Search results for "ddc:"
showing 10 items of 3080 documents
Aerosol characteristics and particle production in the upper troposphere over the Amazon Basin
2018
Airborne observations over the Amazon Basin showed high aerosol particle concentrations in the upper troposphere (UT) between 8 and 15 km altitude, with number densities (normalized to standard temperature and pressure) often exceeding those in the planetary boundary layer (PBL) by 1 or 2 orders of magnitude. The measurements were made during the German–Brazilian cooperative aircraft campaign ACRIDICON–CHUVA, where ACRIDICON stands for Aerosol, Cloud, Precipitation, and Radiation Interactions and Dynamics of Convective Cloud Systems and CHUVA is the acronym for Cloud Processes of the Main Precipitation Systems in Brazil: A Contribution to Cloud Resolving Modeling and to the GPM …
Detection of reactive nitrogen containing particles in the tropopause region? Evidence for a tropical nitric acid trihydrage (NAT) belt
2008
The detection of nitric acid trihydrate (NAT, HNO<sub>3</sub>&times;3H<sub>2</sub>O) particles in the tropical transition layer (TTL) harmonizes our understanding of polar stratospheric cloud formation. Large reactive nitrogen (NO<sub>y</sub>) containing particles were observed on 8 August 2006 by instruments onboard the high altitude research aircraft M55-Geophysica near and below the tropical tropopause. The particles, most likely NAT, have diameters less than 6 &mu;m and concentrations below 10<sup>-4</sup> cm<sup>&minus;3</sup>. The NAT particle layer was repeatedly detected at altitudes between 15.1 and 17.5 km ove…
Natural Convection Cooling of a Hot Vertical Wall Wet by a Falling Liquid Film
2008
Abstract The system studied is a plane channel in which one of the two vertical walls is kept at an arbitrary temperature profile and may be partially or completely wet by a falling liquid film, while the opposite wall is adiabatic. Air from the environment flows along the channel with a mass flow rate which depends on the balance between hydraulic resistances and buoyancy forces. These latter, in their turn, depend on the distribution of temperature and humidity (hence, density) along the channel and eventually on the heat and mass transferred from wall and film to the humid air. A simplified computational model of the above system was developed and applied to the prediction of relevant qu…
La Zone euro, noyau fédérateur de l'Europe
2016
L'Union Européenne manque clairement d'Union politique. Seule une Union politique pourrait promouvoir une vision globale à l'intérieur de l'UE, qui contrasterait avec l'approche actuelle, trop étroite et trop centrée sur l'économie et la finance. Le fonctionnement de la Zone euro, qui devrait représenter le noyau dur de l'Union, reste paradoxalement intergouvernemental. Il est donc important d'aligner la Zone euro sur ce qui constitue le régime général du traité de Lisbonne : la méthode communautaire. Les institutions de la Zone euro devraient plus s'inspirer des institutions ordinaires de l'Union, avec une Commission et un Parlement jouant leur rôle. Cette évolution peut être conduite par …
The frequent stressor and mental health monitoring-paradigm: a proposal for the operationalization and measurement of resilience and the identificati…
2021
Resilience has been defined as the maintenance or quick recovery of mental health during and after times of adversity. How to operationalize resilience and to determine the factors and processes that lead to good long-term mental health outcomes in stressor-exposed individuals is a matter of ongoing debate and of critical importance for the advancement of the field. One of the biggest challenges for implementing an outcome-based definition of resilience in longitudinal observational study designs lies in the fact that real-life adversity is usually unpredictable and that its substantial qualitative as well as temporal variability between subjects often precludes defining circumscribed time …
How and when do mobile media demands impact well-being? Explicating the integrative model of mobile media use and need experiences (IM3UNE)
2021
Using mobile media can be both detrimental and beneficial for well-being. Thus, explaining how and when they elicit such effects is of crucial importance. To explicate boundary conditions and processes for digital well-being, this article introduces the Integrative Model of Mobile Media Use and Need Experiences (IM³UNE). Instead of assuming mobile media to be pathogenic, the IM³UNE offers a salutogenic perspective—it focuses on how we can stay healthy when using mobile media ubiquitously in daily life. More specifically, the model assumes that both the satisfaction and the frustration of basic psychological needs are key underlying mechanisms linking demanding mobile media use to well-being…
Fighting the COVID-19 Crisis: Debt Monétisation and EU Recovery Bonds
2020
AbstractThis paper highlights some peculiar characteristics of the economic crisis induced by the spread of COVID-19. It suggests two intertwined policy measures in order to tackle the emergency phase of the crisis and to support the economy in the subsequent recovery phase. The proposed short-term policy measures offer policy responses in the event of a second wave of coronavirus infections in the coming months. In the aftermath of the emergency phase, the current proposal puts forward the implementation of a massive EU-wide recovery plan addressing the long-lasting technological and environmental challenges of these years, which will be financed by European institutions through the issuan…
Search for topological defect dark matter with a global network of optical magnetometers
2021
Ultralight bosons such as axion-like particles are viable candidates for dark matter. They can form stable, macroscopic field configurations in the form of topological defects that could concentrate the dark matter density into many distinct, compact spatial regions that are small compared with the Galaxy but much larger than the Earth. Here we report the results of the search for transient signals from the domain walls of axion-like particles by using the global network of optical magnetometers for exotic (GNOME) physics searches. We search the data, consisting of correlated measurements from optical atomic magnetometers located in laboratories all over the world, for patterns of signals p…
Characteristics of the diffuse astrophysical electron and Tau neutrino flux with six years of IceCube high energy cascade data
2020
We report on the first measurement of the astrophysical neutrino flux using particle showers (cascades) in IceCube data from 2010-2015. Assuming standard oscillations, the astrophysical neutrinos in this dedicated cascade sample are dominated (∼90%) by electron and tau flavors. The flux, observed in the sensitive energy range from 16 TeV to 2.6 PeV, is consistent with a single power-law model as expected from Fermi-type acceleration of high energy particles at astrophysical sources. We find the flux spectral index to be γ=2.53±0.07 and a flux normalization for each neutrino flavor of φastro=1.66-0.27+0.25 at E0=100 TeV, in agreement with IceCube's complementary muon neutrino results and wit…
Stochastic fluctuations of bosonic dark matter
2021
Numerous theories extending beyond the standard model of particle physics predict the existence of bosons that could constitute the dark matter (DM) permeating the universe. In the standard halo model (SHM) of galactic dark matter the velocity distribution of the bosonic DM field defines a characteristic coherence time $\tau_c$. Until recently, laboratory experiments searching for bosonic DM fields have been in the regime where the measurement time $T$ significantly exceeds $\tau_c$, so null results have been interpreted as constraints on the coupling of bosonic DM to standard model particles with a bosonic DM field amplitude $\Phi_0$ fixed by the average local DM density. However, motivate…