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排序方式: 共有346条查询结果,搜索用时 15 毫秒
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Mokhtar Benhanifia Wessam M. Mohamed Yuva Bellik Hama Benbarek 《International Journal of Food Science & Technology》2013,48(12):2521-2527
The aim of this study was the investigation of antimicrobial and antioxidant activities of different ethanolic extracts of propolis (EEP) collected from north‐western Algeria. Total polyphenols and flavonoids contents of extracts were measured. The UV absorption spectrum showed and confirmed their polyphenols constituents. All EEPs exerted antibacterial activity against Gram‐positive bacteria, but no effect on Gram‐negative bacteria. The minimum inhibitory concentration (MIC) of EEPs ranged from 0.01% to 2.6% v/v. The antioxidant activity was measured using ferric‐reducing power (FRAP), 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) free radical‐scavenging and ESR methods. Propolis TIA‐2 and MOH‐MAS samples showed the highest antioxidative capacity, after 35 min, while TIA‐1, NED‐TL and SFS‐SBA samples showed the highest antioxidative potential of measured EEPs, after 3 min. TIA‐2 sample showed the highest antibacterial, antioxidant activity and highest DPPH free radical‐scavenging activity as well as the highest polyphenols and flavonoids content, compared with other propolis samples. 相似文献
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This article examines how web-based interorganizational information systems(ios)can efficiently support coordination mechanisms between outsourcer and third party logistics (3PL). First, we review the literature on coordination mechanisms andios. Second, we report on the methodology used for gathering information on outsourcers and 3PLs. Third, armed with limited but quality data, we identified two fundamental dimensions: 3PL involvement andios impacts on logistics outsourcing decisions. By combining the two dimensions, we propose a conceptual framework that highlights four main categories ofios that we characterize as neutralios, supply chainios, strategicios and dynamicios. After characterizing and analyzing each category, we discuss how these web basedios support outsourcers and 3PL along the supply chain. Finally, the article discusses the framework’s relevancy and its limits. 相似文献
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Niyaz Mohammad Mahmoodi Mokhtar Arami Nargess Yousefi Limaee Farahnaz Nourmohammadian 《Materials Research Bulletin》2007,42(5):797-806
In this paper, the degradation and mineralization of Butachlor in aqueous solution by nanophotocatalysis using immobilized TiO2 nanoparticles were investigated. Butachlor (N-butoxymethyl-2-chloro-2′,6′-diethylacetanilide) is a persistent organic pollutant in agricultural soil and watercourses. A simple and effective method was used for immobilization of titanium dioxide nanoparticles. UV-vis and Ion Chromatography (IC) analyses were employed to obtain the details of the photocatalytic degradation and mineralization of Butachlor. The effects of operational parameters such as H2O2, inorganic anions (NO3−, Cl− and SO42−) and pH were investigated. The lack of any absorbance in 254 nm was indicative of the complete degradation of aromatic intermediates. The mineralization of Butachlor was evaluated by monitoring of the formed inorganic anions (NO3− and Cl−). Butachlor is effectively degraded following first order kinetics model. Results show that the immobilized titanium dioxide nanoparticle photocatalysis is an effective method for treatment Butachlor from contaminated water. 相似文献
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Mokhtar Aly Gamal M. Dousoky Masahito Shoyama 《IEEJ Transactions on Electrical and Electronic Engineering》2016,11(Z2):S75-S83
As promising and suitable candidates for high‐power applications, multilevel inverters have become one of the most promising solutions in various applications. However, power switching devices are highly subjected to thermal overheating, which leads to shortened lifetime and reduced reliability. Thermal overheating may result from the degradation of power switching devices due to continuous overloading and power cycling. In addition, degradation and faults in the cooling system of power switching devices may cause thermal stresses as well. A new overheating‐tolerant space vector modulation algorithm is proposed in this paper to alleviate thermal stresses from overheated power switching device. The proposed algorithm relies on using the redundancy property between switching states in multilevel inverters to continuously evaluate a cost function of the junction temperature of the overheated device for all possible switching sequence sets and then selects the optimal switching sequence. In addition, the proposed algorithm preserves the DC‐link capacitor voltage without reduction in the output current of the inverter. The proposed algorithm is general, which can be applied to n‐level inverters. Both simulation and experimental results reveal the efficient performance of the proposed algorithm using a three‐level T‐type inverter as a case study. Accordingly, the lifetime and reliability of the inverter are enhanced considerably using the proposed algorithm. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
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Mokhtar Guissous Yveline Le Dréau Hasna Boulkhroune Toufik Madani Jacques Artaud 《Journal of the American Oil Chemists' Society》2018,95(3):267-281
Differences in triacylglycerol, fatty acid, squalene, and tocopherol compositions were demonstrated between 8 varieties of virgin olive oils (Aberkane, Aguenaou, Aharoun, Aimel, Bouchouk Guergour, Bouichret, Chemlal, and Sigoise) from Petite Kabylie area, north eastern Algeria. Fatty acid and triacylglycerol morphotypes characterized each variety. A principal component analysis, based on triacylglycerol, fatty acid, and squalene compositions, differentiates between varieties. Minor fatty acids and squalene, usually not taken into account individually in authentication studies, are strongly involved in this differentiation, whereas the discriminant power of tocopherols is weak. Soft Independent Modeling of Class Analogy classification using chemical compositions as variables showed a high potential to authenticate the varietal origin of Algerian virgin olive oils. 相似文献
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Samia Dabbou Faten Brahmi Ameni Taamali Manel Issaoui Youssef Ouni Mohamed Braham Mokhtar Zarrouk Mohamed Hammami 《Journal of the American Oil Chemists' Society》2010,87(10):1199-1209
The effects of the contents of lipids, pigments, α-tocopherol and phenols were studied in relation to the antioxidant capacity
of five virgin olive oils obtained from five olive cultivars planted in Tunisia (Arbequina, Koroneiki, Leccino, Oueslati and
Chemchali). The antioxidant capacities were evaluated by two different radical scavenging activities: radical scavenging activity
by the DPPH assay (RSA-DPPH) and total antioxidant status by the ABTS test (TAA-ABTS). The highest contents of antioxidant
compounds (75.96, 10.34, 6.32, 15.39 and 241.52 mg kg−1 for oleic acid, O/L ratio, carotenes, chlorophylls and total phenols, respectively) were found for the Koroneiki cultivar
except for α-tocopherol and o-diphenols, which had the highest contents (369 and 160.7 mg kg−1, respectively) in the Leccino and Chemchali cultivars (cvs). Furthermore, the highest antioxidant capacity in virgin olive
oil was observed in the Koroneiki cultivar (0.24 mmol TE kg−1) followed by the Chemchali and Leccino cvs (0.22 and 0.13 mmol TE kg−1) for the TAA-ABTS test. However, the RSA-DPPH activity was higher for the Chemchali cultivar (19.9%) than for the Koroneiki
and Leccino cvs (18.4 and 13.5%, respectively). Correlation between these capacities and the oil composition revealed that
they were mainly influenced by the carotene content, followed by chlorophyll and phenolic contents where the ABTS test was
more pronounced. Then, the antioxidant capacity of the virgin olive oils was correlated with polar components and the lipid
profile which are important for its shelf life. 相似文献