Influence of wood anatomy on fiber orientation measurement obtained by laser scanning on five European species

Abstract In order to obtain high production rates of sawn timber, the sawmilling industry can use laser scanning, allowing knot detection and machine strength grading. In particular, laser scanners measure grain angle using the so-called tracheid effect on wood surface where an elliptic scattering of the laser light can be observed. This paper aims to describe the light scattering obtained by a laser beam projection on wood surface and to assess the accuracy of such fiber orientation measurement on five European species. Firstly, fiber orientation measurement error was assessed by rotating samples. Secondly, the description of the scattering effect was done considering ellipse axis ratios and areas. This was studied according to several parameters such as wood surface machining, moisture content, and orthotropic planes of symmetry. Fiber orientation measurement was successfully performed on all the tested species. The measurement error was below 1.6°, except for oak longitudinal–radial (LR) plane showing an error up to 3.1°. For most of the species, the error was higher in LR plane because of the influence of medullary rays. Despite the observation of major variabilities in laser light scattering, it was possible to measure the grain angles with a good accuracy for all investigated species

Assessment of the error of fiber orientation measurement obtained by laser scanning on several European hardwood and softwood species

Scanner measurements allow knot detection and machine strength grading on sawn timber. In particular, laser scanners measure fiber orientation by means of the so-called tracheid effect explained by the fact that the wood fibers conduct concentrated light better in the direction of fibers than across. The LaBoMaP has developed a fiber orientation scanner effective on softwood and hardwood species. In the present work, the fiber orientation measurement error is assessed on several European hardwood and softwood species. A method to measure the intensity of the tracheid effect according to the species and wood cutting plane (radial-longitudinal or tangential-longitudinal) is also proposed, and several underlying artefacts of the tracheid effect are discussed. Results showed that fiber orientation measurement was possible on hardwood species with the LaBoMaP laser scanner, especially on oak

Measurement of fiber orientation by laser light scattering on dry and rough sawn green hardwoods

Scanner measurements allow knot detection and machine strength grading on sawn timber, which answers the construction and sawmilling industry needs at high production rates. In particular, laser scanners measure fiber orientation by means of the so-called tracheid effect on wood surface where elliptically scattered laser light can be observed. Many studies showed that a red laser scanner is very effective on softwood species like spruce but ineffective on many hardwood species like oak. However, the LaBoMaP has recently developed a fiber orientation scanner, utilizing another kind of laser, effective on hardwood species, especially oak. Other studies showed that measurement quality is better on sanded and planed wood than on rough sawn timber. Besides, the influence of moisture content on tracheid effect is also known. In practice, light ellipses are biggest on fresh wood than on dry wood. In the present work, a method is proposed to measure the intensity of tracheid effect on fresh sawn hardwoods, according to the species, and the error of the fiber orientation measurement is also assessed. To achieve this, clean fresh wood test pieces were first scanned at 0° orientation and ellipse geometrical parameters were compared to that obtained on an isotropic surface. In a second time, test pieces were scanned at different orientations from 0° to 90°. Measurement error was defined as the difference of scanned fiber angle mean on each iteration and test piece orientation between these same iterations. Comparisons of results between species and moisture content will be presented at the conference

Elastic properties of the α' martensitic phase in the Ti-6Al-4V alloy obtained by additive manufacturing

Elastic behaviour of Ti-6Al-4V alloy elaborated through additive manufacturing process is studied both experimentally and trough atomistic simulation. By studying rough samples after fabrication and after heat treatment, the elastic properties of the α' martensitic phase is compared to that of α+β microstructure. Atomistic calculations were also performed on various super-cells varying their chemical composition in order to simulate α and α' phases and their full elastic stiffness tensors were determined. Both experimental and simulation results show that Youngmodulus of the α' phase is lower than that ofα phase,while it presents a more anisotropic behaviour

TurboSHAKE

In a recent presentation, we promoted the use of 12-round instances of Keccak, collectively called “TurboSHAKE”, in post-quantum cryptographic schemes, but without defining them further. The goal of this note is to fill this gap: The definition of the TurboSHAKE family simply consists in exposing and generalizing the primitive already defined inside KangarooTwelve

BLOOM: A 176B-Parameter Open-Access Multilingual Language Model

Large language models (LLMs) have been shown to be able to perform new tasks based on a few demonstrations or natural language instructions. While these capabilities have led to widespread adoption, most LLMs are developed by resource-rich organizations and are frequently kept from the public. As a step towards democratizing this powerful technology, we present BLOOM, a 176B-parameter open-access language model designed and built thanks to a collaboration of hundreds of researchers. BLOOM is a decoder-only Transformer language model that was trained on the ROOTS corpus, a dataset comprising hundreds of sources in 46 natural and 13 programming languages (59 in total). We find that BLOOM achieves competitive performance on a wide variety of benchmarks, with stronger results after undergoing multitask prompted finetuning. To facilitate future research and applications using LLMs, we publicly release our models and code under the Responsible AI License

