216 research outputs found
L’(in)sécurisation par les technologies militaires et la mise en sens de la violence
En appliquant une sociologie politique de l’international à l’intervention militaire de l’OTAN en Libye, cet article propose une analyse des procédés d’(in)sécurisation émanant de l’emploi de certaines technologies militaires et de la mise en sens de l’usage de la violence dans le cadre d’interventions militaires internationales. L’objet de notre réflexion est de percer les logiques d’(in)sécurisation contenues dans certaines pratiques militaires qui permettent d’établir un sens particulier de l’(in)sécurité sur la base du référentiel de l’usage de la violence. Nous tentons ainsi de démontrer la manière dont l’emploi de la violence est représenté comme plus ou moins sécurisant à travers l’étude de la mise en place pratique et discursive d’une opposition entre l’usage par l’OTAN d’une violence dite instrumentale-rationnelle et celui du régime Kadhafi, dépeint comme irrationnel et indiscriminé.By applying an international political sociology to NATO’s military intervention over Libya, this paper proposes an analysis of securitization processes developed into particular military technologies and representations of the use of violence in the context of international military interventions. Our aim is to study securitization logics contained in the use of highly sophisticated military technologies allowing to create a particular sense of (in)security fixed on the referential of the use of violence. We try to demonstrate the different ways through which the use of violence is represented as more or less securing by an analysis of a practical and discursive construction of an opposition between NATO’s instrumental-rational use of violence and Gaddafi’s one, portrayed as irrational and indiscriminate
Influence of Saccharomyces cerevisiae Strains on General Composition and Sensorial Properties of White Wines Made from Vitis vinifera cv. Albariño
Yeast strains contribute to the oenological and sensorial characteristics of the wines they produce. The present study was performed to determine the influence of Saccharomyces cerevisiae strains on the composition and sensorial properties of Albariño wine. The must obtained from Albariño grapes was inoculated with 12 different yeast strains isolated from a single winery in Galicia, Spain. Chemical and sensorial analyses were performed on the final wines, which differed depending on the yeast strain used
Microbial dysbiosis in roots and rhizosphere of grapevines experiencing decline is associated with active metabolic functions
When grapevine decline, characterized by a premature decrease in vigor and yield and sometimes plant death, cannot be explained by pathological or physiological diseases, one may inquire whether the microbiological status of the soil is responsible. Previous studies have shown that the composition and structure of bacterial and fungal microbial communities in inter-row soil are affected in areas displaying vine decline, compared to areas with non-declining vines within the same plot. A more comprehensive analysis was conducted in one such plot. Although soil chemical parameters could not directly explain these differences, the declining vines presented lower vigor, yield, berry quality, and petiole mineral content than those in non-declining vines. The bacterial and fungal microbiome of the root endosphere, rhizosphere, and different horizons of the bulk soil were explored through enzymatic, metabolic diversity, and metabarcoding analysis in both areas. Despite the lower microbial diversity and richness in symptomatic roots and soil, higher microbial activity and enrichment of potentially both beneficial bacteria and pathogenic fungi were found in the declining area. Path modeling analysis linked the root microbial activity to berry quality, suggesting a determinant role of root microbiome in the berry mineral content. Furthermore, certain fungal and bacterial taxa were correlated with predicted metabolic pathways and metabolic processes assessed with Eco-Plates. These results unexpectedly revealed active microbial profiles in the belowground compartments associated with stressed vines, highlighting the interest of exploring the functional microbiota of plants, and more specifically roots and rhizosphere, under stressed conditions
Visualization of subsurface damage in woven carbon fiber-reinforced composites using polarization-sensitive terahertz imaging
Polarization-sensitive terahertz imaging is applied to characterize subsurface damage in woven carbon fiber-reinforced composite laminates in this study. Terahertz subsurface spectral imaging based on terahertz deconvolution is tailored and applied to detect, in a nondestructive fashion, the subsurface damage within the first ply of the laminate caused by a four-point bending test. Subsurface damage types, including matrix cracking, fiber distortion/fracture, as well as intra-ply delamination, are successfully characterized. Our results show that, although the conductivity of carbon fibers rapidly attenuates terahertz propagation with depth, the imaging capability of terahertz radiation on woven carbon fiber-reinforced composites can nonetheless be significantly enhanced by taking advantage of the terahertz polarization and terahertz deconvolution. The method demonstrated in this study is capable of extracting and visualizing a number of fine details of the subsurface damage in woven carbon fiber-reinforced composites, and the results achieved are confirmed by comparative studies with X-ray tomography.The authors gratefully acknowledge the financial support of the Conseil Régional du Grand Est of the Fonds Européen de Développement Régional (FEDER), and of the Institut Carnot ARTS
