Influence Of Hydrothermal Conditions Research Articles

The influence of hydrothermal conditions on the strawberries flower buds formation in the Middle Urals

The influence of hydrothermal conditions on the strawberries flower buds formation in the Middle Urals

Determination of the thermal state of a block gravel filter during its transportation along the borehole

Purpose. Development of a methodology for determining the thermal state of block inverse gravel filters manufactured using low-temperature technology during their transportation in a well based on computer and mathematical modeling. Methods. The study of hydrodynamic processes occurring during the transportation of the filter in the borehole, as well as the calculation of thermal fields in the filter body, was performed using the Ansys Fluent software package. To determine the effective thermophysical characteristics of the filter, the approaches of the heat transfer theory in porous media were applied. To investigate the thermal conditions of the filter at heat exchange with well fluid, the use of analytical solution of the heat conduction problem in a cylindrical shell, taking into account the properties of porous dispersed water-saturated medium, is proposed. Findings. The methodology for calculating the thermal state of a gravel filter during its operation in a well has been developed. For estimation of the filter surface temperature, the expression obtained on the basis of the analytical solution of the heat conduction equation, taking into account the characteristics of the porous filter medium, is proposed. Hydrodynamic and thermal fields in the borehole and the filter body during the filter transportation process in the borehole have been obtained. Originality. For the first time, the problem of heat exchange of a gravel inversion filter, manufactured by low-temperature technology in a well is considered. The influence of hydrothermal conditions in the well on the process of filter heating during its transportation in the well is shown. The hydrodynamic fields during the flow of the drilling mud around the inverse gravel filter are determined. Practical implications. The proposed approaches and results of the study allow to determine and can be used in the development of technological regulations for the use of block gravel filters produced by low-temperature technology for the equipment of hydrogeological wells. The methodology for modelling the process of two-phase inversion transition of aggregate state of the binding agent during transportation of inverted block-type gravel filter during well construction has been developed.

Influence of hydrothermal conditions on the mechanical properties of hybrid composite pipes

Composite materials are becoming widespread in many sectors today, especially in the defence and space industry. Composite materials can be exposed to significant temperature changes and various environmental conditions depending on their usage areas. Therefore, composite materials with high resistance to high temperatures and harsh environmental conditions are being studied today. In this study, four types of 6-layer composite pipes with glass/glass/glass, basalt/basalt/basalt, glass/basalt/glass and basalt/glass/basalt stacking sequences were fabricated with filament wound method. In order to simulate the behavior of composite materials under environmental conditions, specimens were subjected to hydrothermal aging in pure water at 70°C for three different periods of 500, 1000 and 1500 hours. During the aging process, the mass changes of the pipes were measured regularly, and the water absorption behavior was determined with reference to ASTM D5229 standard. Hardness tests were carried out with Rockwell hardness tester based on ASTM D785 standard. As a result of the study, it was determined that the mechanical performance of hybrid specimens was higher than that of non-hybrid specimens. It was observed that the hydrothermal aging process caused a loss of mechanical strength in all specimens. It was concluded that the hybrid composite specimen with basalt/glass/basalt stacking order had the highest resistance to hydrothermal aging.

Influence of hydrothermal conditions on algae of the Shurinda thermal spring (Bauntovsky district, Republic of Buryatia)

Studies of the water temperature in the Shurinda thermal spring in the winter of 2009 and 2021 showed lower values in 2021. The number of habitats with different temperatures increased in the space of the thermal field. In 2021, 10 previously unrecorded species were identified in the flora of macroalgae and cyanobacterial mats, including aggregations of Spirogyra sp. The greatest diversity of cyanobacterial mats was found in the temperature range of 50-25°С; in the range of 20-10°С, accumulations of Spirogyra sp. occupied the entire water column. Cyanobacteria again prevailed in the area with a temperature of 4.0ºС. The higher species diversity of algae in March 2021 is due to the lower temperatures of the therms and their lower flow, which led to a greater diversity of temperature within the thermal spring.

