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Previous multi-proxy records have revealed the advantages of well-preserved and long-scale geological archives from the lake sediments of Barkol Lake, which is located at northeast Xinjiang in northwest China. However, the exact organic matter (OM) sources in the sediments and their response to climatic variability still remain unclear in this area. In this study, we present an 8.8 kyr n-alkane record extracted from the sediments in Barkol Lake to explore the OM sources and the relationship between n-alkanes and climatic changes. The results indicate that the n-alkane composition was dominated by long-chain n-alkanes(C27–C31), implying a dominant origination of OM from the terrestrial higher plants and emergent aquatic plants. The n-alkane data further revealed that changes in OM sources were related to the surface erosion-transportation-deposition processes controlled by climatic changes. Lake level changes, which are also regulated by climate conditions, played an important role in impacting OM accumulation. Relatively wetter conditions would result in a rising lake level that favored more aquatic OM and less terrestrial OM input, and vice versa. The regional climate patterns have been generally dominated by alternations of cold-wet and warm-dry episodes over the past ~8.8 kyr. We preliminarily concluded the dynamic changes of OM input and the hydrological changes in Barkol Lake was mainly controlled by SSTs in the North Atlantic region and melting water supply modulated by Eurasian ice sheet. [ABSTRACT FROM AUTHOR]

Herein, we report a modular photocatalytic platform for the site‐selective pyridination of saturated hydrocarbon compounds employing organic photoredox catalysis to forge new carbon‐carbon bonds. The site‐selective C−H pyridination could couple benzylic/allylic C−H bonds with pyridylphosphonium salts, which installed directly and regioselectively from C−H heteroarenes through a radical‐radical cross coupling mechanism. This synthetic methodology could tolerate a variety of functional groups, complex heteroarenes, even late‐stage functionalization of pharmaceuticals selectively. [ABSTRACT FROM AUTHOR]

One year after an emergency spill of diesel fuel in Norilsk, hydrocarbon concentrations in bottom sediments of the Norilo-Pyasinskaya Water System decreased, but, on the average over the regions, they decreased in the surface layer in the same order as in 2020: Ambarnaya River mouth (835 µg/g, σ = 1788) > Bezymyannyi Creek—Daldykan River—Ambarnaya River (306 µg/g, σ = 273) > Pyasina River (23 µg/g, σ = 20) > Pyasino Lake (12 µg/g, σ = 8). The decrease in the concentrations was due to the degradation of low-molecular hydrocarbons. The concentration of polycyclic aromatic hydrocarbons in 2021 also varied within a narrower interval (0–1027 ng/g) than in 2020 (0–3865 ng/g). The oil origin of the hydrocarbons in the sediments of the Bezymyannyi Creek and the rivers of Daldykan and Ambarnaya is confirmed by their high content of alkylied naphthalene homologues. The accumulation of hydrocarbons in some horizons of the sedimentary stratum is due not only to the seepage of diesel fuel, but also to the input of organic matter from swampy areas and floodplain lakes, as well as to the burial of the surface layer by the flood of 2021. [ABSTRACT FROM AUTHOR]

The Fenton method to remediate oil-contaminated soils has long suffered from low utilization of ·OH, resulting in waste of costs during practical application. This study investigated the efficient utilization of ·OH in oxidation using three different soils contaminated with oil (S1, S2, and S3). The mechanisms of promoting oxidation of long-chain alkanes by self-produced surfactant-like substance at the solid-liquid interface were studied. These results (take S1 as an example) showed that the average ·OH utilization rate of oxidized long-chain alkanes (Ka) at the solid-liquid interface reached 88.34 (mg/kg∙(a.u.)), which was higher than the non-solid-liquid interface stage (I: 54.02 (mg/kg∙(a.u.)), II: 67.36 (mg/kg∙(a.u.))). Meanwhile, the average oxidation of long-chain alkanes could increase unit ·OH intensity added (Kb) in the solid-liquid interface (990.00 mg/kg), which was much higher than Kb of the non-solid-liquid interface stage (I: 228.34 mg/kg, II: −1.48 mg/kg). Furthermore, there was a significant correlation between the proportion of humic acid-like in soil organic matter and the oxidation of long-chain alkanes at the solid-liquid interface. Thus, the surfactant-like substance generated during oxidation promoted the oxidation of long-chain alkanes at the solid-liquid interface. Moreover, when the surfactant-like substance had a matching degree (φ) with the long-chain alkanes (S1 0.18, S2 0.15, and S3 0.25), the efficiency of the ·OH utilization reached the peak, and the direct oxidation of long-chain alkanes at the solid-liquid interface was finally achieved (S1: 1373.00 mg/kg, S2: 1473.18 mg/kg, and S3: 1034.37 mg/kg). The appropriate surfactant-like substance agents in the construction can reduce the dosing of H2O2 and the construction costs by improving the efficient utilization of ·OH. Study on the mechanism promoting oxidation of long-chain alkanes by self-produced surfactant-like substance at the solid-liquid interface. [ABSTRACT FROM AUTHOR]

