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[en] Photochemical transformation of petroleum hydrocarbons, n-alkanes, polycyclic and monoaromatic hydrocarbons under the influence of UV radiation of a mercury lamp have been studied by chromatography and UV spectroscopy. It has been established the kinetic regularities of the formation of abovementioned hydrocarbons within the irradiation up to 90 min at 2x10''15 photon/s UV-light intensity in various concentrations of crude oil up to 5000 ppm on the water surface. A mechanism of possible photochemical processes is discussed. Photochemical degradation of crude oil in an aqueous medium is one of the physicochemical processes, taking place under the influence of UV part of solar radiation and constitutes about 10% of oil conversion in case of oil film on the surface of seawater. Degradation of crude oil occurs under the influence of various physical factors - including the effects of temperature, wind speed, chemical composition and the biological state of seawater. Simultaneous influence of the abovementioned factors makes it very difficult to clarify the mechanism of degradation process of crude oil. Taking into account the abovementioned features of photochemical degradation, it is expedient to study model system consisting of crude oil and distilled water. This work is devoted to the study of photochemical processes under the influence of UV radiation in model system of crude oil-water
[en] Full text: The petroleum and accompanying layer water are contained in the structure many chemical elements,including natural radionuclides and placed in the interior of the Earth.There is in process production of petroleum ,polycyclic and aromatic hydrocarbons,salts of heavy metals,including soluble and not of soluble connections of stable and radioactive isotopes etc. on a surface.The radioactive reservoir dry up in places of the tax of petroleum and occurs concentrating of radioactive substances on a surface of the Earth with following adverse for the man and environment by consequences. As a result of result of process of accumulation on oil-extracting sites the natural radiating background changes.Gross weight of the polluted ground makes of 155 thousand tons on Absheron peninsula on precomputation.Similar negative influence processes of dissolution of minerals, precipitation and accumulation radionuclides.We chose object of research the second site of the first field /surahany region which is a southeast of absheron peninsula.Samples layer waters were taken from seven drill holes,which have different depths and accordingly different mineral structure and also from lake,which was formed as a result of functioning of drill holes.The result of functioning of drill holes.
[en] Data on the chemistry of D3-trishomocubane and its derivatives are described systematically. Different versions of construction of D3-trishomocubane cage are presented. The methods of synthesis of mono-, di- and poly-substituted D3-trishomocubanes and their heteroanalogues as well as their properties are considered. Data on biological activity of homocubanes are generalized.
[en] This paper summarizes a work conducted on the isolation of microorganisms of contaminated sediments with a high percentage of hydrocarbons aromatic polynuclear (Polynuclear Aromatic Hydrocarbons, PAHS) The methodology involved two selection systems called fast route and slow route in which exposure periods and contaminant concentrations are the key determinants. The microorganisms isolated through the slow route system are more likely to be successful in degrading high molecular weight PAH'S. The six strains obtained through the fast route system were able to grow on low molecular weight PAH's showing preference towards the first four compounds of the sixteen demanded by the EPA (Environmental Protection Agency)
[en] Accumulating evidence suggests that abnormal inflammation plays a critical role in the pathogenesis of pulmonary arterial hypertension (PAH). CD8+CD25+Foxp3+ T cell is a novel cell subtype, and its role in PAH is not yet investigated. Here, we observed that PAH patients presented a significant upregulation of CD8+CD25+Foxp3+ T cells and a downregulation of CD4+CD25+Foxp3+ T cells compared to healthy controls. Regardless, the total number of CD25+Foxp3+ T cells in PAH patients was still smaller than that in healthy controls. Compared to CD8+CD25- T cells, CD8+CD25+ T cells presented higher Foxp3 expression, lower interferon (IFN)-γ expression and higher transforming growth factor (TGF)-β expression, in both healthy and PAH individuals. The CD8+CD25+ T cells in PAH patients also demonstrated regulatory function by suppressing the proliferation of CD4+CD25- and CD8+CD25- effector T cells, albeit at lower efficiency than CD4+CD25+ T cells from PAH patients and healthy volunteers. CD8+CD25+ T cells from PAH responded to interleukin (IL)−2 supplement by expansion and upregulating Foxp3 expression. In PAH patients, IL-2-treated CD8+CD25+ T cells were more potent at inhibiting CD4+CD25- effector T cell proliferation than IL-2-untreated CD8+CD25+ T cells. Together, we found an upregulation of CD8+CD25+Foxp3+ T cells in PAH patients, and this T cell population presented suppressive activity that could be enhanced by IL-2 treatment.
[en] We report the first mid-infrared detection of highly disturbed ionized gas in the ultraluminous infrared galaxy (ULIRG) IRAS F00183-7111. The gas, traced by the 12.81 μm [Ne II] and 15.56 μm [Ne III] lines, spans a velocity range of-3500 to +3000 km s-1 with respect to systemic velocity. Optical and near-infrared spectroscopic studies show no evidence for similarly high velocity gas components in forbidden lines at shorter wavelengths. We interpret this as the result of strong extinction (AV = 10-50) on the high-velocity gas, which identifies the base of the outflow traced in 5007 A [O III] as a plausible origin. Unusual excitation conditions are implied by a comparison of the mid-infrared low-excitation neon line emission and the polycyclic aromatic hydrocarbon (PAH) emission for a sample of 56 ULIRGs. For IRAS F00183-7111, the neon/PAH ratio is 8 times higher than the average ratio. Similar mid-infrared kinematic and excitation characteristics are found for only two other ULIRGs in our sample: IRAS 12127-1412NE and IRAS 13451+1232. Both sources have an elevated neon/PAH ratio and exhibit pronounced blue wings in their 15.56 μm [Ne III] line profiles. IRAS 13451+1232 even shows a strongly blueshifted and broad 14.32 μm [Ne V] line. While for IRAS 13451+1232 the observed [Ne III]/[Ne II] and [Ne V]/[Ne II] line ratios indicate exposure of the blueshifted gas to direct radiation from the AGN, for IRAS F00183-7111 and IRAS 12127-1412NE the neon line ratios are consistent with an origin in fast shocks in a high-density environment, and with an evolutionary scenario in which strongly blueshifted [Ne II] and [Ne III] emission trace the (partial) disruption of the obscuring medium around a buried AGN. The detection of strongly blueshifted [Ne V] emission in IRAS 13451+1232 would then indicate this process to be much further advanced in this ULIRG than in IRAS F00183-7111 and IRAS 12127-1412NE, where this line is undetected.