Distribution characteristics and prediction model of farmland soil organic carbon in eastern China

Soil organic carbon (SOC) plays a key role in soil improvement, carbon sequestration, and increasing crop yield. In this study, the distribution characteristics and the influence of hydrothermal conditions on farmland SOC content in eastern China were studied. The results showed that the spatial heterogeneity of SOC content in eastern China was obvious. In the area with the mean average temperature (MAT) below 10.42 °C, the SOC content was negatively correlated with MAT and ≥10 °C accumulated temperature, but positively correlated with the ratio of precipitation to temperature (P/T). In the area with the MAT between 10.42 °C and 20.75 °C, the SOC content was negatively correlated with mean average precipitation (MAP), MAT, P/T and ≥10 °C accumulated temperature. In the area with the MAT above 20.75 °C, the SOC content was negatively correlated with MAT and ≥10 °C accumulated temperature, but positively correlated with MAP and P/T. In the area with the MAP below 400 mm, the SOC content was negatively correlated with P/T, but positively correlated with MAP, MAT and ≥10 °C accumulated temperature. In the area with the MAP between 400 mm and 800 mm, the SOC content was negatively correlated with P/T, but positively correlated with MAT and ≥10 °C accumulated temperature. In the area with the MAP more than 800 mm, the SOC content was negatively correlated with MAP, MAT, P/T and ≥10 °C accumulated temperature. Based on the above results, a model for predicting SOC content was established. This is of great significance for the rapid estimation of SOC content on a regional large scale.

Duration of the vegetation period of pea collection specimens in the Eastern Siberia

The authors presented the results of the study of the effect of temperature regime and precipitation on the duration of the growing season and its components for the crop Pisum sativum L. These studies were analyzed on the basis of three-year experiments in the conditions of Eastern Siberia and the most early maturing samples were selected. The objects of the study were 20 collection varieties of pea sowing of Russian and foreign selection. The authors conducted studies in accordance with the methodological guidelines for the study of grain legume crops collection in 2018-2020 in the forest-steppe zone of Krasnoyarsk region, on the fields of the Krasnoyarsk Research Institute of Agriculture. The soil of the experimental plot was common black earth heavyloamy. The humus content of the arable layer was 7.8 %, the pH of the salt extract was 6.8. Over the three years of the experiment, the content of nitrate nitrogen N-NO3 in the soil at the time of sowing averaged 10.12 mg/kg, mobile phosphorus P2O5 was high 23.26 mg/100 g; potassium K2O was elevated 10.06 mg/100 g (by Chirikov method). Agronomic techniques were common for grain legume crops in the region. Clean fallow was the precursor. The work aims to determine the duration of vegetation period of pea collection samples and the influence of hydrothermal conditions on it. The tasks of the study are to determine the duration of pea growing season and its components in different heat and moisture supply years. In addition, another task of the study is to determine the variability of pea plants depending on hydrothermal conditions, as well as to identify the most early-ripening varieties. The authors identifined that the maximum duration of the growing season was characteristic of excessively moist 2020. The longest period is «flowering - ripening» (38 - 49 days), the shortest period was «sowing - sprouting» (18 - 27 days). Duration of vegetation period is characterized by medium variability (Vcf = 16.5 %). Directly proportional dependence of vegetation period duration on precipitation amount (r = 0.979) and inversely proportional on average temperature (r = - 0.982) were revealed. For all periods, the correlation in terms of temperature is negative, in terms of precipitation amount - positive, except for the period «sowing - sprouting» (r = - 0,867). The authors recommend using the Canadian selection variety Profi with a growing season of 66 days for early maturity breeding

Vegetation dynamics and their response to hydrothermal conditions in Inner Mongolia, China

Inner Mongolia grassland is a sensitive area of vegetation response to climate change in China and an ecologically fragile area of terrestrial ecosystem, which is easily degraded due to the coordinated interference of natural and human factors. Therefore, it is of great practical significance to explore the spatial-temporal variation of vegetation coverage and the influence of hydrothermal conditions on its growth, to protect the regional ecological environment, to realize the sustainable development of animal husbandry and to make more reasonable and effective use of grassland resources in Inner Mongolia. In this study, linear regression, partial correlation analysis and Copula method were used to investigate the spatial patterns of NDVI internal variability and its relationship with climate change in various regions of Inner Mongolia from 1982 to 2020, and the results are as follows:(1) From 1982–2020, the surface vegetation coverage in Inner Mongolia showed an increasing trend, and the main climatic factors affecting vegetation growth in Inner Mongolia were different. In the eastern and central parts of the study area, vegetation growth is highly dependent on precipitation, while in the western part of the study area, vegetation growth is greatly affected by climate and precipitation. (2) When the temperature and precipitation of vegetation growth exceed a certain threshold, the probability of plant growth inhibition is higher. (3) NDVI variation trends of different vegetation types are also different. The meadow vegetation degraded obviously, while the marsh vegetation and desert vegetation increased obviously. (4) In addition to climate influences such as temperature and rainfall, livestock numbers and human population are the main forms of human activities accelerating grassland degradation. The results of this study can help us understand the appropriate range or types of environmental factors affecting vegetation growth in Inner Mongolia, and on this basis, we can take appropriate interventions to effectively mitigate the impact of environmental change on vegetation. • It shows an overall greening trend with great heterogeneity in space. • Precipitation and temperature interact to influence NDVI changes. • Copula function helps to quantify the influence of hydrothermal factors on NDVI changes. • NDVI correlates differently with hydrothermal factors in different regions.