Resting cell batch kinetic studies were performed to evaluate the alcohol-dependent cometabolic degradation of chlorinated aliphatic hydrocarbons (CAHs) and 1,4-dioxane (1,4-D) by Rhodococcus rhodochrous strain ATCC 21198. This strain grew on diverse alcohols, organic acids, esters, and other organic compounds. Only growth on 2-butanol resulted in labeling of monooxygenase enzymes and the ability to oxidize propylene, the cylic ether 1,4-D, and its close structural analog tetrahydrofuran. In single compound rate tests, 2-butanol-grown cells exhibited faster degradation rates for less chlorinated compounds. The rates of degradation are ranked as follows from high to low: vinyl chloride > cis-dichloroethene (cis-DCE) >1,1-dichoroethane >1,1-dichoroethene (1,1-DCE) >1,4-D > 1,1,1-trichoroethane (1,1,1-TCA) >1,1,2-trichoroethene. All rates were significantly lower than isobutane-grown cells. 2-Butanol-grown cells exhibited a lag period before cometabolic degradation of most CAHs, including cis-DCE; however, production of cis-1,2-dichloro-1,2-epoxyethane (cis-DCE epoxide) was detected with no lag. Cells grown on 1-butanol, 2-butanol, or 2-ethyl-1-butanol also cometabolically degraded 1,4-D and various CAHs. However, compared to cells grown on 1-butanol or 2-ethyl-1-butanol, cells grown on 2-butanol had a larger transformation capacity and faster degradation rates and were able to fully degrade (>99% removal) a mixture of 1,4-D, cis-DCE, and 1,1,1-TCA. With CAH mixtures, alcohol-grown cells degraded cis-DCE faster than both 1,1,1-TCA and 1,4-D. sec-Butyl-acetate (sBA) was demonstrated as a potential slow-release substrate that hydrolyzes to yield 2-butanol and acetate. Cells grown on this ester degraded a mixture of 1,1,1-TCA and 1,4-D at rates faster than 2-butanol-grown cells. The cometabolic transformation of 1,1,1-TCA and 1,4-D was also observed in reactors where growth occurred with sBA as the growth substrate. [ABSTRACT FROM AUTHOR]

In this study, organic geochemical and petrological analyses were conducted on 111 shale samples from a well to understand the retention, intraformational migration and segmented accumulation (shale oil enrichment in different intervals is unconnected) features of shale oil within the organic‐rich shale in the Qingshankou Formation of the Gulong Sag. Our study shows that retained petroleum characteristics in the investigated succession are mainly influenced by three factors: organic richness, intraformational migration and segmented accumulation. Organic matter richness primarily controls the amount of retained petroleum, especially the 'live' component indicated by the S2 value rather than the total organic carbon (TOC) figure alone. The negative expulsion efficiencies determined by mass‐balance calculations of hydrocarbons reveal that petroleum from adjacent organic‐rich intervals migrates into the interval of about 2386–2408 m, which is characterized by high free hydrocarbon (S1), OSI and saturated hydrocarbons content, along with a greater difference in δ13C values between polar compounds (including resins and asphaltenes) and saturated hydrocarbons. The depth‐dependent heterogeneity of carbon isotope ratios (δ13C) of mud methane gas, δ13C of extracts gross composition (SARA), δ13C of kerogen and SARA content of extracts suggest that the studied succession can be subdivided into four intervals. The shale oil sealing enrichment character in each interval is further corroborated by the distinct δ13C values of mud methane gas in different intervals. Due to the migration of petroleum into the 2386–2408 m interval, the S1, OSI and saturated hydrocarbons content of the interval show higher relative values. The maturity of organic matter in the 2471–2500 m interval is at the highest with the smaller size molecular components of the retained petroleum. Thus, favorable 'sweet spots' may be found in the 2386–2408 m interval and the 2471–2500 m interval, according to the experiment results in this study. [ABSTRACT FROM AUTHOR]

