11 research outputs found
Analyse fréquentielle de l'usinage des composites
le perçage des assemblages hybrides composite-mĂ©tal reste un enjeu important dans le domaine aĂ©ronautique compte tenu de son impact sur la tenue en service des assemblages structuraux. En service, les alĂ©sages rĂ©alisĂ©s sont fortement sollicitĂ©s sous chargement cycle en matage. Les contraintes gĂ©omĂ©triques, dimensionnelles et dâĂ©tat de surface imposĂ©es par les Bureaux dâEtude sont donc trĂšs exigeantes et nĂ©cessitent un process de fabrication extrĂȘmement bien maitrisĂ© sur lâensemble des alĂ©sages rĂ©alisĂ©s. La dĂ©tection automatique des matĂ©riaux lors dâune opĂ©ration de perçage reste un point clef pour la mise en place des stratĂ©gies de smart-drilling intĂ©grant de lâusinage auto-adaptatif. Dans le cadre de cette Ă©tude, une analyse dans le domaine temporel et frĂ©quentiel des signaux dâefforts de coupe dans diffĂ©rentes configurations de perçage dâempilage hybride composite-mĂ©tal est proposĂ©e. Dans un premier temps, une analyse via une reprĂ©sentation polaire des signaux dâefforts temporels permet de mettre en Ă©vidence lâeffet des phĂ©nomĂšnes dâusure sur lâĂ©volution des signatures temporelles. Dans un second temps, une analyse frĂ©quentielle des phĂ©nomĂšnes vibratoires induits par les diffĂ©rents modes de coupe des fibres selon la stratification utilisĂ©e, permet de distinguer de maniĂšre plus fiable que dans le domaine temporel, les matĂ©riaux composites des matĂ©riaux mĂ©talliques. La mĂ©thode dâanalyse frĂ©quentielle proposĂ©e est appliquĂ©e sur diffĂ©rentes configurations (composite-mĂ©tal, composite-composite avec diffĂ©rentes stratifications) afin de dĂ©montrer sa robustesse
Reverse Blending: An economically efficient approach to the challenge of fertilizer mass customization
Reverse blending : une réponse efficace au défi de la personnalisation de masse dans la production de granulés
International audienceMass customization, a major trend in modern economy, relies, in discrete production, on the alternative components assembly while it consists, in the continuous one, in the production of a sequence of batches of different products, which limits feasible diversity, increases transportation issues and therefore prevents economies of scale. In the context of sustainable agriculture, fertilizer producers must significantly increase the variety of their produced fertilizers; any deviation from the recommended formula, for a certain crop on a given soil, results in a loss of productivity and/or soil depletion. The disruptive solution of the Reverse Blending (RB) that we are proposing for this problem, is based on a delayed differentiation performed nearby end-users. It is an extension of the blending problem where inputs does not pre-exist and are to be defined, in number and composition, simultaneously with their use in blending to satisfy exactly outputs requirement. Of course, the number of the inputs to be produced must be as small as possible. RB formulation lays on a parametric quadratic problem. A real case study of this approach is provided.Dans la production manufacturiĂšre, la personnalisation de masse sâeffectue par une combinaison de composants alternatifs montĂ©s sur une ligne dâassemblage. Dans lâindustrie de process, elle est plus difficile car elle implique la fabrication successive de lots de produits diffĂ©rents, ce qui limite la diversitĂ© offerte en raison de lâinertie temporelle que cette production sĂ©quentielle implique. Dans ce contexte, la diversitĂ© croissante des flux Ă produire et transporter empĂȘche toute Ă©conomie dâĂ©chelle. Dans le cadre dâune agriculture durable, les producteurs dâengrais doivent accroĂźtre considĂ©rablement la variĂ©tĂ© des engrais produits, tout Ă©cart par rapport Ă la formule recommandĂ©e pour un couple « sol - culture », se traduisant par une perte de productivitĂ© et/ou un appauvrissement des sols. La solution disruptive du Reverse Blending (RB) que nous apportons Ă ce problĂšme, repose sur une diffĂ©renciation retardĂ©e rĂ©alisĂ©e Ă proximitĂ© des lieux de distribution et non sur les lieux de production. Câest une extension du problĂšme de blending dans laquelle les inputs ne sont pas prĂ©existants et doivent ĂȘtre dĂ©finis, en nombre et en composition, simultanĂ©ment Ă leur utilisation pour produire les engrais dĂ©sirĂ©s. Sa formulation repose sur un programme quadratique paramĂ©trique. Une illustration numĂ©rique de ce modĂšle est proposĂ©e sur un jeu de donnĂ©es rĂ©el
ModĂ©lisation de lâeffet des impuretĂ©s de lâacide phosphorique sur la qualitĂ© physique des engrais phosphate dâammonium