Influence of hydrothermal synthesis conditions on lattice defects in cerium oxide

Cerium oxide makes one of the most promising materials for chemical transformations in environmental and energy applications. Herein, the influence of hydrothermal conditions on the physico-chemical characteristics of cerium oxide prepared from salt solution via ammonia precipitation is analyzed. The systems are well characterized using SEM, TEM, XRD analysis, photoluminescence spectra, Raman spectra, TPR study. and XPS analysis. Normal aqueous conditions lead to particles of size ~8 ​nm, with truncated octahedral geometry, closer to spheroid shape (RT-Ce) bound by {111} and {100} planes. Elevated temperature facilitated preferential exposed {100} plane bounded cubic ceria structures of size ~15 ​nm (HT-Ce), which are stabilized by more number of anion vacancies. Low temperature synthesis yielded smaller sized particles with less crystallinity and higher surface area, when compared to hydrothermal route. Lattice defects, represented in terms of Ce3+ ions and associated lattice oxygen vacancies are seen in higher amounts in ceria synthesised via hydrothermal path, as supported by various characterization results. CeO2 achieved via hydrothermal path exhibited higher catalytic oxidation activity, which is examined using a model oxidation reaction, vis., CO oxidation. The enhanced activity of HT-Ce is explained through the defect structure induced facile redox shift in the system.

Influence of hydrothermal conditions on the phase transformations of amorphous alumina

Amorphous Al2O3 transforms into the pseudoboehmite and boehmite phases of AlO(OH) under hydrothermal conditions. Specific surface area, pore volume and the amount of acidic sites decrease upon complete conversion of amorphous Al2O3 into boehmite.

Characteristics of NDVI Temporal and Spatial Variation in the Source Area of the Yangtze River and Its Response to Hydrothermal Conditions

vegetation cover change monitoring is the basis of regional resources and environmental carrying capacity research. Based on the data set MODIS-NDVI 2001∼2018, this paper analyzes the spatial and temporal characteristics of annual NDVI in the Yangtze River source area by using maximum synthesis method and various statistical methods. The effects of surface hydrothermal conditions on space and time were discussed. The results show that:1) the NDVI of the source area of the Yangtze River shows a significant increase trend, and only some areas of Dongyuan NDVI show a downward trend. In spatial distribution, the vegetation coverage in the source area of the Yangtze River is mainly low and medium vegetation coverage, the vegetation coverage increases gradually from northwest to southeast, and the vegetation coverage of Yushu Tibetan Autonomous region is generally higher than that of Hercynian Mongolian Tibetan Autonomous region. At above 4000 m, the vegetation coverage increases more obviously with the increase of altitude. 2) precipitation in the source area of the Yangtze River decreases gradually from southeast to northwest, the low value area is located in the north of the source area of the Yangtze River, and the high value area is located in the eastern part of the Yushu Tibetan Autonomous region. However, the spatial trend of annual mean temperature and precipitation in the source area of the Yangtze River is opposite. The precipitation tendency rate in the source area of the Yangtze River shows obvious spatial difference, the precipitation in the south source generally shows a decreasing trend, and the precipitation in the north source generally shows an increasing trend. The southwest source and east source NDVI of 3) Yangtze River source area are negatively correlated with precipitation, while NDVI and temperature are positively correlated in most areas of the Yangtze River source area, and the effect of temperature on interannual variation is stronger than that of temperature. With the increase of temperature and precipitation, the NDVI also shows an increasing trend in spatial distribution, but precipitation has a stronger effect on the spatial heterogeneity of NDVI. From this we can see that the influence of hydrothermal conditions on the interannual variation of NDVI depends on the temperature, while the effect on spatial distribution mainly depends on the precipitation.

