182 research outputs found
Evaluation of the resistance of few citrus rootstocks to alkalinity by applying a faste test of secreening
Alkalinity of Moroccan soils is the major abiotic constraint on citrus production area. The best choice of citrus rootstocks adequate and resistant is a better solution to avoid this problem. The aim of this study is to develop a fast test of citrus rootstocks screening towards alkalinity. The alkaline stress was applied on ten citrus rootstocks two month old, using irrigation with a Hoagland and Arnon solution added with 1 g CaCO(3)/L and adjusted at various pH levels 6, 7 and 9. Observations concerned symptoms incidence and severity of iron chlorosis after two months of rearing. Results permitted to classify Poncirus trifoliata and Flying dragon as the most sensitive to alkalinity stresses, whereas, Citrus volkameriana and Citrus macrophylla were resistant. These conclusions are equivalent with those obtained with old citrus rootstocks in field trials
La grossesse chez les hémodialysées chroniques
La survenue d'une grossesse en hĂ©modialyse chronique (HDC) est rare, mais depuis la description du premier cas par Confortini en 1971, plusieursobservations ont Ă©tĂ© rapportĂ©es. L'hĂ©modialyse a considĂ©rablement amĂ©liorĂ© la fertilitĂ© de ces patientes. Nous rapportons l'expĂ©rience de douze grossesses survenues entre 1999 et 2014, chez douze patientes d'Ăąge mĂ©dian 34 ans (22-44), en hĂ©modialyse (HD) depuis 40 mois (3-72), l'Ăąge gestationnel moyen de diagnostic est de 16 semaines d'amĂ©norrhĂ©e, la grossesse Ă©tait compliquĂ©e dans 50% des cas par un hydramnios. Le terme moyen est de 35 semaine d'amĂ©norrhĂ©e (SA) et l'accouchement a Ă©tĂ© rĂ©alisĂ© dans 90% des grossesses par voie basse. Le poids moyen des nouveau-nĂ©s est de 1800g. De telles grossesses sont Ă haut risque du fait de la frĂ©quence des complications. Elles devraient ĂȘtre contrĂŽlĂ©es par les Ă©quipes multidisciplinaires, et la consultation prĂ©natal ne devrait pas ĂȘtre nĂ©gligĂ©e. L'objectif de ce travail est de rapporter notre expĂ©rience concernant la survenue d'une grossesse chez les patientes dialysĂ©es et de la confronter aux donnĂ©es de la littĂ©rature
Comparative evaluation of surface quality, tool wear, and specific cutting energy for wiper and conventional carbide inserts in hard turning of aisi 4340 alloy steel
This paper presents an experimental study into the comparative response of wiper and round-nose conventional carbide inserts coated with TiCN + ALO + TiN when turning an AISI 4340 steel alloy. The optimal process parameters, as identified by pre-experiments, were used for both types of inserts to determine the machined surface quality, tool wear, and specific cutting energy for different cutting lengths. The wiper inserts provided a substantial improvement in the attainable surface quality compared with the results obtained using conventional inserts under optimal cutting conditions for the entire range of the machined lengths. In addition, the conventional inserts showed a dramatic increase in roughness with an increased length of the cut, while the wiper inserts showed only a minor increase for the same length of cut. A scanning electron microscope was used to examine the wear for both types of inserts. Conventional inserts showed higher trends for both the average and maximum flank wear with cutting length compared to the wiper inserts, except for lengths of 200â400 mm, where conventional inserts showed less average flank wear. A higher accumulation of deposited chips was observed on the flank face of the wiper inserts than the conventional inserts. The experimental results demonstrated that edge chipping was the chief tool wear mechanism on the rake face for both types of insert, with more edge chipping observed in the case of the conventional inserts than the wiper inserts, with negligible evidence of crater wear in either case. The wiper inserts were shown to have a higher specific cutting energy than those detected with conventional inserts. This was attributed to (i) the irregular nose feature of the wiper inserts differing from the simpler round nose geometry of the conventional inserts and (ii) a higher tendency of chip accumulation on the wiper inserts
Optimization of NPK levels of Clementine Sidi Aissa (Citrus reticulata Blanco) trees grafted on different citrus rootstocks
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):
(0â0â0), (0â25â50), (25â25â50), (50â25â50), and (100â25â50). 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 100â25â50 (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
