Centre dedocumentation
scientifique

X-ray microdensitometry of wood: A review of existing principles and devices / Philippe Jacquin in Dendrochronologia, vol 42 (March 2017)  

Public [article]  inDendrochronologia > vol 42 (March 2017) . - pp 42 - 50 Titre : X-ray microdensitometry of wood: A review of existing principles and devices Type de document : Article/Communication Auteurs : Philippe Jacquin, Auteur ; Fleur Longuetaud, Auteur ; Jean-Michel Leban, Auteur ; Frédéric Mothe, Auteur Année de publication : 2017 Article en page(s) : pp 42 - 50 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Végétation [Termes descripteurs IGN] dendrochronologie [Termes descripteurs IGN] densité du bois [Termes descripteurs IGN] rayon X [Termes descripteurs IGN] tomographie Résumé : (auteur) Wood microdensitometry is the analysis of radial variations of density at the annual or intra-annual growth ring level. Density is related to wood quality, biomass, carbon content, tree growth and climate. Wood microdensitometry is particularly used in dendrochronology and climatology studies. The present study focuses on X-ray based methods used in wood microdensitometry analyses and provides a review of the main available devices. An exhaustive review of 75 works published on this topic in 2014 and 2015 showed that film-based equipment is still commonly used. The three other most popular devices, SilviScan, Itrax and QTRS, are also based on X-ray radiography and deliver results with comparable accuracy, below 50 μm per pixel. X-ray tomography (CT) is still rarely used in wood densitometry. Medical CT scanners currently offer a lower accuracy (above 100 μm per pixel) that is insufficient in most cases for ring or intra-ring scales. Micro-CT scanners offer good performance at the cost of much longer acquisition and reconstruction times. Numéro de notice : A2017-893 Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.dendro.2017.01.004 date de publication en ligne : 27/01/2017 En ligne : https://doi.org/10.1016/j.dendro.2017.01.004 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91887 [article]

Within-stem maps of wood density and water content for characterization of species: a case study on three hardwood and two softwood species / Fleur Longuetaud in Annals of Forest Science [en ligne], vol 73 n° 3 (September 2016)  

Public [article]  inAnnals of Forest Science [en ligne] > vol 73 n° 3 (September 2016) . - pp 601 - 614 Titre : Within-stem maps of wood density and water content for characterization of species: a case study on three hardwood and two softwood species Type de document : Article/Communication Auteurs : Fleur Longuetaud, Auteur ; Frédéric Mothe, Auteur ; Meriem Fournier, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 601 - 614 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Végétation [Termes descripteurs IGN] Abies alba [Termes descripteurs IGN] acer pseudoplatanus [Termes descripteurs IGN] analyse discriminante [Termes descripteurs IGN] caractérisation [Termes descripteurs IGN] espèce végétale [Termes descripteurs IGN] Fagus sylvatica [Termes descripteurs IGN] pseudotsuga menziesii [Termes descripteurs IGN] quercus (genre) [Termes descripteurs IGN] teneur en eau de la végétation [Termes descripteurs IGN] tomographie [Termes descripteurs IGN] tronc [Termes IFN] densité du bois Résumé : (auteur) Key message : Variability and interrelations between wood density, water content, and related properties were analyzed by CT scanning of five species. Relative water content of lumens is proposed as the best complement to basic specific gravity for discrimination of species with respect to their functioning. Context : X-ray computed tomography (CT) is an efficient tool for analysis of wood properties related to density and water content all along a tree stem. Basic specific gravity, an inherent property of the wood material, is well known and widely used in wood sciences. Aims : The first aim of this study was to describe a method for mapping a set of wood properties within a tree stem. The second objective was to analyze the relations among these properties and to identify the one that offers the best information in addition to basic specific gravity for discrimination of species. Methods : Wood discs were collected at various heights along a tree stem. We used a method consisting of comparing the CT images of the discs in the green state and after oven drying. Finally, 10 variables were computed for 115 trees of five temperate species: green, oven-dry, and basic specific gravities; moisture content; relative water content; relative water content of lumens; and fractions of air, water, free water, and cell walls. Results : Maps of wood properties summarizing the radial and vertical variations were obtained, allowing us to highlight species-specific patterns. The five species were discriminated best when plotted in the plane defined by basic specific gravity and relative water content of lumens. Conclusion : The proposed method is original and simple enough to process large samples. Because it correlated less with basic specific gravity than with moisture content, relative water content of lumens was selected for species characterization. This is the first study of such wood properties at this fine scale within a tree stem, simultaneously and for a substantial number of trees of five species including both hardwoods and softwoods. Numéro de notice : A2016-710 Thématique : FORET Nature : Article En ligne : http://dx.doi.org/10.1007/s13595-016-0555-4 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=82088 [article]

