67 research outputs found

    Introducing the Novatron, a novel reactor concept

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    A new magnetic mirror design is described - the Novatron - with the potential to confine fully stable compact mirror-cusp fusion plasmas. The novel design features an axisymmetric magnetic field configuration with concave curvature throughout, as seen from the outside. Moreover, the Novatron is designed to be self-stabilized against the drift cyclotron loss-cone modes (DCLC). This paper describes the fundamental topology of the magnetic field and presents an outline for the design of the magnet system

    Tradition as asset or burden for transitions from forests as cropping systems to multifunctional forest landscapes: Sweden as a case study

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    Expectations of what forests and woodlands should provide vary among locations, stakeholder groups, and over time. Developing multifunctional forests requires understanding of the dynamic roles of traditions and cultural legacies in social-ecological systems at multiple levels and scales. Implementing policies about multifunctional forests requires a landscape and social-ecological perspective, and recognition of both spatial and temporal features at multiple scales. This study explores the dissemination of even-aged silviculture in central, eastern and northern Europe, and the consequences of choosing different vantage points in social-ecological systems for mapping of barriers, and to identify levers, towards multifunctional forest landscapes. Using a narrative approach, we first summarise the development of even-aged silviculture in four European regions. Next, we focus on Sweden as a keen adopter of even-aged silviculture, and identify levers at three groups of vantage points. They were (1) biosphere with biodiversity as short-hand for composition, structure and function of ecosystems, which support human well-being at multiple scales; (2) society in terms of different levels of stakeholder interactions from local to global, and (3) economy represented by value chain hierarchies and currencies. The emergence of even-aged silviculture >200 years ago formed an expanding frontier from central to northern Europe. Sustained yield wood production and biodiversity conservation encompass different portfolios of ecosystem aspects and spatio-temporal scales. Ignorance and lack of knowledge about these differences enforce their mutual rivalry. An exploratory review of six groups of stakeholders at multiple levels in the traditional industrial forest value chain highlights inequalities in terms of distribution of income and power across different levels of governance. This effectively marginalises other than powerful industrial actors. The distribution of financial results along the value chain is dynamic in space and time, and not all benefits of forest ecosystems can be measured using monetary valuation. There are also other currencies and incentives. A discussion of cultural trajectories in central and eastern European, Russian and Swedish forest management illustrates that forest history patterns repeat themselves. Longitudinal case studies of countries and regions can help foster holistic multi-dimensional and multilevel systems thinking. Application of deep levers of change is likely to require external drivers. A key challenge is to handle the manufacturing of doubt and decay of truth, i.e., the appearance of alternative facts, and the diminishing role of evidence and systems analyses in political and civic discourses. This transition is fuelled by new and rapidly evolving digital arenas

    Media Events in her majesty's service : om nationella identiteter i olympiska spelens invigningsceremonier

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    De olympiska spelens invigningsceremonier är till brädden fyllda med symboler, tecken och myter som alla syftar till att konstruera nationella identiteter och -narrativ. Ofta hämtas dessa symboler och tecken ur populärkulturen. Jag har semiotiskt försökt analysera dessa tecken för att se på vilka sätt värdländernas nationella identiteter porträtteras. Jag har också valt att analysera detta utifrån teorier om media events som tv-genre. De sekvenser jag har valt att studera har visat på att nationens narrativ i stor utsträckning konstrueras för att gagna socialt dominerande grupper och befästa maktpositioner

    Crises, investments, and political institutions

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    On the basis of a game-theoretic model, this paper argues that governments typically manage crises more effectively in systems where political power is concentrated in a single party, but they are more likely to make investments in future welfare in systems where political power is shared among several parties. The paper makes two contributions. First of all, it shows that both crisis-management failures and investment failures can be explained by a common mechanism: an inter-temporal commitment problem that arises from the inability of political agents to commit to future policy choices. Second, it shows that power-sharing institutions are often associated with more effective government than power-concentration institutions, in contrast to much of the normative literature in comparative politics, in which power-sharing institutions are often justified on other grounds, such as representativeness, responsiveness, or social cohesion. In a world where crises dominate, power-concentration institutions typically perform better; in a world where investment problems dominate, power-sharing institutions typically perform better

    Dräneringsrörs igensättning - En jämförande laboratoriestudie

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    Development of an extremely fatigue-resistant Shock Absorber

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    An extremely fatigue resistant shock absorber was developed from basic mechanics principles using nonlinear elastic material models and finite element analysis. Prototypes were manufactured and tested to confirm the calculations and to find out the fatigue properties. The rubber body fills a cavity at gradually increasing compression. This idea has some clear advantages: A large part of the rubber body is protected against accidental external influences and it is backed up during the deformation by the cavity walls. Also, the stress in the rubber body becomes evenly distributed as only compressive stress is developed in it. The prototypes were tested in nearly 6 million cycles with no visible defects

    Intrasellar pressure is related to endocrine disturbances in patients with pituitary tumors

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    Objective: The aim of this study was to investigate the association between intraoperative intrasellar pressure (ISP) and pre- and postoperative endocrine disturbances with focus on hyperprolactinemia and hypopituitarism in patients with pituitary tumors. Methods: The study is a consecutive, retrospective study with ISP collected prospectively. One hundred patients operated with transsphenoidal surgery due to a pituitary tumor, who had their ISP measured intraoperatively, were included. Data on patient endocrine status preoperatively and from 3-month postoperative follow-up were collected from medical records. Results: The risk of preoperative hyperprolactinemia in patients with nonprolactinoma pituitary tumors increased with ISP (unit odds ratio 1.067, n = 70) (P = 0.041). Preoperative hyperprolactinemia was normalized at 3 months after surgery. Mean ISP was higher in patients with preoperative thyroid-stimulating hormone (TSH) deficiency (25.3 ± 9.2 mmHg, n = 37) than in patients with intact thyroid axis (21.6 ± 7.2 mmHg, n = 50) (P = 0.041). No significant difference in ISP was found between patients with and without adrenocorticotropic hormone(ACTH) deficiency. No association was found between ISP and postoperative hypopituitarism at 3 months after surgery. Conclusions: In patients with pituitary tumors, preoperative hypothyroidism and hyperprolactinemia may be associated with higher ISP. This is in line with the theory of pituitary stalk compression, suggested to be mediated by an elevated ISP. ISP does not predict the risk of postoperative hypopituitarism 3 months after surgical treatment
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