Impact of species and antibiotic therapy of enterococcal peritonitis on 30-day mortality in critical care - An analysis of the OUTCOMEREA database

Introduction: Enterococcus species are associated with an increased morbidity in intraabdominal infections (IAI). However, their impact on mortality remains uncertain. Moreover, the influence on outcome of the appropriate or inappropriate status of initial antimicrobial therapy (IAT) is subjected to debate, except in septic shock. The aim of our study was to evaluate whether an IAT that did not cover Enterococcus spp. was associated with 30-day mortality in ICU patients presenting with IAI growing with Enterococcus spp. Material and methods: Retrospective analysis of French database OutcomeRea from 1997 to 2016. We included all patients with IAI with a peritoneal sample growing with Enterococcus. Primary endpoint was 30-day mortality. Results: Of the 1017 patients with IAI, 76 (8%) patients were included. Thirty-day mortality in patients with inadequate IAT against Enterococcus was higher (7/18 (39%) vs 10/58 (17%), p = 0.05); however, the incidence of postoperative complications was similar. Presence of Enterococcus spp. other than E. faecalis alone was associated with a significantly higher mortality, even greater when IAT was inadequate. Main risk factors for having an Enterococcus other than E. faecalis alone were as follows: SAPS score on day 0, ICU-acquired IAI, and antimicrobial therapy within 3 months prior to IAI especially with third-generation cephalosporins. Univariate analysis found a higher hazard ratio of death with an Enterococcus other than E. faecalis alone that had an inadequate IAT (HR = 4.4 [1.3-15.3], p = 0.019) versus an adequate IAT (HR = 3.1 [1.0-10.0], p = 0.053). However, after adjusting for confounders (i.e., SAPS II and septic shock at IAI diagnosis, ICU-acquired peritonitis, and adequacy of IAT for other germs), the impact of the adequacy of IAT was no longer significant in multivariate analysis. Septic shock at diagnosis and ICU-acquired IAI were prognostic factors. Conclusion: An IAT which does not cover Enterococcus is associated with an increased 30-day mortality in ICU patients presenting with an IAI growing with Enterococcus, especially when it is not an E. faecalis alone. It seems reasonable to use an IAT active against Enterococcus in severe postoperative ICU-acquired IAI, especially when a third-generation cephalosporin has been used within 3 months. © 2019 The Author(s)

Assessment of groundwater recharge and circulation controls in arid and hyperarid piedmont areas, at different time scales : example of the Pampa del Tamarugal Aquifer (Northern Chile)