A new computerized ionosphere tomography model using the mapping function and an application to the study of seismic-ionosphere disturbance / Jian Kong in Journal of geodesy, vol 90 n° 8 (August 2016)  

Public [article]  inJournal of geodesy > vol 90 n° 8 (August 2016) . - pp 741 – 755 Titre : A new computerized ionosphere tomography model using the mapping function and an application to the study of seismic-ionosphere disturbance Type de document : Article/Communication Auteurs : Jian Kong, Auteur ; Yi Bin Yao, Auteur ; Lei Liu, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 741 – 755 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale [Termes descripteurs IGN] altération [Termes descripteurs IGN] correction troposphérique [Termes descripteurs IGN] International Reference Ionosphere [Termes descripteurs IGN] Japon [Termes descripteurs IGN] séisme [Termes descripteurs IGN] teneur totale en électrons [Termes descripteurs IGN] tomographie [Termes descripteurs IGN] troposphère Résumé : (auteur) A new algorithm for ionosphere tomography using the mapping function is proposed in this paper. First, the new solution splits the integration process into four layers along the observation ray, and then, the single-layer model (SLM) is applied to each integration part using a mapping function. Next, the model parameters are estimated layer by layer with the Kalman filtering method by introducing the scale factor (SF) γ to solve the ill-posed problem. Finally, the inversed images of different layers are combined into the final CIT image. We utilized simulated data from 23 IGS GPS stations around Europe to verify the estimation accuracy of the new algorithm; the results show that the new CIT model has better accuracy than the SLM in dense data areas and the CIT residuals are more closely grouped. The stability of the new algorithm is discussed by analyzing model accuracy under different error levels (the max errors are 5TECU, 10TECU, 15TECU, respectively). In addition, the key preset parameter, SFγ, which is given by the International Reference Ionosphere model (IRI2012). The experiment is designed to test the sensitivity of the new algorithm to SF variations. The results show that the IRI2012 is capable of providing initial SF values. Also in this paper, the seismic-ionosphere disturbance (SID) of the 2011 Japan earthquake is studied using the new CIT algorithm. Combined with the TEC time sequence of Sat.15, we find that the SID occurrence time and reaction area are highly related to the main shock time and epicenter. According to CIT images, there is a clear vertical electron density upward movement (from the 150-km layer to the 450-km layer) during this SID event; however, the peak value areas in the different layers were different, which means that the horizontal movement velocity is not consistent among the layers. The potential physical triggering mechanism is also discussed in this paper. Compared with the SLM, the RMS of the new CIT model is improved by 16.78%, while the CIT model could provide the three-dimensional variation in the ionosphere. Numéro de notice : A2016-504 Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern En ligne : http://dx.doi.org/10.1007/s00190-016-0906-9 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81528 [article]

Variations in the natural density of European oak wood affect thermal degradation during thermal modification / Joël Hamada in Annals of Forest Science [en ligne], vol 73 n° 2 (June 2016)  

Public [article]  inAnnals of Forest Science [en ligne] > vol 73 n° 2 (June 2016) . - pp 277 - 286 Titre : Variations in the natural density of European oak wood affect thermal degradation during thermal modification Type de document : Article/Communication Auteurs : Joël Hamada, Auteur ; Anélie Pétrissans, Auteur ; Frédéric Mothe, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 277 - 286 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Végétation [Termes descripteurs IGN] bois [Termes descripteurs IGN] économie industrielle [Termes descripteurs IGN] effet thermique [Termes descripteurs IGN] industrie forestière [Termes descripteurs IGN] quercus (genre) [Termes descripteurs IGN] sylviculture [Termes descripteurs IGN] tomographie Résumé : (auteur) Key message : Thermogravimetric analysis, performed on small samples of earlywood (EW) or latewood (LW), indicated that earlywood is more susceptible to thermal degradation than latewood. These results suggest a direct relationship between wood density (which depends on the EW/LW ratio and indirectly on silviculture) and the response of wood during thermo-modification processes. Context: One of the main difficulties in developing thermo-modified wood products at an industrial scale lies in the difficulty of obtaining consistent products with a stable quality (durability, dimensional stability, color). This may be due either to the thermal treatment process itself or to inter- or intra-specific heterogeneity of wood properties. Aims: We investigated the effect of the natural variability of oak wood, particularly in density, on the degree of thermo-degradation during thermal treatments. Methods: X-ray computed tomography was used to assess the effect of initial wood density of oak boards on their thermo-degradation. Intra-ring wood density was estimated using thermogravimetric analysis and micro-densitometry. Results: X-ray CT did not allow establishment of a clear correlation between initial wood density and mass loss due to thermo-degradation, while thermogravimetric analysis, performed separately on earlywood and latewood samples, revealed a larger susceptibility to thermal degradation of the less dense earlywood samples compared to more dense latewood samples Conclusion: Initial wood density, which is directly controlled by the earlywood/latewood ratio modulated by silvicultural practices, directly influences thermo-degradation during thermal treatment. Initial wood density therefore appears to be a potential parameter influencing industrial thermal treatment processes. Numéro de notice : A2016-349 Thématique : FORET Nature : Article En ligne : http://dx.doi.org/10.1007/s13595-015-0499-0 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81060 [article]

