Tree-based Forecasting of Day-ahead Solar Power Generation from Granular Meteorological Features

Accurate forecasts for day-ahead photovoltaic (PV) power generation are crucial to support a high PV penetration rate in the local electricity grid and to assure stability in the grid. We use state-of-the-art tree-based machine learning methods to produce such forecasts and, unlike previous studies, we hereby account for (i) the effects various meteorological as well as astronomical features have on PV power production, and this (ii) at coarse as well as granular spatial locations. To this end, we use data from Belgium and forecast day-ahead PV power production at an hourly resolution. The insights from our study can assist utilities, decision-makers, and other stakeholders in optimizing grid operations, economic dispatch, and in facilitating the integration of distributed PV power into the electricity grid

Effect of a broccoli green manure, soil solarization, and isolates of Verticillium dahliae on Verticillium wilt of agronomic and nursery crops

Green manures, soil solarization, and long rotations with crops not susceptible to Verticillium wilt are among the disease management tactics currently under investigation as alternatives to chemical fumigation of soil. The effect of a broccoli green manure on soil microsclerotial populations of three isolates of Verticillium dahliae and on Verticillium wilt of peppermint, potato, and red maple was evaluated in a field study. Compared to the fallow control, soil populations of V. dahliae declined by at least 30% (P=0.0405) following the incorporation of a broccoli green manure (3.87-4.63 kg/m²). Disease severity of potato was reduced by up to 40%, (P=0.0001); however, disease severity of peppermint was not affected by the broccoli green manure treatment. No symptoms of Verticillium wilt were observed in red maple. Potato tuber yield was up to 38% greater following the broccoli green manure compared to the fallow treatment (P=0.2484). The effects of a broccoli green manure and of soil solarization, individually and in combination, on soil populations of V. dahliae and on Verticillium wilt of royal purple smokebush and amur maple were examined in a field study. Following incorporation of the broccoli green manure (2.65 kg/m²) and 2 mo of soil solarization, soil populations of V. dahliae were 40% less (P=0.0377) in plots that received the broccoli green manure treatment compared to fullowed plots, however, the solarization treatment did not affect soil populations on any sampling date. Disease severity of smokebush soon after symptom onset was 35% less (P=0.0264) in plots which were solarized compared to nonsolarized plots; however, the broccoli green manure treatment did not affect disease severity. Aggressiveness of three isolates of V. dahliae on potato, eggplant, and peppermint were evaluated in three field studies. An isolate recovered: from potato was more aggressive on potato than was an isolate recovered from maple (P=0.0329) and more aggressive on eggplant than were isolates obtained from maple and mint (P=0.0001). Mint and potato isolates were more aggressive on the host from which they were isolated than the mint isolate was to potato and vice versa. Inoculum density of the mint and potato isolates as a predictor of disease severity was significant only in the host: from which the isolate was recovered

Prompt dipole radiation in fusion reactions

The prompt gamma ray emission was investigated in the 16A MeV energy region by means of the 36,40Ar+96,92Zr fusion reactions leading to a compound nucleus in the vicinity of 132Ce. We show that the prompt radiation, which appears to be still effective at such a high beam energy, has an angular distribution pattern consistent with a dipole oscillation along the symmetry axis of the dinuclear system. The data are compared with calculations based on a collective bremsstrahlung analysis of the reaction dynamics

Understanding the Potential Impact of Multiple Robots in Odor Source Localization

We investigate the performance of three bio-inspired odor source localization algorithms used in non-cooperating multi-robot systems. Our performance metric is the distance overhead of the first robot to reach the source, which is a good measure for the speed of an odor source localization algorithm. Using the performance distribution of single-robot experiments, we calculate an ideal performance for multi-robot teams. We carry out simulations in a realistic robotic simulator and provide quantitative evidence of the differences between ideal and realistic performances of a given algorithm. A closer analysis of the results show that these differences are mainly due to physical interference among robots

Tracking Odor Plumes in a Laminar Wind Field with Bio-Inspired Algorithms

We introduce a novel bio-inspired odor source localization algorithm (surge- cast) for environments with a main wind flow and compare it to two well-known algorithms. With all three algorithms, systematic experiments with real robots are carried out in a wind tunnel under laminar flow conditions. The algorithms are compared in terms of distance overhead when tracking the plume up to the source, but a variety of other experimental results and some theoretical considerations are provided as well. We conclude that the surge-cast algorithm yields significantly better performance than the casting algorithm, and slightly better performance than the surge-spiral algorithm

Selection of high temperature materials for concentrated solar power systems: Property maps and experiments

© 2014 Elsevier Ltd. Concentrated solar power systems are receiving increasing attention as electricity generating systems, whereby the sun's heat is focused onto a receiver heated to high temperatures. Systems operating today are generally limited to temperatures below about 600. °C, but there is considerable interest in increasing operating temperatures, with heat receivers generally constructed using refractory metallic alloys or ceramics. The present study compares the behaviour of a range of metallic or ceramic materials with advanced intermetallic alloys which have been developed for high-temperature aeronautic or power-generating systems. A few experiments are reported using intense solar heating to demonstrate the damage that may be sustained, depending on the material that is considered. Accelerated cyclic oxidation experiments further emphasize the sensitivity of the various materials to oxidation and thermal damage accumulation. The important characteristics required of the material to be used for the receiver are described and used to generate property maps where the suitability of different classes of materials (metal, intermetallic, ceramic) may be compared. Depending on the precise conditions of where the receiver will operate, and whether creep, fracture or oxidation/spalling is the most important damaging process, either refractory Ni-base alloys, Mo-silicides, or ceramics may be the best material for the application.Peer Reviewe

Quelle réponse humanitaire à l'insécurité alimentaire ? Etude de cas en région pastorale et agropastorale éthiopienne.

Le présent mémoire a pour objet général l’analyse des différentes formes d’actions humanitaires répondant à l’insécurité alimentaire en région pastorale et agropastorale Somali d’Ethiopie. Au travers des premiers chapitres, la recherche se développe à partir de l’exploration de la notion de sécurité alimentaire. L’étude aborde cette notion sous différents angles qui en soulignent les multiples dimensions, déterminants et acteurs qui serviront de points de départ à l’analyse de l’action humanitaire dans la région étudiée. L’exploration de l’action humanitaire dans le domaine de la sécurité alimentaire vient ensuite compléter les précédentes bases théoriques. Dans un second temps, la présente recherche aborde le contexte propre à l’insécurité alimentaire en région Somali et les principaux protagonistes de la problématique : les populations insécurisées, les acteurs étatiques et les acteurs humanitaires. L’analyse démontre que les acteurs humanitaires sont amenés à collaborer avec l’Etat au travers des cadres et structures mis en place par ce dernier. Par ailleurs, elle démontre la variété des actions humanitaires implémentées en région Somali dans le but de répondre à l’insécurité alimentaire. Si l’action humanitaire y aborde cette dernière dans ses différentes dimensions et démontrent une bonne connaissance de celle-ci comme du terrain, l’analyse souligne par ailleurs que peu des actions humanitaires menées incluent une approche sur le long terme afin de réduire les risques futurs. Cette recherche sous-tend ainsi un questionnement sur la démarche humanitaire et sur sa capacité à rendre les populations plus résilientes dans le domaine de la sécurité alimentaire.Master [120] en sciences politiques, orientation relations internationales, Université catholique de Louvain, 201

Transfert de moment angulaire dans les collisions très inélastiques entre ions lourds

Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe

Transfert de moment angulaire dans les collisions très inélastiques entre ions lourds

Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe