Highlighting the effects of co‐eluting interferences on compound specific stable isotope analysis of polycyclic aromatic hydrocarbons using comprehensive two‐dimensional gas chromatography

Accuracy is the most important issue when carrying out compound specific stable isotope analysis of polycyclic aromatic hydrocarbons extracted from complex samples. It depends on two main factors: the possible isotopic fractionation of the compounds during extraction and the potential co‐elution with interfering compounds with different isotopic signatures. We present here a simplified pressurised liquid extraction method for compound specific stable isotope analysis of polycyclic aromatic hydrocarbons (PAHs) in non‐aqueous phase liquids of coal tar. Samples extracted using the new method and using fractionation on silica gel column were analysed using comprehensive twodimensional gas chromatography. We were able to evaluate the effect of coelution on carbon and hydrogen stable isotope signatures of the 16 US EPA priority PAHs in the coal tars with various proportions of aromatic and aliphatic content. Even in samples that presented a good baseline resolution, the PAHs of interest co‐eluted with other aromatic compounds with a notable effect on their stable isotope values; it demonstrated the necessity to check the quality of all extraction and clean‐up methods (either the simplified pressurized liquid extraction or more traditional labour‐intensive methods) for the more complex samples prior to data interpretation. Additionally, comprehensive twodimensional gas chromatography enabled visualisation of the suspected coelutions for the first time

Water Management Strategies for Improved Coalbed Methane Production in the Black Warrior Basin

The modern coalbed methane industry was born in the Black Warrior Basin of Alabama and has to date produced more than 2.6 trillion cubic feet of gas and 1.6 billion barrels of water. The coalbed gas industry in this area is dependent on instream disposal of co-produced water, which ranges from nearly potable sodium-bicarbonate water to hypersaline sodium-chloride water. This study employed diverse analytical methods to characterize water chemistry in light of the regional geologic framework and to evaluate the full range of water management options for the Black Warrior coalbed methane industry. Results reveal strong interrelationships among regional geology, water chemistry, and gas chemistry. Coalbed methane is produced from multiple coal seams in Pennsylvanian-age strata of the Pottsville Coal Interval, in which water chemistry is influenced by a structurally controlled meteoric recharge area along the southeastern margin of the basin. The most important constituents of concern in the produced water include chlorides, ammonia compounds, and organic substances. Regional mapping and statistical analysis indicate that the concentrations of most ionic compounds, metallic substances, and nonmetallic substances correlate with total dissolved solids and chlorides. Gas is effectively produced at pipeline quality, and the only significant impurity is N{sub 2}. Geochemical analysis indicates that the gas is of mixed thermogenic-biogenic origin. Stable isotopic analysis of produced gas and calcite vein fills indicates that widespread late-stage microbial methanogenesis occurred primarily along a CO{sub 2} reduction metabolic pathway. Organic compounds in the produced water appear to have helped sustain microbial communities. Ammonia and ammonium levels increase with total dissolved solids content and appear to have played a role in late-stage microbial methanogenesis and the generation of N{sub 2}. Gas production tends to decline exponentially, whereas water production tends to decline hyperbolically. Hyperbolic decline indicates that water volume is of greatest concern early in the life of a coalbed methane project. Regional mapping indicates that gas production is controlled primarily by the ability to depressurize permeable coal seams that are natively within the steep part of the adsorption isotherm. Water production is greatest within the freshwater intrusion and below thick Cretaceous cover strata and is least in areas of underpressure. Water management strategies include instream disposal, which can be applied effectively in most parts of the basin. Deep disposal may be applicable locally, particularly where high salinity limits the ability to dispose into streams. Artificial wetlands show promise for the management of saline water, especially where the reservoir yield is limited. Beneficial use options include municipal water supply, agricultural use, and industrial use. The water may be of use to an inland shrimp farming industry, which is active around the southwestern coalbed methane fields. The best opportunities for beneficial use are reuse of water by the coalbed methane industry for drilling and hydraulic fracturing. This research has further highlighted opportunities for additional research on treatment efficiency, the origin of nitrogen compounds, organic geochemistry, biogenic gas generation, flow modeling, and computer simulation. Results of this study are being disseminated through a vigorous technology transfer program that includes web resources, numerous presentations to stakeholders, and a variety of technical publications

Development of the mathematical model for calculating player ratings using soft calculations