Dans les zones arides, la grande variabilité des eaux de surface a conduit les Hommes à exploiter les eaux souterraines. Cependant, afin de préserver durablement cette ressource, une bonne connaissance des processus de recharge est nécessaire. Ces travaux de thèse ont pour objectifs de caractériser les facteurs de contrôle de la recharge et des écoulements souterrains en zone de piedmont aride et hyper-aride. Dans le Nord du Chili, l’activité minière et les villes nouvelles associées aux déplacements de populations depuis quelques dizaine d’années ont engendré une surexploitation des ressources en eaux souterraines contenues dans l’Aquifère de la Pampa del Tamarugal. Cet aquifère régional est l’une des principales ressources en eau de l’ensemble du Nord du Chili, ce qui en fait une ressource stratégique. Le contexte hyper-aride de cette zone de piedmont (extension nord du Désert d’Atacama) semble suggérer que la recharge actuelle de l’aquifère ne permet pas de soutenir son bilan hydrologique.Afin d’identifier et de caractériser les facteurs de contrôle de la recharge et des écoulements souterrains de l’Aquifère de la Pampa del Tamarugal, une approche multidisciplinaire a été utilisée. Cette approche est basée dans un premier temps sur la caractérisation géologique et géomorphologique de la Dépression Centrale et notamment du Piedmont Andin entre 19,5°S et 20°S. Celle-ci a permis d’identifier le rôle du substratum pré-Oligocène sur l’organisation de la couverture fin-Cénozoïque (i.e. axes de drainages, barrières sédimentaires & paléovallées) et sur les circulations souterraines au niveau du piedmont. Dans un second temps, une approche hydrogéophysique et hydro(géo)logique a été utilisée afin de caractériser et d’identifier les conditions aux limites ainsi que l’évolution spatiale de la piézométrie au sein de la plaine de la Pampa del Tamarugal et du piedmont. De nombreux sondages de résistivité, réalisé par TDEM, ont permis d’identifier un contraste bien défini et corrélé avec le niveau piézométrique de la nappe libre. Des relevés hydro(geo)logiques ont permis de valider les échanges rivière-nappe (zones de recharge) qui ont été déduits à partir de l’étude géophysique. Dans un troisième temps, la caractérisation géochimique et isotopique des eaux souterraines de la zone d’étude a permis d’identifier les origines, les circulations ainsi que les processus de recharge de l’aquifère. La distribution des âges de l’eau de la zone saturée a permis d’identifier les grandes phases de recharge paléoclimatiques de l’Holocène. Dans un quatrième temps, une approche exploratoire par la modélisation des écoulements au sein de la zone non saturée, basée sur un modèle à base physique (Hydrus-1D) et complétée par des relevés de terrain, ont permis d’évaluer la recharge induite par une crue au niveau des cônes alluviaux. L’analyse des chroniques piézométriques a apporté de nombreuses informations sur la quantification de la recharge.Sur la base des résultats de cette étude multidisciplinaire, ces travaux de recherche ont permis de définir, au niveau de l’Aquifère de la Pampa del Tamarugal (Nord Chili), les facteurs de contrôle de la recharge et des écoulements souterrains en zone de piedmont aride et hyper-aride.In drylands, the scarcity of surface waters has led the population to mainly extract the groundwater resource for water supply. To preserve the groundwater resource of the over-exploitation, the understanding of the groundwater recharge processes is required. The present work aims to assess the factors of control on both the groundwater recharge and the groundwater circulation in dryland piedmonts.In Northern Chile, since a few tens of years, mining activities and the associated population movements have induced an over-exploitation of the Pampa del Tamarugal Aquifer. This regional size aquifer is one of the main groundwater resources of Northern Chile as a whole.In order to assess the controls on the groundwater recharge processes that allow recharging the Pampa del Tamarugal Aquifer as well as the groundwater circulation in the Andean Piedmont, a multidisciplinary approach was carried out in the endorheic catchment of the Pampa del Tamarugal (i.e. lowlands and piedmont) between 19.5°S and 20°S. Firstly, the study is based on a geological and geomorphological assessment of the Central Depression sedimentary basin with a focus on the Andean Piedmont. This work allowed identifying the control of the pre-Oligocene bedrock on both the late-Cenozoic piedmont cover (i.e. alluvial drainage axis, sedimentary barriers, and paleovalleys) and the groundwater circulation. Secondly, a hydrogeophysical (resistivity soundings, via TDEM) and hydrogeological characterization of the vadose zone and the saturated zone of the aquifer was carried out. These measurements allowed identifying a well-defined contrast of resistivity that is correlated with the water-table. This allows to better define the boundary conditions of the aquifer and to shift eastwards (i.e. in the piedmont) the oriental limit of the aquifer. Hydrological surveys allowed to validate the identification of groundwater recharge areas where the rivers fed the aquifer. Thirdly, the study is based on the assessment of the geochemical, isotopic and dissolved gas content of the groundwater. This approach allowed identifying the origin and also the groundwater circulation of the aquifer. The characterization of the groundwater distribution ages allowed to identify the main stages of recharge during Holocene and late-Pleistocene times. Fourthly, an exploratory approach was carried out in order to address the recharge fluxes in the vadose zone. Based on Hydrus-1D model and soil sampling carried out in the field, the recharge fluxes induced by one flood in the alluvial fans were estimated. The behavior analysis of water-table on time series of a few years were also used to estimate the recharge in the lower part of alluvial fans according to the surface geomorphology features.Based on this multidisciplinary approach, these works (performed in Northern Chile) allow defining the controls on the groundwater recharge and circulation in arid and hyperarid piedmont areas

Caractérisation des facteurs de contrôle de la recharge et des écoulements souterrains à différentes échelles de temps en zone de piedmont aride et hyper-aride : exemple de l'aquifère de la Pampa del Tamarugal (Nord Chili)

