Utilization of the wastes of vital activity

The recycling of wastes from the biological complex for use in life-support systems is discussed. Topics include laboratory equipment, heat treatment of waste materials, mineralization of waste products, methods for production of ammonium hydroxide and nitric acid, the extraction of sodium chloride from mineralized products, and the recovery of nutrient substances for plants from urine

Choice of Anesthesia for Orthopedic Surgery in Elderly and Senile Patients (Review)

Management of elderly and senile patients is a major challenge due to significant comorbidity, especially in surgery under general anesthesia.The aim of the review was to identify the optimal method of anesthesia for knee arthroplasty in elderly patients based on the available clinical and experimental studies.We searched PubMed, Medline, and Elibrary.ru databases for relevant sources. Out of more than 300 publications initially analyzed, 113 literature sources (dating from 1951 to 2021) were included in the review, of which 80 were published within the last five years (2016–2021). The inclusion criteria were high informative value and relevance, except for sources cited as historical references. Both randomized multicenter studies and individual case reports were included in the review. Exclusion criteria were low informative value, outdated and repetitive data.We reviewed the physiology of elderly and senile patients, various variants of anesthesia, the use of neuroaxial anesthesia and peripheral regional blocks, xenon-based general anesthesia, assessed the advantages and drawbacks of each method, and discussed the monitoring of the depth of anesthesia and the issues of inraoperative awareness during knee arthroplasty in elderly and senile patients.Conclusion. The choice of anesthesia for knee arthroplasty in elderly and senile patients should be based on the risks of decompensation of cardiovascular comorbidities and cognitive impairment. No known anesthetic method is ideal in terms of safety. The use of xenon as the main anesthetic seems promising due to its cardio- and neuroprotective properties. However, its use is limited due to relatively high cost. Therefore, the search for optimal (lower than recommended) inhalation concentrations may lead to expanding use of xenon in elderly and senile patients. At the same time, the use of lower concentrations of the drug is associated with the intraoperative awakening and the need for its combination with narcotic analgesics or amnestic agents, which may not be optimal. In addition, the protective effect of xenon retrograde amnesia against the stress of unintended intraoperative awakening has not been studied, and routine methods of monitoring the depth of hypnosis when using xenon often yield skewed measurement results inconsistent with the clinical manifestations of anesthesia.Therefore, there is a need for further studies concerning the retrograde amnesic effect of xenon and search for optimal methods of assessing the depth of hypnosis when using this gas to safely reduce its inhalation concentration

Фитосанитарные нормы и их влияние на международную торговлю растительной сельскохозяйственной продукцией (постановка проблемы)

Relevance and methods. he article examines the impact of phytosanitary standards on international trade in plant products. It is noted that it is complex in two ways: on the one hand, phytosanitary control protects against low-quality goods, non-native pests and diseases, on the other – negatively affects international trade, makes it difficult for small producers to enter the market, especially when it comes to developing countries. The study provides examples of Vietnam and Chile. Results. It is concluded that excessively strict phytosanitary regulations act more as a barrier than as a catalyst for trade. Moreover, there is a tendency to tighten requirements. The authors draw attention not only to the necessity, but also to the complexity of harmonization of phytosanitary standards.Актуальность. В статье рассматривается влияние фитосанитарных норм на международную торговлю растительной продукцией. Отмечается сложный двоякий характер фитосанитарного контроля: с одной стороны он защищает от некачественных товаров, неместных вредителей и болезней, с другой – негативно влияет на международную торговлю, затрудняет выход на рынок некрупных производителей, особенно когда речь идет о развивающихся странах. В исследовании приведены примеры Вьетнама, Чили. Результаты. Сделан вывод, что излишне строгая фитосанитарная регламентация действует в большей мере как барьер, нежели чем катализатор для торговли. Причем отмечена тенденция ужесточения требований. Авторы обращают внимание не только на необходимость, но и на сложность гармонизации фитосанитарных норм

Assessment of soil erosion rate trends in two agricultural regions of European Russia for the last 60 years