Combining spaceborne SAR images with 3D point clouds for infrastructure monitoring applications / Andrei Anghel in ISPRS Journal of photogrammetry and remote sensing, vol 111 (January 2016)

Public [article]  inISPRS Journal of photogrammetry and remote sensing > vol 111 (January 2016) . - pp 45 – 61 Titre : Combining spaceborne SAR images with 3D point clouds for infrastructure monitoring applications Type de document : Article/Communication Auteurs : Andrei Anghel, Auteur ; Gabriel Vasile, Auteur ; Rémy Boudon, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 45 – 61 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image mixte [Termes descripteurs IGN] analyse combinatoire (maths) [Termes descripteurs IGN] appariement d'images [Termes descripteurs IGN] France métropolitaine [Termes descripteurs IGN] image radar moirée [Termes descripteurs IGN] semis de points [Termes descripteurs IGN] test de performance [Termes descripteurs IGN] tomographie Résumé : (auteur) The measurement and monitoring of critical infrastructure elements by remote sensing has become necessary for economical and security reasons. Information provided by remote sensing for infrastructure monitoring is extracted with specific signal processing chains that have to be adapted to the geometric particularities of the structure. In this paper we present in detail the first monitoring results obtained by combining spaceborne synthetic aperture radar (SAR) data with externally measured point clouds describing an infrastructure element. The processing core is essentially based on refocusing each available SAR image on the provided point cloud and identifying the scatterers that can be monitored by means of four dimensional tomography. The key points and limitations which appear in the measurement and data processing are illustrated on two test sites in France: the Puylaurent water-dam and the Chastel landslide. The SAR products used are high-resolution sliding spotlight SAR images acquired in the TerraSAR-X and TanDEM-X missions, whereas the point clouds of the structures were generated using GPS localization, topographic measurements and laser scans. The estimated deformations of the scatterers using the SAR images were in good agreement with available in-situ data provided through regular topographic surveys and embedded measuring systems. Numéro de notice : A2016-040 Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=79520 [article]

Voxel-optimized regional water vapor tomography and comparison with radiosonde and numerical weather model / Biyan Chen in Journal of geodesy, vol 88 n° 7 (July 2014)  

Permalink

Assessment of an ancient bridge combining geophysical and advanced photogrammetric methods: Application to the Pont De Coq / Cyrille Fauchard in Journal of applied geophysics, vol 98 (November 2013)  

Permalink

Ground-based array for tomographic imaging of the tropical forest in P-band / Ho Tong Minh Dinh in IEEE Transactions on geoscience and remote sensing, vol 51 n° 8 (August 2013)

Permalink

Phenomenology of ground scattering in a tropical forest through polarimetric synthetic aperture radar tomography / Mauro Mariotti d'Alessandro in IEEE Transactions on geoscience and remote sensing, vol 51 n° 8 (August 2013)

Permalink

Three-dimensional reconstruction of man-made objects using polarimetric tomographic / Shi-Qi Xing in IEEE Transactions on geoscience and remote sensing, vol 51 n° 6 Tome 2 (June 2013)

Permalink

Quantification de l'accélération des plaques tectoniques / Michelle Aubrun (2013)

Permalink

Near real-time estimation of water vapour in the troposphere using ground GNSS and the meteorological data / Jaroslaw Bosy in Annales Geophysicae, n° 30 (27/09/2012) 

Permalink

A photogrammetric technique for acquiring accurate head surfaces of newborn infants for optical tomography under clinical conditions / M. Abreu De Souza in Photogrammetric record, vol 27 n° 139 (September - November 2012)  

Permalink

GPU-based volumetric reconstruction and rendering of trees from multiple images / D. Vock in Photogrammetric record, vol 27 n° 138 (June - August 2012)  

Permalink

Photogrammetric techniques for voxel-based flow velocity field measurement / P. Westfeld in Photogrammetric record, vol 26 n° 136 (December 2011 - February 2012)  

Permalink