[en] Eight types of agricultural and forest fuels including 4 cereal crop residues and 4 wood fuels were burned in a combustion wind tunnel to simulate the open burning of biomass. Concentrations for 19 PAH species in particulate matter were found to range between 120 and 4000 mg kg(-1), representing between 1 and 70% of total PAH emission. Weakly flaming spreading fires in the cereals were observed to produce higher levels of heavier PAH than more robust fires, with greater partitioning of PAH to the particle phase. Individual species concentrations appeared well correlated within groups based primarily on molecular weight, but no single species was observed to correlate with all others to serve as an indicator of PAH emission strength. Equilibrium gas-particle partitioning did not appear to be achieved within the 3-5 s residence time prior to sampling for sampling temperatures between 32 and 87 degrees C, and in particular for the heavier species emitted from wood fuel pile fires with higher stack gas temperatures and shorter residence times. Total PAH emission, particle-phase concentrations, and fraction of PAH on particles were more strongly influenced by burning conditions than by fuel type. (UK)
[en] The feasibility of degrading 16 USEPA priority polycyclic aromatic (PAH) hydrocarbons (PAHs) with heat and Fe(II)-EDTA catalyzed persulfate oxidation was investigated in the laboratory. The experiments were conducted to determine the effects of temperature (i.e. 20 deg. C, 30 deg. C and 40 deg. C) and iron-chelate levels (i.e., 250 mg/L-, 375 mg/L- and 500 mg/L-Fe(II)) on the degradation of dissolved PAHs in aqueous systems, using a series of amber glass jars as the reactors that were placed on a shaker inside an incubator for temperature control. Each experiment was run in duplicate and had two controls (i.e., no persulfate in systems). Samples were collected after a reaction period of 144 hrs and measured for PAHs, pH and sodium persulfate levels. The extent of degradation of PAHs was determined by comparing the data for samples with the controls.The experimental results showed that persulfate oxidation under each of the tested conditions effectively degraded the 16 target PAHs. All of the targeted PAHs were degraded to below the instrument detection limits (∼4 μ/L) from a range of initial concentration (i.e., 5 μ/L for benzo(a)pyrene to 57 μ/L for Phenanthrene) within 144 hrs with 5 g/L of sodium persulfate at 20 deg. C, 30 deg. C and 40 deg. C. The data indicated that the persulfate oxidation was effective in degrading the PAHs and that external heat and iron catalysts might not be needed for the degradation of PAHs.The Fe(II)-EDTA catalyzed persulfate also effectively degraded PAHs in the study. In addition, the data on the variation of persulfate concentrations during the experiments indicated that Fe(II)-EDTA accelerated the consumption of persulfate ions.The obtained degradation data cannot be used to evaluate the influence of temperature and Fe(II) levels on the PAH degradation because the PAHs under each of the tested conditions were degraded to below the instrument detection limit within the first sampling point. However, these experiments have demonstrated the feasibility of degrading PAHs in aqueous systems with persulfate oxidation. Additional tests are being conducted to evaluate the effectiveness of treating PAHs in soils and obtaining the rate of degradation of PAHs with persulfate oxidation.Two sets of laboratory experiments were conducted to evaluate the ability of sodium persulfate in oxidizing real world PAH-contaminated soils collected from a Superfund site in Connecticut. The first set of soil sample were treated only with persulfate and to the second batch, mixture of persulfate and Fe(II)-EDTA solutions were added. The results of the second test showed that within 24 hours, 75% to 100% of the initial concentrations of seven PAH compounds detected in the soil samples were degraded by sodium persulfate mixed with FE(II)-EDTA
[en] In this investigation, primary, secondary, and tertiary amines are evaluated for their efficiency and selectivity as fluorescence quenchers for polycyclic aromatic hydrocarbons (PAHs) and nitrogen-containing polycyclic aromatic hydrocarbons (N-PAHs). In general, the quenching efficiency tends to increase from primary to tertiary amine due to a greater number of alkyl groups that increase the electron-donating ability. However, the selectivity decreases from primary to tertiary amine. The effect of low concentrations of water is also examined. Because water can form hydrogen bonds with amines, the nonbonding electron pair is not available for interaction with the fluorophore, thus the quenching constant is decreased. These aliphatic amines are then applied to PAHs and N-PAHs and some interesting trends are observed. Whereas amino-PAHs remain virtually unquenched by different amines, aza-PAHs are all quenched well. The selectivity between aza-PAHs and amino-PAHs is as high as several hundred. This trend provides an easy and effective method to discriminate between these classes of N-PAHs. Moreover, the alternant aza-PAHs are quenched more than their corresponding alternant PAHs