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Production scientifique
(35) Production(s) de l'année 2024
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End-to-end multimodal 3D imaging and machine learning workflow for non-destructive phenotyping of grapevine trunk internal structure
Auteur(s): Fernandez Romain, Le Cunff Loïc, Mérigeaud Samuel, Verdeil Jean‐Luc, Perry Julie, Larignon Philippe, Spilmont Anne-Sophie, Chatelet Philippe, Cardoso Maïda
(Article) Publié:
Scientific Reports, vol. 14 p.5033 (2024)
Ref HAL: hal-04501077_v1
PMID 38424155
DOI: 10.1038/s41598-024-55186-3
Exporter : BibTex | endNote
Résumé: Quantifying healthy and degraded inner tissues in plants is of great interest in agronomy, for example, to assess plant health and quality and monitor physiological traits or diseases. However, detecting functional and degraded plant tissues in-vivo without harming the plant is extremely challenging. New solutions are needed in ligneous and perennial species, for which the sustainability of plantations is crucial. To tackle this challenge, we developed a novel approach based on multimodal 3D imaging and artificial intelligence-based image processing that allowed a non-destructive diagnosis of inner tissues in living plants. The method was successfully applied to the grapevine ( Vitis vinifera L.). Vineyard’s sustainability is threatened by trunk diseases, while the sanitary status of vines cannot be ascertained without injuring the plants. By combining MRI and X-ray CT 3D imaging with an automatic voxel classification, we could discriminate intact, degraded, and white rot tissues with a mean global accuracy of over 91%. Each imaging modality contribution to tissue detection was evaluated, and we identified quantitative structural and physiological markers characterizing wood degradation steps. The combined study of inner tissue distribution versus external foliar symptom history demonstrated that white rot and intact tissue contents are key measurements in evaluating vines’ sanitary status. We finally proposed a model for an accurate trunk disease diagnosis in grapevine. This work opens new routes for precision agriculture and in-situ monitoring of tissue quality and plant health across plant species.
Commentaires: The datasets generated and analyzed during the current study are available from the corresponding author upon reasonable request. The extension of the Trainable Segmentation plugin is open-source, and available as a fork of Trainable Segmentation on GitHub https://github.com/Rocsg/Trainable_Segmentation/tree/Hyperweka.
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Elaboration of a neural-network interatomic potential for silica glass and melt
Auteur(s): Trillot Salomé, Lam Julien, Ispas S., Kandy Akshay Krishna Ammothum, Tuckerman Mark, Tarrat Nathalie, Benoit Magali
(Article) Publié:
Computational Materials Science, vol. 236 p.112848 (2024)
Texte intégral en Openaccess :
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Photon mediated transport of energy, linear momentum, and angular momentum in fullerene and graphene systems beyond local equilibrium
Auteur(s): Wang Jian-sheng, Antezza M.
(Article) Publié:
Physical Review B, vol. 109 p.125105 (2024)
DOI: 10.1103/PhysRevB.109.125105
Résumé: Based on a tight-binding model for the electron system, we investigate the transfer of energy, momentum, and angular momentum mediated by electromagnetic fields among buckminsterfullerene (
C
60
) and graphene nanostrips. Our nonequilibrium Green's function approach enables calculations away from local thermal equilibrium where the fluctuation-dissipation theorem breaks down. For example, the forces between
C
60
and current-carrying nanostrips are predicted. It is found that the presence of current enhances the van der Waals attractive forces. For two current-carrying graphene strips rotated at some angle, the fluctuational force and torque are much stronger at the nanoscale compared to that of the static Biot-Savart law.
