Influence of anionic surfactant on stability of nanoparticles in aqueous solutions

Dispersion and aggregation of nanoparticles in aqueous solutions are important factors for safe and effective application of nanoparticles, for instance, in the oil industry. As conventional oil reserves are depleted, it is necessary to advance chemical enhanced oil recovery (cEOR) techniques to develop unconventional oil reservoirs. Nanoparticles modified by surfactants can be a promising reagent in cEOR. These nanomaterials can reduce interfacial tension and change the wettability of reservoir rock, which leads to an increase in oil recovery. However, the application of nanoparticles is limited by their substantial aggregation in aqueous solutions. The purpose of this work is to select nanoparticles for obtaining stable sols in water in the presence of an anionic surfactant and to optimize the conditions (pH) for further modifying the nanoparticles with the anionic surfactant. Sodium dodecyl sulfate (SDS) is used as an anionic surfactant. The aggregation of oxide and carbon nanoparticles in water and anionic surfactant solutions was studied by laser diffraction, dynamic and electrophoretic light scattering methods. Most of the studied nanoparticles in water form aggregates with bi-, three- and polymodal particle size distributions. TiO2 nanoparticles obtained by plasma dynamic synthesis form the most stable sols in anionic surfactant solutions. The range of 5–7 pH is defined as optimal for their modification with surfactants. The stability of carbon nanoparticles in aqueous solutions increases significantly in the presence of a surfactant. The obtained results form the basis for further research on the modification of marked nanoparticles in surfactant solutions

Electrospark doping of steel with tungsten

The paper is devoted to the numerical modeling of thermal processes and the analysis of the structure and properties of the surface layer of carbon steel subjected to electrospark doping with tungsten. The problem of finding the temperature field in the system film (tungsten) / substrate (iron) is reduced to the solution of the heat conductivity equation. A one-dimensional case of heating and cooling of a plate with the thickness d has been considered. Calculations of temperature fields formed in the system film / substrate synthesized using methods of electrospark doping have been carried out as a part of one-dimensional approximation. Calculations have been performed to select the mode of the subsequent treatment of the system film / substrate with a high-intensity pulsed electron beam. Authors revealed the conditions of irradiation allowing implementing processes of steel doping with tungsten. A thermodynamic analysis of phase transformations taking place during doping of iron with tungsten in equilibrium conditions has been performed. The studies have been carried out on the surface layer of the substrate modified using the method of electrospark doping. The results showed the formation in the surface layer of a structure with a highly developed relief and increased strength properties

Assessment of Anthropogenic Impact on the Yenisei River Anabranch within the City of Krasnoyarsk Based on Elemental Analysis of Macrophytes and Water

