النتائج 31 - 40 من 31,011

2024

Alexander V. Gavrilov | Yuriy B. Gerber

Microwave energy facilitates evaporation, thus producing more solids of higher quality than other concentration methods and traditional evaporators. Despite its effectiveness, the food industry has no methods for industrial microwave evaporation. This article introduces design and operating parameters for the working module of a novel microwave vacuum evaporation. The new microwave vacuum evaporator with cylindrical modules was used for juice concentration. The fluid phase level was calculated based on the development and growth of vapor bubbles across the fluid phase volume. The steam phase level depended on the minimal volume of the steam separator. When the operating pressure in the module was 7.4 kPa, the minimal radius of a vapor bubble was 5.6×10–5 m; 100% vapor content was observed 42 mm above the nucleation level of vapor bubbles. The average total height of the fluid phase level above the emitter was 26 mm, which exceeded the level of radiation penetration. The data obtained were used to develop an algorithm that made it possible to calculate the design and operating parameters of the microwave vacuum evaporator, as well as standard size modules with emitter powers of 600–3000 W. The modules with a diameter of 150 mm had the vapor zone at 43–8 mm and the transitional vapor-fluid zone at 9–16 mm. The boiling zone was at 45–60 mm. The new microwave vacuum evaporator covered the entire power range of industrial air-cooled magnetrons. However, the final stage required modules of ≤ 1100 W for high concentrations of ≥ 60–80%.

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2024

Olga N. Terekhova | Yana S. Duyunova

Russia enjoys a stable demand for flour products, including those obtained by the dry method of starch and gluten production. This study featured pneumocentrifugal parameters of fine particles in a spiral separator that classified milled grain into fractions, separated the solid phase from air, and identified the high-protein flour fraction in the flow. Pneumatically classified flour was subjected to mathematical modeling and experimental research. The analysis of movement and deposition of particles in the working area covered particle mass, density, air-flow rate, and geometry, as well as their effect on the trajectory of particle movement and deposition. The experiment also involved the effect of air-flow rate and air-mix concentration on the classification efficiency. Particles from various grinding and break systems demonstrated classification modes that differed in soaring rate, size, and density. At an air-flow rate of 6–8 m/s, turn 1 of the spiral separator had the ratio of the internal coil radius to the inner pipe diameter as r1/dpipe = 7.9; it was r1/dpipe = 7 on turn 2 and fell down to r1/dpipe = 6.25 on turn 3; for all subsequent turns, the ratio was r1/dpipe < 5. Under these conditions, the fraction reached 160 µm and included small high-protein flour fractions with a particle size of 17–20 µm. The percentage of product accumulated on turns 1, 2, and 3 was 80, 12, and 8%, respectively. The maximal product separation efficiency of the third drain system was as high as 98% at an input rate of 6 m/s. The maximal separation efficiency for premium flour reached 99.2% at an input rate of 4.2 m/s. The separator proved efficient in classifying wheat grain flour into fractions as it was able to separate high-protein fraction and dispersed particles from the air flow. The separator could be used both as an independent device and as part of a complex technological scheme at the stage of pneumatic separators and unloaders.

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2024

Anatoly A. Khvostov | Gazibeg O. Magomedov | Victor I. Ryazhskih | Aleksey A. Zhuravlev | Magomed G. Magomedov | Inessa V. Plotnikova | Aleksei S. Taratukhin

Whipped yeast-free bakery products require effective energy supply to dough in order to optimize energy consumption, baking time, and quality. This article introduces a verified mathematical model of microwave and convective baking for whipped bread based on heat and mass exchange equations. A full-scale experiment to verify the calculations involved dough samples with a humidity of 56 ± 1%. The samples underwent microwave and convective processing until the temperature in the crumb center reached 98 ± 1°C. The mathematical model was formalized as energy and mass conservation equations, which made it possible to consider baking as a non-stationary process of heat and mass transfer of moisture in an isotropic incompressible continuous medium in the diffusion approximation. The equation took into account the unstable phase transition boundary. The practical verification showed the mean error for microwave baking as 14.5% in temperature and 18.2% in moisture content. For convective baking, the results included 12.6% in temperature and 9.7% in moisture content. The mathematical model proved adequate to the real processes of heat and mass transfer. The error in calculating the temperature and moisture content fields was sufficient tooptimize the process. The physical and mathematical model of the baking process made it possible to evaluate the effect of technological variables on the temperature and moisture concentration fields in the dough samples. The mathematical model and the computational experiment can be used to identify static and dynamic characteristics of baking as an object of automatic control, i.e., to identify optimal control channels and actions, as well as to adjust the automatic control system to specific quality indicators.

