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991.
Degradation of alachlor and pyrimethanil by combined photo-Fenton and biological oxidation 总被引:1,自引:0,他引:1
Ballesteros Martín MM Sánchez Pérez JA García Sánchez JL Montes de Oca L Casas López JL Oller I Malato Rodríguez S 《Journal of hazardous materials》2008,155(1-2):342-349
Biodegradability of aqueous solutions of the herbicide alachlor and the fungicide pyrimethanil, partly treated by photo-Fenton, and the effect of photoreaction intermediates on growth and DOC removal kinetics of the bacteria Pseudomonas putida CECT 324 are demonstrated. Toxicity of 30–120 mg L−1 alachlor and pyrimethanil has been assayed in P. putida. The biodegradability of photocatalytic intermediates found at different photo-treatment times was evaluated for each pesticide. At a selected time during batch-mode phototreatment, larger-scale biodegradation kinetics were analysed in a 12 L bubble column bioreactor. Both alachlor and pyrimethanil are non-toxic for P. putida CECT 324 at the test concentrations, but they are not biodegradable. A 100 min photo-Fenton pre-treatment was enough to enhance biodegradability, the biological oxidation response being dependent on the pesticide tested. The different alachlor and pyrimethanil respiration and carbon uptake rates in pre-treated solutions are related to change in the growth kinetics of P. putida. Reproducible results have shown that P. putida could be a suitable microorganism for determining photo-Fenton pre-treatment time. 相似文献
992.
Estrella Aspé Marlene Roeckel M. Cristina Martí Romel Jiménez 《Packaging Technology and Science》2008,21(7):395-404
Beef chops (longissimus dorsi) were pre-treated with 5% carbon monoxide (CO) − 95% N2 for 24 h, vacuum packed in thermo-contractile bags and stored at 0 ± 2°C. Shelf life, as determined by the viable aerobic bacterial load, was 11 weeks. Vacuum-packed chops with heat-contractile film produced a smaller drip loss, had a more intense red colour and higher colour stability under storage than chops with non-heat-contractile film. Chops pre-treated with CO were redder during all the storage period than controls without CO. The pre-treatment did not affect pH, water-holding capacity, drip loss or rancidity of the meat stored in vacuum. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
993.
M. Borges-Quintana M. A. Borges-Trenard P. Fitzpatrick E. Martínez-Moro 《Applicable Algebra in Engineering, Communication and Computing》2008,19(5):393-411
In this paper we introduce a binomial ideal derived from a binary linear code. We present some applications of a Gröbner basis of this ideal with respect to a total degree ordering. In the first application we give a decoding method for the code. In the second one, by associating the code with the set of cycles in a graph, we can solve the problem of finding all codewords of minimal length (minimal cycles in a graph), and show how to find a minimal cycle basis. Finally we discuss some results on the computation of the Gröbner basis. 相似文献
994.
Alves HL Dos Santos LA Bergmann CP 《Journal of materials science. Materials in medicine》2008,19(5):2241-2246
Calcium phosphate cements are biomaterials made from a mixture of calcium phosphate powder in aqueous solutions that forms
a paste that reacts at the body temperature and hardens as a result of precipitation reactions. These cements are commonly
used in dentistry and orthopedic bone filling surgeries, which require extremely invasive procedures. The challenge consists
in formulating an injectable paste by additives incorporation. In this work, three different additives (carboxymethylcellulose,
agar polymer and sodium alginate) were incorporated to tricalcium phosphate, in concentrations of 0.4, 0.8, 1.6, 3.2 and 6.4 wt.%.
Injectability was evaluated through a new method developed for this purpose. Results showed that it was possible to obtain
injectable compositions of α-tricalcium phosphate cement. It was verified that the injectability depends on the rheological
behavior of the pastes and injection time. In this study, pastes with viscosity suitable for good homogenization and injection
were obtained. 相似文献
995.
Martínez-Herrero R Mejías PM 《Journal of the Optical Society of America. A, Optics, image science, and vision》2008,25(8):1902-1905
Stochastic electromagnetic fields characterized by optimized fringe visibility in a Young interferometric arrangement are shown to be those whose random character is position independent. The optimization procedure involves local unitary transformations, which can be implemented by using reversible anisotropic polarization devices placed at the two pinholes. It is also shown that the local degree of polarization in the optimized interferometer is constant across the superposition region and coincides with the degree of polarization at the two pinholes. 相似文献
996.
Balcells L Abad L Rojas H Perez del Pino A Estrade S Arbiol J Peiro F Martínez B 《Small (Weinheim an der Bergstrasse, Germany)》2008,4(3):365-371
The transport properties across perovskite oxides heterointerfaces are analyzed. Epitaxial La(2/3)Ca(1/3)MnO3/SrTiO3 (LCMO/STO) heterostructures with different STO insulating-barrier thicknesses are systematically investigated and their behavior compared with LCMO/metal junctions. Atomic force microscopy (AFM) measurements in current-sensing mode show typical features associated with tunneling conduction. Careful analysis of the I-V curves across LCMO/STO heterointerfaces, using the Simmons model in the intermediate voltage range, clearly shows the existence of an interface-induced enhancement of the tunneling barrier of about 1.6 nm on the LCMO side. These results confirm recent theoretical studies predicting electronic phase segregation and the formation of an orbital-ordered insulating phase at the manganite-insulator interface that is a result of the reduction in the number of charge carriers at the interface. 相似文献
997.