Абаканская протока р. Енисей в черте г. Красноярска подвержена влиянию антропогенных факторов (дамба в верховьях, подогретые воды ТЭЦ, рыбоводное хозяйство). Цель работы – оценить антропогенное влияние на лентический участок реки Енисей в г. Красноярске на основе элементного анализа макрофитов и воды. С помощью атомно-эмиссионной спектрометрии с индуктивно-связанной плазмой (ИСП-АЭС) определено содержание макро- и микроэлементов в воде и макрофитах Абаканской протоки. В воде обнаружено превышение ПДК для рыбохозяйственных водоемов по Cu, Mn, Mo, Al и фоновых значений по минерализации, концентрации B, Ba, Ca, Mg, Li, Na, Sr, Mn, что могло быть связано с поступлением ливневых сточных и грунтовых вод; концентрации Cu, вероятно, поступающей с подогретыми водами ТЭЦ; концентрации K и NO2 - в воде, вероятно, под воздействием рыбоводного хозяйства. Выявлено увеличение содержания Ba, Сa, Cu, Sr, Zn в элодее, Ca, Cu, Pb, Sr, Li в урути на участках, подверженных антропогенному воздействию. Содержание металлов в погруженных макрофитах свидетельствовало о загрязнении экосистемы Cu, Sr, Fe, Ni и Zn. Выявлены три группы макрофитов, различающиеся по содержанию элементов: элодея (Elodea canadensis Michx.) и рдест стеблеобъемлющий (Potamogeton perfoliatus L.); уруть (Myriophyllum sp.), рдест гребенчатый (Stuckenia pectinata (L.) Börner), роголистник погруженный (Ceratophyllum demersum L.); спирогира (Spirogyra sp.). Отличия могут быть связаны с морфологическими и физиологическими особенностями аккумуляции эссенциальных (Mg, Zn, Fe и V) и неэссенциальных (As, Li, Sr) элементов погруженными макрофитамиThe ‘Abakanskaya’ anabranch of the Yenisei River located in Krasnoyarsk is influenced by several anthropogenic factors (a dam in the upper reaches; heated water discharge from a thermal power plant; fish farming). The aim of the present work was to assess the anthropogenic impact on the lentic part of the Yenisei River in Krasnoyarsk based on elemental analysis of macrophytes and water. Inductively coupled plasma atomic emission spectrometry (ICP-AES) was used to determine the contents of macro- and trace elements in water and macrophytes. Results showed that Cu, Mn, Mo, and Al concentrations in water were higher than their MACs for fishery reservoirs, and specific conductivity and concentrations of B, Ba, Ca, Mg, Li, Na, Sr, and Mn in water exceeded their background values, which could be associated with the input of sewage and ground waters. The elevated concentration of Cu could be attributed to the input of that element with the heated waters of the thermal power plant, and increased concentrations of K and NO2- in water were probably caused by fish farming. Increased contents of Ba, Ca, Cu, Sr, and Zn in Elodea canadensis Michx. and Ca, Cu, Pb, Sr, and Li in Myriophyllum sp. were revealed at sites subjected to anthropogenic impact. The contents of metals in submerged macrophytes were indicative of the contamination of the ecosystem with Cu, Sr, Fe, Ni, and Zn. Three groups of macrophytes have been identified, differing in the contents of elements: E. canadensis, Potamogeton perfoliatus L.; Myriophyllum sp., Stuckenia pectinata (L.) Börner, Ceratophyllum demersum L.; and Spirogyra sp. These dissimilarities may be related to the morphological and physiological differences in the accumulation of essential (Mg, Zn, Fe, and V) and non-essential (As, Li, and Sr) elements by submerged macrophyte

Influence of the Water Level in the Yenisei River on the Ecosystem of its Anabranch within the City of Krasnoyarsk

