3,426 research outputs found
Four nucleon pickup studies on medium-weight and heavy nuclei with the (d, 6Li) reaction
This thsis summarizes several years of experimental work performed at the "Kernfysisch Versneller Instituut" in Groningen. Medium-weight and heavy nuclei were studied with the (d,6Li) reaction at a bombarding energy of MeV. The present study will focus on nuclei with mass A > 70 with an emphasis on nuclei in the A = 100 mass region. ... Zie: Summar
Towards simultaneous electrical and optical investigation of BLMS using a novel microfluidic device
We firstly describe the influence of the phospholipid (PL) composition of bilayer lipid membrane on their electrical properties: (i) the more unsaturations in the tail, the earlier the BLM breakdown and (ii) the bulkier the head group, the less stable the membrane. Secondly, we design and fabricate novel devices that couple such electri-cal characterization to optical investigation and that enable the preparation of asym-metrical membranes: a “macro” device including a drilled PMMA plate as well as microfluidic device consisting of a glass-teflon foil-glass sandwich
How high schools teach quantum physics – a cross-national analysis of curricula in secondary education
Quantum physics (QP) changed our worldview, it brought us modern electronic devices, and its almost mythical image fascinates. Although QP is relatively new in secondary education, it is now part of the national curricula of many countries. To understand the current state of QP content in high schools, we scrutinised upper secondary school physics curriculum documents in 15 countries. In these countries, we identified a similar core curriculum of QP which contains the following seven main categories: discrete atomic energy levels, interactions between light and matter, wave-particle duality, de Broglie wavelength, technical applications, Heisenberg's uncertainty principle, and the probabilistic nature of QP. We also found differences in the focus of the listed topics of individual countries, which indicate different views on teaching QP. The thematic focus of QP items is related to the underlying goal of science education and to the way students' knowledge is tested. This overview shows which QP content is generally feasible at a secondary level and which pedagogical perspectives are possible. Therefore this study might lead to reflections on existing QP curricula, and inspire countries that do not have QP in their curriculum yet
Thermal response of an induction-heated fabric reinforced thermoplastic composite with anisotropic electrical conductivity:An experimental study
Performance analysis of a dynamic query processing scheme
Traditional query optimizers produce a fixed query evaluation plan based on assumptions about data distribution and processor workloads. However, these assumptions may not hold at query execution time. In this paper, we propose a dynamic query processing scheme and we present the performance results obtained by simulation of a queueing network model of the proposed software architecture
Determination of the anisotropic electrical conductivity of carbon fabric reinforced composites by the six-probe method
Currently, it is challenging to obtain consistent values for the anisotropic electrical conductivity of fabric ply based thermoplastic composites. In this study, the anisotropic electrical conductivity of this type of material was obtained by combining six-probe voltage measurements with a numerical evaluation method to process the voltage measurements. The effect of probe distance and specimen dimensions on the test results was investigated. The measurements show low specimen to specimen variability and the obtained electrical conductivities agree with values obtained by the rule of mixtures and the two-probe measurement method. The conducted research shows that with one experiment, both the in- and the out-of-plane electrical conductivity of polymer composites reinforced with carbon fabrics can be reliably determined, simultaneously.</p
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