Bacterial degradation of crude oil is a promising strategy for reducing the concentration of hydrocarbons in contaminated environments. In the first part of this study, we report the enrichment of two bacterial consortia from deep sediments of the Gulf of Mexico with crude oil as the sole carbon and energy source. We conducted a comparative analysis of the bacterial community in the original sediment, assessing its diversity, and compared it to the enrichment observed after exposure to crude oil in defined cultures. The consortium exhibiting the highest hydrocarbon degradation was predominantly enriched with Rhodococcus (75%). Bacterial community analysis revealed the presence of other hydrocarbonoclastic members in both consortia. In the second part, we report the isolation of the strain Rhodococcus sp. GOMB7 with crude oil as a unique carbon source under microaerobic conditions and its characterization. This strain demonstrated the ability to degrade long-chain alkanes, including eicosane, tetracosane, and octacosane. We named this new strain Rhodococcus qingshengii GOMB7. Genome analysis revealed the presence of several genes related to aromatic compound degradation, such as benA, benB, benC, catA, catB, and catC; and five alkB genes related to alkane degradation. Although members of the genus Rhodococcus are well known for their great metabolic versatility, including the aerobic degradation of recalcitrant organic compounds such as petroleum hydrocarbons, this is the first report of a novel strain of Rhodococcus capable of degrading long-chain alkanes under microaerobic conditions. The potential of R. qingshengii GOMB7 for applications in bioreactors or controlled systems with low oxygen levels offers an energy-efficient approach for treating crude oil-contaminated water and sediments. [ABSTRACT FROM AUTHOR]

Copyright of Geology & Resources is the property of Geology & Resources Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Shales in the Carboniferous–Permian Fengcheng (FC) and Lucaogou (LCG) formations in Junggar Basin are important organic rich rocks containing significant oil resources. To evaluate the difference in sedimentary environment conditions and hydrocarbon-generating potential between the FC and LCG formations. Total organic carbon (TOC), Rock-Eval pyrolysis, solvent extraction, column fractionation, stable carbon isotope, gas chromatography-mass spectrometry (GC-MS) of saturated hydrocarbons and organic petrology from the source rocks of FC and LCG formations. were analyzed. The biomarker composition indicates that during the deposition of FC, LCG-1 to LCG-2, the sedimentary environment for the source rock formations changed with gradual decrease of salinity, from anoxic to dyoxic/suboxic in redox conditions, and from strong stratification to weakened stratification of water. The FC Formation source rock, with main telalginite (planktonic green algae), archaebacteria and minor terrestrial organic matter, deposited in the environment characterized by high salinity and strongly reducing condition. Its TOC content is relatively low with a high original hydrocarbongenerating potential of unit organic material. The LCG Formation source rock deposited in the environment with low salinity and large variations, the organic matter is mainly sourced from telalginite (planktonic green algae), lamalginite, bacteria and higher plants, resulting in strong heterogeneity of the source rock. The abundance of TOC is high, but the original hydrocarbon generation potential of unit organic matter is lower than that of FC Formation. The results provide a geochemical basis for further study of saline-brackish water sedimentary environment shales in the Junggar Basin. [ABSTRACT FROM AUTHOR]

One year after the emergency diesel fuel spill in Norilsk, the hydrocarbon concentrations in bottom sediments of the Norilo-Pyasinsk water system decreased. However, the average decrease in the areas occurred in the same sequence (µg/g) as in 2020: the mouth of the Ambarnaya River (835, σ = 1788) > Bezymyannyi Creek–Daldykan River–Ambarnaya River (306, σ = 273) > the Pyasina River (23, σ = 20) > Pyasino Lake (12, σ = 8). The concentrations decreased due to degradation of low molecular weight hydrocarbons. The content of polycyclic aromatic hydrocarbons also changed in a smaller range (0–1027 ng/g) in 2021 than in 2020 (0–3865 ng/g). The petroleum origin of polycyclic aromatic hydrocarbons in the sediments of the Ambarnaya River (including the mouth), Bezymyannyi Creek, and the Daldykan River confirms the dominance of alkylated naphthalene homologs in their composition. Hydrocarbon accumulation in certain horizons of the sedimentary stratum is caused not only by seepage of diesel fuel, but also by the input of organic matter from the surrounding swamps and floodplain lakes, as well as by the burial of the surface layer by the 2021 flood. [ABSTRACT FROM AUTHOR]

In this paper, the geochemical studies of API gravity, content of asphaltenes and gross compositions were performed on samples from two crude oils collected in the Al Bayda Platform Area (Samah formation), central part of the Sirte Basin. The results showed that the fraction of saturates is the dominant fraction in oils in comparison to aromatics and NSO components, with high API gravity and low content of asphaltenes which indicates that the oils are mature, generated from marine organic sources and that they can be classified as light crude oils. The aim of this study is to provide evidence about precursor of organic material, depositional environment, and maturity of the studied oils. Saturated hydrocarbons were analyzed by gas chromatography-mass spectrometry and gas chromatography-mass spectrometry-mass spectrometry technique. Results indicates that the oil samples are originating from high marine organic matter phytoplankton and algae, with few terrestrial inputs, reflecting that oils can be sourced from siliciclastic, possibly marine shales deposited in a clayrich marine, deposited under intermediate conditions with high maturity. All results showed that the oil samples are similar in their characteristics, likely due to the migration pathways in the same region. [ABSTRACT FROM AUTHOR]

