1,197 research outputs found
Charge Transfer and Charge Broadening of GEM Structures in High Magnetic Fields
We report on measurements of charge transfer in GEM structures in high
magnetic fields. These were performed in the framework of the R&D work for a
Time Projection Chamber at a future Linear Collider. A small test chamber has
been installed into the aperture of a superconducting magnet with the GEM
structures mounted perpendicular to the B field direction. The charge transfer
is derived from the electrical currents monitored during irradiation with an
Fe source. No severe loss of primary ionisation charge is observed,
but an improved ion feedback suppression is achieved for high magnetic fields.
Additionally, the width of the charge cloud released by individual Fe
photons is measured using a finely segmented strip readout after the triple GEM
structure. Charge widths between 0.3 and 0.5 mm RMS are observed, which
originate from the charge broadening inside the GEM readout. This charge
broadening is only partly suppressed at high magnetic fields.Comment: 11 pages, 9 figure
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The impact of climate change on incomes and convergence in Africa
© 2019 Elsevier Ltd Climate change is projected to detrimentally affect African countries’ economic development, while income inequalities across economies is among the highest on the planet. However, it is projected that income levels would converge on the continent. Hitherto there is limited evidence on how climate change could affect projected income convergence, accelerating, slowing down, or even reversing this process. Here, we analyze convergence considering climate-change damages, by employing an economic model embedding the three dimensions of risks at the country-level: exposure, vulnerability and hazards. The results show (1) with historical mean climate-induced losses between 10 and 15 percent of GDP per capita growth, the majority of African economies are poorly adapted to their current climatic conditions, (2) Western and Eastern African countries are projected to be the most affected countries on the continent and (3) As a consequence of these heightened impacts on a number of countries, inequalities between countries are projected to widen in the high warming scenario compared to inequalities in the low and without warming scenarios. To mitigate the impacts of economic development and inequalities across countries, we stress (1) the importance of mitigation ambition and Africa's leadership in keeping global mean temperature increase below 1.5 °C, (2) the need to address the current adaptation deficit as soon as possible, (3) the necessity to integrate quantitatively climate risks in economic and development planning and finally (4) we advocate for the generalization of a special treatment for the most vulnerable countries to access climate-related finance. The analysis raises issues on the ability of African countries to reach their SDGs targets and the potential increasing risk of instability, migration across African countries, of decreased trade and economic cooperation opportunities as a consequence of climate change – exacerbating its negative consequences
The impact of climate change on incomes and convergence in Africa
© 2019 Elsevier Ltd Climate change is projected to detrimentally affect African countries’ economic development, while income inequalities across economies is among the highest on the planet. However, it is projected that income levels would converge on the continent. Hitherto there is limited evidence on how climate change could affect projected income convergence, accelerating, slowing down, or even reversing this process. Here, we analyze convergence considering climate-change damages, by employing an economic model embedding the three dimensions of risks at the country-level: exposure, vulnerability and hazards. The results show (1) with historical mean climate-induced losses between 10 and 15 percent of GDP per capita growth, the majority of African economies are poorly adapted to their current climatic conditions, (2) Western and Eastern African countries are projected to be the most affected countries on the continent and (3) As a consequence of these heightened impacts on a number of countries, inequalities between countries are projected to widen in the high warming scenario compared to inequalities in the low and without warming scenarios. To mitigate the impacts of economic development and inequalities across countries, we stress (1) the importance of mitigation ambition and Africa's leadership in keeping global mean temperature increase below 1.5 °C, (2) the need to address the current adaptation deficit as soon as possible, (3) the necessity to integrate quantitatively climate risks in economic and development planning and finally (4) we advocate for the generalization of a special treatment for the most vulnerable countries to access climate-related finance. The analysis raises issues on the ability of African countries to reach their SDGs targets and the potential increasing risk of instability, migration across African countries, of decreased trade and economic cooperation opportunities as a consequence of climate change – exacerbating its negative consequences
Overcoming global inequality is critical for land-based mitigation in line with the Paris Agreement
Transformation pathways for the land sector in line with the Paris Agreement depend on the assumption of globally implemented greenhouse gas (GHG) emission pricing, and in some cases also on inclusive socio-economic development and sustainable land-use practices. In such pathways, the majority of GHG emission reductions in the land system is expected to come from low- and middle-income countries, which currently account for a large share of emissions from agriculture, forestry and other land use (AFOLU). However, in low- and middle-income countries the economic, financial and institutional barriers for such transformative changes are high. Here, we show that if sustainable development in the land sector remained highly unequal and limited to high-income countries only, global AFOLU emissions would remain substantial throughout the 21st century. Our model-based projections highlight that overcoming global inequality is critical for land-based mitigation in line with the Paris Agreement. While also a scenario purely based on either global GHG emission pricing or on inclusive socio-economic development would achieve the stringent emissions reductions required, only the latter ensures major co-benefits for other Sustainable Development Goals, especially in low- and middle-income regions. © 2022, The Author(s)
Modulation of EMG Power Spectrum Frequency During Motor Imagery
To provide evidence that motor imagery (MI) is accompanied by improvement of intramuscular conduction velocity (CV), we investigated
surface electromyographic (EMG) activity of 3 muscles during the elbow flexion/extension. Thirty right-handed participants were asked to lift
or to imagine lifting a weighted dumbbell under 3 types of muscular contractions, i.e. concentric, isometric and eccentric, taken as independent
variables. The EMG activity of the agonist (long and short heads of biceps brachii) and the antagonist (long portion of triceps brachii) muscles was
recorded and processed to determine the median frequency (MF) of EMG power spectrum as dependant variable. The MF was significantly higher
during the MI sessions than during the resting condition while the participants remained strictly motionless. Moreover, the MF during imagined
concentric contraction was significantly higher than during the eccentric. Thus, the MF variation was correlated to the type of contraction the
muscle produced. During MI, the EMG patterns corresponding to each type of muscle contraction remained comparable to those observed during
actual movement. In conclusion, specific motor programming is hypothesized to be performed as a function of muscle contraction type during MI
High cooperativity in coupled microwave resonator ferrimagnetic insulator hybrids
We report the observation of strong coupling between the exchange-coupled
spins in gallium-doped yttrium iron garnet and a superconducting coplanar
microwave resonator made from Nb. The measured coupling rate of 450 MHz is
proportional to the square-root of the number of exchange-coupled spins and
well exceeds the loss rate of 50 MHz of the spin system. This demonstrates that
exchange coupled systems are suitable for cavity quantum electrodynamics
experiments, while allowing high integration densities due to their
extraordinary high spin densities. Our results furthermore show, that
experiments with multiple exchange-coupled spin systems interacting via a
single resonator are within reach.Comment: 5 pages, 3 figure
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Climate impact research: Beyond patchwork
Despite significant progress in climate impact research, the narratives that science can presently piece together of a 2, 3, 4, or 5 °C warmer world remain fragmentary. Here we briefly review past undertakings to characterise comprehensively and quantify climate impacts based on multi-model approaches. We then report on the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP), a community-driven effort to compare impact models across sectors and scales systematically, and to quantify the uncertainties along the chain from greenhouse gas emissions and climate input data to the modelling of climate impacts themselves. We show how ISI-MIP and similar efforts can substantially advance the science relevant to impacts, adaptation and vulnerability, and we outline the steps that need to be taken in order to make the most of the available modelling tools. We discuss pertinent limitations of these methods and how they could be tackled. We argue that it is time to consolidate the current patchwork of impact knowledge through integrated cross-sectoral assessments, and that the climate impact community is now in a favourable position to do so
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