Расположенная в черте города Красноярска в 35 км ниже Красноярской ГЭС Абаканская протока р. Енисей является, с одной стороны, важным рекреационным водоемом, а с другой стороны, подвержена нескольким типам антропогенного воздействия (зарегулирование дамбой, поступление ливневых и теплых вод, наличие садкового рыбоводного хозяйства), ухудшающего ее рекреационные свойства из-за чрезмерного зарастания макрофитами и скоплений метафитона нитчатой водоросли рода Spirogyra, ухудшения органолептических и микробиологических показателей воды. Природные климатические факторы способны существенно модифицировать влияние антропогенных факторов, что представляет интерес в плане прогнозирования и принятия решений по ликвидации негативных явлений. Целью работы является оценка влияния режима уровня воды р. Енисей в весенне-летний период на экосистему протоки через сравнение данных в многоводный (2021) и средневодный (2020) годы. Гидрофизические, гидрохимические и гидробиологические измерения проводили с мая по август 2020 и 2021 гг. сверху вниз на станциях левобережья: 1 – выше дамбы (фон), 2 – ниже дамбы, 3 – напротив выпуска теплых вод ТЭЦ, 4 – пляж, ниже рыбоводных садков. В 2021 г. вода в протоку поступала только снизу (к ст. 4 и 3), так как водопропускные трубы в теле плотины были засыпаны. В 2021 г., по сравнению с 2020 г., на зарегулированном участке протоки значительно увеличились численность и биомасса фито- и зоопланктона, возросла первичная продукция планктона, а аналогичные показатели фитоперифитона и зообентоса, напротив, снизились по причине их формирования на свежезалитых грунтах. Метафитон отсутствовал, но в августе спирогира стала доминировать в биомассе фитоперифитона. Концентрации нитрит-иона в воде увеличились в зарегулированной части протоки, а нитрат-иона и общего фосфора – на всех станциях протоки, в том числе и на фоновой, получающей воды из Красноярского водохранилища. Наблюдаемая в 2021 г. «вспышка трофии» в планктоне ст. 3 и 4 обусловлена длительным (полтора месяца) удержанием высокого уровня воды в протоке, позволившим использовать биоте вымываемые из затопленных берегов органические вещества и биогены, и аналогична таковой в экотонных зонах выклинивания подпора водохранилищ. Ежегодное увеличение концентраций минеральных форм азота и общего фосфора на нижних станциях, по сравнению с другими станциями, вероятно, обусловлено эвтрофирующим влиянием садкового рыбоводного хозяйстваLocated within the city of Krasnoyarsk, 35 km downstream of the Krasnoyarsk Hydropower Plant, the Abakanskaya anabranch of the Yenisei River, on the one hand, is an important recreational water body and, on the other hand, is subject to several types of anthropogenic impact (regulation by a dam, inflow of storm and warm waters, fish farming). These impacts worsen its recreational properties due to excessive growth of macrophytes and metaphytic filamentous algae of the genus Spirogyra, causing deterioration of organoleptic and microbiological parameters of water. Natural climatic factors can significantly modify the influence of anthropogenic factors, which is of interest in terms of forecasting and decision-making about the elimination of negative factors. The aim of the present work is to assess the influence of the water level regime of the Yenisei River in the spring–summer period on the anabranch ecosystem by comparing the data for the high-water (2021) and medium-water (2020) years. Hydrophysical, hydrochemical, and hydrobiological measurements were carried out from May to August 2020 and 2021 at locations on the left bank: 1 – upstream of the dam (reference), 2 – downstream of the dam, 3 – opposite the outlet of warm water, 4 – at the beach, downstream of the fish farm. In 2021, water entered the anabranch only from downstream (to locations 4 and 3), since the culverts in the dam body were filled up. In 2021, compared to 2020, the abundance and biomass of phyto- and zooplankton in the regulated section of the anabranch significantly increased, the primary production of plankton increased, but the corresponding parameters of phytoperiphyton and zoobenthos, on the contrary, decreased due to their formation on freshly flooded soils. Metaphyton was absent, but in August, Spirogyra began to dominate in the phytoperiphyton biomass. Nitrite ion concentrations in the water increased in the regulated part of the anabranch, and the nitrate ion and total phosphorus concentrations increased at all locations, including the reference location, receiving water from the Krasnoyarsk Reservoir. The plankton “abundance outbreak” observed in 2021 at locations 3 and 4 was caused by the water level in the anabranch remaining high over a long period (one and a half months), which made it possible for the biota to use organic matter and nutrients washed out from the flooded banks; the outbreak was similar to those occurring in the ecotone zones of inputs to the upper parts of reservoirs. The annual increase in the concentrations of mineral forms of nitrogen and total phosphorus at the lower locations compared with other locations was probably due to the eutrophic influence of fish farmin

Worldwide trends in underweight and obesity from 1990 to 2022: a pooled analysis of 3663 population-representative studies with 222 million children, adolescents, and adults