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2024

Anatoly P. Kaledin | Lyubov V. Malovichko | Alexander G. Rezanov | Lyudmila S. Drozdova | Andiya T. Serikbayeva

Quails (Coturnix coturnix (Linnaeus, 1758)) are the only migratory Galliformes species. Quails are nestling ground-dwelling birds, feeding on seeds and crawling insects. Wild quails inhabit many parts of Russia. Quail farming is quite popular because quail meat is low in calories and possesses a number of beneficial properties, e.g., it is rich in proteins, contains little fat and virtually no carbohydrates, etc. As a rule, quails winter in Transcaucasia and Southern Europe; however, they sometimes prefer to stay in southern regions for the winter. This article introduces the autumn food habits of quails in the Central Ciscaucasia. The research relied on the analysis of stomach contents of 156 birds killed by hunters or hit by vehicles in several districts of the Stavropol Region. The material was collected in the autumn in 2008–2021. In the Central Ciscaucasia, quails are mesophiles and inhabit abandoned wheat and pea fields. The population fluctuates from year to year, depending on spring weather conditions. Their optimal nestling grounds include irrigated fields and areas near canals and ponds. In the steppe regions, they prefer agricultural areas, e.g., orchards, vineyards, holiday villages, sheep sheds, green belts along fields, roads, and railways, etc. Being phytophages, they rely on plant and, to a lesser extent, animal forage. In the autumn, they feeding on green plants, wheat grain, seeds of cultivated and wild plants, and insect larvae.

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2024

Полина Андреевна Никитина | Андрей Николаевич Шихов | Ольга Михайловна Макарьева | Анастасия Александровна Землянскова | Наталия Вадимовна Нестерова

Добыча золота на россыпных месторождениях Восточной Сибири и Дальнего Востока играет важную роль в экономике этих регионов. Магаданская область в данной отрасли занимает первое место в России. Однако увеличение объемов добычи сопровождается негативными последствиями для природной среды, включая изменение русел рек, уничтожение растительного покрова, увеличение мутности воды и др. Эти изменения могут стать источником опасных гидрометеорологических явлений, таких как паводки. Настоящее исследование посвящено оценке воздействия изменения климата и антропогенных факторов на формирование стока рек в Сусуманском районе, одном из центров золотодобычи в Магаданской области, с помощью математической модели «Гидрограф». Объектом исследования выбран бассейн реки Сусуман, где добыча золота и гидрометеорологические наблюдения начались в 30-х гг. прошлого века. По спутниковым данным Sentinel-2 доля нарушенных земель в бассейне р. Сусуман (до п. Тонгора) оценена в 8,8 % от общей площади бассейна, в том числе 3 % полностью лишено растительности. На первом этапе исследований проведено моделирование процессов формирования стока в бассейне р. Сусуман за период 1966–1987 гг. без учета нарушенных территорий. Средний критерий Нэша-Сатклиффа за период моделирования составил 0,59, невязка годового слоя стока – 12 мм или 4 %. Результаты моделирования в значительной мере зависят от качества и репрезентативности входных метеорологических данных об осадках. Следующим этапом станет разработка параметров нарушенных ландшафтов и численных экспериментов по их верификации на основе гидрологической модели.