A. Martínez-Cob E. Playán N. Zapata J. Cavero E. T. Medina M. Puig 《Canadian Metallurgical Quarterly》2008,134(6):745-756
The effect of reduced corn evapotranspiration (ET) during solid-set sprinkler irrigation on application efficiency was analyzed on two subplots. During each irrigation event, one subplot was irrigated (moist treatment) while the other was not (dry treatment). ET (weighing lysimeter) and transpiration (heat balance method) rates were determined at each subplot before, during, and after the irrigations. During daytime irrigations, there was a significant decrease in ET (32–55%) and transpiration (58%) for the moist treatment. After the irrigations (1–2?h), ET significantly increased (34%) and transpiration decreased (20%). Gross wind drift and evaporation losses (WDELg) were found to be 19.3% of the applied water. Taking into account the ET changes during and after the irrigations, net sprinkler evaporation losses (SELn) were 14.4–17.5% of the applied water. During nighttime irrigations, changes in ET and transpiration were almost negligible, and SELn were slightly greater than WDELg (9.5 and 8.1%, respectively, of applied water). SELn was mainly a function of wind speed. Reduced ET and transpiration during daytime irrigations moderately increased solid-set sprinkler application efficiency. 相似文献
998.
Emilia Novillo-Díaz César Villa-Collar Mónica Narváez-Peña José Luis R. Martín 《Contact lens & anterior eye》2018,41(3):258-262
Purpose
To determine if the discontinuation of commercially-available simultaneous vision Multifocal Soft Contact Lenses is independent from the multifocal design. To determine causes for discontinuation and psychosocial factors involved.Methods
Multicentre single-blinded randomised controlled trial with external blinded evaluation for a three months follow-up period for three intervention groups. 150 single-vision soft wearers were randomly assigned a spherical near centred lens (S-CN), distance centred lens (CD) or aspherical near centred lens (A-CN). Cases of discontinuation, anxiety and quality of life were measured at one week and one month.Results
120 females and 30 males were included with an age range of 40–62 (48.79?±?5.23). At one month, the S-CN design had a statistically significant higher risk of discontinuation than the other two OR: 6.12 (95%CI 2.5–14.9). Twenty-eight subjects discontinued wearing S-CN at first week (56%), while discontinuation of CD and A-CD were 15 (30%) and 11 (22%), with a statistically significant difference between S-CN design and the other two (p?=?0.001). There were not statistically significant differences when direct comparison between discontinuation of CD and A-CN was made (p?=?0.36). Thirty-two percent discontinued the use because of poor distance vision and 28% because of both poor distance and near vision. Psychosocial factors were not statistically significant.Conclusions
Discontinuation of Multifocal Soft Contact Lenses is dependent on the design. Most common cause for discontinuation is poor distance vision. Psychosocial factors do not impact on discontinuation rates. 相似文献999.
The single-phase and multiphase Eulerian equations of change are derived by applying a suitable averaging procedure to the local instantaneous equations of change. In the present work, the local instantaneous equations of change for mass, species mass, momentum and energy are gross-scale averaged over the cross-sectional area. In particular, the internal energy equation is achieved by subtracting the kinetic energy equation from the total energy balance. Thus, two paths are to our disposal for deriving the cross-sectional averaged internal energy balance: (i) the averaged kinetic energy equation is subtracted from the averaged total energy equation, or (ii) the local instantaneous kinetic energy equation is subtracted from the local instantaneous energy equation and the resulting equation is averaged. The resulting Euler equations of change for internal energy are not identical for these two approaches. Approach (ii) is recommended because of its simplicity. 相似文献
1000.
In this work, a new chiral micellar electrokinetic chromatography with laser-induced fluorescence detection (chiral-MEKC-LIF) method is proposed to identify and quantify D- and L-amino acids in three lines of transgenic maize and their corresponding nontransgenic parental lines grown under identical conditions. The optimized procedure includes amino acids extraction, derivatization with FITC and chiral-MEKC-LIF separation in a background electrolyte composed of 100 mM sodium tetraborate, 80 mM SDS, and 20 mM beta-CD at pH 10.0. The D- and L-forms of Arg, Ser, Ala, Glu, and Asp, corresponding to the majority amino acids usually found in maize, are separated in less than 25 min with efficiencies up to 890,000 plates/m and high sensitivity (i.e., LODs as low as 160 nM were obtained for D-Arg for a signal-to-noise ratio of three), allowing the detection of 1% D-Arg in the presence of 99% of its opposite enantiomer. Using this method, different D-amino acids are detected in all investigated maize samples providing the reproducible quantification of the D-enantiomeric excess (% d-aa) for each amino acid calculated as % D-aa = 100D-aa/(D-aa + L-aa). Thus, significant differences were observed among the % d-aa values for the different conventional varieties (Aristis, Tietar, and PR33P66 maize) as could be expected from their natural variability. More interestingly, comparing each conventional maize with its corresponding transgenic line, very similar % D-aa values were obtained for one of the studied maize couples (Tietar vs Tietar-Bt) what could be presented as a new proof of their substantial equivalence. However, significant differences in the % d-aa values were observed for the other lines of maize studied. It is concluded that enantioselective procedures can open new perspectives in the study of transgenic organisms in order to corroborate (or not) the equivalence with their conventional counterparts. 相似文献