Background Underweight and obesity are associated with adverse health outcomes throughout the life course. We estimated the individual and combined prevalence of underweight or thinness and obesity, and their changes, from 1990 to 2022 for adults and school-aged children and adolescents in 200 countries and territories. Methods We used data from 3663 population-based studies with 222 million participants that measured height and weight in representative samples of the general population. We used a Bayesian hierarchical model to estimate trends in the prevalence of different BMI categories, separately for adults (age ≥20 years) and school-aged children and adolescents (age 5–19 years), from 1990 to 2022 for 200 countries and territories. For adults, we report the individual and combined prevalence of underweight (BMI <18·5 kg/m2) and obesity (BMI ≥30 kg/m2). For schoolaged children and adolescents, we report thinness (BMI <2 SD below the median of the WHO growth reference) and obesity (BMI >2 SD above the median). Findings From 1990 to 2022, the combined prevalence of underweight and obesity in adults decreased in 11 countries (6%) for women and 17 (9%) for men with a posterior probability of at least 0·80 that the observed changes were true decreases. The combined prevalence increased in 162 countries (81%) for women and 140 countries (70%) for men with a posterior probability of at least 0·80. In 2022, the combined prevalence of underweight and obesity was highest in island nations in the Caribbean and Polynesia and Micronesia, and countries in the Middle East and north Africa. Obesity prevalence was higher than underweight with posterior probability of at least 0·80 in 177 countries (89%) for women and 145 (73%) for men in 2022, whereas the converse was true in 16 countries (8%) for women, and 39 (20%) for men. From 1990 to 2022, the combined prevalence of thinness and obesity decreased among girls in five countries (3%) and among boys in 15 countries (8%) with a posterior probability of at least 0·80, and increased among girls in 140 countries (70%) and boys in 137 countries (69%) with a posterior probability of at least 0·80. The countries with highest combined prevalence of thinness and obesity in school-aged children and adolescents in 2022 were in Polynesia and Micronesia and the Caribbean for both sexes, and Chile and Qatar for boys. Combined prevalence was also high in some countries in south Asia, such as India and Pakistan, where thinness remained prevalent despite having declined. In 2022, obesity in school-aged children and adolescents was more prevalent than thinness with a posterior probability of at least 0·80 among girls in 133 countries (67%) and boys in 125 countries (63%), whereas the converse was true in 35 countries (18%) and 42 countries (21%), respectively. In almost all countries for both adults and school-aged children and adolescents, the increases in double burden were driven by increases in obesity, and decreases in double burden by declining underweight or thinness. Interpretation The combined burden of underweight and obesity has increased in most countries, driven by an increase in obesity, while underweight and thinness remain prevalent in south Asia and parts of Africa. A healthy nutrition transition that enhances access to nutritious foods is needed to address the remaining burden of underweight while curbing and reversing the increase in obesit

Cardiovascular Complications in Patients with Acute Ischemia of the Limbs in the Early Period of Ischemic Stroke

Aim. To define risks and complications for patients with the sharp ischemia of lower extremities in the sharp period of stroke after reconstructive surgical treatment for the decline of amount of amputations and sharp violations of cerebral circulation of blood postoperative period.Materials and methods. In the period 2015–2019 based on the Department of Acute Diseases of Vessels of the State Institution «ICUS by. VT Zaitsev NAMNU »we operated 31 patients for acute ischemia of the lower extremities during the period of acute ischemic stroke (namely, within 3–4 weeks after the neurological manifestations). The mean age of the patients was 72.9±1.65 years. Among them are 17 women and 14 men. The diagnosis of acute ischemia of the lower extremities was established in 19 patients, the upper – in 12 patients.Results. All patients (31) were operated; the main blood flow was restored. In 28 cases of patients were performed embolectomy, in 3 cases – bypass surgery.Conclusions. Ultrasound examination of the lower extremities should be performed for patients with acute stroke ischemia with paresis to verify acute lower limb ischemia, which allows timely diagnosis of ischemia and reduce the number of amputations in patients with acute lower limb ischemia I-II degree to 0 %, and the risk of stroke to 3.2

Compensation for moral harm in foreign law and order

The authors of the paper conducted a comparative law research of the current civil legislation governing compensation for moral harm in foreign countries. The article defines the basic terms used in foreign law which are analogues of the institute of “compensation for moral harm” existing in Russia and neighboring countries.Los autores del artículo realizaron una investigación de derecho comparado de la legislación civil vigente que rige la indemnización por daños morales en países extranjeros. El artículo define los términos básicos utilizados en el derecho extranjero que son análogos del instituto de "compensación por daños morales" existente en Rusia y los países vecinos