National audienceLa surveillance des propriĂ©tĂ©s physiques des engrais prĂ©sente beaucoup d'intĂ©rĂȘt Ă diffĂ©rents niveaux. Tous les problĂšmes liĂ©s au comportement des granulĂ©s (sĂ©grĂ©gation, Ă©pandage, granulation, duretĂ© ...) nĂ©cessitent une meilleure caractĂ©risation des engrais pour les comprendre et/ou les prĂ©dire. La communautĂ© scientifique est amenĂ©e Ă dĂ©velopper diverses approches de modĂ©lisation pour, dâune part, comprendre la dynamique des impuretĂ©s provenant de lâacide phosphorique lors de la fabrication des engrais et, dâautre part, Ă©valuer lâefficacitĂ© des mesures et suivi des donnĂ©es de la production et des fluctuations de la qualitĂ© physique des engrais. Nous avons collectĂ© et suivi pendant plusieurs mois les donnĂ©es des lignes de production dâengrais phosphatĂ©s (MAP). Lâobjectif de ce travail est de comprendre, Ă travers la modĂ©lisation en appliquant l'approche du rĂ©seau de neurones artificiels (ANN), l'effet des impuretĂ©s d'acide phosphorique sur la qualitĂ© physique des engrais tels que le rendement de granulation, la taille des grains et le diamĂštre moyen des granulĂ©s D50. Des modĂšles ont Ă©tĂ© construits en utilisant la rĂ©gression linĂ©aire multiple (MLR) et l'analyse en composantes principales (ACP)
Study of the Effect of Calcium Substitution by Magnesium in the Vitreous System 3P2O5-2K2O-(1 â x) CaO-x MgO
Phosphate glasses have potentially interesting properties that can be used in various applications. Recently, different studies are focusing on their dissolution behaviours that can be modified to suit some environmental applications, such as controlled-release fertilisers. In this work, magnesium had been suggested to improve the glass durability of 3P2O5-2K2O-(1 − x)CaO-xMgO glasses (0 ≤ x ≤ 1). Indeed, its effect on glass structure, thermal properties and most important dissolution behaviours were studied, in order to evaluate their suitability of being used as controlled-release fertilisers. Various compositions in which calcium was partially replaced by magnesium were prepared by melting at 800 °C. The samples were characterised by differential scanning calorimetry, density measurements, X-Ray diffraction, FTIR spectroscopy and Raman spectroscopy. The dissolution behaviours were investigated using inductively coupled plasma optical emission spectrometry ICP-OES, pH measurements and SEM. Substitution of calcium by magnesium reduced the glass density, owing to the lower atomic weight of magnesium compared to calcium, and caused an increase in glass transition and crystallisation temperatures. Magnesium substitution significantly improved the chemical durability of the glasses due to more covalent Mg–O bond than the Ca–O bond. This study demonstrated that 3P2O5-2K2O-0.3CaO-0.7MgO (x = 0.7) had a dissolution profile adequate to the criteria of controlled-release fertilisers and could be used to nourish the plants with phosphorus, potassium, calcium and magnesium
Innovative Formulations of Phosphate Glasses as Controlled-Release Fertilizers to Improve Tomato Crop Growth, Yield and Fruit Quality
Three phosphate glass compositions, VF1, VF2, and VF3, containing macro and micronutrients with different [K2O/(CaO+MgO)] ratio, were formulated to be used as controlled release fertilizers for tomato crop, depending on their chemical durability in water and their propriety with respect to the standards of controlled-release fertilizers. This study investigated the influence of [K2O/(CaO+MgO)] ratio variation on glass properties. For this, the elaborated glasses have undergone a chemical characterization using inductively coupled plasma atomic emission spectroscopy, a thermal characterization using differential thermal analysis, a physicochemical characterization based on density and molar volume measurements, and a structural characterization using Raman spectroscopy, Fourier-transform infrared spectroscopy, and X-ray diffraction. In addition, the chemical durability was determined by measuring the percentage of weight loss and the pH. Results revealed that the glass structure and composition have the mean role in controlling the release of nutrients in water. By increasing [K2O/(CaO+MgO)] ratio, the dissolution rates of the glasses increased due to the shrinking in the rate of crosslinking between phosphate chains, accompanied with a diminution in transition and crystallization temperatures, and an increase in the molar volume. An agronomic valorization of VF1 and VF2 glass fertilizers, which showed dissolution profiles adequate to the criteria of controlled-release fertilizers, was carried out to evaluate their efficiency on tomato crops. These glass fertilizers improved soil mineral content and tomato performances in comparison to the control and NPK treatments with the distinction of VF2. The results highlight the effectiveness of these smart fertilizers toward their potential large-scale application to improve crop production and quality for high nutritional value foods
STATISTICAL STUDY AND MODELING OF THE EFFECT OF PHOSPHORIC ACID IMPURITIES ON THE PHYSICAL QUALITY OF AMMONIUM PHOSPHATE DETERMINED FROM THE PRODUCTION DATA