Lâobjectif de cet essai est d'Ă©valuer l'effet de la dose d'azote sur le rendement et la qualitĂ© des fruits et de dĂ©terminer la dose optimale en azote pour les arbres de lâorange Navel greffĂ© sur le porte-greffe citrange Troyer plantĂ© en 1964 en plein champ Ă un espacement de 7mx7m (204 arbres/ha) au niveau de la station expĂ©rimentale dâEl Menzeh, INRA Maroc. Le dispositif adoptĂ© est un bloc alĂ©atoire complet avec trois blocs rangĂ©s en 4 arbres consĂ©cutifs par bloc sur la mĂȘme ligne. Quatre doses de N ont Ă©tĂ© testĂ©s : (T0 (TĂ©moin) : 0, T1 : 100, T2 : 200, T3 : 300 Kg N/ha). Les paramĂštres mesurĂ©s sont : le calibre des fruits, le poids moyen par fruit, la qualitĂ© des fruits (le rendement en jus, lâaciditĂ© du jus, lâextrait sec soluble (ESS ou °Brix) et lâindice de maturitĂ© (E/A)) et le rendement en fruits. Le rendement en fruits, le poids moyen des fruits, le calibre des fruits, lâextrait sec soluble (TSS), l'aciditĂ© du jus et l'indice de maturitĂ© de lâorange Navel ont rĂ©pondu significativement Ă lâaugmentation de la dose dâazote. Le rendement en kg de fruits/arbre a Ă©tĂ© considĂ©rablement amĂ©liorĂ© avec l'augmentation de la dose d'azote. Par ailleurs, les rendements les plus Ă©levĂ©s (129.21 et 139.82 kg/arbre) ont Ă©tĂ© enregistrĂ©s sous les traitements T2 et T3 respectivement. Par contre, le rendement en fruits/arbre le plus faible a Ă©tĂ© obtenu chez les arbres non fertilisĂ©s (tĂ©moin). Le poids des fruits (268.54 et 276.50g) et la taille des fruits (78.94 et 80.87 mm) les plus Ă©levĂ©s ont Ă©tĂ© enregistrĂ©s avec les mĂȘme traitements T2 et T3 respectivement. La teneur totale en sucre soluble (TSS) la plus Ă©levĂ©e a Ă©tĂ© enregistrĂ©e chez les arbres des traitements T2 et T3 (12.20 et 11.70 °Brix respectivement). Par ailleurs, une augmentation significative de l'aciditĂ© du jus de fruits de lâorange Navel a Ă©tĂ© Ă©galement enregistrĂ©e en augmentant la dose dâazote. L'aciditĂ© la plus Ă©levĂ©e a Ă©tĂ© obtenue par les mĂȘmes traitements T2 et T3 (1,13 et 1.20 % respectivement). Lâapplication de 200 Kg de N /ha a permis dâavoir un rendement maximal et une qualitĂ© optimale des fruits des oranges Navel greffĂ©s sur le porte-greffe citrange Troyer sur un sol sableux dans la rĂ©gion 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
Physical Activity Recognition Based on a Parallel Approach for an Ensemble of Machine Learning and Deep Learning Classifiers
Human activity recognition (HAR) by wearable sensor devices embedded in the
Internet of things (IOT) can play a significant role in remote health
monitoring and emergency notification, to provide healthcare of higher
standards. The purpose of this study is to investigate a human activity
recognition method of accrued decision accuracy and speed of execution to be
applicable in healthcare. This method classifies wearable sensor acceleration
time series data of human movement using efficient classifier combination of
feature engineering-based and feature learning-based data representation.
Leave-one-subject-out cross-validation of the method with data acquired from 44
subjects wearing a single waist-worn accelerometer on a smart textile, and
engaged in a variety of 10 activities, yields an average recognition rate of
90%, performing significantly better than individual classifiers. The method
easily accommodates functional and computational parallelization to bring
execution time significantly down
Utilisation Des CaractĂšres Biochimiques, Agronomiques Et Morphologiques Pour LâĂ©valuation De La DiversitĂ© GĂ©nĂ©tique Des Variants Dâorangers Dans La RĂ©gion Du Gharb, Maroc
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
Nylon/Ag fiber sensor for real-time damage monitoring of composites subjected to dynamic loading
In this article, the goal is to monitor the deformation and damage behavior of composites in real-time using a Nylon/Ag fiber sensor when subjected to dynamic loading. Composite samples are integrated with Nylon/Ag fiber sensors at distinct locations and directions between the plies. Then, these samples are experimentally impacted with low-velocity impact using the Taylor Cannon Gun apparatus at three different velocities i.e. 2.5 m sâ1, 3 m sâ1, and 6.5 m sâ1, respectively. These three sets of tests are conducted to determine the detection performance of the Nylon/Ag fiber sensor when the composite sample experiences no damage, some microdamage, and overall breakage. Besides, the fiber sensor placed in each position showed distinct electrical behavior in all three tests and detected the deformation, damage initiation, quantification, identification, and damage propagation. The results confirmed the ability of the fiber sensor to monitor and identify the mechanical deformation during dynamic loading and showed that the sensor can be used as a flexible sensor reinforcement in composites for in-situ monitoring as well
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