Larix decidua Mill. is a breed planted for initial introduction testing more than 120 years ago on the territory of East Prussia, now the Kaliningrad region. These plantings are of considerable interest in terms of the success of the introduction. An assessment of the taxation indicators has been carried out, specifying the age of individual trees, the number of plantings, its sanitary condition, the species composition of related species, the composition of the undergrowth, the presence of undergrowth and its condition, the presence and abundance of self-seeding. The characteristics of the soil cover are also given. In the studied area, the type of forest conditions is D2, and the type of forest is linden larch. Plantations are developing according to the I growth class, as part of the European larch stand from 6 to 10 units, the wood stock is 322–386 m³/ha. A comparison with the 2013 taxation figures showed that the allotments differ little in terms of the composition of the plantation and the stand density at the time of the study. A noticeable difference is observed in standing crop. The sanitary condition of the surveyed sample areas has been determined on a scale of tree condition categories and classified into categories of living conditions that differ in two quarters: in quarter 32, the state of the stand is classified as "weakened", in quarter 171 – as "healthy". In the Kaliningrad region, European larch has successfully acclimatized and adapted well to local conditions. However, in block 32, due to the aging and high density of trees, the population becomes less stable, pests appear that damage the trunks, and the risk of windstorms increases. Undergrowth or self-seeding of the main breed, European larch, have not been found in the test areas and on the neighboring allotments.

At each production facility engaged in the processing or recycling of materials, it is necessary to provide for multi-stage wastewater treatment. This requirement is due to the fact that untreated wastewater discharged into water bodies causes significant harm to ecosystems. In the process of discharging such water, there is a sharp increase in oxygen consumption, which is necessary for the biochemical oxidation of organic compounds contained in wastewater. Many of these organic substances are in a bound state, which makes their decomposition a complex and labor-intensive process. In this work, based on wastewater monitoring, an environmental assessment of the quality of industrial wastewater has been carried out, which will help specialists in making decisions on the planned activity or choosing methods for treating enterprise wastewater. As a result of the work, heterogeneity of discharged wastewater during the day has been revealed. In the resulting wastewater, when they are transported through drainage networks to filtration fields, anaerobic processes, oxidative-destructive microbiological and chemical processes occur, resulting in a significant excess of the main pollutants. At the enterprises under study, the ratio of biochemical oxygen consumption for 5 days to chemical oxygen consumption is within 0.40–0.56, which indicates that the water contains easily oxidizable substances that are subject to biochemical oxidation. Therefore, it is necessary to improve the wastewater treatment system at enterprises of the milk processing industry. In this case, biological methods can be used, according to the reference book on the best available technologies, which include the metered introduction of microbiological preparations and additional aeration, which will allow the use of filtration fields as local treatment facilities without large capital investments.

This paper presents a comprehensive study of Antarctic krill (Euphausia superba, Dana 1850) nutrition, which is an important object of domestic fishery in the areas of the Powell Basin and Bransfield Strait (Antarctic sector of the Atlantic Ocean). As a result of complex laboratory analysis, the material including 12 samples of E. superba was evaluated, the total number of individuals was 2128 (of which 49% were juveniles, 22% males and 29% females). Based on the analysis of 545 krill stomachs (all stomachs in which food was present in one way or another) in summer 2020, the main diet components were identified: peridinium (g. Peridinium spp., frequency of occurrence 78%) and diatom (g. Fragilaria, g. Fragilariopsis and g. Synedra) algae, paddlefish (g. Calanus sp.) and planktonic foraminifera (g. Foramenifera). Particular attention was paid to the phenomenon of seasonal cannibalism during the mass moult of krill (17% of the crustaceans were found to have numerous remains of the bodies of related individuals). The first assessment of the relationship between the degree of feeding activity of E. superba, larval cycle stage, sex composition and reproductive state of males and females did not reveal a pronounced relationship between these parameters, the overall low feeding activity of individuals of the species in the summer of 2020 was noted. The study confirmed the polyphagous nature of the diet of E. superba, which actively consumes available phytoplanktonic wo-weeds, supplementing the diet with highcalorie animal food (zooplankton and related individuals of E. superba). The data obtained expand the understanding of food preferences of Antarctic krill at different periods of its life cycle.

Soils contaminated with heavy metals become unsuitable for growing environmentally friendly products. Cadmium (Cd) is one of the most dangerous ecotoxicants. The Cd content is subject to mandatory standardization in soil, agricultural raw materials, feed and food products. Cadmium enters arable fields, including as part of manure. This study is devoted to the investigation of the effect of systematic application of high rates of traditional organic fertilizers (liquid fractions of pig manure and cattle manure) on the accumulation of Cd in soil and plant products (green mass of corn). As a result of research, it has been established that long-term application of significant rates (~200–250 tons per hectare) of manure effluents leads to an increase in the content of total and mobile Cd in agrosoddy-podzolic soils. When assessing the risks of Cd pollution of plant products, it is important to take into account the ratio of pH and organic matter in agrozem. The most active bioaccumulation of Cd occurs in acidic soils with a low content of organic matter. Application of manure to neutral or slightly alkaline soils promotes the formation of mobile, but poorly accessible to plants fulvic complexes. The coefficient of biological absorption of Cd for the green mass of corn grown on fields fertilized with manure effluents is 1,5–2,0, which indicates biogenic accumulation of the corresponding heavy metal. The dependence of the value of the biological absorption coefficient on soil properties is insignificant. The coefficient of biogeochemical absorption of Cd by the green mass of corn varies within a wider range (from 2 to 9) and significantly depends on soil properties. The highest level of the biogeochemical absorption coefficient has been found for acidic agro-sodpodzolic soils.

