We describe genetic variation at three microsatellite single loci and six allozyme loci of seven natural Atlantic salmon populations from Ireland and Spain. A comparison of genetic variability detected at both types of loci is performed. Also, the relative value of microsatellite single locus variability with regard to the identification of individual salmon populations is assessed. Microsatellite loci are shown to display higher levels of variation than allozyme loci.Mean number of alleles (6 1.53) and heterozygosity (0.46 0.04) at microsatellite loci are greater than those found for allozymes (1.85±0.05 and 0.21±0.03, respectively), and some microsatellite alleles appear to be specific for a location or geographical area. Allozyme and microsatellite variation show the same pattern of differentiation between populations with Irish and Spanish populations grouped into different clusters. However, greater values of genetic distance were found among microsatellite (D = 0.0747±0.011) rather than among allozyme loci (D = 0.0449 0.008). These results provide evidence that microsatellite-based analysis of genetic variation will be useful in the identification of individual populations of Atlantic salmon.
This research compares the environmental properties (bacterial toxicity and biodegradability) of 12 ionic liquids-ILs-(7 phosphonium, 2 imidazolium and 3 ammonium cation-based ones), potentially applicable as lubricant additive, with two types of the traditional lubricant additive ZDDP. Aquatic toxicity was determined by means of Vibrio fischeri and Escherichia coli bacteria, while biodegradability was evaluated through biological oxygen demand (BOD 5) and chemical oxygen demand (COD) measurements. Regarding toxicity results, [P 4442 ][DEP] was the least toxic IL (acute 3 according to GHS) for both bacteria, whereas ZDDP fell into the acute 1 category (very toxic). All samples tested turned out to be poorly biodegradable, showing BOD 5 /COD values below 0.1. Two ILs showed better combined tribological and environmental properties than ZDDP.
The ionic liquid (IL) tributylmethylammonium bis(trifluoromethylsulfonyl)amide ([N 4441 ][NTf 2 ]) was used as neat lubricant and as an additive (1.5 wt%) in a polar oil to study its friction and wear reducing properties. Tribological tests were completed for 90 minutes at room temperature and 100 °C in a reciprocating configuration at loads of 30 and 70 N, 10 Hz-frequency, and 4 mm stroke length. Wear volume was measured by confocal microscopy and the surface-IL interaction determined by XPS. The main findings were that neat IL showed the best tribological behavior; the IL-containing mixture behaved similar to the base oil regarding friction, however outperformed the antiwear behavior of the base oil under higher temperature; surface-IL chemical interaction was found mainly at 100 °C .
The ionic liquid (IL) dodecyl-3 methylimidazolium bis(trifluoromethylsulfonyl)imide was tested as neat lubricant and as additive (at 1 and 4 wt%) in a polar oil (diester). Tribological tests were performed using a reciprocating configuration for 90 minutes at 30 and 70 N, 10 Hz, 4 mm stroke length, and at room temperature and 100 ºC. Wear volume and surface-IL interaction were determined by confocal microscopy, SEM and XPS. The main findings were: neat ionic liquid showed the best tribological behavior; the IL-containing mixtures had similar behavior than the base oil at the lower load, meanwhile the mixture with 4 wt% of IL outperformed the antiwear behavior of the neat base oil at the higher load; surface-IL chemical interaction was found mainly at 100 ºC.
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