International audienceFertilizer producing entity, OCP group.SA, Jorf lasfar, BP118 â 24025 El Jadida, Maroc Ammonium phosphate fertilizer is produced by simple reaction (neutralization) between ammonia and phosphoric acid resulting in the formation of the basic salt.The knowledge of the physical properties of fertilizers presents a lot of interest at different level. All the problems dealing with the behavior of the particles (segregation, spreading, granulation, hardnessâŠ) need a better characterization of the fertilizers in order to understand and/or predict them.Several works were carried out to define and control the effect of impurities from phosphoric acid on the physicochemical properties of ammonium phosphates fertilizers. In the investigation of the influence of elements such as Fe, Al, MgO, F-, SiO2, Na2O, K2O and Cl- on fertilizer quality, we followed the production lines of Ammonium phosphate fertilizers for several months, even more than a year.The aim of the current work is the statistical study and modeling the effect of phosphoric acid qualities on the physical quality of fertilizers such as granulation yield, grain size, and the average diameter of granules D50, based on the analysis of data from different production lines by applying the Principal Components Analysis (PCA). In addition models were constructed using Multiple Linear Regression (MLR) and Artificial Neural Network (ANN)
Properties of Coated Controlled Release Diammonium Phosphate (DAP) Fertilizers Prepared with the Use of Bioâbased Amino Oil
International audienceIn an effort to enhance the efficiency of fertilizer use and minimize their negative impact on the environment, a novel biomass-based, functional controlled-release fertilizer was use to improve nutrient use efficiency and increase crop production systems for more sustainable agriculture practices. Here, biobased amino-oil (Priamine) mixtures were proposed as an outer coating with different layers for the control of phosphorus release from diammonium Phosphate (DAP). These hydrophobic coatings conferred excellent barrier properties and flexibility to coatings. The morphological characterization of the coated fertilizer was performed by Scanning Electronic Microscopy (SEM), and Electronic Diffraction X-ray (EDX) maping, and revealed the formation of a cohesive film and a good adhesion between DAP fertilizer and coating film. The release rate of nutrients (phosphate) in water was investigated by UV-Vis spectrophotometer. The effect of coating thickness was investigated on release time and diffusion coefficient of phosphor release in distilled water. Release time increased with the coating thickness. The diffusion coefficient of nutrient release decreased with the coating thickness. Compared with uncoated granule which is totally solubilized after less than 2 hours, the P release profiles of the coated granules reached the equilibrium stage approximatively after 98 and 126 hours when the DAP is coated with only Priamine single-layer (1L) and double-layer (2L), respectively. Moreover, the strategy adopted has successfully provided a very slow release and long-term availability of nutrients sources with biobased coating oil compared to uncoated fertilizer (DAP) and therefore exhibited promising application for sustainable development of modern agriculture and circular economic
Statistical Study and Modeling of the Effect of Phosphoric Acid Impurities on the Physical Quality of Ammonium Phosphate Determined from the Production Data Using Artificial Neural Network
International audienceThe monitoring of the physical properties of fertilizers presents a lot of interest at different levels. All the problems related to the behavior of the granules (segregation, spreading, granulation, hardnessâŠ) need a better characterization of the fertilizers in order to understand and/or predict them.The scientific community is led to develop a variety of modeling approaches for, on the one hand, the understanding of the dynamics of impurities originating from phosphoric acid during the manufacture of fertilizers, and on the other hand, the evaluation of the effectiveness of measurements and data monitoring from production and the fluctuations in the physical quality of the fertilizers that follow. In this investigation of the influence of elements such as Fe, Al, Mg, F-, Si, Na, K and Cl on fertilizer quality, we gathered and followed-up data from production lines of Ammonium phosphate fertilizers for several months. The aim of the current work is the statistical study and modeling of the phosphoric acid impurities effect on the physical quality of fertilizers such as granulation yield, grain size, and the average diameter of granules D50, based on the analysis of data from different production lines by applying the Artificial Neural Network (ANN) approach. In addition models, were constructed using Multiple Linear Regression (MLR) and Principal Components Analysis (PCA)