A new 3MW ECRH system at 105 GHz for WEST

The aim of the WEST experiments is to master long plasma pulses (1000s) and expose ITER-like tungsten wall to deposited heat fluxes up to 10 MW/m$^2$. To increase the margin to reach the H-Mode and to control W-impurities in the plasma, the installation of an upgraded ECRH heating system, with a gyrotron performance of 1MW/1000s per unit, is planned in 2023. With the modifications of Tore Supra to WEST, simulations at a magnetic field B$_0$∼3.7T and a central density n$_{e0}$∼6 × 10$^{19}$ m$^{−3}$ show that the optimal frequency for central absorption is 105 GHz. For this purpose, a 105 GHz/1MW gyrotron (TH1511) has been designed at KIT in 2021, based on the technological design of the 140 GHz/1.5 MW (TH1507U) gyrotron for W7-X. Currently, three units are under fabrication at THALES. In the first phase of the project, some of the previous Tore Supra Electron Cyclotron (EC) system components will be re-installed and re-used whenever possible. This paper describes the studies performed to adapt the new ECRH system to 105 GHz and the status of the modifications necessary to re-start the system with a challenging schedule

Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey

Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020

Image-based high strain rate testing of orthopaedic bone cement

Bone cement is widely used for the fixation of orthopaedic implants. It is a multi-component material that consists of a PMMA base with a small proportion of (usually ceramic) radiopacifier to enable the cement to be observed by X-ray. Bone cement is formed through an exothermic reaction in which a powder of pre-polymerised beads of PMMA reacts with MMA monomer. The resulting polymer microstructure consists of PMMA beads in a matrix of newly formed PMMA containing radiopacifier particles. In service, bone cement can experience deformation over a range of strain rates, from the lower end in normal gait to 100s of s-1 in the case of falls or impacts. In the current study, it is hypothesised that the response of homogeneous (clear) PMMA to high strain rates will be different to that of bone cement due to the microstructural differences. There have been very few studies on this topic in the past, mostly because of the difficulty involved in adapting the Hopkinson bar protocol to this material, particularly for dynamic tension. The objective of this paper is to present new results on the stiffness and damping of bone cement at strain rates in the range of 100 s-1, and to compare the data with that obtained on clear PMMA. The technique employed here to measure the mechanical properties of both commercial grade PMMA and bone cement is a new image-based DMTA method recently proposed by Seghir and Pierron (Seghir, Pierron, Exp. Mech., 2018). This allows for the measurement of the complex modulus over a range of temperatures and strain rates (100s of s-1). The method relies on imaging the deformation of the specimen bearing a printed grid using a Shimadzu HPV-X camera at up to 5 million frames per second. This allows for the time-resolved displacements to be measured, leading to fields of strain and acceleration, the latter being used to derive stress information to build up stress-strain curves. The methodology is described in more details in www.photodyn.or

Image-based high strain rate testing of orthopaedic bone cement

Bone cement is widely used for the fixation of orthopaedic implants. It is a multi-component material that consists of a PMMA base with a small proportion of (usually ceramic) radiopacifier to enable the cement to be observed by X-ray. Bone cement is formed through an exothermic reaction in which a powder of pre-polymerised beads of PMMA reacts with MMA monomer. The resulting polymer microstructure consists of PMMA beads in a matrix of newly formed PMMA containing radiopacifier particles. In service, bone cement can experience deformation over a range of strain rates, from the lower end in normal gait to 100s of s-1 in the case of falls or impacts. In the current study, it is hypothesised that the response of homogeneous (clear) PMMA to high strain rates will be different to that of bone cement due to the microstructural differences. There have been very few studies on this topic in the past, mostly because of the difficulty involved in adapting the Hopkinson bar protocol to this material, particularly for dynamic tension. The objective of this paper is to present new results on the stiffness and damping of bone cement at strain rates in the range of 100 s-1, and to compare the data with that obtained on clear PMMA. The technique employed here to measure the mechanical properties of both commercial grade PMMA and bone cement is a new image-based DMTA method recently proposed by Seghir and Pierron (Seghir, Pierron, Exp. Mech., 2018). This allows for the measurement of the complex modulus over a range of temperatures and strain rates (100s of s-1). The method relies on imaging the deformation of the specimen bearing a printed grid using a Shimadzu HPV-X camera at up to 5 million frames per second. This allows for the time-resolved displacements to be measured, leading to fields of strain and acceleration, the latter being used to derive stress information to build up stress-strain curves. The methodology is described in more details in www.photodyn.org

