169 research outputs found

    State feedback linearization and adaptive model predictive control applied to a simulated MSMPR crystalliser [Abstract]

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    State feedback linearization and adaptive model predictive control applied to a simulated MSMPR crystalliser [Abstract

    Input-output state feedback linearization and model predictive control of an MSMPR crystalliser [Abstract]

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    Input-output state feedback linearization and model predictive control of an MSMPR crystalliser [Abstract

    Optimization of NPK levels of Clementine Sidi Aissa (Citrus reticulata Blanco) trees grafted on different citrus rootstocks

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    Received: August 15th, 2023 ; Accepted: October 18th, 2023 ; Published: November 5th, 2023 ; Correspondence: [email protected] present study aims to investigate the impact of various nitrogen concentrations on young Clementine Sidi Aissa citrus trees (Citrus reticulata Blanco), grafted on five citrus rootstocks namely Moroccan Carrizo citrange, French Carrizo citrange, Troyer citrange, Citrus macrophylla, and sour orange (Citrus aurantium L.). The experiment took place in greenhouses at the Experimental station of El Menzeh INRA-Morocco, with the young trees grown in containers. We applied five different nitrogen treatments (expressed as mg L-1 of N-P2O5-K2O): (0–0–0), (0–25–50), (25–25–50), (50–25–50), and (100–25–50). The split-plot experimental design was used with three replications. The findings demonstrate that the nitrogen enrichment resulted in enhanced plant growth, marked by increased plant height, rootstock and scion stem diameters, diameter and shoot length, relative water content (RWC), as well as leaf chlorophyll and proline content. Optimal growth of the Clementine Sidi Aissa trees was observed under the 100–25–50 (mg L-1 of N-P2O5-K2O) treatment. The study also found that leaf nitrogen concentration increased in line with the quantity of nitrogen added, whereas the percentages of phosphorous and potassium in the leaves decreased. The most significant growth increase across the majority of the studied parameters was noted in Clementine Sidi Aissa trees grafted on Moroccan Carrizo citrange and Troyer citrange rootstocks

    Effect of nitrogen level application on yield and fruit quality of Navel orange variety in a sandy soil