We compiled an experimental database for the surface tension of binary mixtures containing a wide variety of fluids, from the chemical classes (water, alcohols, amines, ketones, linear and branched alkanes, naphthenes, aromatics, refrigerants, and cryogens). The resulting data set includes 65 pure fluids and 154 binary pairs with a total of 8205 points. We used this database to test the performance of a parachor model for the surface tension of binary mixtures. The model uses published correlations to determine the parachors of the pure fluids. The model has a single, constant binary interaction parameter for each pair that was found by fitting experimental mixture data. It can be also used in a predictive mode when the interaction parameters are set to zero. We present detailed comparisons on the performance of the model for both cases. In general, the parachor model in a predictive mode without fitted interaction parameters can predict the surface tension of binary mixtures of non-polar mixtures such as linear and branched alkanes, linear and branched alkanes with naphthenes, aromatics with aromatics, aromatics with naphthenes, and mixtures of linear alkanes of similar sizes with an average absolute percentage deviation of about 3 % or less. Polar mixtures of halocarbons with other halocarbons and also polar/nonpolar mixtures of alkanes with halocarbons could be modeled with an average absolute deviation of less than 0.35 mN·m−1 with the use of a binary interaction parameter. The parachor model even with a fitted binary interaction parameter performs poorly for mixtures of water and organic compounds and is not recommended. [ABSTRACT FROM AUTHOR]

Saturated hydrocarbons are widely used in the valuation of source rocks and oils, but the applicability of related parameters has received less attention. Based on the thermal simulation experiments on Mesozoic source rocks in the Yingen-Ejinaqi Basin, and the GC-MS analysis of the saturated hydrocarbon fractions of the expelled oils and extracts from solid residues, the applicability of the parameters related to lacustrine source rocks and oil were discussed. The results indicated that: Controlled by thermal degradation, both the relative abundance of the tricyclic terpenoids in terpenoids and the pregnane (including L pregnane) in steroids increased with the increase in maturity. Maturity had little effect on some environmental parameters of lacustrine source rocks and oils, such as Pr/Ph and gammacerane index, they were still effective even at the high-over maturity stage. But maturity had a significant influence on the method of using saturated hydrocarbons to identify the source of organic matter, because only at the thermal stage of Ro < 1.45%, might it effectively identify the source of organic matter by using the dominant peak of n-alkanes method and the relative abundance of C27–C29 steranes method. Most saturated hydrocarbon maturity parameters had their valid scope of application, such as C29 20S/(20S + 20R) steranes, C29αββ/(ααα + αββ) steranes and C31αβ22S/(22S + 22R) homohopanes were only effective when the Ro value was below 2.06%, for the parameter's value would be "inverted" in the stage of over-maturity (Ro > 2.06%). However, the parameter Ts/(Ts + Tm) was effective in the whole thermal evolution process, reflecting good applicability. This study clarifies the validity of the application of commonly used saturated hydrocarbon parameters, and it can provide some reference for relevant studies. [ABSTRACT FROM AUTHOR]

The well-developed mudstone and gypsum mudstone in the Oligocene Linhe Formation (E3l) in the Hetao Basin are the main source rocks for gypsum. However, the sedimentary environment and organic matter (OM) enrichment factors of E3l are not clear, and this inhibits the prediction of hydrocarbon source rock distribution and resource calculation. Major and trace elements, total organic carbon (TOC), pyrolysis using the Rock-Eval II, and saturated hydrocarbon gas chromatography–mass spectrometry (GC–MS) analyses were performed in this study. The results show that E3l was deposited in brackish water and saline–ultrasaline water, with weak oxidation reduction in an arid and hot environment. Terrestrial input inhibits OM enrichment, while the redox, paleosalinity, paleoclimate, and paleoproductivity play a catalytic role. The main controlling factors of the same lithologic source rocks are different: terrestrial input and paleoclimate have a greater impact on mudstone, and the redox and paleosalinity were more favorable to gypsum mudstone. Although the main controlling factors are different for different lithologies, their OM enrichment characteristics are still consistent. The E3l water body was deep, and the contribution of nutrients from terrigenous debris to OM enrichment was less. In addition, the water retention environment changed significantly during the E3l sedimentary period, resulting in fewer nutrients, which limited the improvement of surface water paleoproductivity. The arid climate increased water evaporation and salinity, which to some extent prevented consumption and decomposition. Weak oxidation-reduction fluctuations and the stratification of the water body were obvious, and this was not only conducive to the enrichment of OM but also to its preservation. [ABSTRACT FROM AUTHOR]

