1,165 research outputs found
Ionizing radiation compatibility in the MITICA neutral beam prototype
No full textThis paper deals with an R&D activity in progress in support of the design of the ITER NBI prototype (MITICA), aimed at the identification of the most appropriate design solutions and installation guidelines to keep under control and minimize the effects of ionizing radiation on the electronic and passive components related to control, diagnostics, and electrical insulation located inside the MITICA vessel and its concrete biological shield. The method followed to approach the problem is based on three steps: estimation of expected radiation levels map, identification of electronic and passive components database for MITICA diagnostics and finally the assessment of the ionizing radiation compatibility for the identified components. The ultimate aim of this activity is the definition, on the basis of this assessment, of a list of preventive or mitigating actions (such as relocation, shielding or preventive maintenance) for the most high-risk components. (C) 2011 S. Peruzzo. Published by Elsevier B.V. All rights reserved
Miocene andalusite leucogranite in Central-East Himalaya (Everest-Masang Kang area): low-pressure melting during heating.
No full textThe studied Miocene andalusite-bearing leucogranites intrude the upper part of the High Himalayan Crystallines (HHC) and the north Himalayan domes and outcrop in an area stretching from Mt. Everest to the Kula Khangri massif (Bhutan) towards the east.
The leucogranites constitute both dykes as well as sills and parts of larger andalusite-free leucogranite plutons (e.g., Makalu). They represent mainly of two-mica muscovite+biotite± tourmaline±cordierite±andalusite±sillimanite±dumortierite) leucogranite, and tourmaline muscovite+tourmaline±biotite± andalusite±sillimanite±garnet± kyanite±spinel±corundum) leucogranites. Microstructures reveal several generations of andalusite (from residual/peritectic early magmatic to cotectic late magmatic), even in the same sample. The occurrence of residual and/or peritectic andalusite, together with inclusions of sillimanite+biotite in cordierite, indicates that melts formed by dehydration melting of biotite at T=660–700 °C during prograde heating at low-pressure conditions (Pbabout 400 MPa).
According to current models, leucogranites are produced by dehydration melting of muscovite and/or biotite during exhumation of the HHC. In this case, micas are consumed in the sillimanite stability field. As a consequence, these models cannot explain the occurrence of residual and/or peritectic magmatic andalusite. Conditions for anatexis in the andalusite field may have been achieved by heat transfer within the exhuming (extruding) HHC, from structurally lower and hotter rocks towards upper and colder fertile lithologies
Resistencia genética a la Cancrosis del tallo de soja causada por Diaporthe phaseolorum var. caulivora: una estrategia innovadora y sustentable
Get PDFFil: Peruzzo, Alejandra. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; Argentin
Miocene andalusite leucogranite in central-east Himalaya (Everest–Masang Kang area): Low-pressure melting during heating
No full textThe studied Miocene andalusite-bearing leucogranites intrude the upper part of the High Himalayan Crystallines (HHC) and the north Himalayan domes and outcrop in an area stretching from Mt. Everest to the Kula Khangri massif (Bhutan) towards the east. The leucogranites constitute both dykes as well as sills and parts of larger andalusite-free leucogranite plutons (e.g., Makalu). They represent mainly of two-mica (muscovite + biotite ± tourmaline ± cordierite ± andalusite ± sillimanite ± dumortierite) leucogranite, and tourmaline (muscovite + tourmaline ± biotite ± andalusite ± sillimanite ± garnet ± kyanite ± spinel ± corundum) leucogranites. Microstructures reveal several generations of andalusite (from residual/peritectic early magmatic to cotectic late magmatic), even in the same sample. The occurrence of residual and/or peritectic andalusite, together with inclusions of sillimanite + biotite in cordierite, indicates that melts formed by dehydration melting of biotite at T = 660-700. °C during prograde heating at low-pressure conditions (P < about 400. MPa). According to current models, leucogranites are produced by dehydration melting of muscovite and/or biotite during exhumation of the HHC. In this case, micas are consumed in the sillimanite stability field. As a consequence, these models cannot explain the occurrence of residual and/or peritectic magmatic andalusite. Conditions for anatexis in the andalusite field may have been achieved by heat transfer within the exhuming (extruding) HHC, from structurally lower and hotter rocks towards upper and colder fertile lithologies
Effects of environmental parameters and their interactions on the spreading of SARS-CoV-2 in North Italy under different social restrictions. A new approach based on multivariate analysis