© 2018, Springer-Verlag GmbH Germany, part of Springer Nature. Purpose: Forest–steppe and the southern forest ecotones of European Russia (ER) are the most productive agricultural areas in Russia. Both climate and land use changes have occurred within the ER during last 30 years. These changes can lead to changes in the timing, magnitude, and spatial distribution of soil erosion rates on cultivated lands. The objective of this research was to assess the trends in soil erosion rates since the 1960s for two agricultural regions of ER. Materials and methods: Rates of soil erosion were estimated for two time windows (1963–1986 and 1986–2015) within the two agricultural regions. Both regions are characterized by a high proportion of cropland (> 60%), and within each region, one river basin and one 1st–3rd-order agricultural catchment were selected for a detailed assessment of soil erosion rates. Erosion models and visual interpretation of satellite images were used for the evaluation of the erosion rates for the river basins. Sediment budget assessments, 137Cs dating, geomorphologic mapping, and erosion models were used for the evaluation of the sediment redistribution for the two time windows in agricultural catchments. Results and discussion: At the river basin scale, the mean annual erosion rate did not change in the western part of forest–steppe ecotone; however, there was a weak negative trend in the mean annual erosion rate for the eastern part of the southern forest ecotone. A large negative trend in the erosion rate was found for both small agricultural catchments. In all cases, the reduction in the erosion rates was mainly associated with a decrease of surface runoff during snowmelt, as a result of an increase in both the air and soil temperatures during winter season. The soil loss reduction during snowmelt was counteracted by an equal increase in rainfall erosion due to increase of rainfall intensity in western part of forest–steppe ecotone. Conclusions: Reduction of surface runoff during spring snowmelt was the main reason the erosion rates declined on cultivated lands within the forest–steppe and southern forest ecotones of ER. Evaluation of ephemeral gully erosion rate was not incorporated into State Hydrological Institute erosion model used for the evaluation of the soil losses during snowmelt. This has led to an underestimation of the total soil losses for the 1963–1986 time window for all study sites

Аналитический расчет температуры в процессе сушки тонких капиллярно-пористых плоских материалов

In the paper, the authors analyzed the solution of the differential equation of non-stationary heat conduction for an unbounded plate during the heat exchange of plate surfaces with the surrounding medium according to Newton’s law at a constant temperature of the medium. To use the results of solving the equations in the drying of thin flat materials, the dependence of the heat transfer coefficients on temperature and moisture content was studied. As a result of studying and analyzing a number of literature sources, the regularities of the change in the heat transfer coefficients during drying are established with high reliability. Studies of drying of thin wet plates of white and red clays with known heat transfer coefficients have shown that for small values of the heat transfer criterion of the Bio and small temperature gradients over the section of a thin material, application of the results of solutions of the heat transfer equations gives completely satisfactory agreement between the calculated and experimental values of the temperatures and the duration of drying. It is established that for small Bio numbers, the main factor is the external heat and mass transfer of the surface of the material with the surrounding medium and the rate of drying depends little on internal mass transfer. It is shown that the use of numerical methods for solving differential equations is possible with varying degrees of approximation only for accurate and reliable dependences of heat and mass transfer coefficients on moisture content and temperature. For a number of materials with known heat transfer coefficients, the use of analytical methods in calculations is of considerable interest and brings the theory closer to the practice of drying.Приведен анализ решения дифференциальных уравнений нестационарной теплопроводности для неограниченной пластины при теплообмене ее поверхностей с окружающей средой по закону Ньютона при постоянной температуре среды. Для использования результатов решений уравнений в процессах сушки тонких плоских материалов проведено исследование зависимости коэффициентов переноса от температуры и влагосодержания. В результате изучения и анализа ряда литературных источников с высокой достоверностью установлены закономерности изменения коэффициентов теплопереноса в процессе сушки. Исследования сушки тонких влажных пластин из белых и красных глин с известными коэффициентами переноса показали, что при малых значениях теплообменного критерия Био и малых градиентах температур по сечению тонкого материала использование результатов решений уравнений теплопереноса дает вполне удовлетворительное совпадение расчетных и экспериментальных значений температур и длительности сушки. Установлено, что при малых числах Био главным фактором является внешний тепломассообмен поверхности материала с окружающей средой и скорость сушки слабо зависит от внутреннего массопереноса. Показано, что использование численных методов решения дифференциальных уравнений возможно с разной степенью приближенности только при точных и достоверных зависимостях коэффициентов переноса от влагосодержания и температуры. Для ряда материалов с известными коэффициентами переноса использование в расчетах аналитических методов представляет значительный интерес и сближает теорию с практикой сушки

