Determination of fatty acid profiles of total, neutral, and polar lipids in different tissues of Vimba vimba (L., 1758) from Eğirdir Lake (Isparta, Turkey)

Abstract

Clean and efficient engine research and development work needs reliable models where autoignition for automotive reference fuels are described well. These models have to include chemistry containing numbers of reactions. The predictive capability depends more on the quality of reactions describing the chemical phenomena in the mechanism than on the number of the reactions. In this work three chemical mechanisms containing 1034, 74 and 63 species for primary reference fuels (PRFs) are compared with respect to the prediction of autoignition at conditions relevant for HCCI Engines and knock in SI Engines. After validation to experimental data for iso-octane, n-heptane and mixtures of the two fuels obtained from shock tube experiments over the temperature range 700 < T < 1200K at pressures 15-60 bars, a single zone engine model is used to simulate the point of autoignition and compared against experimental results obtained from an HCCI engine in KTH labs in Stockholm. The work shows the performance of the chemical mechanisms in prediction of autoignition delay time in HCCI engines.

Determination of Fatty Acid Profiles and Esterase Activities in the Gills and Gonads of Vimba vimba (L., 1758)

“…Gills Gonads C18:1n-9 was one of the primary fatty acids in fish species, especially in different tissues of V. vimba, [17]. The data obtained are in good agreement with previous published articles.…”

“…The highest and lowest UFA levels were determined in TLs of the gills (68.25 %) and gonads (60.14 %), respectively. In the muscle, liver, and intestine of V. vimba, C18:1 n-9 had the highest percentages of all the fatty acids and MUFAs were the main group due to this acid [17]. In this context, patterns of groups of fatty acids in the gills and gonads confirm this data.…”

“…In the present study, the gills had C22:6n-3 levels of 5.01 % in the TLs, 4.32 % in the NLs, and 4.31 % in the PLs, while the gonads had the highest percentage in the PLs at 2.90 %. Görgün et al [17] determined similar levels of C22:6n-3 in the muscle, liver, and intestine of V. vimba. They found C22:6n-3 percentages for TLs between 2.27 % in the intestine and 4.55 % in muscle, while in the NLs these values were determined to be 1.56 % in the liver and 3.50 % in muscle.…”

“…Fatty acids were methylated using a standard BF 3 -CH 3 OH method [20]. Lipid class purification in three replicates, saponification of samples, and gas chromatographic analyses of the FAMEs in the present study were the same as in a previous study on V. vimba published by Görgün et al [17], from which more detailed information can be obtained.…”

“…Seasonal variations in the muscle fatty acid composition of Vimba vimba were noted by Kalyoncu et al [16]. Liver, muscle, and intestine of Vimba vimba have also been investigated for the fatty acid composition of TLs, NLs, and PLs [17]. In fish, liver and muscle tissue have especially been investigated due to their roles in the metabolic process and their nutritional importance.…”