84 research outputs found

    Inspire: Challenging the lack of interest in physics among students

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    The Inspire project tested and analyzed the use of digital Learning resources (LR) in the field of Maths, Science and Technology (MST) in 63 schools in Austria, Germany, Italy, Lithuania and Spain. MST teachers used the LR from a pool of 60 resources (12 for Physics) in class and the effects on teachers and 5–18+ year old students were measured. We found the use of LR increases the understanding of students of MST and allows for differentiated learning within a class. LR have a larger impact on boys than girls, and it decreases with age. Overall, it appears the use of LR has a positive impact on MST education but special attention has to be placed on technical requirements and localization of the LR

    Impact of Lagrangian transport on lower-stratospheric transport timescales in a climate model

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    We investigate the impact of model trace gas transport schemes on the representation of transport processes in the upper troposphere and lower stratosphere. Towards this end, the Chemical Lagrangian Model of the Stratosphere (CLaMS) was coupled to the ECHAM/MESSy Atmospheric Chemistry (EMAC) model and results from the two transport schemes (Lagrangian critical Lyapunov scheme and flux-form semi-Lagrangian, respectively) were compared. Advection in CLaMS was driven by the EMAC simulation winds, and thereby the only differences in transport between the two sets of results were caused by differences in the transport schemes. To analyze the timescales of large-scale transport, multiple tropical-surface-emitted tracer pulses were performed to calculate age of air spectra, while smaller-scale transport was analyzed via idealized, radioactively decaying tracers emitted in smaller regions (nine grid cells) within the stratosphere. The results show that stratospheric transport barriers are significantly stronger for Lagrangian EMAC-CLaMS transport due to reduced numerical diffusion. In particular, stronger tracer gradients emerge around the polar vortex, at the subtropical jets, and at the edge of the tropical pipe. Inside the polar vortex, the more diffusive EMAC flux-form semi-Lagrangian transport scheme results in a substantially higher amount of air with ages from 0 to 2 years (up to a factor of 5 higher). In the lowermost stratosphere, mean age of air is much smaller in EMAC, owing to stronger diffusive cross-tropopause transport. Conversely, EMAC-CLaMS shows a summertime lowermost stratosphere age inversion – a layer of older air residing below younger air (an “eave”). This pattern is caused by strong poleward transport above the subtropical jet and is entirely blurred by diffusive cross-tropopause transport in EMAC. Potential consequences from the choice of the transport scheme on chemistry–climate and geoengineering simulations are discussed

    Developing intermediate cities

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    Intermediate cities have experienced economic dynamism in recent years, but, with the focus firmly on large metropoles and sprawling megacities, the development potential of intermediate cities has stayed out of the limelight. This paper upholds the relevance and potential of intermediate cities, arguing that they can play as important a role – if not a more important one – than the large metropoles that, until now, have been the focus of attention. Intermediate cities hold considerable advantages, in particular for poverty reduction and as more efficient ecosystems to live and work. Untapping the potential of intermediate cities requires, however, more territorially balanced, place-sensitive strategies

    Non-supersymmetric heterotic model building

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    We investigate orbifold and smooth Calabi-Yau compactifications of the non-supersymmetric heterotic SO(16)xSO(16) string. We focus on such Calabi-Yau backgrounds in order to recycle commonly employed techniques, like index theorems and cohomology theory, to determine both the fermionic and bosonic 4D spectra. We argue that the N=0 theory never leads to tachyons on smooth Calabi-Yaus in the large volume approximation. As twisted tachyons may arise on certain singular orbifolds, we conjecture that such tachyonic states are lifted in the full blow-up. We perform model searches on selected orbifold geometries. In particular, we construct an explicit example of a Standard Model-like theory with three generations and a single Higgs field.Comment: 1+30 pages latex, 11 tables; v2: references and minor revisions added, matches version published in JHE

    Determination of nutrient salts by automatic methods both in seawater and brackish water: the phosphate blank

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    9 pĂĄginas, 2 tablas, 2 figurasThe main inconvenience in determining nutrients in seawater by automatic methods is simply solved: the preparation of a suitable blank which corrects the effect of the refractive index change on the recorded signal. Two procedures are proposed, one physical (a simple equation to estimate the effect) and the other chemical (removal of the dissolved phosphorus with ferric hydroxide).Support for this work came from CICYT (MAR88-0245 project) and Conselleria de Pesca de la Xunta de GaliciaPeer reviewe

    Testung der BiokompatibilitÀt von Magnesium-substituierten Calcium-Phosphat Zementen

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