Image-based high strain rate testing of orthopaedic bone cement

Bone cement is widely used for the fixation of orthopaedic implants. It is a multi-component material that consists of a PMMA base with a small proportion of (usually ceramic) radiopacifier to enable the cement to be observed by X-ray. Bone cement is formed through an exothermic reaction in which a powder of pre-polymerised beads of PMMA reacts with MMA monomer. The resulting polymer microstructure consists of PMMA beads in a matrix of newly formed PMMA containing radiopacifier particles. In service, bone cement can experience deformation over a range of strain rates, from the lower end in normal gait to 100s of s-1 in the case of falls or impacts. In the current study, it is hypothesised that the response of homogeneous (clear) PMMA to high strain rates will be different to that of bone cement due to the microstructural differences. There have been very few studies on this topic in the past, mostly because of the difficulty involved in adapting the Hopkinson bar protocol to this material, particularly for dynamic tension. The objective of this paper is to present new results on the stiffness and damping of bone cement at strain rates in the range of 100 s-1, and to compare the data with that obtained on clear PMMA. The technique employed here to measure the mechanical properties of both commercial grade PMMA and bone cement is a new image-based DMTA method recently proposed by Seghir and Pierron (Seghir, Pierron, Exp. Mech., 2018). This allows for the measurement of the complex modulus over a range of temperatures and strain rates (100s of s-1). The method relies on imaging the deformation of the specimen bearing a printed grid using a Shimadzu HPV-X camera at up to 5 million frames per second. This allows for the time-resolved displacements to be measured, leading to fields of strain and acceleration, the latter being used to derive stress information to build up stress-strain curves. The methodology is described in more details in www.photodyn.org.</p

The effect of noise on directional bands

In a recent study on the effect of disturbring noiseon the localization of pure tones in the median plane, an attraction of tones toward the actual position of noises was discovered. The experiments reported here are part of a general study on this attraction effect

Misdiagnosis as asphyxiating thoracic dystrophy and CMV-associated haemophagocytic lymphohistiocytosis in Shwachman-Diamond syndrome

Shwachman-Diamond syndrome (SDS) is an autosomal recessive disorder characterised by skeletal dysplasia, exocrine pancreatic insufficiency and bone marrow failure. Various other conditions, such as hepatopathy and failure to thrive have been associated with SDS. A retrospective study was conducted to describe mutations, clinical features, and the immunological profile of 11 Belgian patients with genetically confirmed diagnosis of SDS. This study confirms the existing understanding of the classical features of SDS although the typical triad was present in only six out of nine fully studied patients. The following important observations are made in this cohort. Four out of eleven patients were misdiagnosed as having Asphyxiating Thoracic Dystrophy (Jeune syndrome) because of severe thoracic dystrophy. Another two patients presented with unexplained episodes of symptomatic hypoglycaemia. The immunological phenotype was heterogeneous although laboratory abnormalities were noticed in eight out of ten patients assessed. Three patients experienced a life threatening viral infection (respiratory syncytial virus, cytomegalovirus (CMV) and rotavirus). In one patient, CMV infection caused an episode of haemophagocytic lymphohistiocytosis. One patient has bronchiectasis at the age of 3 years due to recurrent respiratory tract infections. These findings strengthen the suspicion of an abnormal immune system in SDS. Liver anomalies, usually described as benign and transitory in SDS patients, were severe in two patients of the cohort. One patient developed hepatopulmonary syndrome. The findings in this national cohort of SDS patients could contribute to the prevention of misdiagnosis in the future and enable more rapid recognition of certain severe complications

ITER Robots: Introducing School Students to Robotics and Project Management

International audienceOriginally developed by ITER, CEA, Agence ITER France and the French Ministry of Education, the ITER Robots Contest is an engineering robotics based competition open to high school and primary students across the South of France. The challenge is to build a reduced scale robot to simulate a maintenance situation inside the future ITER Tokamak machine, namely the remote handling of components in a hostile environment. The ITER Robots Contest has grown in popularity, with more than 600 participants in the 2019 edition. As part of their technical and science curriculum, students work in teams, for over 6 months, to acquire technical skills and knowledge on robotics and fusion energy, solve problems, develop communication skills, and run their projects. This contest corresponds to the high-school educational "cross disciplinary approach", from technology to French, foreign languages, as well as history from science to general international knowledge. The contest day, each team`s robot undertakes a number of tasks evaluated by jury composed of ITER and CEA engineers. Teams are also evaluated on communication skills and fusion energy knowledge