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2024

Вера Александровна Дмитриева | Силас Хатунгимана

На примере областей Центрального Черноземья рассмотрены основные черты водного режима рек, формирующегося вследствие климатических изменений, и связанные с ними потенциальные эколого-хозяйственные риски водопользования. Для региона с выраженными аграрной и промышленной составляющими в экономике гидроэкологическое состояние рек и искусственных водоемов, как источников водоснабжения, является актуальной. Цель настоящего исследования – анализ трансформации водности речных потоков Центрального Черноземья и потенциально возможных рисков водопользования в условиях меняющихся природно-климатических условий. Исходная база данных сформирована на основе открытых и доступных источников гидрометеорологической и водохозяйственной информации. Обработка материалов производилась традиционными методами гидрометеорологической статистики, гидрологической аналогии, графической интерпретации результатов. Установлено, что в первом десятилетии текущего века в водопользовании сохранялись тенденции сокращения объемов потребления воды. В качестве примера рассмотрены объемы забора свежей воды. Во втором десятилетии количественное изъятие вод стабилизировалось. На реках наблюдается активная трансформация водности. В водном режиме отмечены уменьшение объемов стока и максимумов половодья, увеличение зимнего стока и летне-осенней межени. Особая черта водного режима – образование аномально высоких дождевых паводков в 2016 и 2022 гг. Изменения связаны с климатическими флуктуациями. В исключительно маловодном 2020 г. зафиксирован максимальный расход воды половодья величиной 211 м3/с, что в 53 раза меньше исторического максимума 1888 г., равного 11200 м3/с. Одна из причин низких половодий – состояние почвы накануне снеготаяния, ее влагосодержание и глубина промерзания. Маловодье текущих лет чревато эколого-хозяйственными рисками, связанными как с недостатком воды в дефицитные сезоны водопотребления, например, в сельскохозяйственной отрасли летом 2020 г., так и заполнением малых искусственных водоемов, играющих важную роль в сельскохозяйственном водопользовании. При сокращении объемов стока половодья угнетается экологическая функция водного потока, его разбавляющая способность.

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2024

Дмитрий Александрович Шаров | Алексей Сергеевич Коротков | Игорь Владимирович Пырков | Владимир Петрович Поваров | Алексей Павлович Щукин | Сергей Викторович Росновский | Вячеслав Николаевич Карасев | Виктор Сергеевич Росновский

Данная статья посвящена радиационному мониторингу зоны влияния утечки жидких радиоактивных отходов (ЖРО) из хранилища жидких отходов № 2 (ХЖО-2) Нововоронежской АЭС (НВАЭС) 1985 г. Инцидент привел к радиоактивному загрязнению грунта и грунтовых вод, при этом перенос радионуклидов с грунтовыми водами из места утечки способствовал радиоактивному загрязнению водных объектов, находящихся в зоне влияния утечки. Все эти годы проводились исследования, в ходе выполнения расчетных и полевых экспериментальных работ по радиационному мониторингу зоны влияния утечки из хранилища жидких отходов были получены основные результаты по выявлению причин и оценен масштаб инцидента на Нововоронежской АЭС. Результаты исследований использованы для обоснования безопасности при эксплуатации объектов Нововоронежской и других АЭС, но несмотря на большой объем проведенных исследований, остается нерешенными ряд задач по оценке отдаленных последствий утечки жидких радиоактивных отходов из хранилища жидких отходов-2. Так как требования и правила по радиационной безопасности ужесточаются с каждым днем, а в зоне влияния утечки жидких радиоактивных отходов обнаруживаются новые источники поступления 60Со, а также происходит перераспределение активности донных отложений в р. Дон на участках локализации радиоактивного загрязнения. после последствий утечки в 1985 г. и характеристики загрязнения 60Со донных отложений на этом участке указывают на возможность поступления данного радионуклида в реку Дон с берегового грунта, необходимо непрерывно проводить мониторинг гидросферы в районе размещения АЭС и поэтому существует потребность в новых методиках, программах по исследованию гидросферы. В связи с этим Нововоронежская АЭС разработала новую программу по радиационному дозиметрическому мониторингу реки Дон и береговой полосы до 2030 г.

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2024

G. A. Lihodeevsky | P. S. Bogatova | O. E. Lihodeevskaya

The review presents the generalized material of experimental studies and review works (114 sources, including 110 foreign) on studying the composition of bacterial microbiota of the gastrointestinal tract in cattle depending on age, clinical condition of animals and level of productivity, shows the influence of the functional activity of microbiota on the formation and development of the organism. The microbiota affects the health and productive qualities of dairy cattle. The bacterial community of the gastrointestinal tract plays a crucial role in the digestive system. This complex system with feedback, where on the one hand, the microbiota is influenced by the genotype of the host, feed base, living conditions, breeding methods, and drugs used, and on the other hand, the microbiota primarily affects plastic and energy metabolism, but also indirectly affects respiratory, urinary, central nervous, and immune systems of the body. Bacterial diversity is laid down during the fetal period, undergoes significant changes during calf growth, and remains stable throughout life, adapting to changing conditions. Modern studies of gastrointestinal diseases are increasingly focusing on the composition of the microbial community, pointing to the dangers of antibiotic use and the need for a transition to probiotic and prebiotic therapy. Productive qualities of cows, such as milk yield and fat and protein content, also depend on the composition of the microbiota.