Lobe pumps (LP) are used for transporting food media with high viscosity when it is necessary to preserve a product structure. The article presents a comparative analysis of the LP performance manufactured by three companies. The publicly available test results of these three companies are served as the initial data. The approach based on the load characteristics when pumping media with the highest values of effective dynamic viscosity (EDV) has been used to simulate the performance of processed cheese (PC) by the lobe pumps. LP performance is calculated as the product of the working volume by the difference between the current rotor speed (RS) and its minimum required value (MRV) to start the liquid flow. The MRV RS decreases with an increase in EDV and a decrease in pressure drop in all studied LP. However, the absolute MRV RS may differ significantly for different LP with an EDV of less than 200 sP. The method is proposed for reducing the load characteristic to a dimensionless form (the dependence of the dimensionless performance on the dimensionless values of the pressure drop, EDV and the RS for a correct comparison of the LP performance with a small difference in the working volume. The dimensionless feed of LP 034-WCB turned out to be the largest of the three studied aggregates. However, the difference between the values of the dimensionless performance of different LP turned out to be significant only at a pressure drop of about 1 MPa and an EDV of less than 300 sP. PS, as a rule, are transported at lower pressures. Under such conditions, the difference in the dimensionless performance of the studied LP becomes insignificant. The results of this study can be used to select LP with the necessary parameters.

The article discusses the use of Matcha green tea in the production of Cinnabon buns to improve bakery products’ nutritional value and consumer properties. The study is aimed at studying the effect of Matcha green tea powder on the physicochemical properties of bakery products, determining the mass fraction of green tea powder added to the recipe to impart the best organoleptic properties to the product, and analyzing the effect of Matcha tea on losses during heat treatment (baking). In the course of the study, recipes for Cinnabon buns with different contents of Matcha green tea were developed and a comparative analysis of the experimental samples organoleptic properties was carried out. The recommended recipe is 0.7 g of green tea powder per 100 g of product. For the Cinnabon buns produced according to this recipe, the following physical and chemical parameters were determined: the acidity of the finished bakery products with Matcha green tea was 2.7 degrees, and the humidity was 36.0%. Heat treatment losses (baking) were 11.8%. It was found that adding Matcha tea in the amount of 0.7 g per 100 g of product improved the taste characteristics and appearance of the products, and also increased the content of useful substances, such as antioxidants, dietary fiber, and vitamins. The content of dietary fiber increased in relation to the control (without Matcha tea) by 1.8 times and is 5.3 g; polyphenols – 74 times (74.0 mg); vitamin A (retinol equiv.) – 1.7 times (140.0 mcg); vitamin K – 35.0 (24.5 mcg); vitamin B1 – 1.9 times (0.19 mg), vitamin A (beta-carotene) – 10.2 times (0.47 mg).

This paper presents a detailed study of machine learning methods application for predicting ships key hydrodynamic parameters. The relevance of the work is due to the need to reduce the time and financial costs of traditional hydrodynamic calculations in ship design. In the study a comparative analysis of three machine learning methods – Linear Regression, Random Forest, Gradient Boosting is carried out. Experiments are performed on an original dataset including 52 existing vessels of Feeder and Panamax classes, with characteristics: length, width, draft, speed, wetted surface area and total completeness ratio. The focus is on predicting Froude and Reynolds numbers for preliminary drag estimation. The results demonstrate the superiority of linear regression: for Froude number, R² = 0.9986 was achieved at MSE = 5.15e-07 and for Reynolds number, R² = 0.9998 at MSE = 9.00e+13. The mean absolute percentage error (MAPE) was 0.15% and 0.57%, respectively. The final result is an AI-based calculation program that is able to read Fr and Re values. The practical significance of the work is due to the demonstration of the possibilities of the new calculation methods, which, with a proper approach, can improve the accuracy and optimize the process of classical calculation. The obtained results allow to recommend the method of linear regression for preliminary assessment of hydrodynamic characteristics at the early stages of design. The practical significance of the work is due to the possibility of improving the accuracy of hydrodynamic calculations and hull shape optimization based on the predicted data. Prospects for further research include expansion of the data set, consideration of additional parameters and testing of hybrid models.

The basis for the efficient and trouble-free operation of marine propulsion systems is the study of processes occurring with their components. In this regard, an important aspect is the uninterrupted operation of diesel engines, which depends on the state of diesel fuel used on ships at present. The need to control the state of fuel is a priority task facing mechanics. Improving existing and developing new methods for monitoring the physical and chemical characteristics of diesel fuels, and analyzing the factors affecting the processes in engines remain relevant to this day. In this paper, an attempt has been made to apply a combination of spectrophotometry, refractometry and microscopy methods to study the characteristics of diesel fuels. Using an SF-2000 spectrophotometer and a diffuse and mirror reflection attachment, transmission coefficient spectra of all diesel fuel samples in the visible part of the spectrum (400–800 nm) have been obtained. Determination of color coordinates and color difference indices using standard and non-standard methods makes it possible to restore the color of the fuel surfaces. This method allows to identify contamination and promptly take measures to eliminate the causes. The work shows that a non-standard method (using a smartphone and software) for obtaining color coordinates for contamination control is appropriate in maritime conditions. The refractometric method makes it possible to determine the values of the refractive index and average dispersion of fuels, which change during contamination. An additional method for studying inclusions in fuel is microscopy. This method is especially effective for dark diesel fuels.