Influence of hydrothermal conditions on the phase transformations of amorphous alumina

Amorphous Al 2 O 3 transforms into the pseudoboehmite and boehmite phases of AlO(OH) under hydrothermal conditions. Specific surface area, pore volume and the amount of acidic sites decrease upon complete conversion of amorphous Al 2 O 3 into boehmite.

Influence of hydrothermal conditions on the duration of the phenophase of common beans at different sowing dates in the forest-steppe conditions of the Ob region

The influence of hydrothermal conditions on the duration of phaseolus vulgaris L. phenophases of the grain direction at different sowing dates in the forest-steppe conditions of the Ob region was studied. The research was carried out on the experimental field of the training and production farm «Sad Michurintsev» at the Novosibirsk State Agrarian University. The objects of the study were the Rubin variety and the promising variety Krasno-pestriy. The structure of the growing season was studied and the samples were assessed by the duration of individual phenological phases. The influence of hydrothermal conditions on the change in the duration of the «sowing-emergence» interphase period was established at different sowing periods (up to 8 days) and the «seedlings-flowering» and «flowering-biological ripeness’ periods (up to 4 days). A one-way analysis of variance was carried out with a confidence interval of 5%. The optimal average sum of active temperatures for the passage of the main phenological phases «sowing-germination», «seedling-flowering» and «flowering-biological ripeness’ has been established: in Rubin it is 244, 518 and 709оС, and Krasno-pestriy is 241, 564 and 760оС, respectively. A relationship between the duration of the growing season and the average daily temperature (–0.90), the sum of temperatures (0.96), the duration of the growing season and the sum of precipitation (0.90) was revealed. The difference in precipitation of growing seasons at different sowing dates is insignificant and ranges from 120 to 131 mm. According to the results of the study, the recommended sowing time for the main groups of beans ripeness in the foreststeppe conditions of the Ob region is the second half of May.

Pathogenic organisms on spring barley in the eastern forest-steppe of Ukraine

Purpose. To detect harmful organisms on spring barley and their variability under the influence of hydrothermal conditions during the crop vegetation period in the Eastern Forest-Steppe of Ukraine and to improve methods of pathogen detecting on plants and grains.Material and methods. The prevalence of diseases and pests was determined by conventional and special methods in accordance with the existing assessment scales and by methods modified by us in the course of work. We improved methods for determining pathogenic species on spring barley upon spring (optimal) and autumn (simulation of wet conditions) sowing followed by evaluating the disease signs during the tillering phase of plants and selecting nutrient medium for phytoexamination of grain and assessment of its infection rate.Results and discussion. The 2009–2020 assessments of the prevalence of diseases and pests on spring barley plants from seeds sown on different dates (autumn and spring) showed that the autumn sowing was more effective for barley net blotch manifestation on spring barley compared to the conventional method of spring sowing, since the autumn conditions are favorable for development of this fungus. Pathogens on spring barley were mainly represented by head smut (Ustilago hordei), barley leaf stripe disease, root rots and corn flies. The greatest prevalence of head smut (up to 67.0%) was observed in the years when the weather was excessively humid during the growing period (HTC =1.7 in 2020) or slightly arid (HTC =1.1 in 2015). The greatest spread of barley net blotch (100%) was observed on sufficient water supply in 2014 (HTC = 1.4). The numbers of frit flies during the study period were significant (up to 100%), only in 2016 there was a decline to 39%. The pathogen species that develop on spring barley seeds were determined. Alternaria contamination of grain ranged 9.0 to 77.0% from year to year; Drechslera contamination - 4.0 to 55.0%, Fusarium contamination - 0.0 to 12.4%.Conclusions. Head smut (Ustilago hordei (Pers. Lagerh.)) and Drechslera fungi causing leaf blotch and root rot (Drechslera teres Ito, D. graminea (Rabenh.) Shoemaker, D. sorokiniana Subram) were found to be the most common diseases of spring barley in the Eastern Forest-Steppe of Ukraine. Of pests, frit flies (Oscinella frit Linnaeus and O. pusilla Meigen) were most common. Major diseases of spring barley seeds are of fungal etiology (genera Drechslera spp., Fusarium Link. and Altenararia Fries). Two new methods of phytopathological analysis of the prevalence of diseases on spring barley crops have been developed: one of them is carried out by autumn sowing of seeds and evaluating plant damage during the tillering phase; the second method is phytoexamination of seeds for pathogens via germination of caryopses in sucrose solution