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2024

D. S. Fomin | S. S. Polyakova | Dm. S. Fomin

The research was carried out in the conditions of the Perm Region on sod-podzolic heavy loamy soils in a long stationary plot trial, laid down in 1977. The purpose of the research is to study the effect of various types of fallow on crop rotation productivity and humus content in the soil. The data are given for two rotations (2009–2022) of fallow-grain–grass crop rotations with various types of fallow – with manurial, sown with clover, sown with melilot, sideral with clover and sideral with melilot – without mineral fertilizers and with fertilizers (N60P30K60). It was found that in the sown fallows, the mass of root and mowing plant residues of meadow clover and yellow melilot, depending on the nutrition background, reaches 4.08–4.36 t/ha with a nitrogen content of 41.8–46.9 kg/ha, phosphorus 16.7–18.6 kg/ha and potassium 42.7–69.6 kg/ha. In sideral fallow with clover and clover biomass, 6.99–9.04 t/ha and 6.83–8.53 t/ha of dry matter with a content of 133.5–148.1 kg/ha of nitrogen, 34.3–41.2 phosphorus and 121.2–148.9 potassium were supplied to the soil, respectively. The application of organic fertilizers in the fallow field contributed to an increase in the humus content by 0.19 abs.% to the initial (2.04 %) in the variant without mineral fertilizers and by 0.69 abs.% in the variant with the introduction of mineral fertilizers to the initial (2.08 %) Clover sideral fallow also contributed to an increase in the humus content in the soil by – 0.38–0.52 abs.%. There was an increased productivity of crop rotation with sideral melilot fallow (2.22–2.25 t/ha of grain units per year) relative to the traditional crop rotation with pure fallow (2.08–2.11 t/ha of grain units per year). Cultivation of crops in all studied crop rotations was energetically efficient, the energy efficiency coefficient was 3.63...4.48 in the variants without mineral fertilizers, against the background of NRK – 2.38...3.21.

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2024

L. M. Shchekleina | T. K. Sheshegova | E. I. Utkina

The study was carried out in the conditions of Kirov region in 2019–2023. Against provocative and infectious backgrounds of snow mold, root rot, ergot, powdery mildew, leaf and stem rust, the immunological state and yield of 15 varieties of winter rye created over a 73-year period were studied. Taking into account the breeding methods, the source material used and the year of creation, they were conditionally distributed over five successive periods of breeding and variety change: I – Vyatka 2, Kirovskaya 89; II – Falenskaya 4, Snezhana, Rushnik; III – Flora, Grafinya, Batist; IV – Lika, Talitsa; V – Symphoniya, Garmoniya, Graphit, Graphit FP, Perepel. When recording diseases, well-known methods were used. Research has shown that as a result of breeding, on artificial infectious backgrounds newly created varieties showed a decrease in the development of root rot (Flora, Perepel, Garmoniya – degree of damage 14.6, 15.5 and 15.0 %) and ergot (Flora, Grafinya, Batist, Lika, Symphoniya, Graphit FP, Garmoniya – damage 11.4...15.9 %), grain contamination with sclerotia – 0.38...1.84 %. In varieties of the I period of breeding the degree of root rot infection was 18.8 %, ergot infection – 31.7 %. There is no progress in breeding for resistance to powdery mildew and rust types. The most productive varieties are Lika and Batist (769.3 and 738.7 g/m2), which significantly exceed the Falenskaya 4 standard (578.8 g/m2). A close and significant dependence (p ≥ 095) was revealed between the yield of winter rye varieties and regrowth of plants after snow mold infection (r = 0.693...0.830) as well as grain contamination with sclerotia (r = -0.531...-0.712). The relationship between the yield of winter rye and the development of other studied diseases is insignificant and weak. Considering the high harmfulness of snow mold and ergot in the research region, it is necessary to continue to carry out breeding improvement of varieties for these characteristics, as well as to increase resistance to powdery mildew and types of rust.

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