Application of Ultrasonic Coda Wave Interferometry for Micro-cracks Monitoring in Woven Fabric Composites
The consequences of a four-point bending test, up to 12 mm, are examined by emitting 1 MHz ultrasonic guided waves in woven carbon fiber reinforced polymer specimens, using coda wave interferometry (CWI), revealing a potential use for nondestructive evaluation. It is known that CWI is more sensitive to realistic damage than the conventional method based on the first arriving time of flight in geophysical, or in civil engineering applications such as concrete structures. However, in composite materials CWI is not well established because of the involved structural complexity. In this paper, CWI is investigated for monitoring the occurrence of realistic defects such as micro-cracks in a woven carbon fiber composite plate. The micro-cracks are generated by a four-point bending test. The damage state is stepwise enhanced by gradually increasing the load level, until failure initiation. The damage is monitored, after each loading, using ultrasound. It is demonstrated that CWI is a powerful tool to detect damage, even low levels, in the sample. Two damage indicators based on CWI, i.e. signals correlation coefficient and relative velocity change, are investigated and appear to be complimentary. Under significant loading levels, the normalized cross-correlation coefficient between the waveforms recorded in the damaged and in the healthy sample (reference at 0 mm), decreases sharply; this first indicator is therefore useful for severe damage detection. It is also demonstrated, by means of a second indicator, that the relative velocity change between a baseline signal taken at zero loading, and the signals taken at various loadings, is linear as a function of the loading, until a critical level is reached; therefore this second indicator, is useful for low damage level detection. The obtained evolution of the relative velocity measurement is supported by relative comparison to the evolution of the bending modulus in function of displacement. The relative velocity change exhibits the same evolution as the bending modulus with loading. It could be used to indicate when the material stiffness has decreased significantly. The research is done in the framework of composite manufacturing quality control and appears to be a promising inspection technique.This work is supported by the Région Grand Est
Cosmicflows-4
With Cosmicflows-4, distances are compiled for 55,877 galaxies gathered into
38,065 groups. Eight methodologies are employed, with the largest numbers
coming from the correlations between the photometric and kinematic properties
of spiral galaxies (TF) and elliptical galaxies (FP). Supernovae that arise
from degenerate progenitors (SNIa) are an important overlapping component.
Smaller contributions come from distance estimates from the surface brightness
fluctuations of elliptical galaxies (SBF) and the luminosities and expansion
rates of core collapse supernovae (SNII). Cepheid Period-Luminosity Relation
(CPLR) and Tip of the Red Giant Branch (TRGB) observations founded on local
stellar parallax measurements along with the geometric maser distance to NGC
4258 provide the absolute scaling of distances. The assembly of galaxies into
groups is an important feature of the study in facilitating overlaps between
methodologies. Merging between multiple contributions within a methodology and
between methodologies is carried out with Bayesian Markov chain Monte Carlo
procedures. The final assembly of distances is compatible with a value of the
Hubble constant of km s Mpc with the small statistical
error km s Mpc but a large potential systematic error
~3 km s Mpc. Peculiar velocities can be inferred from the
measured distances. The interpretation of the field of peculiar velocities is
complex because of large errors on individual components and invites analyses
beyond the scope of this study.Comment: 38 pages, 24 figures. catalogs available at edd.ifa.hawaii.edu.
Accepted to Ap
Sociology and hierarchy of voids: A study of seven nearby CAVITY galaxy voids and their dynamical CosmicFlows-3 environment
Context. The present study addresses a key question related to our
understanding of the relation between void galaxies and their environment: the
relationship between luminous and dark matter in and around voids. Aims. To
explore the extent to which local Universe voids are empty of matter, we study
the full (dark+luminous) matter content of seven nearby cosmic voids that are
fully contained within the CosmicFlows-3 volume. Methods. We obtained the
matter-density profiles of seven cosmic voids using two independent methods.
These were built from the galaxy redshift space two-point correlation function
in conjunction with peculiar velocity gradients from the CosmicFlows-3 dataset.
Results. The results are striking, because when the redshift survey is used,
all voids show a radial positive gradient of galaxies, while based on the
dynamical analysis, only three of these voids display a clear underdensity of
matter in their center. Conclusions. This work constitutes the most detailed
observational analysis of voids conducted so far, and shows that void emptiness
should be derived from dynamical information. From this limited study, the
Hercules void appears to be the best candidate for a local Universe pure
"pristine volume", expanding in three directions with no dark matter located in
that void.Comment: Submitted A\&A Nov 29, 2022 - AA/2022/45578 / Accepted March 3rd,
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