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971.
    
The decolorisation and mineralisation of a model mixture of reactive dyes, under Fenton and photo‐Fenton conditions, have been investigated. A kinetic study was performed and rate constants and half‐life times determined from batch experimental data according to a pseudo‐first‐order degradation kinetic model. Moreover, the use of natural or artificial light, as well as the effect of temperature, was evaluated with the aim of finding the best Fenton process to promote the efficient degradation of the standard trichromatic system. The experimental results showed that the Fenton process run under solar light was the most effective. It is suggested that Fenton‐ and photo‐Fenton‐type reactions are viable techniques for the treatment of these types of dye mixtures, according to the high levels of colour, chemical oxygen demand and total organic carbon removal.  相似文献   
972.
    
This article is regarding the polymerization of 1,3‐butadiene with a neodymium catalyst activated by diisobutylaluminum‐hydride and diethylaluminum chloride (DEAC). The effects of the polymerization conditions (ratio between DEAC and neodymium molar concentrations, polymerization temperature, catalyst concentration, and butadiene concentration) on the polymer yield and molecular weight distribution (MWD) of polybutadiene (PB) samples were evaluated. It is shown that the DEAC/Nd ratio and the polymerization temperature are the reaction variables that influence the MWD and the catalyst performance most significantly. PBs with broad and sometimes bimodal MWD were produced at the analyzed reaction conditions. For this reason, the MWD of the obtained polymer materials was deconvoluted with the help of the Flory most probable distribution, indicating that three or more catalyst sites are required to explain the final MWD of the polymer samples. Finally, it was observed that the analyzed neodymium catalyst is able to produce branched PBs at mild reaction conditions and that the branching frequency depends on the polymerization conditions, which may be useful for development of operation policies at plant site and production of materials with improved performances. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers  相似文献   
973.
    
In this paper we evaluate the stability, purity and regulated quality composition of fatty acids and sterols (both physico‐chemical and sensory) of commercial Argentinean virgin olive oils in order to evaluate their acceptance on the world market. For this purpose, samples of the best known and most widely distributed oils in supermarkets located in Buenos Aires (Argentina) were acquired. After thoroughly analysing these samples, only 20% were considered to have an acceptable quality. However, some were excluded because of their high campesterol content, which could be an intrinsic characteristic of these oils. The most useful analytical parameter used to confirm authenticity was ECN‐42 R – ECN‐42 T, followed by wax content and 3.5 stigmastadienes. Only 24% of the extra‐virgin olive oil samples were classified as ‘extra‐virgin’ from the regulated quality viewpoint. The low oleic and high linolenic acid contents of the Argentinean virgin olive oils stand out when compared with European virgin olive oils. The oxidative stability values may be considered very low, indeed even lower than those obtained in Spanish virgin olive oils.  相似文献   
974.
    
The oil obtained from the Caryocar coriaceum Wittm. (pequi) fruit pulp (C. coriaceum fixed oil – CCFO), rich in fatty acids, has been secularly employed by traditional medicine in the treatment of respiratory affections, skin inflammation, and wounds. These observations encouraged us to investigate the antimicrobial activity of CCFO and to investigate its effect in combination with aminoglycosides. The minimum inhibitory concentration (MIC) of CCFO alone and associated with aminoglycosides against Escherichia coli and Staphylococcus aureus strains were determined using microdilution assay. CCFO alone had a MIC of 512 µg/mL against E. coli and S. aureus resistant strains. Combining the CCFO with aminoglycosides reduced the MIC of aminoglycosides against the resistant strains of E. coli and S. aureus. The results obtained indicate that CCFO displays a significant synergistic antibiotic effect when combined with aminoglycosides, demonstrating that the oil constituents (fatty acids) may act as potentiators of the antibiotic activity of aminoglycosides. These properties make CCFO oil an interesting alternative as a remedy or nutraceutical against multiresistant bacteria, preventing the development of resistance by these microorganisms. Practical applications: This article demonstrates the capacity of the C. coriaceum oil to enhance the antibiotic activity of aminoglycosides. This activity could represent a new way to combat the growing bacterial resistance to antibiotics, an important problem of public health.  相似文献   
975.
    