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Measurement of near-field thermal radiation between multilayered metamaterials
Auteur(s): Zhang Sen, Dang Yongdi, Li Xinran, Iqbal Naeem, Jin Yi, Choudhury Pankaj k, Antezza M., Xu Jianbin, Yungui Ma
(Article) Publié:
Physical Review Applied, vol. 21 p.024054 (2024)
DOI: 10.1103/PhysRevApplied.21.024054
Résumé: The near-field radiative heat transfer (NFRHT) between one-dimensional metamaterials comprised of phonon dielectric multilayers was investigated experimentally. Large-size (1 × 1
cm
2
) near-field samples were fabricated using
Si
C
,
Si
O
2
, and
Ge
layers at a certain gap distance, and the effects of layer-stacking order and phonon-resonance quality on NFRHT were examined. The measured results show good agreement with the theoretical results obtained by employing the transmission-matrix method. Super-Planckian thermal radiation was observed between emitters and receivers with identical structures. The failure of effective-medium theory (EMT) at predicting the near-field heat flux has been evidenced by measurements, particularly in the presence of bounded surface modes, such as the epsilon-near-zero mode. Additionally, analyses have shown that, in specific scenarios, the EMT can offer reasonable physical insights into the underlying coupling process from the perspective of homogenized media. Furthermore, the conditions for applying the EMT in the near-field regime were also touched upon.
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BPS counting in string compactifications
Auteur(s): Alexandrov S.
Conférence invité: Fields & Strings 2024 (Moscou, RU, 2024-02-05)
Résumé: I'll review the known results about BPS indices, which encode in particular the entropy of BPS black holes, appearing in string compactifications down to four dimensions with various number of supersymmetries. First, I'll recall the well-known results about BPS states in N=8 and N=4 compactifications, and then present what is known about them in the N=2 case. Depending on time, I hope to cover some recent advances where an important role was played by (mock) modular symmetry.
Commentaires: presentation by Zoom
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Collective Relaxation Dynamics in a Three-Dimensional Lattice Glass Model
Auteur(s): Nishikawa Y., Berthier L.
(Article) Publié:
Physical Review Letters, vol. 132 p.067101 (2024)
Texte intégral en Openaccess :
Ref HAL: hal-04453684_v1
Ref Arxiv: 2307.08110
DOI: 10.1103/PhysRevLett.132.067101
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
Résumé: We numerically elucidate the microscopic mechanisms controlling the relaxation dynamics of a three-dimensional lattice glass model that has static properties compatible with the approach to a random first-order transition. At low temperatures, the relaxation is triggered by a small population of particles with low-energy barriers forming mobile clusters. These emerging quasiparticles act as facilitating defects responsible for the spatially heterogeneous dynamics of the system, whose characteristic lengthscales remain strongly coupled to thermodynamic fluctuations. We compare our findings both with existing theoretical models and atomistic simulations of glass-formers.
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A new approach combining microwave heat pulse and infrared thermography for non-invasive portable sap flow velocity measurement
Auteur(s): Louche Hervé, Pénarier Annick, Clair Bruno, Nouvel Philippe, Coillot C., Do Frederic
(Article) Publié:
Agricultural And Forest Meteorology, vol. 347 p.109896 (2024)
Texte intégral en Openaccess :
Ref HAL: hal-04445925_v1
DOI: 10.1016/j.agrformet.2024.109896
Exporter : BibTex | endNote
Résumé: Xylem sap flow measurement is a key method to quantify plant water use and assess the responses to environmental conditions and climatic change. However, available methods are generally invasive and of limited portability. This paper presents a non-invasive approach called TIMFLOW that combines microwave heat pulse and infrared thermography, while having a high portability and versatility potential. The methodology was tested in laboratory conditions for black poplar (Populus nigra) stems of various diameters (10–45 mm) and for the known sap flow velocity range (10–100 cm h−1). The heat pulse was generated by microwaves with a power amplifier supplying a bi-quad antenna at 2.45 GHz frequency located near the stem. The scene was filmed using a relatively low-cost light and compact InfraRed (IR) thermography camera. A stem temperature map was used to determine the heat pulse propagation velocity. The calculated heat velocity was highly correlated with the applied flow velocity with a unique relationship regardless of the diameter. The latter result confirms the equation of Marshall (1958) which links the sap velocity to the heat velocity with a vessel fraction of around 25 % within samples. The feasibility of outdoor measurements was also successfully tested. The assumed potentials and limitations of the proposed methodology are discussed. In summary, the study demonstrates the concept and validates, in woody stems, this new methodology for non-invasive portable sap flow velocity measurement.
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