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T. K. Alexandridis A. Panagopoulos G. Galanis I. Alexiou I. Cherif Y. Chemin E. Stavrinos G. Bilas G. C. Zalidis 《Irrigation Science》2014,32(2):127-140
Despite being necessary for effective water management, the assessment of an irrigation system requires a large amount of input data for the estimation of related parameters and indicators, which are seldom measured in a regular and reliable manner. In this work, spatially distributed surface energy balance fluxes and geographical information systems analysis of multiple groundwater parameters were used to estimate water availability, supply, and demand, in order to calculate water-accounting indicators. This methodology was used to evaluate the performance of an irrigation system in the Pinios river basin (Greece) at two selected years of high and low water availability. Time series of archived satellite images and groundwater measurements have been used for past years to support comparative analyses, due to the limited availability of actual water measurements. The resulting maps from the proposed methodology show that the performance of the irrigation system varied across space and time due to differences in its characteristics and changes in its operation, driven by fluctuation of water availability and the response of stakeholders to water depletion. Irrigation districts with unsustainable water management were identified and, together with those with slow and/or limited groundwater recharge, were brought to the attention of water managers. The observed differences in the system operation between the wet and dry years were attributed not only to the hydrological conditions of each year, but also to the changing behaviour of farmers and the improvement actions of the water managers. 相似文献
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Survey of viruses infecting open‐field pepper crops in Côte d'Ivoire and diversity of Pepper veinal mottle virus and Cucumber mosaic virus 
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下载免费PDF全文 B. A. Bolou Bi B. Moury K. Abo F. Sorho M. Cherif G. Girardot N. P. Kouassi D. Kone 《Plant pathology》2018,67(6):1416-1425
The prevalence of viruses in pepper crops grown in open fields in the different agro‐ecological zones (AEZs) of Côte d'Ivoire was surveyed. Pepper veinal mottle virus (PVMV; genus Potyvirus) and Cucumber mosaic virus (CMV; genus Cucumovirus) were the most frequent viruses among those surveyed, while tobamoviruses (genus Tobamovirus) were detected at low frequency. PVMV showed a high heterogeneity across AEZs, which may be related to climatic, ecological or agronomical conditions, whereas CMV was more homogeneously distributed. The molecular diversity of CMV and PVMV were analysed from partial genome sequences. Despite the low number of CMV isolates characterized, two molecular groups were revealed, one corresponding to subgroup IA and the other to reassortants between subgroups IA and IB. RNAs 1 and 3 of the reassortants clustered with the IB subgroup of CMV isolates, whereas their RNA 2 clustered with the IA subgroup. Importantly, RNA 1 of CMV isolates of the IB subgroup has been shown to be responsible for adaptation to pepper resistance. The diversity of PVMV in the VPg‐ and coat protein‐coding regions revealed multiple clades. The central part of the VPg showed a high level of amino acid diversity and evidence of positive selection, which may be a signature of adaptation to plant recessive resistance. As a consequence, for efficient deployment of resistant pepper cultivars, it would be desirable to examine the occurrence of virulent isolates in the CMV or PVMV populations in Côte d'Ivoire and to follow their evolution as the resistance becomes more widely deployed. 相似文献
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Mohammad Abu Shayed Heike Hund Rolf Dieter Hund Chokri Cherif 《Fibers and Polymers》2016,17(2):229-240
Thermal and oxidation resistant coating is necessary for carbon fiber (CF) in CF reinforced concrete (CFRC) composite application in order to fulfil a high level of safety standard in case of fire. Pre-ceramic coatings such as Polysilazane, Polysiloxane, and Methyl silicone resin have been deposited on CF filament yarn by means of wet chemical continuous dip coating method. The surface analyses e.g. scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy (IR) results showed the changes of surface morphology by the coatings. Thermo gravimetric analysis (TGA) revealed that the high temperature (up to 800 °C) oxidation stability of CF was significantly improved with coatings. Thermo-mechanical properties also significantly enhanced up to 600 °C. CF yarn retains its original strength and elasticity modulus/stiffness at 700 °C due to thermal and oxidation resistant coatings. 相似文献
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Hela Chikh-Rouhou Rafika Sta-Baba Chadha Ayed Sabeh Belgacem Naima Boughalleb Mejda Cherif 《Phytoparasitica》2013,41(5):593-596
Fusarium wilt of melon, caused by Fusarium oxysporum f.sp. melonis (Fom), is an important disease; races of the pathogen were identified by inoculating differential standard host cultivars. A total of ten isolates that were obtained from 23 fields located in four different geographical regions were identified as pathogenic. Results indicate that all four known Fom races, namely, 0, 1, 2 and 1.2, were found in north and middle Tunisia. Race 1.2 was the most prevalent. 相似文献
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Le pouvoir pathogène de certains isolats de Fusarium oxysporum collectés a été testé sur plants et sur tubercules de pomme de terre. L'inoculation de plants du cultivar 'Spunta' par une suspension de spores a engendré une réduction de croissance et le flétrissement vasculaire de l'ensemble des plants inoculés par les différents isolats. L'agent pathogène a été ré-isolé. Sur tubercules, les différents isolats se sont comporté comme agents de pourriture sèche. Cet ensemble de résultats confirme qu'il s'agit de Fusarium oxysporum f.sp. tuberosi , signalé pour la première fois en Tunisie. 相似文献
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Summary To check if the oxygen concentration in the cell medium-higher at low temperatures-is a factor regulating the synthesis of
polyunsaturated fatty acids, the effects of temperature and oxygen concentration were studied in vitro on the activity of
the microsomal oleyl-coenzyme A desaturase of potato tubers. The highest activity of this enzyme was observed at 30° C, and
not at low temperatures, and at an oxygen concentration of about 20%. These results suggest that the above hypothesis is not
valid for the potato tuber cell.