The concentrations and composition of hydrocarbons (HCs), aliphatic (AHCs), and polycyclic aromatic hydrocarbons (PAHs) in the Barents and Kara seas were determined in the surface microlayer (SML, about 300 µm thick), melting ice, and surface waters. Field material was collected on cruises 80 and 83 of the R/V Akademik Mstislav Keldysh in August 2020 and June 2021, respectively. In the SML, HCs occur primarily in suspension. In the Barents Sea, the AHC content in suspension was lower (31–96, 68 µg/L on average) compared to the Kara Sea (187–1051, 693 µg/L on average), where research was carried out in early summer. In the Kara Sea, the AHC concentrations in the SML were 3.6 times higher than in dissolved form (89–270, 158 μg/L on average), while compared to the suspension of surface waters, they were almost 15 times higher. Organic compounds also accumulate in ice, but to a lesser extent than in the SML. From the alkane composition, the influence of autochthonous processes on HC generation in melting ice is insignificant. The PAH contents in suspension were also 4.8 times higher on average than in dissolved form. The influence of the combustion products of ship fuel on the PAH composition was traced by markers, which showed that, in addition to phenanthrene, fluoranthene and pyrene dominated in all samples. [ABSTRACT FROM AUTHOR]

The organic compounds in a suspension of surface water and sediments of the shallow Chernavka River flowing into self-sustaining Lake Elton are studied: Corg and aliphatic (AHCs) and polycyclic aromatic (PAHs) hydrocarbons (HCs). The surface waters are characterized by high contents of lipids, AHCs, and PAHs: 692, 80, and 0.79 µg/L, respectively. The alkane composition of the water suspension corresponded to weathered oil HCs. The HCs are transformed at the water–sediment boundary rather than upon sedimentation. As a result, the AHC composition of sediments differs from that of the suspension in the presence of planktonogenic low molecular homologues of n-С15–С17 and a strong increase in the series of odd high molecular alkanes, whereas the PAH composition has a higher amount of naphthalene. [ABSTRACT FROM AUTHOR]

The distribution of organic matter, hydrocarbons, phytopigments, and ecological-trophic groups of microorganisms was studied in the bottom sediments of ten small tributaries of the Amur R. near Khabarovsk. The water showed high concentrations of organic matter, varying from 44.47 to 279.3 mg/L. The concentration of Corg in bottom sediments varied from 1.9 to 23.1% in different types of sediments; the amount of hydrocarbons reached 5081 mg/kg, exceeding the background level by a factor of up to 50. Studies of the molecular composition of hydrocarbons in sediments revealed in some streams the predominance (up to 100% of the total) of light (C8–C13) n-alkanes, typical of oil products and the products of vegetation combustion. High-molecular compounds dominated in HC composition in most watercourses, including n-alkanes, genetically associated with terrestrial vegetation, and heavy fractions of oil products with various levels of microbial degradation. Volatile organic compounds were quantitatively dominated by the products of microbiological transformation (acetaldehyde and methanol). In terms of the concentration of sedimentary pigments (up to 400 µg/g), the sediments of the majority of watercourses belong to the hypereutrophic type. The total abundance of microorganisms in water varied from 2.7 to 488.0 thousand CFU/mL; in sediments, it was distributed symbatically, but ranged from 0.1 to 19.3 million CFU/g. The number of heterotrophic bacteria in bottom sediments correlated with the parameter of overload of the self-purification capacity (r = 0.718), and the number of oil-oxidizing bacteria correlated with hydrocarbon concentration (r = 0.967), thus confirming the indication properties of this bacterial group. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Northeast Petroleum University is the property of Journal of Northeast Petroleum University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An amphiphilic chitosan-loaded bentonite adsorbent (C18CTS−BT) was prepared for the efficient removal of organic matter from coking wastewater. The structure and surface morphology of adsorbents were characterized by FT−IR, XRD, and SEM. The removal of those organics by C18CTS−BT was investigated by comparing the adsorption performances of C18CTS−BT with bentonite (BT) and chitosan-loaded bentonite (CTS−BT). The results showed that compared with BT and CTS−BT, C18CTS−BT showed the performance advantages of having a low dosage, wide pH range, and short adsorption equilibrium time. The optimized treatment process was as follows: the adsorbent dosage was 1.5 g·L−1, the adsorption time was 60 min, and the pH of the system was 7.0. The chemical oxygen demand (COD) of the coking wastewater treated with BT, CTS−BT, and C18CTS−BT decreased from 342 mg·L−1 in the raw water to 264 mg·L−1, 218 mg·L−1, and 146 mg·L−1, corresponding to COD removal rates of 22.81%, 36.26%, and 57.31%, respectively. The results of GC−MS analysis also confirmed that C18CTS−BT could remove most of the organic compounds in coking wastewater, especially long−chain alkanes and their derivatives. The hydrophobic modification of the adsorbent material can effectively improve the removal performance of organic compounds from coking wastewater. [ABSTRACT FROM AUTHOR]