Get PDFIn 2020 North Italy suffered the SARS-CoV-2-related pandemic with a high number of deaths and hospitalization. The effect of atmospheric parameters on the amount of hospital admissions (temperature, solar radiation, particulate matter, relative humidity and wind speed) is studied through about 8 months (May–December). Two periods are considered depending on different conditions: a) low incidence of COVID-19 and very few regulations concerning personal mobility and protection (“free/summer period”); b) increasing incidence of disease, social restrictions and use of personal protections (“confined/autumn period”). The “hospitalized people in medical area wards/100000 residents” was used as a reliable measure of COVID-19 spreading and load on the sanitary system. We developed a chemometric approach (multiple linear regression analysis) using the daily incidence of hospitalizations as a function of the single independent variables and of their products (interactions). Eight administrative domains were considered (altogether 26 million inhabitants) to account for relatively homogeneous territorial and social conditions. The obtained models very significantly match the daily variation of hospitalizations, during the two periods. Under the confined/autumn period, the effect of non-pharmacologic measures (social distances, personal protection, etc.) possibly attenuates the virus diffusion despite environmental factors. On the contrary, in the free/summer conditions the effects of atmospheric parameters are very significant through all the areas. Particulate matter matches the growth of hospitalizations in areas with low chronic particulate pollution. Fewer hospitalizations strongly correspond to higher temperature and solar radiation. Relative humidity plays the same role, but with a lesser extent. The interaction between solar radiation and high temperature is also highly significant and represents surprising evidence. The solar radiation alone and combined with high temperature exert an anti-SARS-CoV-2 effect, via both the direct inactivation of virions and the stimulation of vitamin D synthesis, improving immune system function
Quantum interference and manipulation of entanglement in silicon wire waveguide quantum circuits
Get PDFIntegrated quantum photonic waveguide circuits are a promising approach to realizing future photonic quantum technologies. Here, we present an integrated photonic quantum technology platform utilizing the silicon-on-insulator material system, where quantum interference and the manipulation of quantum states of light are demonstrated in components orders of magnitude smaller than previous implementations. Two-photon quantum interference is presented in a multi-mode interference coupler, and the manipulation of entanglement is demonstrated in a Mach–Zehnder interferometer, opening the way to an all-silicon photonic quantum technology platform
Scaling strategies for Brinkman penalization in fluid topology optimization
Get PDFTopology optimization provides a rigorous framework for determining optimal flow-path designs in fluid mechanics. A popular technique is the density-based approach, which treats fluid-solid interfaces by considering the solid phase as a porous medium with low permeability. Mathematically, such a problem is governed by the Navier-Stokes equations combined with the Brinkman penalization. To consistently solve the optimization problem, this study examines the theoretical foundations of the method, focusing on dimensionless parameters such as the Reynolds number and a specific Darcy number, D a * . Through dimensional analysis, we derive scaling guidelines for the Brinkman penalization in relation to fluid properties and domain geometry. Numerical simulations show that incorrect scaling can yield nonphysical results, including excessive fluid penetration into solid regions, undermining the optimization. Our findings demonstrate that the invariance of the solution can be maintained by appropriately scaling D a * with the relative velocity in the porous region, ensuring accurate and reliable results in different scenarios. This work provides a systematic framework for parameter selection in fluid topology optimization, addressing key modeling and computational challenges. By emphasizing the importance of dimensional analysis, it contributes to a broader understanding of topology optimization, paving the way for its more robust and consistent application in fluid mechanics
Unravelling the Schneeberg garnet puzzle: a numerical model of multiple nucleation and coalescence
No full textA quantitative kinetic model for the growth of the different garnet porphyroblast microstructures (type 1 and type 2) of the Western Schneeberg Complex (WSC) is presented. These porphyroblasts formed by a multiple nucleation and coalescence mechanism. Our numerical simulation shows that at constant diffusion rates: (1) low interface reaction rates result in a fully amalgamated porphyroblast (type 2); (2) intermediate reaction rates result in a porphyroblast, where coalescence of grains closer to the margin prevented amalgamation of those in the centre (similar to type 1 porphyroblasts); and (3) high interface reaction rates result in a porphyroblast microstructure with an atoll form. All three microstructures are characterised by distinctive cluster size distributions. A 2-D cluster size distribution analysis of type 1 porphyroblasts of WSC shows that these did not form because of intermediate interface reaction rates, but because the diffusion rate of nutrients was too low to keep pace with the interface reaction rate
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