35 research outputs found

    All Doors Lead to the Kitchen – Sustainability and Wellbeing Challenges in a Shared Centrepiece of Living

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    The kitchen figures a central place in the home where a significant share of a household’s resource consumption takes place. Sharing the kitchen between multiple households has potential to bring positive sustainability effects due to more efficient use of both material resources and energy. The concept of shared kitchens has, however, thus far had a limited diffusion. This paper explores the potential of shared kitchens as a future sustainable living environment by studying user experiences from a Living Lab setting. It builds the base for an overarching larger European collaboration on how future shared kitchens should be designed in order to support everyday practices while optimising the conditions for achieving positive impact on both sustainability and wellbeing. Findings are presented from five focus areas concerning different use contexts: (1) accessing, (2) cooking, (3) living and socialising, (4) storing, and (5) cleaning

    Relativistic MHD Simulations of Jets with Toroidal Magnetic Fields

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    This paper presents an application of the recent relativistic HLLC approximate Riemann solver by Mignone & Bodo to magnetized flows with vanishing normal component of the magnetic field. The numerical scheme is validated in two dimensions by investigating the propagation of axisymmetric jets with toroidal magnetic fields. The selected jet models show that the HLLC solver yields sharper resolution of contact and shear waves and better convergence properties over the traditional HLL approach.Comment: 12 pages, 5 figure

    Magnetic field structure of relativistic jets without current sheets

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    We present an analytical class of equilibrium solutions for the structure of relativistic sheared and rotating magnetized jets that contain no boundary current sheets. We demonstrate the overall dynamical stability of these solutions and, most importantly, a better numerical resistive stability than the commonly employed force-free structures which inevitably require the presence of dissipative surface currents. The jet is volumetrically confined by the external pressure, with no pressure gradient on the surface. We calculate the expected observed properties of such jets. Given the simplicity of these solution we suggest them as useful initial conditions for relativistic jet simulations.Comment: 13 pages, 13 figures, Accepted by MNRA

    Relativistic spine jets from Schwarzschild black holes: "Application to AGN radioloud sources"

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    The two types of Fanaroff-Riley radio loud galaxies, FRI and FRII, exhibit strong jets but with different properties. These differences may be associated to the central engine and/or the external medium. Aims: The AGN classification FRI and FRII can be linked to the rate of electromagnetic Poynting flux extraction from the inner corona of the central engine by the jet. The collimation results from the distribution of the total electromagnetic energy across the jet, as compared to the corresponding distribution of the thermal and gravitational energies. We use exact solutions of the fully relativistic magnetohydrodynamical (GRMHD) equations obtained by a nonlinear separation of the variables to study outflows from a Schwarzschild black hole corona. A strong correlation is found between the jet features and the energetic distribution of the plasma of the inner corona which may be related to the efficiency of the magnetic rotator. It is shown that observations of FRI and FRII jets may be partially constrained by our model for spine jets. The deceleration observed in FRI jets may be associated with a low magnetic efficiency of the central magnetic rotator and an important thermal confinement by the hot surrounding medium. Conversely, the strongly collimated and accelerated FRII outflows may be self collimated by their own magnetic field because of the high efficiency of the central magnetic rotator.Comment: Accepted for publication in the A&

    Resilien-tech: Recommendations for bringing resilience into practice

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    Is resilience just another buzzword? What use can we make of the term and the underlying concept? Resilience is the ability to repel, prepare for, take into account, absorb, recover from and adapt ever more successfully to actual or potential adverse events. Those events are either catastrophes or processes of change with catastrophic outcome, which can have human, technical or natural causes. In Germany, there is a lack of “hands-on” approaches that try to implement some characteristics of resilient thinking into practice. By using the experience of national and international experts, the study RESILIEN-TECH comes up with a list of recommendations that can be used as guidelines for further research and development activities in the field of resilience – from developing methods for modeling and simulation of complex socio-technical systems to establishing resilience as key component for sustainable development

    十九世紀香港粵商的商業網絡

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    In the process of making drawn and ironed cans out of a steel sheet, non-metallic inclusions such as chemical oxides in the steel sheet may cause cracks. Therefore, steel sheets are inspected before they are drawn and the magnetic flux leakage testing is usually employed for the inspection [1]. When there are non-metallic inclusions in the steel sheet, magnetic fields produced by a magnetizer leak out around such defects because of the differences in material permeability. These leakage fields are detected by flux sensitive sensors such as Hall plates or magnetodiodes [2]
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