Исследование нестационарного теплообмена в комбинированных пакетах водотермостойкой защитной одежды пожарных

The results of research of non-stationary heat exchange in combined packages intended for creation of special water- and heat-resistant protective clothing of firefighters from dangerous and harmful factors during emergency rescue and other urgent works, with participation of non-toxic substances, acid solutions, alkalis, oil and petroleum products, liquid toxic substances, as well as during operation in water with temperature from 0 to 70 °С are presented. The stability of clothing material packs has been investigated as a transient heat exchange process in a multilayer plate with ideal thermal contact at the joints of the layers. The unlimited plate is heated on both sides under different heat exchange conditions according to Newton’s Law, with constant action of the heat source on one of the surfaces of the hot liquid contacting through the waterproof thin surface. Second surface of the plate interacts with external medium, temperature of which varies according to linear law. At solving the equation of non-stationary thermal conductivity with nonlinear transport coefficients, linearization methods are used based on the approximation of nonlinear coefficients, such that nonlinear equations become approximately linear. The entire heat transfer process is divided into a plurality of small-time intervals within which the transfer coefficients are constant. The zonal method of investigation of non-stationary thermal conductivity in clothing packages establishes equations for calculation of temperature, densities of thermal flows, distribution of temperature across thickness of clothing packages. It has been shown that under accepted calculation simplifications, parameter values are well consistent with the experiment. The composition of the clothing package is proposed, which meets the technical requirements of TУ BY 101114857.082-2015 “Personal Protective Kits”.Представлены результаты исследования нестационарного теплообмена в комбинированных пакетах, предназначенных для создания специальной водотермостойкой защитной одежды пожарных от опасных и вредных факторов при проведении аварийно-спасательных и других неотложных работ с участием нетоксичных веществ, растворов кислот, щелочей, нефти и нефтепродуктов, жидких токсичных веществ, а также при работе в воде с температурой от 0 до 70 °С. Устойчивость пакетов материалов одежды исследовалась как нестационарный процесс теплообмена в многослойной пластине с идеальным тепловым контактом на стыках слоев. Неограниченная пластина нагревается с обеих сторон при различных условиях теплообмена по закону Ньютона, с постоянным воздействием теплового источника на одну из поверхностей, контактирующей с горячей жидкостью через водонепроницаемую тонкую поверхность. Вторая поверхность пластины взаимодействует с внешней средой, температура которой изменяется по линейному закону. При решении уравнения нестационарной теплопроводности с нелинейными коэффициентами переноса использовались методы линеаризации, основанные на аппроксимации нелинейных коэффициентов, такими, при которых нелинейные уравнения становятся приблизительно линейными. Весь процесс теплопереноса разбивается на множество малых временных интервалов в пределах, которых коэффициенты переноса постоянны. Зональным методом исследования нестационарной теплопроводности в пакетах одежды установлены уравнения для расчета температуры, плотностей тепловых потоков, распределения температуры по толщине пакетов одежды. Показано, что при принятых упрощениях расчета значения параметров хорошо согласуются с экспериментом. Установлен состав пакета одежды, соответствующий техническим требованиям ТУ BY 101114857.082-2015 «Комплекты индивидуальной защиты»

Changes in Biomass and Diversity of Soil Macrofauna along a Climatic Gradient in European Boreal Forests

Latitudinal gradients allow insights into the factors that shape ecosystem structure and delimit ecosystem processes, particularly climate. We asked whether the biomass and diversity of soil macrofauna in boreal forests change systematically along a latitudinal gradient spanning from 60° N to 69° N. Invertebrates (3697 individuals) were extracted from 400 soil samples (20 × 20 cm, 30 cm depth) collected at ten sites in 2015–2016 and then weighed and identified. We discovered 265 species living in soil and on the soil surface; their average density was 0.486 g d·w·m−2. The species-level diversity decreased from low to high latitudes. The biomass of soil macrofauna showed no latitudinal changes in early summer but decreased towards the north in late summer. This variation among study sites was associated with the decrease in mean annual temperature by ca 5 °C and with variation in fine root biomass. The biomass of herbivores and fungivores decreased towards the north, whereas the biomass of detritivores and predators showed no significant latitudinal changes. This variation in latitudinal biomass patterns among the soil macrofauna feeding guilds suggests that these guilds may respond differently to climate change, with poorly understood consequences for ecosystem structure and functions