Search results for "Pulvérisation"
showing 10 items of 13 documents
Caractérisation quantitative de la pulvérisation de pesticides par imagerie
2015
In recent years, advances in plant protection have contributed considerably to increasing crop yields in a sustainable way. Easy to apply and rather inexpensive, pesticides have proven to be very efficient. However, when pesticides are applied to crops some of the spray may not reach the target, but move outside the intended spray area. This can cause serious economic and environmental problems. Most of the pesticides are applied using agricultural sprayers. These sprayers use hydraulic nozzles which break the liquid into droplets with a wide range of droplet sizes and velocities and determine the spray pattern. Small droplets are prone to wind drift, while large droplets can runoff from th…
Etude et modélisation du comportement des gouttelettes de produits phytosanitaires sur les feuilles de vignes par imagerie ultra-rapide et analyse de…
2013
In the domain of vineyard precision spraying research, one of the most importantobjectives is to minimize the volume of phytosanitary products ejected bya sprayer in order to be more environmentally respectful with more effectivevine leaf treatments. Unfortunaltely, even if lot of works have been carriedout at a parcel scale, mainly on losses caused by drift, less works have beencarried out at the leaf scale in order to understand which parameters influencethe spray quality. Since few years, recent improvements in image processing,sensitivity of imaging systems and cost reduction have increased the interestof high-speed imaging techniques. Analyzing the behavior of droplets afterimpact with…
Modélisation d'images agronomiques - application a la reconnaissance d'adventices par imagerie pour une pulvérisation localisée
2009
Plant (crop and weed) identification is a very active field of research in agriculture since the reinforcement of European laws about pesticide applications for a site-specific management of spraying practices. A new crop/weed simulation model was developed to allow the evaluation of crop/weed spatial identification methods from imaging. Considering multiples agronomic parameters – crop location, weed infestation rate, weed spatial distribution – the first step of this model allows the simulation of an infested crop field. Then, in a second step, a world to camera transformation is applied to allow every kind of picture (with or without perspective effect). The validation of this model was …
Étude par microscopie électronique et spectroscopie de films minces catalytiques pour micro piles à combustibles
2016
Předložená dizertační práce se zabývá studiem nových katalyzátorů na bázi kov-oxid vhodných pro použití v palivových článcích na straně anody. Platinou dopovaný oxid ceru připravený magnetronovým naprašováním ve formě tenkých vrstev na uhlíkových mezivrstvách nesených křemíkovým substrátem byl zkoumán prostřednictvím mikroskopických a spektroskopických metod. Vliv složení uhlíkového nosiče (a-C a CNx filmy), depozičního času CeOx vrstvy a dalších depozičních parametrů, např. depoziční rychlosti, složení pracovní atmosféry a Pt koncentrace na morfologii Pt-CeOx vrstev byl studován převážně pomocí transmisní elektronové mikroskopie (TEM). Získané výsledky ukazují, že vhodnou kombinací depozič…
Growth of metal/oxide periodic multilayer : relation between structure and electrical behaviour in systems based on titanium and tungsten
2014
Periodic multilayers have found many applications in the fields of optics, mechanics or electronics. However, few studies focus on the electrical responses of the metal/oxide periodic structures versus temperature. The interest of this work was focused on the characterization of the multilayers and their electrical properties versus temperature. In TiO/Ti/TiO/TiO2 and WO/W/WO/WO3 systems produced by the reactive gas pulsing process, sample structures were established by transmission electron microscopy for sublayers thicknesses between 1.3 and 50.8 nm. Then, this study highlights a modification of conventional electrical behavior versus temperature. An empirical relationship was established…
Elaboration and interfacial reactivity of Lanthanum Strontium Chromium Ruthenium (LSCrRu) perovskite oxides as intermediate temperature fuel cell (IT…
2005
New data on the interest of ruthenium doped lanthanum strontium chromite La1-xSrxCr1-yRuyO3δ (LSCrRu) as anode in ITSOFC are presented. Microwave synthesis of mixed oxides allowed shaping of half-cells and complete cells using sputtering and screen printing methods. LSCrRu methane reforming property had been studied in a mono-chamber system coupled with a mass spectrometer in collaboration with Institut de REcherche Hydro-Québec. Anode/electrolyte interfacial reactivity had been analysed using SIMS and XRD on half cells models after ageing under H2 at 800°C. This experiment gave the chemical composition of the film after treatment. Complete cells, tested under working conditions, highlight…
Co-GLAD sputtering of tungsten-based nanostructured metallic thin films
2022
A structural and electrical study of tungsten-based metal thin films prepared by co-sputtering GLAD is the subject of this thesis. For this purpose, three different systems (W-W, W-Ag and W-Mo) have been developed using two opposite metallic targets (tilt angle α = 80° with the substrate). In addition to the choice of the second metallic element, different parameters involved in the growth of these films have undergone a variation (working pressure, thickness and second target current) to understand their influence on structural and electrical behaviors of these films. All three systems present a columnar and porous structure. The morphology of these films (especially the inclination of the…
Développement opérationnel en grandes cultures semées en ligne d’une rampe de pulvérisation grande largeur localisée sur le rang
2019
National audience; Pour réduire l’utilisation des herbicides, une des solutions possibles est de ne traiter que le rang en post-levée et de biner l’inter-rang ensuite. Terres Inovia, en collaboration avec la Coopérative Agricole Lorraine, a mis en place des essais au champ sur colza et tournesol avec la rampe localisée Marechal, dans le but de mettre au point cette technique pour des rampes de grande largeur avec une bonne qualité de pulvérisation sur le rang et un type de guidage adapté à des terres à colza, plus irrégulières que les terres à betterave sur lesquelles la rampe avait été développée. L’objectif est également d’évaluer les efficacités de la technique (satisfaction du désherbag…
I-Weed Robot : un robot autoguidé pour un désherbage localisé
2013
We present the development of an autonomous robot, called I-Weed Robot (Intelligent Weed Robot), which aims at reducing herbicides in crop fields (maize, sunflower…). Using a high precision positioning signal (RTK) to locate the robot in the field, a Kalman filter and a proportional-integral-derivative controller (PID controller) allows adjusting the orientation and the speed of the robot depending on a predefined trajectory. As for the specific spraying system, a commercial system is used (weedseeker, Trimble) where the plant detection is obtained by an optical sensors just before to spray specifically on them. The performance of the guidance algorithm using numerical simulations (virtual …
I-Weed robot : un outil pour l'étude de population de plantes adventices
2016
The I-Weed robot is a small autonomous platform that aims to characterize the vegetation in an inter-row maize crop for a spot spraying: spraying is done only where a weed is detected. This article presents how the robot works and aims to experimentally evaluate the ability to map weeds from a WeedSeeker system (Trimble) embedded on the I-Weed robot. The results are compared to those from an imaging system, used as ground truth. After analyzing a confusion matrix, it reveals that the system is able to correctly geotag plants at 75 % and is ready for a spot spraying.