Semi-Rigid Moment-Resisting Behavior of Multiple Tab-and-Slot Joint for Freeform Timber Plate Structures

Historically based on the transfer of ancestral know-how, the art of carpentry changed considerably at the beginning of the 21st century with the arrival on the market of engineered wood products (EWP) and computer numerically controlled machines (CNC). The development of these wood products was initially started for the needs of aeronautics : lightweight panels but with high structural capacity. It is also in this field that automated multi-axis milling machines and the accompanying computing tool, computer-aided design and manufacturing (CAD / CAM), have begun to be developed to produce more complex mechanical parts. It was also in the early 2000s that several teams of researchers in the field of computer graphics but also in architecture were interested in complex free forms. One of the many challenges is still the discretization with planar elements of doubly curved surfaces oriented freely in space. The encounter of these `` algorithms '' with the high-performant wood panels was ineluctable. However, the assembly of polygonal panels in space to form a structure is not trivial. Optimization efforts are made so that the topology in itself favors the distribution of forces to tend towards a behavior of shells. But the problem is sometimes insoluble for very irregular shapes alternating negative, zero and positive Gaussian curvatures. To ensure the transmission of the axial, shear and bending internal forces induced by vertical or horizontal external loads, whether symmetrical or not, the performance of the assemblies used to connect these panels by their edges becomes paramount. In wood construction, this is a topic currently being studied by a few research laboratories including EPFL for innovative wood-to-wood joints with multiple tab and slots (MTSJ). The main difficulty lies in how to connect thin wood panels with the best stiffness and strength. In the recent past, the assembly of wood parts between them, often with metal fasteners to provide a certain ductility, was assimilated to a hinge. With the new standards like the Eurocodes, the notion of semi-rigidity is now essential to obtain a realistic response of structures to both ultimate and service limit states. The solution proposed at IBOIS enters into this new context. It allows, without glue or metallic connectors, to interconnect thin engineered wood panels, ensuring both locator and connector features and the transfer of multidirectional forces. This thesis focuses on the semi-rigid moment resisting behavior of the through tenon variant (TT) with closed slots. The numerous experiments conducted during this study demonstrated the ability of this variant to compete with screws to resist a moment around the angularly connected edges. The joint is directly generated during the multiaxial cutting of laminated veneer lumber(LVL) panels which include a certain percentage of cross-layers. From a structural point of view, the local mechanical study under a bending moment was inspired by a wood-to-wood joint in service in the ancestral Japanese shrines, the "Nuki" joint. Analyzed by Japanese researchers as it historically participates in the resilience of their ancestral constructions to typhoons and earthquakes, it activates embedment mechanisms of wood in rotational partial compression (RPC) to resist the moment resulting from the external loads. It is these mechanisms that are taken into account for through tenon variant. ..

Shear Resistance and Failure Modes of Edgewise Multiple Tab-and-Slot Joint (MTSJ) Connection with Dovetail Design for Thin LVL spruce plywood Kerto-Q Panels

The objective of this study is to experimentally analyse effects of geometry variations of Multiple Tab and Slot Joint (MTSJ) connection with dovetail design on shear mechanical behaviour. Direct shear test was performed on angular (phi=90°) MTSJ connection made of Kerto-Q 21mm-thick spruce plywood laminated veneer lumber (LVL) panels. Connection was examined in its configuration of three tabs/slots per edge. Nine different geometries of MTSJ connection were tested. In order to provide better understanding of mechanical behaviour of the connection, results were compared with finger joint (F) connection. Two characteristic failure modes were observed. Influence of three theta angles which define geometry of MTSJ connection was analysed concerning shear strength and stiffness. Connection showed very ductile shear behaviour with relatively high stiffness. It has been shown that by increasing θ3 angle above 30°, shear strength decreases. On the other hand, the highest influence on shear stiffness is due to θ2 and θ3 rotations

Segregation between SMCHD1 mutation, D4Z4 hypomethylation and Facio-Scapulo-Humeral Dystrophy: a case report

International audienceBackground: The main form of Facio-Scapulo-Humeral muscular Dystrophy is linked to copy number reduction of the 4q D4Z4 macrosatellite (FSHD1). In 5 % of cases, FSHD phenotype appears in the absence of D4Z4 reduction (FSHD2). In 70-80 % of these patients, variants of the SMCHD1 gene segregate with 4qA haplotypes and D4Z4 hypomethylation.Case presentation: We report a family presenting with neuromuscular symptoms reminiscent of FSHD but without D4Z4 copy reduction. We characterized the 4q35 region using molecular combing, searched for mutation in the SMCHD1 gene and determined D4Z4 methylation level by sodium bisulfite sequencing. We further investigated the impact of the SMCHD1 mutation at the protein level and on the NMD-dependent degradation of transcript. In muscle, we observe moderate but significant reduction in D4Z4 methylation, not correlated with DUX4-fl expression. Exome sequencing revealed a heterozygous insertion of 7 bp in exon 37 of the SMCHD1 gene producing a loss of frame with premature stop codon 4 amino acids after the insertion (c.4614-4615insTATAATA). Both wild-type and mutated transcripts are detected.Conclusion: The truncated protein is absent and the full-length protein level is similar in patients and controls indicating that in this family, FSHD is not associated with SMCHD1 haploinsufficiency

Real-time Monitoring for the Next Core-Collapse Supernova in JUNO

Core-collapse supernova (CCSN) is one of the most energetic astrophysical events in the Universe. The early and prompt detection of neutrinos before (pre-SN) and during the SN burst is a unique opportunity to realize the multi-messenger observation of the CCSN events. In this work, we describe the monitoring concept and present the sensitivity of the system to the pre-SN and SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is a 20 kton liquid scintillator detector under construction in South China. The real-time monitoring system is designed with both the prompt monitors on the electronic board and online monitors at the data acquisition stage, in order to ensure both the alert speed and alert coverage of progenitor stars. By assuming a false alert rate of 1 per year, this monitoring system can be sensitive to the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos up to about 370 (360) kpc for a progenitor mass of 30$M_{\odot}$ for the case of normal (inverted) mass ordering. The pointing ability of the CCSN is evaluated by using the accumulated event anisotropy of the inverse beta decay interactions from pre-SN or SN neutrinos, which, along with the early alert, can play important roles for the followup multi-messenger observations of the next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure

ARIA digital anamorphosis: Digital transformation of health and care in airway diseases from research to practice

Digital anamorphosis is used to define a distorted image of health and care that may be viewed correctly using digital tools and strategies. MASK digital anamorphosis represents the process used by MASK to develop the digital transformation of health and care in rhinitis. It strengthens the ARIA change management strategy in the prevention and management of airway disease. The MASK strategy is based on validated digital tools. Using the MASK digital tool and the CARAT online enhanced clinical framework, solutions for practical steps of digital enhancement of care are proposed

COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

Primary spontaneous pneumothorax: French guidelines are ready for launching!

International audienceNo abstract availabl