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1.
Fakhari Amir Hossein Shafaghat Rouzbeh Jahanian Omid Ezoji Hossein Motallebi Hasankola Seyed Sadegh 《Journal of Thermal Analysis and Calorimetry》2020,139(4):2455-2464
Journal of Thermal Analysis and Calorimetry - Due to global concerns about the emissions, limited hydrocarbon fuel resources and high fuel prices, a lot of researches have been done to improve the... 相似文献
2.
Shafaghat A 《Natural product communications》2011,6(11):1739-1742
The hexane extracts of flower, leaf, stem, and seed of Hypericum scabrum, which were collected from northwestern Iran, were obtained by extraction in a Soxhlet apparatus. The fatty acids were converted to methyl esters and determined by gas chromatography/flame ionization detector (GC/FID) and gas chromatography/mass spectrometry (GC/MS) systems. The hexane extract from the flower, leaf, stem, and seed contained 39.1%, 43.2%, 29.0%, and 37.6% of omega-3 fatty acids, respectively. The other main components of the flower extract were tetracosane (12.2%) and palmitic acid (9.3%), and that of the leaf extract was palmitic acid (7.4%). The stem and seed extracts contained bis(2-ethylhexyl)phthalate (18.7% and 35.7%), nonacosane (11.7% and 3.9%) and linoleic acid (6.5% and 6.9%) as major components. The hexane extracts of different parts from H. scabrum represent an important source of omega-3 fatty acids in several Hypericum species. The antioxidant activity of all hexane extracts was evaluated by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method. The results indicate that hexane extracts from different parts of H. scabrum possess considerable antioxidant activity. The highest radical scavenging activity was detected in seed, which had an IC50 = 165 microg/mL. The antimicrobial activity of the extracts of those samples were determined against seven Gram-positive and Gram-negative bacteria (Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureus, S. epidermidis, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae), as well as three fungi (Candida albicans, Saccharomyces cerevisiae, and Aspergillus niger). The bioassay showed that the oil exhibited moderate antimicrobial activity. This study reveals that the all parts of this plant are attractive sources of fatty acid components, especially the essential ones, as well as of effective natural antioxidants. 相似文献
3.
Ezoji Hosein Shafaghat Rouzbeh Jahanian Omid 《Journal of Thermal Analysis and Calorimetry》2019,135(3):1775-1785
Journal of Thermal Analysis and Calorimetry - Homogeneous charge compression ignition (HCCI) combustion phasing control is one of the most difficult challenges of operating this new concept of... 相似文献
4.
The chemical constituents from the flower, leaf and stem of Helichrysum armenium DC. (Asteraceae) growing in Iran were obtained by hydrodistillation and analyzed by GC and GC/MS. The oil of flower was characterized by higher amount of limonene (21.2%), alpha-cadinol (18.2%), borneol (11.9%), delta-cadinene (9.0%), bornyl acetate (8.0%) and alpha-humulene (7.3%). Twenty one constituents representing 96.2% of the chromatographical leaf oil were identified of which limonene (29.2%), alpha-pinene (14.4%), caryophyllene oxide (6.5%), alpha-gurjunene (6.3%), bornyl acetate (5.5%) and torreyol (5.2%) were the major components. The main components of the stem oil were limonene (23.6%), alpha-pinene (13.4%), spathulenol (6.4%), alpha-gurjunene (6.3%), caryophyllene oxide (5.3%), bornyl acetate (5.2%), beta-cubebene (4.8%) and delta-cadinene (4.3%). The composition of the oils is different, although the most abundant components are identical in leaf oil (96.2%). The antimicrobial effect of flower, leaf and stem essential oils from Helichrysum armenium was studied according to the agar diffusion cup method. The essential oils had a moderate effect on the Gram-positive and Gram-negative bacteria and had a substantial fungicidal effect on the fungi under study. 相似文献
5.