Zusammenfassung Um zu prüfen. ob die Sauerstoffkonzentration in der Zelle-bei niedriger Temperatur h?herein regulierender Faktor bei der Synthese der mehrfach unges?ttigten Fetts?uren ist, wurde der Einfluss der Temperatur und der Sauerstoffkonzentration auf die Aktivit?t der mikrosomalen Oleyl-coenzym A Desaturase der Kartoffelknollen in vitro untersucht. Die h?chste Aktivit?t des Enzyms wurde bei einer Temperatur von 30°C gefunden und nicht bei tieferen Temperaturen (Abb. 1) und bei einer Konzentration von ca. 20% Sauerstoff (Abb. 2). Diese Ergebnisse zeigen, dass die angeführte Hypothese im Falle der Kartoffelknollen nicht zutrifft.
Résumé Pour vérifier si l'hypothèse selon laquelle la concentration en oxygène du milieu cellulaire-plus élevée à basse température-est un facteur régulant la synthèse des acides gras polyinsaturés, les effets de la température et de la concentration en oxygène sur l'activité de l'oléyl-coenzyme A désaturase microsomale du tubercule de pomme de terre ont été étudiés in vitro. L'activité la plus élevée de l'enzyme est observée pour la température de 30°C et non à basse température (Fig. 1) et pour une concentration en oxygène d'environ 20% (Fig. 2). Ces résultats suggèrent que l'hypothèse exposée plus haut n'est pas valable dans le cas du tubercule de pomme de terre.相似文献
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This article correlates draw frame settings with quality characteristics of sliver and ring spun yarn using artificial neural
networks. Considering the importance of draw frame as the last quality improvement machine in the spinning process, the quality
influencing parameters of the draw frame were used as input for artificial neural networks. The neural networks were trained
using a combination of Levenberg-Marquardt algorithm and Bayesian regularization for better generalization of the networks.
Cross validation was performed for each trained network to test the performance of networks. The promising results achieved
by this research work emphasize the ability of neural networks to predict the quality characteristics of sliver and yarn using
the artificial neural networks. Therefore, draw frame parameters can be adjusted on the basis of required sliver and yarn
quality. Furthermore, machines can be involved in the decision making process in spinning mills. 相似文献
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Ultrahigh molecular weight polyethylene (UHMW PE) has high chemical resistance, good flexibility and remarkable strength along with low density, which makes it a good choice for lightweight textile reinforced composites. One drawback is the low melting point, limiting the possible applications at high temperatures. However its chemical structure leads to almost no chemical interactions of the interface. One way to enhance these interactions is the application of atmospheric pressure plasma. Polyethylene (PE) as yarn and in woven form was plasma treated in atmospheric air plasma generated by means of dielectric barrier discharge technique and the resulting effects on wettability, chemical composition and surface structure were studied. It was found that oxygen containing functional groups are introduced into the outer layer of the PE, thus increasing wettability and dyeability significantly. It could be shown that the changes last for at least 3 months in air without the necessity of any precautions. A degradation of the textile fibre during air plasma treatment was also observed, leading to a decrease of tensile strength and maximum elongation after more than five minutes of air plasma treatment. 相似文献