In this study, the thermal degradation and pyrolysis of hospital plastic waste consisting of polyethylene (PE), polystyrene (PS), and polypropylene (PP) were investigated using TG-GC/MS. The identified molecules with the functional groups of alkanes, alkenes, alkynes, alcohols, aromatics, phenols, CO and CO2 were found in the gas stream from pyrolysis and oxidation, and are chemical structures with derivatives of aromatic rings. They are mainly related to the degradation of PS hospital waste, and the alkanes and alkenes groups originate mainly from PP and PE-based medical waste. The pyrolysis of this hospital waste did not show the presence of derivatives of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans, which is an advantage over classical incineration methodologies. CO, CO2, phenol, acetic acid and benzoic acid concentrations were higher in the gases from the oxidative degradation than in those generated in the pyrolysis with helium. In this article, we propose different pathways of reaction mechanisms that allow us to explain the presence of molecules with other functional groups, such as alkanes, alkenes, carboxylic acids, alcohols, aromatics and permanent gases. [ABSTRACT FROM AUTHOR]

Cuticular hydrocarbons are the major organic compounds synthesized by oenocytes. The CHCs act as sex pheromones, cell communicators, inhibits dissection, and chemotaxonomic cues. The CHCs were isolated from non-Drosophila species Phorticella striata (Sajjan and Krishnamurthy, 1975) (Diptera, Drosophilidae) by employing whole body extract through GCMS method. Among the identified organic compounds, a total of 38 compounds were obtained from male flies and 68 organic compounds were isolated from female flies, Majority of the CHCs identified were methyl branched alkanes, some of them were esters and alcohols. Male flies exhibit 15 specific CHCs in which tetradecane, 2, 6, 10-trimethyl was dominant with a relative abundance (15.60%) and cyclopropane tetradecanoic acid was the least found CHCs with a relative abundance (RA) of 0.75 per cent. The flies exhibit 28 female specific CHC's, among them tetradecane was dominant (r value of 19.20%) and Iodomethyl undecane was the least (RA=0.70%). Both male and female flies shared 23 CHCs, but the ratio among them showed great variance. Among the shared CHCs 3-Trifluoroacetoxy dodecane was dominant in female (RA=14.50%), the male exhibited RA of 4.66 per cent. In male flies 3-Trifluoroacetoxy pentadecane was most abundant CHC (RA=10.90%), than female (4.31%). [ABSTRACT FROM AUTHOR]

Cuticular hydrocarbons (CHCs) are the organic compounds secreted by specialized secretory cells called oenocytes. The synthesized CHCs are transported to the outer cuticle through hemolymph. The CHCs play a dual role in insects, i.e., desiccation resistance and pheromonal communication. CHCs were isolated from inversion strains of the Drosophila ananassae subgroup of the melanogaster and identified by gas chromatography/mass spectrometry (GC-MS) analysis. The results showed a significant variation in the number and concentration of CHC profile. In D. ananassae, 82 CHCs were identified with a carbon chain length of C7 to C44. It included all cuticular hydrocarbons, but methylated alkanes were dominant CHCs. Males had 39 CHCs in 2LA+3LA inversion strains, 37 and 28 in single inversion strains such as 3LA and 2LA, respectively, followed by an inversion-free strain of 17 hydrocarbons. However, a female with double inversion strains (2LA+3LA) showed 36 CHCs, single inversion strains such as 3LA consisting of 27, 2LA with 24 CHCs, and 18 CHCs in inversion-free strain. The present investigation revealed the highest number of CHCs in double inversion strains and the least number of CHCs in inversion-free strains of both sexes of D. ananassae. [ABSTRACT FROM AUTHOR]