CONCENTRATIONS AND SOURCES OF POLYCYCLIC AROMATIC HYDROCARBONS IN WATER AND SEDIMENTS OF RIVERS OF NORTHERN OIL AND GAS PRODUCING TERRITORIES OF WESTERN SIBERIA

The relevance. Huge reserves of both fresh water and hydrocarbons are concentrated on the territory of Western Siberia, the extraction and development of which is increasing every year. Oil is one of the main environmental risk factors for the natural ecosystems of the North. Among the components of oil, polycyclic aromatic hydrocarbons stand out, which have carcinogenic and mutagenic properties and have a negative impact on natural ecosystems. However, there are quite a lot of sources of these organic pollutants entering the environment, including they can be of both natural and anthropogenic origin. The relevance of the study of the content and composition of these components is caused not only by their toxicity, but also by their resistance to chemical and biological transformation, high migration activity and ability to accumulate in natural environments. The aim of this work was to study the individual composition and distribution of polycyclic aromatic hydrocarbons in water and bottom sediments of rivers, and to identify possible sources of polycyclic aromatic hydrocarbons entering water bodies of the Arctic zone of Western Siberia. Objects: river waters and bottom sediments taken from 8 watercourses in the territory of the Yamalo-Nenets Autonomous Okrug. The objects were chosen in such a way as to cover rivers of various orders within the catchment basins of the main rivers of the Yamalo-Nenets Autonomous Okrug. Methods. The content and individual composition of polycyclic aromatic hydrocarbons in water and bottom sediments of rivers was determined in the laboratory of physical and chemical studies of core and reservoir fluids of the Trofimuk Institute of Petroleum Geology and Geophysics SB RAS (Tomsk) using high-performance liquid chromatography. Statistical processing of the obtained data was carried out using the Microsoft Office Excel and PAST V2.17 software packages. Results. The features of the distribution of polycyclic aromatic hydrocarbons in water and bottom sediments of the rivers of the northern territories of Western Siberia have been studied. The total content of polycyclic aromatic hydrocarbons in the river waters of the YaNAO varies from 292,8 to 1098,0 ng/l. The minimum content of polycyclic aromatic hydrocarbons, represented mainly by low molecular weight compounds (mainly phenanthrene), associated with terrestrial higher vegetation, was established in the Mahanyad-Pusyakha River, which is a tributary of the Nadym River. The highest concentration of the studied compounds, represented mainly by high molecular weight polycyclic aromatic hydrocarbons, was identified in the water of the Apoku-yakha River, tested near the developed deposits and related to the catchment area of ​​the Pur River. The sources of identified compounds in this sample can be associated with both petrogenic and pyrogenic processes. The total content of polycyclic aromatic hydrocarbons in bottom sediments varies from 1900 to 20000 µg/kg, which is due to the presence of not only natural, but also anthropogenic pollution. The maximum concentration of these compounds was found in the bottom sediments of the Apoku-yakha River. Using statistical analysis, indices diagnosing polycyclic aromatic hydrocarbon sources were established: for water – ratios Flt/Pyr and (Pyr+BaP)/(Chr+Phen), for bottom sediments – ratios BaA/(BaA+Chr), Phen/(Phen+Chr ) and (Pyr+BaP)/(Chr+Phen).On the basis of the data obtained, it was found that polycyclic aromatic hydrocarbons enter the rivers, as a rule, from natural sources. The probable sources of polycyclic aromatic hydrocarbons entering bottom sediments can be divided into several groups: oil burning, combustion processes, as well as mixed sources. Polycyclic aromatic hydrocarbons identified in water and bottom sediments of the Apoku-yaha River have an anthropogenic genesis. The environmental assessment of the state of the rivers, based on the calculation of the polycyclic aromatic hydrocarbon hazard coefficient and the bottom accumulation coefficient, indicates a high level of chronic pollution of the studied objects. It was established that the most intense pollution is characteristic of the rivers belonging to the catchment area of the Pur River, where the most active hydrocarbon production takes place