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11.
Masumeh Sadat Shahidi Rizi Abbas Akhavan Sepahi Keivan Beheshti Maal Farzaneh Hosseini 《Petroleum Science and Technology》2017,35(9):831-838
Oil sludge is obtained from the contaminated site of Bahregan area in the Persian Gulf in Iran. Chemotaxis was used for the isolation of alkane-degrading bacteria from oil sludge and the alk genes were determined with specific primers. bac1 identified in Thalassospira was selected as a powerful strain for biodegradation of oil sludge. Biodegradation of oil sludge by bac1 in the presence of nanoparticles was investigated by GC-MS analysis. Synergistic effect of Fe2O3 and Fe3O4 nanoparticles on bacteria increases the biodegradation of oil sludge and produces cyclosiloxane compound which is used in the field of medicine; however, the Thalassospira reduced its toxicity in the environment. 相似文献
12.
Solvent and Extraction Conditions Control the Assayable Phenolic Content and Antioxidant Activities of Seeds of Black Beans,Canola and Millet
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Anoma Chandrasekara Omar Abdel Rasek Jenny Ann John Neel Chandrasekara Fereidoon Shahidi 《Journal of the American Oil Chemists' Society》2016,93(2):275-283
The effects of extraction solvent and conditions on the total phenolic content (TPC) and antioxidant activity of black beans, canola and foxtail millet were investigated. The antioxidant activity was assayed using 2,2‐diphenyl‐1‐picrylhydrazyl radical scavenging activity (DRSA) and oxygen radical absorbance capacity (ORAC). Four solvent systems, namely 70 % acetone, 80 % ethanol, 80 % methanol and a mixture of acetone/methanol/water (7:7:6, v/v/v) were used. The extraction methods adopted in this study included refluxing, homogenization, cold extraction and sonication. The TPC as measured using the Folin Ciocalteu's method were 12.35–28.39, 2.43–16.73, and 1.78–5.06 µmol catechin equivalents/g dry matter (dm) for canola, black beans and foxtail millet, respectively. Aqueous acetone afforded the highest TPC for black beans and canola. Within the same solvent system used, the TPC, DRSA and ORAC obtained from different extraction techniques differed for black beans, canola and foxtail millet. The results demonstrated that the solvent system as well as method influenced the extraction of phenolic compounds and their antioxidant activities, depending on the type of matrix in which phenolics were embedded. 相似文献
13.
S.?P.?J.?Namal Senanayake Fereidoon?ShahidiEmail author 《Journal of the American Oil Chemists' Society》2002,79(10):1003-1013
This study utilized γ-linolenic acid (18∶3n−6; GLA)-rich borage oil (BO) and evening primrose oil (EPO) for the synthesis
of structured lipids (SL) and compared the oxidative stability of the products with those of unmodified BO and EPO as controls.
Immobilized Novozym 435 lipase from Candida antarctica was used as the biocatalyst for SL production. BO or EPO eas enzymatically modified with docosahexaenoic acid (22∶6n−3; DHA),
as the acyl donor, to produce SI. The SI were characterized and their oxidative stabilities evaluated. Among the oils examined,
SL gave rise to higher quantities (P≤0.05) of conjugated dienes, TBARS, and headspace volatiles as compared to their unmodified counterparts. Results indicated
that modified oils were less stable than their unmodified counterparts. The double bond index (DBI) and methylene bridge index
(MBI) of oils decreased (P<0.05) during oxidation in the more unsaturated oils. An attempt was made to correlate various parameters of oxidation with
DBI and MBI of oils; correlation coefficients (−r) were within the range of 0.574–0.973. This suggests that indicators such as DBI and MBI can reflect oxidative stability
of oils. 相似文献
14.
H. A. Abou-Gharbia F. Shahidi A. Adel Y. Shehata M. M. Youssef 《Journal of the American Oil Chemists' Society》1997,74(3):215-221
Oxidative stability of oils extracted from intact and dehulled sesame seeds was determined by monitoring changes in fatty
acid composition, iodine value (IV), peroxide value (PV), conjugated diene (CD), para-anisidine value (p-AV), and 2-thiobarbituric acid (TBA) value and by nuclear magnetic resonance spectroscopy after storage under Schaal oven
conditions at 65°C for up to 35 d. The oils from coated seeds were more stable, as reflected in PV, CD, p-AV and TBA values, than those extracted from dehulled seeds after roasting at 200°C, steaming at 100°C, roasting at 200°C
plus steaming, or microwaving at 2450 MHz, except for TBA values of oil from microwaved seeds. After 35 d of storage at 65°C,
the CD, p-AV, and TBA values of extracted oil from dehulled microwaved seeds were 17.72, 10.20, and 1.22, respectively, while those
of their coated counterparts were significantly (P<0.05) different at 14.20, 16.47, and 1.26, respectively. Few significant changes were evident in the fatty acid composition
of oil obtained from either coated and dehulled seeds subjected to different treatments. Nuclear magnetic resonance analyses
found that Rao (aliphatic to olefinic protons) and Rad (aliphatic to diallylmethylene protons) ratios increased steadily over the entire storage period, which indicated progressive
oxidation of unsaturated fatty acids. 相似文献
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The small deflection equation for isotropic and non-homogenous thin annular sector subject to transverse loading is derived in polar coordinate. The Poisson’s ratio of the plate is assumed to be constant, but the Young’s modulus varies continuously through the radial direction according to the power-law function. A closed-form solution with fast convergence rate is obtained using the extended Kantorovich method and the classical theory of thin plates (Kirchhoff theory). The validity and accuracy of results are examined by resolving the problem using commercial finite element code ABAQUS and a good agreement between them is obtained for either deflection or stress resultants. 相似文献
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The aim of this study is to manufacture quaternary polymer concretes (PCs) and optimize the weight percentages of the epoxy resin, ultrafine fly ash, silica sand and basalt aggregates. For this, we first manufactured binary PCs of epoxy/basalt, epoxy/silica sand and epoxy/fly ash and then studied the mechanical properties such as compressive, flexural and splitting tensile strength. The mixture design method was used as an approach for design of experiment to reduce the number of tests and optimize the mechanical strength of the PC. The best weight percentages of the PC components were 25 (epoxy), 5 (fly ash), 52.5 (silica sand) and 17.5 (basalt). The compressive, flexural and splitting tensile strength of the quaternary PC were equal to 94.1, 39.0 and 11.8, which were 3.76, 11.1 and 6.5 times higher than those of ordinary Portland cement, respectively. Finally, a scanning electron microscopy test was implemented to study the microstructure of the PC. 相似文献
20.
Fereidoon Moghadas Nejad Javad Tanzadeh Gholam Hossein Hamedi 《International Journal of Pavement Engineering》2016,17(4):353-362
Rutting is considered as one of the major damages in asphalt mixtures. In this study, different types of nanoparticles such as TiO2, Al2O3, Fe2O3 and ZnO in different percentages were added to the base asphalt binder in order to decrease the rutting potential of hot-mix asphalt (HMA). In the first step, asphalt binder tests for characteristics such as penetration grade, ductility, softening point and viscosity were performed on the asphalt binder modified by the nanoparticles. Then, after preparing HMA samples, the static creep test was done at two stress levels at a specific temperature. Results of this study showed that using the nanoparticles improved the behavioural properties of the asphalt binder and decreased rutting in asphalt mix samples. Furthermore, scanning electron microscope images taken from the asphalt binder samples modified by the nanoparticles demonstrated that these nanoparticles were properly distributed in the asphalt binder space and had a positive effect on the rutting performance of the asphalt mixes. 相似文献