Search results for "casi"

Durée et fréquence des vagues de chaleur en Afrique tropicale septentrionale selon 5 indices de chaleur

2019

Thermal extremes generate health risks that are increasingly taken into account, including in tropical Africa. This work compares the duration and the frequency of spring heat waves (HWs) in West Africa according to 5 indices: Warm Spell (WS), Heat Index (HI) with and without the relative humidity, Apparent Temperature (AT), and Excess Heat Factor (EHF). The daily relative humidity and temperature data (minimum, maximum, dew point are provided by the GSOD database for the period 1973-2014 and cover 145 stations spread over a large African area (3-24°N; 24°W-36°E). The results show that the duration of the HWs is short on the coast (3 days) and they last longer inland the continent and in th…

Biostratigraphy of Triassic Ammonoids

2015

The Triassic is a turning point in the evolutionary history of ammonoids, characterized by the flourishing Ceratitida and the appearance of the first heteromorphs. Following the end-Permian mass extinction, ammonoids were among the first groups to rediversify by producing many new taxa. Already in the late nineteenth century, the still currently recognized Triassic stages and substages were introduced. The historical development of Triassic ammonoid biostratigraphy is a good example of worldwide cooperation between many geographically-diverse research groups, which initially began in Germany and the European Alps. This cooperation was then extended to North America, Transcaucasia, North Ind…

Febbre di origine sconosciuta (FUO): due casisitiche di una medesima divisione di medicina interna a confronto

2002

The Bohm-Aharonov effect: A seven-dimensional structural group

1996

We realize a nonfaithful representation of a seven-dimensional Lie algebra, the extension of which to its universal enveloping algebra contains most of the observables of the scattering Aharonov-Bohm effect, as essentially self-adjoint operators: the scattering Hamiltonian, the total and kinetic angular momenta, the positions and the kinetic momenta. By restriction, we obtain the model introduced in Lett. Math. Phys.1 (1976), 155–163.

El capitalismo, contra el planeta / 4

2007

Dynamical Casimir-Polder force between an excited atom and a conducting wall

2016

We consider the dynamical atom-surface Casimir-Polder force in the non-equilibrium configuration of an atom near a perfectly conducting wall, initially prepared in an excited state with the field in its vacuum state. We evaluate the time-dependent Casimir-Polder force on the atom, and find that it shows an oscillatory behavior from attractive to repulsive both in time and in space. We also investigate the asymptotic behavior in time of the dynamical force and of related local field quantities, showing that the static value of the force, as obtained by a time-independent approach, is recovered for times much larger than the timescale of the atomic self-dressing, but smaller than the atomic d…

MISTERI BURUNG BERACUN (Pitohui dicrous) DARI PEGUNUNGAN ARFAK, MANOKWARI.

2008

<p><em>An observation was carried out to reveal the mystery of the poison bird Pitohui dichrous from the Arfak Mountains.   According to the Arfak tribe, the poison came from plants (Amorphalus galbra and Alocasia flabellifera) and not from the beetle such as in PNG.  Therefore, a furthur study was needed to reveal the poison of Pitohui dicrous from the Arfak mountains.</em></p>

Présentation générale des trois textes publiés

2016

National audience

Les vagues de chaleur au Sahel : définition et principales caractéristiques spatio-temporelles (1973-2014).

2016

A definition of heat waves (HW) relevant for dry tropical regions is proposed and tested in the Sahel (i.e. duration,intensity and frequency). The Heat Index (HI derivative of Steadman’s (1979) formula) is calculated on dailydata of 145 West African stations from the GSOD database over the period 1973-2014. HWs recorded inSahelian and Sudanese climates mainly occur in boreal spring, i.e. April-May-June. They are more frequentsince 1998 (+ 8% very hot days, T90p) and they become longer (+1.2 days per decade) and more intense (from+0.3 to 0.4 ° C / decade respectively Sudanese and Sahelian climate) on the end of the period 1973-2014.

Axionic and nonaxionic electrodynamics in plane and circular geometry

2023

Various aspects of axion electrodynamics in the presence of a homogeneous and isotropic dielectric medium are discussed. 1. We consider first the "antenna-like" property of a planar dielectric surface in axion electrodynamics, elaborating on the treatment given earlier on this topic by Millar {\it et al.} (2017). We calculate the electromagnetic energy transmission coefficient for a dielectric plate, and compare with the conventional expression in ordinary electrodynamics. 2. We consider the situation where the medium exterior to the plate, assumed elastic, is "bent back" and glued together, so that we obtain a circular dielectric string in which the waves can propagate clockwise or counter…