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    L’objectif de cet essai est d'évaluer l'effet de la dose d'azote sur le rendement et la qualité des fruits et de déterminer la dose optimale en azote pour les arbres de l’orange Navel greffé sur le porte-greffe citrange Troyer planté en 1964 en plein champ à un espacement de 7mx7m (204 arbres/ha) au niveau de la station expérimentale d’El Menzeh, INRA Maroc. Le dispositif adopté est un bloc aléatoire complet avec trois blocs rangés en 4 arbres consécutifs par bloc sur la même ligne. Quatre doses de N ont été testés : (T0 (Témoin) : 0, T1 : 100, T2 : 200, T3 : 300 Kg N/ha). Les paramètres mesurés sont : le calibre des fruits, le poids moyen par fruit, la qualité des fruits (le rendement en jus, l’acidité du jus, l’extrait sec soluble (ESS ou °Brix) et l’indice de maturité (E/A)) et le rendement en fruits. Le rendement en fruits, le poids moyen des fruits, le calibre des fruits, l’extrait sec soluble (TSS), l'acidité du jus et l'indice de maturité de l’orange Navel ont répondu significativement à l’augmentation de la dose d’azote. Le rendement en kg de fruits/arbre a été considérablement amélioré avec l'augmentation de la dose d'azote. Par ailleurs, les rendements les plus élevés (129.21 et 139.82 kg/arbre) ont été enregistrés sous les traitements T2 et T3 respectivement. Par contre, le rendement en fruits/arbre le plus faible a été obtenu chez les arbres non fertilisés (témoin). Le poids des fruits (268.54 et 276.50g) et la taille des fruits (78.94 et 80.87 mm) les plus élevés ont été enregistrés avec les même traitements T2 et T3 respectivement. La teneur totale en sucre soluble (TSS) la plus élevée a été enregistrée chez les arbres des traitements T2 et T3 (12.20 et 11.70 °Brix respectivement). Par ailleurs, une augmentation significative de l'acidité du jus de fruits de l’orange Navel a été également enregistrée en augmentant la dose d’azote. L'acidité la plus élevée a été obtenue par les mêmes traitements T2 et T3 (1,13 et 1.20 % respectivement). L’application de 200 Kg de N /ha a permis d’avoir un rendement maximal et une qualité optimale des fruits des oranges Navel greffés sur le porte-greffe citrange Troyer sur un sol sableux dans la région de Gharb.The objective of the present paper was to evaluate the effect of nitrogen level on yield and fruit quality of citrus and to determine the optimum N fertilizer rates of Navel orange variety budded on Troyer citrange rootstock in field conditions. The orange Navel orchard spaced 7mx7m (204 trees/ha) grown in 1964 on a sandy soil at the experimental station of El Menzeh, INRA Morocco. The experiment was set up in a complete randomized block design with three blocks and the experimental unit was composed on 4 consecutive trees in the row. Four fertilization treatments of N (Kg/ha) (T0 (control): 0, T1: 100, T2: 200, T3: 300) were applied to Navel citrus tree in field conditions over two seasons 2012-2013 and 2013-2014.Fruit yield, fruit weight, fruit size, total soluble sugar (TSS) content, acidity of juice and maturity index of Navel orange were significantly affected by increasing N level. Fruit yield/tree was improved significantly with increase in N rate. Significant highest yields (129.21 and 139.82. kg/tree) were recorded under treatments T2 and T3 respectively. The lowest fruit yield/tree was obtained from untreated control plot. Maximum fruit weight (268.54 and 276.50 g) and fruit size (78.94 and 80.87 mm) was recorded with the same treatments T2 and T3 respectively. Total soluble sugar content was also maximum in trees receiving treatment (T2) and treatment (T3) 12.20 and 11.70°Brix respectively. Significant increase in acidity of juice of fruit Navel orange was also recorded by increasing the rate of N. The highest acidity (1.13 and 1.20%) was achieved by the same treatments T2 and T3 respectively. Two-year studies showed that application of fertilizers at the rate of 200 Kg N/ha would be optimum for achieving higher yield and better fruit quality of Navel orange variety in sandy soil in Gharb area

    Analysis of optimal operation of a fed-batch emulsion copolymerization reactor used for production of particles with core–shell morphology

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    This paper was accepted for publication in the journal Computers and Chemical Engineering: http://www.sciencedirect.com/science/article/pii/S0098135414000532In this paper dynamic optimization of a lab-scale semi-batch emulsion copolymerization reactor for styrene and butyl acrylate in the presence of a chain transfer agent (CTA) is studied. The mathematical model of the process, previously developed and experimentally validated, is used to predict the glass transition temperature of produced polymer, the number and weight average molecular weights, the monomers global conversion, the particle size distribution, and the amount of residual monomers. The model is implemented within gPROMS environment for modeling and optimization. It is desired to compute feed rate profiles of pre-emulsioned monomers, inhibitor and CTA that will allow the production of polymer particles with prescribed core-shell morphology with high productivity. The results obtained for different operating conditions and various additional product specifications are presented. The resulting feeding profiles are analyzed from the perspective of the nature of emulsion polymerization process and some interesting conclusions are drawn

    Utilisation Des Caractères Biochimiques, Agronomiques Et Morphologiques Pour L’évaluation De La Diversité Génétique Des Variants D’orangers Dans La Région Du Gharb, Maroc

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    20 clones of orange trees, identified at the level of the collection of nucellar citrus varieties, have been the subject of several tests of behavior at the level of different citrus fruit sites in Morocco. Indeed, the present work aims to evaluate these variants on a clay soil at the Gharb region (INRA/Kenitra). The variants grafted on Citrange troyer were divided into three groups. Each group contains variants, genetically similar, from seedlings of the same parent variety. Clonal selection is based on the synthesis of the results of the study of the variability of the criteria of fruit quality and production. The average yield varies from 44.25 kg / tree to 217.30 kg / tree. While the average weight of a fruit varies from 95 g to 360 g. The results showed a predominance of juicy and medium-sized fruits with an equatorial diameter greater than 56 mm, acceptable for the fresh fruit market or the juice industry. The maturity coefficient study of the variants within each group, or between the three groups, showed that the harvest period extends over four months, from December to March. The final selection was focused on six productive and good quality variants. These promising variants have been described according to UPOV, and then presented for registration in the official catalog