R. Shafaghat S. M. Hosseinalipour S. M. E. Derakhshani 《Archive of Applied Mechanics (Ingenieur Archiv)》2010,80(7):771-784
Artificial neural networks (ANNs) are used as a new approach for the determination of the relations between drag coefficient
and Cavitation Number with cavity geometry in supercavitating flows which have been most widely used in the hydrodynamics
researches. Also the result of the ANNs as a cost function potentially will be used in an optimization algorithm. Instead
of complex differential equations and limited experimental data, faster and simpler solutions were obtained using equations
derived from the ANN model. For training of the ANN the numerical results are used that are obtained from a boundary element
method (BEM). At this problem, a two-dimensional supercavitation potential inviscid flow pasts a symmetric two-dimensional
cavitator, which is placed perpendicular to the flow in a channel of infinite width and immediately a cavity is formed behind
the cavitator. It was found that the coefficient of multiple determination (R
2-value) between the actual and ANN predicted data is equal to about 0.9998 for the drag coefficient and Cavitation number.
As seen from the obtained results, the calculated cavity geometry for all drag coefficients and Cavitation Numbers are obviously
within acceptable limits. 相似文献
6.
Motallebi Hasankola Seyed Sadegh Shafaghat Rouzbeh Jahanian Omid Nikzadfar Kamyar 《Journal of Thermal Analysis and Calorimetry》2020,139(4):2509-2516
Journal of Thermal Analysis and Calorimetry - Nowadays, due to the environmental problems caused by pollution and high fossil fuels prices, the study on the internal combustion engines have... 相似文献
7.
Shafaghat A 《Natural product communications》2011,6(9):1351-1352
Essential oils obtained from flowers, leaves and stems of Origanum vulgare L. ssp. viride (Boiss.) Hayek., growing wild in Ardabil Province (north-west Iran), were analyzed by GC and GC/MS. beta-Caryophyllene was the major constituent in all three oils (48.1%, 50.1% and 60.2%, respectively). Of the 19 components detected in the flower oil, comprising 96.3% of the total, the major components were 1,8-cineole (11.6%), alpha-pinene (6.9%), and gamma-cadinene (4.8%). 1-Octen-3-ol (23.8%), and 1,8-cineole (8.5%) predominated in the leafoil. In the stem oil, other main constituents were bicyclogermacrene (9.8%), 1,8-cineole (6.4%), borneol (5.1%), and pinocarvone (4.4%). The essential oils were evaluated for their antibacterial activity against 10 selected microorganisms. The data obtained contribute to the future use of certain essential oils as natural preservatives for food products, due to their safety and positive effect on shelf life. 相似文献
8.
9.
Ghaedi Ashkan Shafaghat Rouzbeh Jahanian Omid Motallebi Hasankola Seyed Sadegh 《Journal of Thermal Analysis and Calorimetry》2020,139(4):2475-2485
Journal of Thermal Analysis and Calorimetry - In this investigation, the mechanical injector (four orifices in nozzle) in a compression ignition single-cylinder engine (Daedong with the maximum... 相似文献
10.
Asbaghian S Shafaghat A Zarea K Kasimov F Salimi F 《Natural product communications》2011,6(1):137-140
A comparison of the chemical composition, and antioxidant and antibacterial activities of the essential oils obtained from the aerial parts of Thymus caucasicus, T. kotschyanus, and T vulgaris was carried out. The oils, obtained by hydrodistillation, were analyzed by GC and GC/MS. Twenty, 29 and 22 compounds representing 94.8%, 96.6% and 98.2% of the essential oils of T. caucasicus, T. kotschyanus and T. vulgaris, respectively, have been identified. The oil of T. caucasicus was characterized by 1,8-cineol (21.5%), thymol (12.6%), beta-fenchyl alcohol (8.7%), nerolidol (7.8%), terpinolene (7.2%), alpha-pinene (7.0%) and myrcene (6.8%). In the oil of T. kotschyanus, carvacrol (24.4%), beta-caryophyllene (14.5%), gamma-terpinene (12.4%), alpha-phellandrene (10.8%), p-cymene (9.8%) and thymol (6.8%) were the predominant compounds, whereas the main components of T. vulgaris oil were thymol (43.8%), p-cymene (15.2%), germacrene-D (11.7%), terpinolene (3.4%), carvacrol (3.2%), beta-caryophyllene (2.8%) and alpha-thujene (2.2%). In all three plants oil, hydrocarbon monoterpenes predominated over sesquiterpenes. Antioxidant activities were assessed by determining IC50 values in the DPPH radical scavenging assay. Antibacterial activity was determined by measuring minimum inhibitory concentration (MIC) using the broth dilution method. The essential oils of T. caucasicus, T. kotschyanus and T. vulgaris showed free radical scavenging and antibacterial activity. 相似文献