Fifteen roes from different marine fish species available in Spain were analyzed in order to determine their fatty acid (FA) composition, especially the eicosapentaenoic acid (20:5n‐3, EPA) and docosahexaenoic acid (22:6n‐3, DHA) contents. Roes from Atlantic bonito (Sarda sarda), European squid (Loligo vulgaris), cuttlefish (Sepia spp.), lumpfish (Cyclopterus lumpus), European hake (Merluccius merluccius), Atlantic salmon (Salmo salar) and gonads of male Atlantic mackerel (Scomber scombrus) reached EPA + DHA amounts higher than 30% of the total FA, and among them, roes from lumpfish, European hake and salmon provide different FA type ratios that could make them adequate as dietary sources of EPA and DHA.  相似文献   
976.
    
The surface of natural Brazilian amazonic fibers (curauá, Ananas erectifolius) was modified with polyaniline nanoparticles, through in situ preparation of polyaniline nanoparticles in presence of the curauá fibers. This allowed for a significant increase in the electrical conductivity of the fibers (≈2 500 times). As the electrical resistivity of the modified fibers is a function of the applied external pressure, the produced composites can be used as a cheap pressure‐sensing material. The modified materials were also characterized by FT‐IR, XPS and SAXS, and the obtained results were used to explain some of the observed characteristics of the materials.

  相似文献   

977.
    
PDE7 inhibitors regulate pro‐inflammatory and immune T‐cell functions, and are a potentially novel class of drugs particularly useful for treatment of a wide variety of immune and inflammatory disorders. Structural optimization of thioxoquinazoline derivatives led to new compounds with very interesting profiles as PDE7 or PDE7/PDE4 dual inhibitors, which may be further developed as new drugs for inflammatory and neurological diseases.

  相似文献   

978.
    
In scheduling, estimations are affected by the imprecision of limited information on future events, and the reduction in the number and level of detail of activities. Overlapping of processes and activities requires the study of their continuity, along with analysis of the risks associated with imprecision. In this line, this article proposes a fuzzy heuristic model for the Project Scheduling Problem with flows and minimal feeding, time and work Generalized Precedence Relations with a realistic approach to overlapping, in which the continuity of processes and activities is allowed in a discretionary way. This fuzzy algorithm handles the balance of process flows, and computes the optimal fragmentation of tasks, avoiding the interruption of the critical path and reverse criticality. The goodness of this approach is tested on several problems found in the literature; furthermore, an example of a 15‐story building was used to compare the better performance of the algorithm implemented in Visual Basic for Applications (Excel) over that same example input in Primavera© P6 Professional V8.2.0, using five different scenarios.  相似文献   
979.
    
The Cullera Estany is a coastal lagoon located in a highly intensified agriculture and tourist area in Valencia. This coastal lagoon has connections with the sea that produce marine intrusion and generate a freshwater interface. Four sampling campaigns were carried out during 2010 in order to analyse the phytoplankton composition and its relation to nutrient content through a Redundancy Analysis. Temperature, dissolved oxygen, nitrite and salinity are the main factors controlling the dynamics of phytoplankton community. During July and October, there is water column stratification; meanwhile in March, there is a well‐mixed water column. In addition, in May and July campaigns, hypoxia/anoxia conditions are detected at the bottom. The most abundant phytoplankton groups are Diatoms and Cryptophyceae. Diatoms and Cyanophyceae respond positively to temperature while Cryptophyceae, Prasinophyceae and Dinophyceae respond to high salinity and dissolved oxygen values. Furthermore, picoplankton is correlated inversely with nutrient concentrations.  相似文献   
980.
    
The Water Framework Directive (WFD) aims at improving the ecological status of the water bodies in Europe. In this context, some rivers are currently being restored and, in accordance with this Directive, the restoration actions have to be evaluated from a socio‐economic approach. This work applies the Choice Modelling method to the WFD provisions for river restoration. This method proves to be useful for the economic valuation of the restoration measures, as well as a very important tool for people's public participation. In this sense, the water quality improvement has been defined as a priority action from a social point of view. Moreover, the method used has provided answers to both basic questions included in the WFD: the calculation of the economic value of the Segura River's ecological flow, the decrease of which would pose an environmental cost, and the estimation of the environmental income generated by this river.  相似文献   
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