    Bronchodilation induced by PGE2 is impaired in Group-III pulmonary hypertension

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    BACKGROUND AND PURPOSE: In patients with pulmonary hypertension (PH) associated with lung disease and/or hypoxia (Group III), a reduction of pulmonary vascular tone and tissue hypoxia are considered therapeutically beneficial. Prostaglandin (PG) E2 and PGI2 induce potent relaxation of human bronchi from non-PH (control) patients via EP4 and IP receptors, respectively. However, the effects of PGE2 /PGI2 and their mimetics on human bronchi from PH-patients are unknown. Our aim was to compare the relaxant effects of several PGI2 -mimetics approved for treating PH-Group I with several PGE2 -mimetics in bronchial preparations derived from PH-Group III and control patients. EXPERIMENTAL APPROACH: Using an organ bath system, the tone of bronchial muscle was investigated in tissue from either control or PH-Group III patients. Expression of prostanoid receptors were analyzed by Western blot and real-time PCR and endogenous PGE2 , PGI2 and cAMP levels were determined by ELISA. KEY RESULTS: Maximal relaxations induced by different EP4 agonists (PGE2 , L-902688, ONO-AE1-329) were significantly decreased in human bronchi from PH-patients versus controls. In contrast, the maximal relaxations produced by PGI2 -mimetics (iloprost, treprostinil, beraprost) were similar for both groups of patients. Both EP4 and IP receptor protein and mRNA expressions were significantly lower in human bronchi from PH-patients. cAMP levels significantly correlated with PGI2 but not with PGE2 levels. CONCLUSION AND IMPLICATIONS: This study shows that PGI2 -mimetics have preserved maximal bronchodilation in PH-Group III patients. The decreased bronchodilation induced by EP4 agonists suggests that restoration of EP4 expression in airways of PH-patients with respiratory diseases could bring additional therapeutic benefit

    The accumulation of assembly intermediates of the mitochondrial complex I matrix arm is reduced by limiting glucose uptake in a neuronal-like model of MELAS syndrome

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    Ketogenic diet (KD) which combined carbohydrate restriction and the addition of ketone bodies has emerged as an alternative metabolic intervention used as an anticonvulsant therapy or to treat different types of neurological or mitochondrial disorders including MELAS syndrome. MELAS syndrome is a severe mitochondrial disease mainly due to the m.3243A > G mitochondrial DNA mutation. The broad success of KD is due to multiple beneficial mechanisms with distinct effects of very low carbohydrates and ketones. To evaluate the metabolic part of carbohydrate restriction, transmitochondrial neuronal-like cybrid cells carrying the m.3243A > G mutation, shown to be associated with a severe complex I deficiency was exposed during 3 weeks to glucose restriction. Mitochondrial enzyme defects were combined with an accumulation of complex I (CI) matrix intermediates in the untreated mutant cells, leading to a drastic reduction in CI driven respiration. The severe reduction of CI was also paralleled in post-mortem brain tissue of a MELAS patient carrying high mutant load. Importantly, lowering significantly glucose concentration in cell culture improved CI assembly with a significant reduction of matrix assembly intermediates and respiration capacities were restored in a sequential manner. In addition, OXPHOS protein expression and mitochondrial DNA copy number were significantly increased in mutant cells exposed to glucose restriction. The accumulation of CI matrix intermediates appeared as a hallmark of MELAS pathophysiology highlighting a critical pathophysiological mechanism involving CI disassembly, which can be alleviated by lowering glucose fuelling and the induction of mitochondrial biogenesis, emphasizing the usefulness of metabolic interventions in MELAS syndrome
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