Concentration of some Polycyclic Aromatic Hydrocarbons in soil samples of Kirkuk province, Iraq

In order to evaluate the quantity of twelve PAHs (Naphthalene, Tetraphan and Acenaphthylene Fluorene, Phenanthrene, Anthracene, Pyrene, Benzo [a] Anthracene, Ovalene, Chrysene, Benzo [a] fluoranthene and DiBenzo [ah] Anthracene) in the soil samples from Kirkuk province, seven sites (Ras El-Gesr, Benja Ali, Wahed Hozeran, North Oil Company (NOC), Lillan, Kubri and Chimen) were selected using Gas Chromatography (GC) during the autumn 2017 and winter 2018. The results showed that the highest concentration of individual hydrocarbons during the autumn season was for the Acenaphthylene compound in the NOC site 131.19 μg/kg, and for Naphthalene compound, was 100.543μg/kg. The NOC recorded the highest concentration of total hydrocarbons 891.65 μg/kg. For the winter season, the highest concentration of polycyclic aromatic hydrocarbons was recorded for the Fluorene compound at the NOC site 79.19 μg/kg. Fluorene and Naphthalene compounds achieved the highest averages for the season (43.24 and 42.984 μg/kg) respectively, and recorded the location of the NOC, the highest summation of total hydrocarbons amounted to 609.77 μg/kg.

LAMINAR BURNING VELOCITY OF INDIVIDUAL HYDROCARBONS AND KEROSENE SURROGATES

Surrogate fuel blends are often used in laboratory experiments and in combustion modeling to reproduce important characteristics of real transportation fuels. Fuel surrogates usually consist of a few class-representative hydrocarbons such as normal and branched alkanes, aromatics, and cycloalkanes. The complexity of a particular blend depends on the number of combustion properties (targets) taken into account. Most often, binary [1] and ternary blends were suggested as kerosene surrogates; yet, in some cases, a single species, n-decane [2], was used to make comparison with kerosene combustion characteristics such as burning velocity and, for example, to determine the emission of polycyclic aromatic hydrocarbons, complex 4-6 component surrogates.

Ant cuticular hydrocarbons are heritable and associated with variation in colony productivity

In social insects, cuticular hydrocarbons function in nest-mate recognition and also provide a waxy barrier against desiccation, but basic evolutionary features, including the heritability of hydrocarbon profiles and how they are shaped by natural selection are largely unknown. We used a new pharaoh ant ( Monomorium pharaonis ) laboratory mapping population to estimate the heritability of individual cuticular hydrocarbons, genetic correlations between hydrocarbons, and fitness consequences of phenotypic variation in the hydrocarbons. Individual hydrocarbons had low to moderate estimated heritability, indicating that some compounds provide more information about genetic relatedness and can also better respond to natural selection. Strong genetic correlations between compounds are likely to constrain independent evolutionary trajectories, which is expected, given that many hydrocarbons share biosynthetic pathways. Variation in cuticular hydrocarbons was associated with variation in colony productivity, with some hydrocarbons experiencing strong directional selection. Altogether, this study builds on our knowledge of the genetic architecture of the social insect hydrocarbon profile and indicates that hydrocarbon variation is shaped by natural selection.

Ant cuticular hydrocarbons are heritable and associated with variation in colony productivity

In social insects, cuticular hydrocarbons function in nestmate recognition and also provide a waxy barrier against desiccation, but basic evolutionary genetic features, including the heritability of hydrocarbon profiles and how they are shaped by natural selection are largely unknown. We used a new pharaoh ant (Monomorium pharaonis) laboratory mapping population to estimate the heritability of individual cuticular hydrocarbons, genetic correlations between hydrocarbons, and fitness consequences of phenotypic variation in the hydrocarbons. Individual hydrocarbons had low to moderate estimated heritability, indicating that some compounds provide more information about genetic relatedness and can also better respond to natural selection. Strong genetic correlations between compounds are likely to constrain independent evolutionary trajectories, which is expected given that many hydrocarbons share biosynthetic pathways. Variation in cuticular hydrocarbons was associated with variation in colony productivity, with some hydrocarbons experiencing strong directional selection. Altogether, our study builds on our knowledge of the genetic architecture of the social insect hydrocarbon profile and demonstrates that hydrocarbon variation is shaped by natural selection.

ADAPTATION OF THE METHOD OF CHROMATOGRAPHIC ANALYSIS OF GASOLINE TO ACHIEVE PURPOSES OF GEOCHEMICAL PROSPECTING FOR OIL AND GAS

Geochemical survey is commonly applied during geological exploration to predict petroleum potential of large areas and to estimate the content of traps identified by the results of seismic survey. C1-C6 hydrocarbon concentrations in samples of surface and subsurface air, soil, snow, water, etc. are used as predictive indicators. At the exploration stage the capabilities of geochemical methods can be significantly expanded by comparing the content of gasoline hydrocarbons in samples of formation fluids and in samples of near-surface sediments. The method of chromatographic analysis of gasolines Chromatec Gazolin has been adapted for sample analysis. The taken measures to increase the sensitivity allowed us to register individual hydrocarbons C1-C10 in concentrations up to 0,01 ppb, which is obviously lower than their background content in the oil prospect areas. The revealed patterns are used in the geological interpretation of geochemical distributions based on theoretical ideas about the subvertical migration of hydrocarbons from the reservoir to the surface.

FEATURES OF ISOTOPIC COMPOSITION OF CARBON AND SULFUR IN OIL-AND-GAS AND OTHER NATURAL SYSTEMS

The comparison of isotope composition of carbon and sulfur in various oils, oil fractions, individual hydrocarbons including methane, organic substance, and other natural systems has shown that oil can be formed due to transformations of the deep abiogenic fluids containing light hydrocarbons and sulfur.