نتایج جستجو برای: extraction of pahs by sfe
تعداد نتایج: 21627770 فیلتر نتایج به سال:
The gas-like mass transfer properties and liquid-like solvation characteristics of supercritical fluid make it a promising medium in performing extractory and chromatographic separations, i.e., supercritical fluid extraction (SFE) and supercritical fluid chromatography (SFC), respectively. The tunable solvation properties of supercritical carbon dioxide not only improve SFE's efficiency and spe...
Polycyclic aromatic hydrocarbons (PAHs) are classified as persistent and carcinogenic organic pollutants. PAHs contamination has been reported in water. Many of relevant regulatory bodies such as EU and EPA have regulated the limit levels for PAHs in drinking water. In this study, 13 priority polycyclic aromatic hydrocarbons (PAHs) were determined in tap water samples of Tehran and water for in...
Cereal Chem. 81(6):693–698 Environmental concerns, the disposal cost of hazardous waste, and the time required for extraction in current methods encouraged us to develop an alternate method for analysis of wheat flour lipids. Supercritical fluid extraction (SFE) with carbon dioxide has provided that medium and the method is fully automatic. Crude fats or nonstarch free lipids (FL) were extracte...
the present paper investigates how far ideologies can be tease out in discourse by examining the employed schemata by two ideologically opposed news media, the bbc and press tv, to report syria crisis during a period of nine months in 2011. by assuming that news is not a valuefree construction of facts and drawing on micro structural approach of schema theory, for the first time in discours...
investigation the archetype of mother can help the reader to understand poes works, especially his fiction, better, if not fully. motivated by internal and external drives to get into the universe in its manifold form poe was impelled to art and, from various modes of art, to symbolism. how much was poe successful to produce works of art has been a matter of dispute among critics. however, ther...
Calophyllum brasiliense is a rich source of bioactive coumarins, xanthones and biflavonoids. The aim of the study was to compare the phenol contents and the antioxidant activity of C. brasiliense extracts obtained by conventional and supercritical fluid extraction (SFE) methods, as well as the quantification of crude extracts and (-)-mammea A/BB yields. Dichloromethane and hexane were used as s...
The relationship between the rate of supercritical fluid extraction of polycyclic aromatic hydrocarbons (PAHs) from coal-tar pitch and some topological invariants are examined. The aim is to explain the appearance of a minimum value on the activation energy/molar mass curve of the PAHs. Rate constants are approximated using spectral moment expansion. It is shown that the size of the PAHs determ...
influence of soil organic matter (som) on the adsorption, desorption and transport of polycyclic aromatic hydrocarbons (pahs) has already been given full investigation in soils. in this paper, confocal laser scanning microscope (clsm) was used to elucidate aqueous leaching of pahs in different types of soil with soil columns, which enhanced understanding on transport of pahs appreciably. four ...
the purpose of the present study was to investigate the relationship between fear of negative evaluation (fne) and communication strategies (css) among iranian efl learners. it was aimed to examine the differences in the use of communication strategies between speakers with high or low degree of fear of negative evaluation. the current study was a case study consisting of 10 english learners at...
concentration levels of 16 polycyclic aromatic hydrocarbons (pahs) consisting of naphthalene, acenaphthylene, acenaphthene, fluorine, phenantherene, anthracene, fluor?anthene, pyrene, benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)p?yrene, dibenzo(a,h)ant?hracene, indeno(1,2,3-cd) pyrene and benzo(g,h,i)perylene were measured in water and sediment samples coll...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید