6 research outputs found
Food innovation in Brazil from the point of view of industries: an evaluation of PINTEC data
Data published in 2016 PINTEC (Innovation Survey), conducted by the Brazilian Institute of Geography and Statistics for the 2012-2014 triennium with 13,846 food companies, showed that only 45% innovated in products and/or processes. Acquisition of machinery / equipment was considered the most important innovative activity followed by personnel training. The products quality improvement and the productive capacity increase were the greater impacts observed. Only 9% of companies claim to spent on R&D activities. The high cost of innovation, the lack of appropriate funding and the excessive economic risks were the main problems pointed out by companies, followed by qualified personnel lack
Investigación joven con perspectiva de género
Libro de Actas del I Congreso de jóvenes investigadorxs con perspectiva de género celebrado en la Universidad Carlos III de Madrid, Getafe, 16 y 17 de junio de 2016
Encendido de plasmas en Stellarators mediante calentamiento electrónico ciclotrónico en segundo armónico
La generación de un plasma en un dispositivo de confinamiento magnético de tipo stellarator, mediante calentamiento por resonancia electrónica (ECRH) en segundo armónico, es el tema central de esta tesis doctoral. El resultado fundamental del trabajo es un modelo de encendido que, dadas unas condiciones de presion inicial y potencia inyectada, reproduce la cascada de ionización del gas neutro inyectado y confirma la responsabilidad de las interacciones no lineales - producidas entre los electrones profundamente atrapados en alguno de los pozos magnéticos del dispositivo de confinamiento y una onda electromagnética propagándose a una frecuencia correspondiente a dos veces la frecuencia de Larmor - en la creación de un plasma de hidrógeno en un stellarator. Con este modelo, podemos plantear un sistema no lineal de ecuaciones de balance acopladas, cuya resolución numérica, mediante un código programado expresamente al efecto, permite conocer la evolución temporal de las densidades de todas las especies implicadas. La discretización del espacio de energía de los electrones, y la consideración de los principales procesos de física atómica y molecular implicados, permite tener en cuenta el balance detallado de energía. Debido a que, gracias a la discretización, electrones de distinta energía son considerados como especies distintas, uno de los resultados de la simulación es la evolución de la función de distribución de energía electrónica durante el encendido. La introducción de los procesos de colisión entre electrones mediante un operador obtenido a partir de la ecuación de Fokker-Planck, demuestra ser absolutamente necesaria para conseguir una evolución realista de dicha función y una descripción correcta del balance de energía. El cálculo aproximado del campo eléctrico inicial, producido por la dispersión del haz de microondas al entrar en el interior del dispositivo, necesario para determinar los parámetros de la interacciones no lineales, es también un resultado relevante del trabajo. El método usado para su determinación es más intuitivo y mejora sustancialmente el empleado en trabajos anteriores. La caracterización, tanto teórica como experimental, del encendido, se hace mediante el ritmo de crecimiento inicial de las especies consideradas y el tiempo de encendido, determinado por la posición del máximo de la emisión de la línea a del espectro de emisión del hidrógeno respecto del inicio del pulso de ECRH. Ambas magnitudes son un resultado directo del modelo y pueden medirse con relativa facilidad. La comparación preliminar con la realidad experimental del stellarator TJ-II indica un acuerdo razonablemente buen
Structural analysis of the ITER ex-vessel plasma position reflectometer components located in the gallery
Active control of Alfvén eigenmodes in magnetically confined toroidal plasmas
Alfvén waves are electromagnetic perturbations inherent to magnetized plasmas that can be driven unstable by a free energy associated with gradients in the energetic particles' distribution function. The energetic particles with velocities comparable to the Alfvén velocity may excite Alfvén instabilities via resonant wave–particle energy and momentum exchange. Burning plasmas with large population of fusion born super-Alfvénic alpha particles in magnetically confined fusion devices are prone to excite weakly-damped Alfvén eigenmodes (AEs) that, if allowed to grow unabated, can cause a degradation of fusion performance and loss of energetic ions through a secular radial transport. In order to control the fast-ion distribution and associated Alfvénic activity, the fusion community is currently searching for external actuators that can control AEs and energetic ions in the harsh environment of a fusion reactor. Most promising control techniques are based on (i) variable fast-ion sources to modify gradients in the energetic particles' distribution, (ii) localized electron cyclotron resonance heating to affect the fast-ion slowing-down distribution, (iii) localized electron cyclotron current drive to modify the equilibrium magnetic helicity and thus the AE existence criteria and damping mechanisms, and (iv) externally applied 3D perturbative fields to manipulate the fast-ion distribution and thus the wave drive. Advanced simulations help to identify the key physics mechanisms underlying the observed AE mitigation and suppression and thus to develop robust control techniques towards future burning plasmas.This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014–2018 and 2019–2020 under grant agreement No 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. Support by US DOE and ITER-CN is also acknowledged. The support from the FP7 People: Marie-Curie Actions (Grant No. 321455) and the Spanish Ministry of Economy and Competitiveness (Grants No. RYC-2011-09152, No. FIS2015-69362-P) is gratefully acknowledged. The work of AVM was funded by the Russian Science Foundation, project 14-22-00193, and was partly supported by the Competitiveness Program of NRNU MEPhI.Peer ReviewedPostprint (published version
Overview of recent TJ-II stellarator results
The main results obtained in the TJ-II stellarator in the last two years are reported. The most important topics investigated have been modelling and validation of impurity transport, validation of gyrokinetic simulations, turbulence characterisation, effect of magnetic configuration on transport, fuelling with pellet injection, fast particles and liquid metal plasma facing components.
As regards impurity transport research, a number of working lines exploring several recently discovered effects have been developed: the effect of tangential drifts on stellarator neoclassical transport, the impurity flux driven by electric fields tangent to magnetic surfaces and attempts of experimental validation with Doppler reflectometry of the variation of the radial electric field on the flux surface. Concerning gyrokinetic simulations, two validation activities have been performed, the comparison with measurements of zonal flow relaxation in pellet-induced fast transients and the comparison with experimental poloidal variation of fluctuations amplitude. The impact of radial electric fields on turbulence spreading in the edge and scrape-off layer has been also experimentally characterized using a 2D Langmuir probe array. Another remarkable piece of work has been the investigation of the radial propagation of small temperature perturbations using transfer entropy. Research on the physics and modelling of plasma core fuelling with pellet and tracer-encapsulated solid-pellet injection has produced also relevant results. Neutral beam injection driven Alfvénic activity and its possible control by electron cyclotron current drive has been examined as well in TJ-II. Finally, recent results on alternative plasma facing components based on liquid metals are also presented.ISSN:0029-5515ISSN:1741-432