Evaluation of urban local-scale aerodynamic parameters: implications for the vertical profile of wind speed and for source areas

Nine methods to determine local-scale aerodynamic roughness length (z0) and zero-plane displacement (zd) are compared at three sites (within 60 m of each other) in London, UK. Methods include three anemometric (single-level high frequency observations), six morphometric (surface geometry) and one reference-based approach (look-up tables). A footprint model is used with the morphometric methods in an iterative procedure. The results are insensitive to the initial zd and z0 estimates. Across the three sites, zd varies between 5 – 45 m depending upon the method used. Morphometric methods that incorporate roughness-element height variability agree better with anemometric methods, indicating zd is consistently greater than the local mean building height. Depending upon method and wind direction, z0 varies between 0.1 and 5 m with morphometric z0 consistently being 2 – 3 m larger than the anemometric z0. No morphometric method consistently resembles the anemometric methods. Wind-speed profiles observed with Doppler lidar provide additional data with which to assess the methods. Locally determined roughness parameters are used to extrapolate wind-speed profiles to a height roughly 200 m above the canopy. Wind-speed profiles extrapolated based on morphometric methods that account for roughness-element height variability are most similar to observations. The extent of the modelled source area for measurements varies by up to a factor of three, depending upon the morphometric method used to determine zd and z0

Des lésions osseuses diffuses [Disseminated bone lesions]

National audienceUn homme, âgé de 55 ans, sans antécédent, consultait pour une bicytopénie découverte lors d’un bilan d’asthénie : thrombopénie à 90 000/mm3, neutropénie à 650/mm3. Les explorations permettaient le diagnostic d’une myélodysplasie de type anémie réfractaire avec excès de blastes (AREB-2) à caryotype normal. Après discussion collégiale, une chimiothérapie intensive d’induction était réalisée en secteur protégé puis suivie d’une chimiothérapie de rattrapage en raison d’un excès blastique sur le myélogramme de contrôle au 15e jour. L’aplasie durait 33 jours et était marquée par l’apparition d’une fièvre hectique prolongée..

Surface treatment response of AISI 2205 and AISI 304L steels: SMAT and plasma-nitriding

Sem informaçãoThe surface behaviour of surface mechanical attrition treated (SMATed) and plasma-nitrided AISI 2205 and AISI 304L steels was investigated in the present study. The intersection of the mechanical twins formed the submicron-size rhombic blocks in the surface region of the SMATed AISI 304L steel. However, such microstructural feature was absent in the SMATed AISI 2205 steel. The improvement in the surface-hardness due to the SMAT was about 70-80% for AISI 2205, and more than 100% for AISI 304L steel. The nature of passive film formed on the AISI 2205 steel was different from the AISI 304L steel. Passive film formed on the SMATed AISI 304L steel was relatively more unstable than that of the AISI 2205 steel at an elevated electric-potential and in a plasma environment. The plasma-nitriding response was affected due to the different passivation behaviour of the SMATed, and non-SMATed steels.353205215Sem informaçãoSem informaçãoSem informaçãoThis work was partially supported by the SERB [grant number EMR/2017/001196]. Their support is kindly acknowledged