This research signifies an ambitious step forward in sports analytics, aiming to formulate a novel mathematical model that assesses team sports players’ performance with higher precision. It aspires to unravel a deeper understanding of player abilities, a complex task that requires advanced computational modeling and statistical analysis. The proposed model is built upon cutting-edge soft computing techniques. These techniques – fuzzy logic, neural networks, and genetic algorithms - are expertly integrated, each contributing unique elements to enhance the model’s accuracy and dependability. Fuzzy logic, with its capacity to handle ambiguity, provides nuanced evaluations, accounting for sports’ inherent uncertainties. Neural networks offer the model a capacity to learn and evolve, refining its evaluations as it processes new data. Genetic algorithms, modeled on natural evolution, optimize the model’s decision-making process, highlighting the most successful player strategies. This innovative approach could reshape player evaluations, replacing one-dimensional, static metrics with a dynamic, multi-faceted framework. Coaches, managers, and analysts will be equipped with a robust tool for decision-making and talent sourcing, ushering in a new era of sports analytics

Compiling a jury in Russia in the context of digitalization

The purpose of this study is to conduct a comprehensive analysis of the legislation governing social relations that develop in the process of compiling a jury when considering criminal cases with a jury trial. The relevance of the research topic is determined by the expansion of the jurors competence from June 1, 2018. Currently, one of the main reasons for revocation of court sentences passed with the participation of a jury is violations committed during formation of a jury. In this regard, the authors highlight the main procedural and organizational shortcomings of this process and make relevant suggestions: a) to improve the legislation governing the procedure for compiling a jury; b) to compile general and reserve lists based on information included in the Unified Federal Information Register; c) to perform video recording of the process [screen broadcasting] of a random selection of citizens from the general and reserve lists by a court staff member when compiling a preliminary list of jurors; d) to stipulate the right of citizens to defer the obligation to appear in court as a candidate for jurors to a later date; e) to apply new forms of sending invitations to appear in court to potential jurors

Effect of Generation of Auger Duplexes

© 2018, Springer Science+Business Media, LLC, part of Springer Nature. The physical mechanism underlying the effect of generation of Auger duplexes as a consequence of the electronic level transformation in the case of local energetic effect in the atoms of complex oxides is suggested. It has been established that the effect of the formation of Auger duplexes is independent of the type of radiation acting on an object and is determined by the energy of the affecting particles and by the time of irradiation leading to accumulation of the reactions induced by electrons (ions)

Molecular simulation of carbon dioxide adsorption in chemically and structurally heterogeneous porous carbons

Capture of carbon dioxide from fossil fuel power plants via adsorption and sequestration of carbon dioxide in unmineable coal seams are achievable near-term methods of reducing atmospheric emissions of this greenhouse gas. To investigate the influence of surface heterogeneity upon predicted adsorption behavior in activated carbons and coal, isotherms were generated via grand canonical Monte Carlo simulation for CO 2 adsorption in slit-shaped pores with underlying graphitic structure and several variations of chemical heterogeneity (oxygen and hydrogen content), pore width, and surface functional group orientation. Adsorption generally increased with increasing surface oxygen content, although exceptions to this trend were observed on structurally heterogeneous surfaces with holes or furrows that yield strongly adsorbing preferred binding sites. Among the heterogeneous pore structures investigated, those with coal-like surfaces adsorbed carbon dioxide more strongly than planar, homogeneous graphitic slit pores of comparable width. Electrostatic adsorbate–adsorbent interactions significantly influenced adsorption onto model surfaces. © 2006 American Institute of Chemical Engineers Environ Prog, 25: 343–354, 2006Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/55883/1/10168_ftp.pd

The Quantitative Theory of Diffraction by Spiral Nanotubes

The quantitative theory of diffraction by spiral nanotubes of any chemical composition is offered. Distribution of diffraction intensities along layer lines and layer planes, strong and diffuse reflexes, pseudoorthogonality effect has been simulated and analyzed. The investigation is oriented to electron microdiffraction from a single nanotube

Geologic Evaluation of Critical Production Parameters for Coalbed Methane Resources, Black Warrior Basin - Final Report

Characterization of coalbed methane occurrence and producibility in the Black Warrior basin of Alabama indicates that geologic factors are the principal controls on the occurrence and producibility of coalbed methane. Results of engineering analysis indicate that application of completion and stimulation techniques may be used to increase recovery once favorable well sites are chosen. Sedimentologic and coal-quality parameters may be used to locate regions for coalbed methane development by characterizing the occurrence, rank, and grade of coal resources. However, high-productivity trends within those regions are localized, and geologic data suggest that productivity trends may be predictable on the basis of structural and hydrologic parameters. Several highly productive trends occur along northeast-oriented lineaments. These trends evidently are the surface expression of zones of enhanced permeability which apparently are related to fractures. Productive trends also are associated with areas of low reservoir pressure, and salinity maps indicate that fresh water has migrated toward these areas from the southeast margin of the basin. The available data indicate that structure and hydrology are critical production parameters that may be used to identify favorable well sites within regions containing significant, high-quality coal resources.Bureau of Economic Geolog