A combined three-dimensional digitisation and subsurface defect detection data using active infrared thermography

International audienceIn recent years, NonDestructive Testing (NDT) systems have been upgraded with three-dimensional information. Indeed, combine the three-dimensional and thermal information allows a more meaningful analysis. In the literature, the data for NDT and three-dimensional (3D) reconstruction analysis are commonly acquired from independent systems. However, the use of two such systems leads to error analysis during the data registration. In an attempt to overcome such problems, we propose a single system based on active thermography approach using heat point-source stimulation to get the 3D digitization as well as subsurface defect detection. The experiments are conducted on steel and aluminum objects, and a combined 3D / thermal-information is presented

Cement matrix containing lightweight aggregate based on Non-Metallic Fraction Printed Circuit Boards (NMFPCB'S)

Materials such as river sand, used in construction, have a high demand, and thus generate great environmental impacts while being extracted, such as erosion of the rivers banks and your siltation. With the increasing restriction of river sand extraction which can generate a reduction in the product's offer in the civil construction sector, it is necessary to develop waste recycling technologies for the production of sands with less environmental impact. One of the alternatives for the production of mortar for construction is the replacement of sands extracted from rivers by waste from other industries, such as the electronics industry that presents large and growing production worldwide, due to technological advances. Thus, this work aims to evaluate the influence of partial replacement of quartz sand by lightweight aggregate based non-metallic fraction of printed circuit boards (NMFPCB's) on the properties of cementitious matrix in the fresh and hardened states. For this, the electronic components of the printed circuit boards (PCBs) were removed, they were grinded and then through magnetic and electrostatic separation processes to separate the most valuable and abundant part of metals. The water to cement ratio was 0.48 in all the experiments, the Portland cement to sand ratio was 1:3 (in mass) for the control, and the mortars with NMFPCB's replacement of sand by volume of 25% and 50% were also made. These were characterized mechanically by axial compressive strength test at different ages. The partial results showed that with the increase of sand substitution by NMFPCB's there was a reduction of the mortar consistency index in the fresh state. Results showed that matrix that suffered the substitution of sand by light aggregate, decreased the compressive strength in relation to the reference, but have potential to use in construction industry as blocks or non-structural elements

Colliding pulse mode-locked VECSEL

We report for the first time a colliding-pulse modelocked VECSEL, with the gain and SESAM inside a ring cavity. We obtained output power of 2.2W, repetition rate of 1GHz and pulse duration of 1.16ps

Language endangerment and language documentation in Africa

Non peer reviewe

Dropped gallstones mimicking peritoneal metastasis: A case report

Dropped gallstones is a rare complication after a cholecystectomy. Computed tomography is the modality of choice for diagnosis. Dropped gallstones can be a fortuitous discovery in an asymptomatic patient but it is usually revealed when a complication occurs, most commonly through an abscess. Our case presents a dropped gallstone found during a routine check-up in a patient with a history of small bowel cancer. We will discuss differential diagnosis with others calcified peritoneal nodular patterns, particularly peritoneal carcinomatosis. We will recall the multimodality imaging findings of dropped gallstone and, based on literature, we will review the different sources of calcified peritoneal nodular pattern. The treatment of gallstone drop consequences depends on the clinical aspect. Keywords: Dropped gallstones, Calcified peritoneal nodular pattern, Computed tomography, Cholecystectom

Intégrale J et champs asymptotiques le long d'une fissure plane

National audience-La méthode G − θ est une méthode de détermination du taux de restitution d'énergie et des facteurs d'intensité de contrainte (FICs) répandue. Dans cette contribution, nous étudions l'influence de la courbure du front de fissure sur la précision de l'évaluation des FICs. Le rôle de la courbure du front de fissure sur la valeur de l'intégrale J de Rice est quantifié. De nouveaux champs de déplacements admissibles, tenant compte de la courbure, sont proposés. Le gain en précision est évalué sur des cas-tests admettant une solution analytique, dans le cas des fissures planes sollicitées en mode I. Mots clés-Mécanique de la rupture, Taux de restitution d'énergie, FICs, Fissures planes à front courbe

Analyse de la méthode G − θ en 3D : cas des fissures planes à front droit

National audience-La méthode G − θ est une méthode de calcul du taux de restitution d'énergie et des facteurs d'intensité de contrainte (FICs) répandue. Dans cette contribution, nous rappelons les frontements de la méthode et discutons sa mise en oeuvre dans le cas tridimensionnel. Une analyse de convergence réalisée sur des cas-tests admettant une solution analytique montre que la méthode est précise. Les erreurs issues de choix de mise en oeuvre naïfs sont également discutés. L'analyse est restreinte au cas des fissures planes à front droit. Mots clés-Mécanique de la rupture, Taux de restitution d'énergie, FICs, Fissures planes à front droit

Méthode G-théta en 3D : interpolation des facteurs d'intensité des contraintes

National audienc