In drylands, the scarcity of surface waters has led the population to mainly extract the groundwater resource for water supply. To preserve the groundwater resource of the over-exploitation, the understanding of the groundwater recharge processes is required. The present work aims to assess the factors of control on both the groundwater recharge and the groundwater circulation in dryland piedmonts.In Northern Chile, since a few tens of years, mining activities and the associated population movements have induced an over-exploitation of the Pampa del Tamarugal Aquifer. This regional size aquifer is one of the main groundwater resources of Northern Chile as a whole.In order to assess the controls on the groundwater recharge processes that allow recharging the Pampa del Tamarugal Aquifer as well as the groundwater circulation in the Andean Piedmont, a multidisciplinary approach was carried out in the endorheic catchment of the Pampa del Tamarugal (i.e. lowlands and piedmont) between 19.5°S and 20°S. Firstly, the study is based on a geological and geomorphological assessment of the Central Depression sedimentary basin with a focus on the Andean Piedmont. This work allowed identifying the control of the pre-Oligocene bedrock on both the late-Cenozoic piedmont cover (i.e. alluvial drainage axis, sedimentary barriers, and paleovalleys) and the groundwater circulation. Secondly, a hydrogeophysical (resistivity soundings, via TDEM) and hydrogeological characterization of the vadose zone and the saturated zone of the aquifer was carried out. These measurements allowed identifying a well-defined contrast of resistivity that is correlated with the water-table. This allows to better define the boundary conditions of the aquifer and to shift eastwards (i.e. in the piedmont) the oriental limit of the aquifer. Hydrological surveys allowed to validate the identification of groundwater recharge areas where the rivers fed the aquifer. Thirdly, the study is based on the assessment of the geochemical, isotopic and dissolved gas content of the groundwater. This approach allowed identifying the origin and also the groundwater circulation of the aquifer. The characterization of the groundwater distribution ages allowed to identify the main stages of recharge during Holocene and late-Pleistocene times. Fourthly, an exploratory approach was carried out in order to address the recharge fluxes in the vadose zone. Based on Hydrus-1D model and soil sampling carried out in the field, the recharge fluxes induced by one flood in the alluvial fans were estimated. The behavior analysis of water-table on time series of a few years were also used to estimate the recharge in the lower part of alluvial fans according to the surface geomorphology features.Based on this multidisciplinary approach, these works (performed in Northern Chile) allow defining the controls on the groundwater recharge and circulation in arid and hyperarid piedmont areas.Dans les zones arides, la grande variabilité des eaux de surface a conduit les Hommes à exploiter les eaux souterraines. Cependant, afin de préserver durablement cette ressource, une bonne connaissance des processus de recharge est nécessaire. Ces travaux de thèse ont pour objectifs de caractériser les facteurs de contrôle de la recharge et des écoulements souterrains en zone de piedmont aride et hyper-aride. Dans le Nord du Chili, l’activité minière et les villes nouvelles associées aux déplacements de populations depuis quelques dizaine d’années ont engendré une surexploitation des ressources en eaux souterraines contenues dans l’Aquifère de la Pampa del Tamarugal. Cet aquifère régional est l’une des principales ressources en eau de l’ensemble du Nord du Chili, ce qui en fait une ressource stratégique. Le contexte hyper-aride de cette zone de piedmont (extension nord du Désert d’Atacama) semble suggérer que la recharge actuelle de l’aquifère ne permet pas de soutenir son bilan hydrologique.Afin d’identifier et de caractériser les facteurs de contrôle de la recharge et des écoulements souterrains de l’Aquifère de la Pampa del Tamarugal, une approche multidisciplinaire a été utilisée. Cette approche est basée dans un premier temps sur la caractérisation géologique et géomorphologique de la Dépression Centrale et notamment du Piedmont Andin entre 19,5°S et 20°S. Celle-ci a permis d’identifier le rôle du substratum pré-Oligocène sur l’organisation de la couverture fin-Cénozoïque (i.e. axes de drainages, barrières sédimentaires & paléovallées) et sur les circulations souterraines au niveau du piedmont. Dans un second temps, une approche hydrogéophysique et hydro(géo)logique a été utilisée afin de caractériser et d’identifier les conditions aux limites ainsi que l’évolution spatiale de la piézométrie au sein de la plaine de la Pampa del Tamarugal et du piedmont. De nombreux sondages de résistivité, réalisé par TDEM, ont permis d’identifier un contraste bien défini et corrélé avec le niveau piézométrique de la nappe libre. Des relevés hydro(geo)logiques ont permis de valider les échanges rivière-nappe (zones de recharge) qui ont été déduits à partir de l’étude géophysique. Dans un troisième temps, la caractérisation géochimique et isotopique des eaux souterraines de la zone d’étude a permis d’identifier les origines, les circulations ainsi que les processus de recharge de l’aquifère. La distribution des âges de l’eau de la zone saturée a permis d’identifier les grandes phases de recharge paléoclimatiques de l’Holocène. Dans un quatrième temps, une approche exploratoire par la modélisation des écoulements au sein de la zone non saturée, basée sur un modèle à base physique (Hydrus-1D) et complétée par des relevés de terrain, ont permis d’évaluer la recharge induite par une crue au niveau des cônes alluviaux. L’analyse des chroniques piézométriques a apporté de nombreuses informations sur la quantification de la recharge.Sur la base des résultats de cette étude multidisciplinaire, ces travaux de recherche ont permis de définir, au niveau de l’Aquifère de la Pampa del Tamarugal (Nord Chili), les facteurs de contrôle de la recharge et des écoulements souterrains en zone de piedmont aride et hyper-aride