, Ezra
(författare)
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Muscarinic M1 and M4 receptor subtypes in normal and pathological conditions in the central nervous system : studies on human and animal tissues using subtype selective ligands
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Snake venoms from different mamba species contain toxins that bind to muscarinic acetylcholine receptors (mAChR). The toxins MT-1 (selective for M1 after iodination), M1 toxin-1 (also known as MT7, selective for MI) and M4 toxin-1 (also known as MT3, selective for M4 receptors) were isolated and used to study M1 and M4 receptor subtypes in normal and pathological conditions. The pharmacological profile of M1 toxin-1 was determined in functional assays using cloned human M1- M4 receptors expressed in CHO cells. It was clearly demonstrated that M1 toxin-1 acts as a selective noncompetitive antagonist of the muscarinic M1 receptors by binding stably to an allosteric site. Age-related loss of mAChRs in rat hippocampus and neocortex is still controversial. The effect of ageing on the level of M1 and M4 mAChR subtypes was investigated in the hippocampus and entorhinal cortex of young (21 days), adult (3 months) and old (25 months) rats. A significant increase in muscarinic M1 receptor binding in all areas of the hippocampus and a significant loss in M4 binding only in the CA1 region and entorhinal cortex have been observed in 25 months compared to 21-day-old rats. The increase of M1 receptors in (old aged) rats could be due to compensatory processes as a result of the changes in M4 receptors. The decrease in M4 receptors in the entorhinal cortex and in the CA1 area of the hippocampus of (old aged) rats could be one of the factors leading to impaired cognitive function. Administration of mAChR agonists or acetylcholinesterase inhibitors produces effective pain relief However, the mAChR subtype(s) involved in the spinal cord are not fully defined. The levels of M1 and M4 receptor subtypes in spinal cord of acute and chronic arthritic rats were investigated. No M1- toxin 1 binding was observed, indicating an absence of M1 receptors. However, the binding Of M4- toxin 1 was reduced between 87-90 % in the Rexed laminae I to X of the spinal cord both in acute and chronic pain as compared to controls. These findings suggest that the mAChR M4 subtype may have a role in cholinergic mechanisms of analgesia. Alzheimers disease (AD) related loss of mAChR subtype has been controversial. Muscarinic M1, M2 and M4 receptor subtype changes in the hippocampus of AD and control brains were evaluated. A significant decrease in M4 receptors was observed in the dentate gyrus and CA4 regions of brain sections from AD patients compared to controls. These findings suggest that, relative to other mAChR subtype, the M4 receptor could be the subtype that is selectively compromised in AD. Long-term adrenalectomy (ADX) has been reported to cause significant loss of cells in the dentate gyrus and CA1-CA4 fields of the hippocampus resulting in impairment of cognitive functions. The effect of ADX on muscarinic M1 and M4 receptors levels in the hippocampus and entorhinal cortex of 3, 14, 30, 90 and 150 days adrenalectomized male Wistar rats was studied. A significant loss Of M4 but not M1 receptors was observed in the different areas of the hippocampus and entorhinal cortex which varied with time after ADX. The vulnerability is in the order entorhinal cortex > dentate gyrus, CA4 > CA3 > CA2, CAI. Our results show that M1 and M4 receptors are differentially affected after ADX and indicate that the M4 receptor subtype is influenced by adrenal hormones and suggest that the M4 receptor might be the subtype linked to memory functions in the hippocampus. In conclusion, the studies from the five papers (Papers I - V) constituting this thesis demonstrate that selective ligands like the muscarinic toxins are valuable tools to establish the roles of the different mAChR subtypes involved in normal and pathological conditions in the CNS. These findings suggest that, relative to the M1, the M4 receptor could be the subtype that is selectively compromised in Alzheimer's disease and in pain response. These findings might lead to new therapeutic strategies in the treatment of pain and Alzheimer's disease.
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