Intermediate volatility organic compounds (IVOCs) and semi-volatile organic compounds (SVOCs) have recently been proposed as important precursors of secondary organic aerosol (SOA). In the present work, 97 volatile organic compounds (VOCs) and 80 intermediate volatility and semi-volatile organic compounds (IVOCs and SVOCs) were measured by online gas chromatography-mass spectrometer/flame ionization detection (GC-MS/FID), and offline thermal desorption gas chromatography-mass spectrometer (TD-GC-MS), respectively. The average concentration of speciated VOCs, IVOCs, and SVOCs were 22.36 ± 9.02 μg m−3, 1.01 ± 0.32 μg m−3, and 0.10 ± 0.17 μg m−3. Alkanes and polycyclic aromatic hydrocarbons (PAHs) are the main compounds of total S/IVOCs. With the increase in molecular weight, the concentrations decreased in the gas phase, while increasing in the particle phase. Vehicular emission is the most significant source according to the carbon preference index (CPI) and the carbon of the most abundant alkane (Cmax). The yield method was used to estimate SOA from the oxidation of VOCs and S/IVOCs. The estimated SOA mass from IVOCs and SVOCs (0.70 ± 0.57 μg m−3) was comparable to that of VOCs (0.62 ± 0.61 μg m−3), and the oxidation of PAHs and alkanes took up 28.70 ± 8.26% and 51.97 ± 20.77% of the total SOA estimation, respectively. Compared to previous work, our study provided detailed molecular information of ambient S/IVOC species and elucidated their importance on SOA formation. Despite their low concentration, S/IVOCs species are important SOA precursors which shared comparable contribution compared with VOCs. [ABSTRACT FROM AUTHOR]

The occurrence characteristics of shale oil in the pores of shale nano organic matter are studied by molecular dynamics simulation. The adsorption characteristics of n-octane on graphene wall at 353 K and 30.7 MPa are simulated under OPLS all atomic force field, and the effects of different pores size, temperature, pressure, carbon chains length and alkane polarity on the adsorption of n-octane on organic matter wall are analyzed. The results show that n-octane has four adsorption layers on the pores wall of organic matter, the peak density of the adsorption layer decreases gradually, and the thickness of the adsorption layer is 0.4-0.5 nm. The vertical diffusion coefficient and parallel diffusion coefficient increase gradually along the z direction and reach stability at the center of the pores. And the parallel diffusion coefficient is greater than the vertical diffusion coefficient. The pressure has little effect on the adsorption capacity of alkane molecules. The larger the pores size, the higher the temperature, the shorter the carbon chains and the lower the molecular polarity, the smaller the adsorption volume fraction of alkane molecules in the pores of nano organic matter. [ABSTRACT FROM AUTHOR]

Marine transgression events and plant species' evolution to terrestrial environments increased the amount of organic matter in sediments during the Devonian Period. Subsequently, a bituminous material known as shale was formed, containing organic compounds that enable the reconstruction of environmental conditions from previous eras. These rock formation events are recorded worldwide, however, in the Ponta Grossa Formation, southern Brazil, a deeper understanding of samples from the Devonian Period is necessary. The goal of this study was to understand the regional environmental conditions, the origin of the organic matter, and the degree of maturation of the bituminous material. Shale samples were collected from an outcrop on the eastern border of the Paraná Basin and processed in the laboratory to obtain the saturated hydrocarbons fraction posteriorly analyzed. The results indicate a poorly oxygenated environment, with various salinity levels, mixed organic sources, and a high thermal maturity of the samples. The analysis of compound hydrocarbons elucidates the environmental conditions during the Devonian Period in the Ponta Grossa Formation, providing inferences applicable to the stratigraphic interval represented by this record and within the domain of the sampled area. • Analysis of Devonian Period shales in the Ponta Grossa Formation in Brazil. • Biomarkers in rocks undergo chemical modification that indicates thermal evolution. • The results were obtained using Ts/(Ts + Tm) and Pr/Ph ratios and the gammaceran index. • The shales contain a mixture of terrestrial and aquatic organic matter. • The samples presented low oxygen concentration and varied salinity. [ABSTRACT FROM AUTHOR]

Shale oil content prediction is currently the focus of exploration. Traditional prediction methods are less accurate, and a large number of analytical tests can increase the cost of exploration. Therefore, new methods need to be introduced to accurately predict sweet spot intervals. In this study, a quick and novel convolutional neural network (CNN) method to predict oil content parameters (TOC, S 1 and S 2) is provided based on well logs (SP, GR, CAL, RT, and AC) in the Dongpu Depression, Bohai Bay basin, China. The results showed that the CNN model showed high accuracy in predicting TOC (R2 = 0.73) than the ΔlogR method (R2 = 0.132). The validation sets for S 1 (R2 = 0.72) and S 2 (R2 = 0.67) also show high prediction accuracy. In addition, Well Wen 318 (located in the same formation) was selected as a blind well to test the performance of the model. The micromigration evaluation method is based on the principle of mass balance, which reflects the changes of the original hydrocarbon generation potential (HGP O) and the real hydrocarbon generation potential (HGP R). Combined with the established CNN model and the micromigration evaluation method, we predicted and evaluated the oil content in lower Mbr 3 of the Shahejie Fm and divided four sweet spots. The differential enrichment of shale oil is controlled by micromigration. Samples with high saturated/aromatic ratio and small main peak carbon of saturated hydrocarbon chromatography are more likely to undergo micromigration, which in turn affects the oil content of shale. Shales with high organic matter abundance and good pore connectivity are more susceptible to micromigration, leading to the differential enrichment of shale oil. This study provides a new idea for evaluating hydrocarbon micromigration of shale oil and predicting favorable zones and the grading evaluation of oil content in petroliferous basins around the world. • A novel CNN method to predict oil content parameters is provided based on well logs. • A micromigration evaluation model was established based on hydrocarbon generation & retention. • 4 sweet spots intervals were predicted combined with micromigration evaluation and CNN model. • The differential enrichment of shale oil is explained from the micromigration perspective. [ABSTRACT FROM AUTHOR]

