This experimental study focuses on the changes to the component composition of rapeseed oil, distilled tall oil, and tall oil fatty acids biodiesel during storage. These changes define the density, dynamic viscosity, ignition, combustion, and anthropogenic emissions of microemulsion fuels prepared with biodiesel as an additive. Density of fresh FAME samples ranged from 880 to 935 kg/m3 at 25 degrees C, with noticeable decrease after storage for RO and DTO samples. Dynamic viscosity of rapeseed FAME was closest to diesel fuel, while DTO and FATO FAME viscosities were approximately twice as high. After storage, significant changes were observed: 13% increase in saturated fatty acid methyl esters in rapeseed FAME; 11-17% change in fatty acid concentrations across all samples; 37% variation in oxygen-containing hydrocarbons in rapeseed FAME. Biodiesel is produced by transesterification using methanol and an alkaline catalyst. Microemulsion blends stabilized with a 9:1 mixture of non-ionic surfactants (Neonol AF 9-6 and isoamyl alcohol) are based on diesel fuel, an 8 wt% bio-additive, and 3.5 wt% distilled water. The findings demonstrate the significant effect of biodiesel microemulsification on fuel ignition and combustion under temperature conditions comparable to those in real power plants. Furthermore, microemulsification reduces harmful emissions by 40-70%, depending on the type of biodiesel used. 10-16% decrease in ignition delay at temperatures above 800 degrees C. These results demonstrate the feasibility of using microemulsion fuel containing biodiesel additives in existing power plants.
Based on the available scientific literature and the results of our own research, with the involvement of information from social and mass media, we have summarized the data on new records, the state of populations, the origin, distribution, and the stages of the invasion of Chinese pond mussels (Sinanodonta spp.) in Russia. Most of the discovered populations apparently reproduce independently and are capable of existing without the arrival of newly introduced juveniles. More than half of the populations were found in water bodies with a natural thermal regime, and less than half were found near fish farms. This finding indicates a successful invasion of mussels into water bodies and watercourses of Russia, as well as their active distribution in zonal (non-heated) water bodies. An assessment of the possibility of expanding the Sinanodonta spp. invasion in Russia and its consequences is provided. Additionally, we assessed the possibility of using the variability of Chinese pond mussel shells to distinguish between species and populations in heated and unheated conditions, as well as the possibility of using the diversity of COI haplotypes to track the phylogeographic relationships and invasion routes.
Chemical and biological approaches are widely applied to assess petroleum hydrocarbon contamination in soils; however, their results are often difficult to compare due to the use of fundamentally different extraction media. Chemical analytical methods typically rely on non-polar organic solvents, whereas biological toxicity assessments are based on aqueous soil extracts, reflecting water-soluble fractions of contaminants. This methodological discrepancy complicates the integrated evaluation of soil contamination and the assessment of remediation effectiveness. This study proposes an FTIR-based approach for assessing petroleum hydrocarbon contamination in sandy podzolic soil based on extraction with aqueous dimethyl sulfoxide (DMSO). The proposed method aims to reduce the methodological gap between classical chemical monitoring and aqueous-based biological assessment frameworks. The extraction performance of distilled water and aqueous DMSO solutions with different concentrations was evaluated using model soil samples artificially contaminated with crude oil. Crude oil was used as a multicomponent contaminant, whereas "petroleum hydrocarbons" refers to the operationally defined hydrocarbon fraction extracted from the soil-oil system and detected by FTIR in the C-H stretching region. Hydrocarbon extraction efficiency was assessed based on characteristic C-H stretching absorption bands in the 2800-3100 cm-1 infrared region. Distilled water exhibited limited extraction capacity and rapidly reached saturation, resulting in weak and concentration-independent absorption responses. In contrast, aqueous DMSO increased the apparent solubility of hydrocarbons and yielded reproducible, concentration-dependent spectral responses. A 75% (v/v) aqueous DMSO solution was selected as a practical compromise extraction medium, increasing analytical sensitivity while remaining more compatible with aqueous conditions than conventional non-polar organic solvents. The proposed method provides a lower-hazard and methodologically coherent extraction approach for FTIR-based chemical monitoring of petroleum-contaminated soils and may facilitate improved comparability between chemical measurements and aqueous-based biological assessment approaches in integrated soil contamination and remediation studies.
The article presents a review of modern functional additives for water- based drilling fluids used to improve drilling efficiency and preserve reservoir properties. The following main groups of additives are considered: nanoparticles capable of improving rheological and filtration properties, reducing friction and fluid losses (up to 40 % when using TiO2); surfactants that improve mud properties by reducing interfacial tension; environmentally safe additives with low toxicity that contribute to sustainable development of the oil and gas industry and reduce production costs. Additionally, natural components of plant origin with biodegradability and promising performance characteristics are considered. Particular attention is paid to polymers acting as swelling and corrosion inhibitors, which allows increasing the resistance of drilling fluids to aggressive conditions. The considered additives allow to optimize the drilling process, reduce the technogenic impact on the environment and increase the working life of the equipment. The article also focuses on the synergetic effects of the combined use of various types of additives, as well as on the potential of their industrial implementation, taking into account modern requirements to environmental friendliness, efficiency and cost- effectiveness. The review reflects current trends in the development of drilling fluids with a focus on stability to thermobaric conditions and environmental safety.
The article examines the theoretical and methodological aspects of accounting for employee benefits and pension plans in accordance with the requirements of international financial reporting standards. The relevance of the research is due to the need for Russian organizations to adapt to international standards in the context of a globalized economy and to increase the requirements for the reliability of financial statements. The legal regulation of employee benefits accounting, classification of pension plans, methodology of actuarial calculations and discounting of long-term liabilities are considered. Practical recommendations for improving the accounting of pension plans in Russian practice are proposed.
