Noise spectroscopy with large clouds of cold atoms

Noise measurement is a powerful tool to investigate many phenomena from laser characterization to quantum behavior of light. In this paper, we report on intensity noise measurements obtained when a laser beam is transmitted through a large cloud of cold atoms. While this measurement could possibly investigate complex processes such as the influence of atomic motion, one is first limited by the conversion of the intrinsic laser frequency noise to intensity noise via the atomic resonance. This conversion is studied here in details. We show that, while experimental intensity noise spectra collapse onto the same curve at low Fourier frequencies, some differences appear at higher frequencies when the probe beam is detuned from the center of the resonance line. A simple model, based on a mean-field approach, which corresponds to describing the atomic cloud by a dielectric susceptibility, is sufficient to understand the main features. Using this model, the noise spectra allow extracting some quantitative informations on the laser noise as well as on the atomic sample

Methods and Systems for Controlling and Determining Size and Quality of Weld Nuggets

Described herein are systems and techniques for joining two or more aluminum alloy products by spot welding and for non-destructively determining the size and quality of a weld nugget created during joining of two or more aluminum alloy products. The systems and techniques described herein may evaluate and/or monitor the welding discharge, which may correspond to a flow of electricity (i.e., electric current) between electrodes and the products to be joined, to determine and/or control a total amount of energy applied for generation of a spot welded joint. For example, the amount of current applied and the voltage at which the current is applied may be used to determine the instantaneous power applied and may, when monitored as a function of time, be used to determine the total energy applied during generation of a spot weld

Combined spectroscopy and intensity interferometry to determine the distances of the blue supergiants P Cygni and Rigel

In this paper, we report on the spatial intensity interferometry measurements within the H$\alpha$ line on two stars: the Luminous Blue Variable (LBV) supergiant \PCygni\,and the late-type B supergiant Rigel. The experimental setup has been upgraded to allow simultaneous measurement of two polarization channels and the zero baseline correlation function. Combined with simultaneous spectra measurements and based on radiative transfer models calculated with the code CMFGEN, we were able to fit our measured visibility curves to extract the stellar distances. Our distance determinations for both \PCygni\ (1.61 $\pm$ 0.18 kpc) and Rigel (0.26 $\pm$ 0.02 kpc) agree very well with the values provided by astrometry with the Gaia and Hipparcos missions, respectively. This is the first successful step towards extending the application of the Wind Momentum Luminosity Relation method for distance calibration from an LBV supergiant to a more normal late-type B supergiant

Neanderthal subsistence at Chez-Pinaud Jonzac (Charente-Maritime, France): A kill site dominated by reindeer remains, but with a horse-laden diet?

During the MIS 4 in Southwestern France, Quina Neanderthal from the north of the Aquitaine was characterized by a hunting specialization on the reindeer and the lack of diversity in their diet. They developed task-specific locations dedicated to the capture, the butchery, and the consumption of reindeer, and the whole society seems, in this region, to be dependent on this food resource. In this context, the site of Chez-Pinaud at Jonzac (France) occupies a specific place. First, interpreted as a reindeer kill and butchery site, the recent recovery of the site underlines the importance of the large ungulate (horse and bison) to the faunal spectrum (30% of the NISP). Considering the quantity of meat and grease that these species can provide to hunters, the new zooarchaeological analyses suggest that at least the horse may have played a major role in the diet of the Neanderthal population. Since Jonzac is one of the largest sites for this period, these results relativize the importance of reindeer specialization of the Quina population and the lack of diversityl in their diet

Altimetry for the future: Building on 25 years of progress

In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the ‘‘Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion

Altimetry for the future: building on 25 years of progress

In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the “Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion

Synthèse one-pot de nanoparticules d'apatite bio-inspirées entourées par de nouveaux agents stabilisants bioactifs à base de peptides : vers une application pour la cicatrisation des plaies

As an alternative to systemic antibiotic treatments generating microbial resistance, APAPTIDE is an innovative approach to the treatment of complex high-risk infectious wounds, based on original bio-inspired apatite hybrid particles doped (antibacterial, anti-inflammatory ions) stabilized by a ring of antibacterial, pro-angiogenic and pro-healing peptides. This concept will be developed as a dressing or ointment.Le projet APAPTIDE repose sur la conception, la synthèse et l'étude de particules hybrides d'apatite bio-inspirée stabilisées par une couronne de peptides bioactifs. Ces particules pourront également être dopées par des ions d'intérêts biologiques (ions antibactériens, anti-inflammatoires). Les particules hybrides préparées seront évaluées biologiquement comme une solution alternative aux traitements antibiotiques systémiques générant une résistance microbienne. De ce fait, des peptides antibactériens, pro-angiogéniques et pro-cicatrisants seront utilisés en priorité pour stabiliser les particules