During the study of Sinian-Cambrian system gas reservoirs in the middle paleo-uplift of Sichuan Basin, some wells of Longwangmiao formation in Moxi area had yellow fluorescent organic matter in thin sections under core-mirror was found. Based on the core observation and dissolution experiments, the characteristics of the biomarkers of saturated hydrocarbons under different conditions were determined by saturated hydrocarbon chromatography-mass spectrometry. The results show that the organic matter observed in the thin section under core-mirror is not the crude oil formed by multi-period accumulation, but polluted by oily substances in the drilling fluid during the drilling process. The presence of pollutants will affect the recovery of crude oil. Therefore, this study uses geochemical methods to identify the pollutants in the core and improve the recovery of crude oil. [ABSTRACT FROM AUTHOR]

The present research is a comprehensive investigation of Dasycladus vermicularis (Scopoli) Krasser 1898 from the Adriatic Sea (Croatia) regarding volatilome–volatile organic compounds (VOCs, mostly nonpolar compounds) and less polar nonvolatile compounds for the first time. Headspace solid-phase microextraction (HS-SPME) and hydrodistillation (HD) were used showing the great volatilome variability among fresh (HS-FrDV and HD-FrDV) and dried (HS-DrDV and HD-DrDV) samples after GC–MS analysis. Aromatic aldehydes were dominant in both fresh and air-dried HS samples with benzaldehyde as the most abundant in fresh samples and decreasing 2.7–3.7 times after drying together with 2-phenylbut-2-enal that was not present after drying. Aliphatic compounds (unsaturated hydrocarbons in HS-FrDV; saturated hydrocarbons in HS-DrDV) were also present. C11-hydrocarbons (dictyopterpene C' and dictyopterpene D') were detected in HS-FrDV. (E)-Phytol was the most dominant compound in HD-FrDV and HD-DrDV. Diterpene alcohols (cembra-4,7,11,15-tetraen-3-ol and (Z)-falcarinol) and sesquiterpene alcohol, cubenol, were dominant in HD-FrDV, and their abundance decreased after drying. C13-norisoprenoides (α-ionone and β-ionone) increased after drying. Aliphatic compounds were present in both HD-FrDV and HD-DrDV samples. The less polar nonvolatile compounds in the obtained fractions F3 and F4 were analysed and identified by UHPLC-ESI(+)-HRMS. Identified compounds belonged to a group of pigments (7 compounds), fatty acid derivatives (13 compounds), as well as steroids and terpenes (10 compounds). Porphyrin-based compounds (C55H74N4O5–7), xanthophylls, sphingolipid compounds, fatty acid amides, and phytosterols represented the majority of identified compounds. By implementing both in vitro and in vivo assays for antioxidant activity determination, F3 showed a higher activity than F4. Inhibitory concentrations (IC50) for F3 and F4 were 498.00 ± 0.01 µg/mL and 798.00 ± 0.81 µg/mL, respectively, while a 1.5-fold reduction in the ROS level was observed after pre-treatment of zebrafish larvae with 45 µg/mL of F3. [ABSTRACT FROM AUTHOR]

Recently, there has been an interest in solvent extraction for extraction organic matter from oil shale. Heating of oil shale in an inert atmosphere facilitated the extraction of the organic matter by solvent extraction. In this research, shale oil obtained by Soxhlet extraction was separated and characterized, and this was not studied previously. The best Soxhlet extraction conditions were 25.0 g oil shale (preheated at 400 °C), particle size of 250–500 µm, 400.0 mL tetrahydrofurane, and 5.0 h extraction time, where 68% of the organic matter was extracted, which is considered a high value compared to published results. Both THF and dichloromethane were effective extractants, the former due to its moderate dipole moment and low hydrophobicity, while the later due to its high solubility factor (20.2) which can swell kerogen and facilitate organic extraction. The significant output of this research is the variability in the composition of oil obtained by solvent extraction compared to conventional thermal retorting, as the first has large fractions of saturated and polar compounds (85%) while small fractions of aromatics (11%). Spectroscopic analysis by FTIR and 1H-NMR was important in identifying the components of the extracted oil, especially saturated hydrocarbons. [ABSTRACT FROM AUTHOR]