Влияние гидротермических условий на урожайность мандарина (CitrusreticulataBl. Var. UnshiuTan.) в субтропиках России

Влияние гидротермических условий на урожайность мандарина (CitrusreticulataBl. Var. UnshiuTan.) в субтропиках России

The influence of hydrothermal conditions in the Middle Amur Region on main characteristics of pea varieties of various uses

The paper considers the influence of meteorological factors on the productivity indicators of different pea varieties in the Middle Amur Region. The studies were conducted in 2017–2019 for three groups of pea varieties identified by their use. A difference was found in the reaction of each group of varieties to unfavourable hydrothermal growing conditions. The average values of productivity indicators for pea classes in favourable and unfavourable years are calculated. It was found that the most significant indicators characterizing the different classes of pea are the number of internodes to the first pod, the length of the stem, and the 1000-seed weight. The relationship between the number of internodes to the first pod and the climatic characteristics of the growing season for both grain and forage varieties were revealed. As independent variables, the model includes the growing duration and the average temperature of the flowering-maturation period (R2 is 0.85 for forage and R2 is 0.56 for grain).

Influence of hydrothermal conditions on the productivity of perennial grasses in South Steppe of Ukraine

The purpose is to determine the productivity of perennial legume and cereal grasses under conditions of natural moisture supply in South Steppe of Ukraine. Method. The studies were conducted during 2016—2018 using conventional methods, and the output of feed units, digestible protein per unit of area was determined by reference books. Results. On average over three years of research, the highest yield of leaf-stem mass of cereals was formed by Bromus inermis and Elytrigia medium tender – 11.6 and 11.2 t/ha, respectively. The lowest yield was formed by Agropyrum pectiniforme – 7.6 t/ha. Among the all legume grasses, Melilotus albus prevailed (14.8 t/ha). Medicago sativa and Onobrychis arenaria were able to form a similar yield (14.5 and 13.5 t/ha, respectively) under the arid conditions of South Steppe of Ukraine. Insufficient rainfall in 2017 caused a decrease in the productivity of the studied crops. Thus, in 2017 the average yield of green mass in the experiment was 10.3 t/ha, while in 2016 under more favorable weather conditions this figure was 13.2 t/ha or 28.2 % more. The highest output of feed and protein units (FPU) per unit of area under cereal grasses was provided by Bromus inermis (2.35 t/ha). The lowest one was recorded in Agropyrum pectiniforme (1.60 t/ha). FPU output per unit of area under legume grasses increased respectively. Lotus corniculatus provides less green mass and therefore dry matter and forage and protein units. Perennial cereals grasses do not prevail over legume grasses, so they do not spread in South Ukraine. Conclusions. The productivity of perennial grasses in the south of Ukraine significantly depends on the type of plants, weather (hydrothermal) conditions of the year. The most effective is the cultivation of perennial legumes, namely Melilotus albus, alfalfa, Onobrychis arenaria. Bromus inermis and Elytrigia medium prevail among cereal grasses.

Вплив гідротермічних умов на видовий склад бур’янів, у посівах соняшника

Вплив гідротермічних умов на видовий склад бур’янів, у посівах соняшника

Influence of hydrothermal conditions on the phase composition of materials from the system MgO-Al2O3-SiO2-H2O

This work directly links the performance with the phase evolution in the MgO-Al2O3-SiO2-H2O system during the hydrothermal treatment. Cement-free refractory binders, considered as alternative to calcium aluminate cements, with the chemical compositions fine-grained mixtures of MgO-Al2O3, MgO-Al2O3-SiO2, and MgO-SiO2 reactive powders were subjected conversion from dry mixture to hydrated matrix at ca. 240 °C under autogenous water vapor pressure for 56 h. The main purpose of this approach is to simulate the thermal behavior of the hydrated castable matrix belonging to the MgO-Al2O3-H2O, MgO-Al2O3-SiO2-H2O, and MgO-SiO2-H2O systems when exposed to heat treatment of large-format precast monolithic refractories. The phase compositions of the hydrated samples were determined by X-ray diffraction (XRD) technique using CuKα radiation. The FT-IR scans were used to evaluate the functional groups of the hydrated materials. Thermal decomposition mechanism and microstructure were examined by coupled DSC-TG-EGA (MS) and SEM-EDS, respectively. It is shown through presented results that boehmite (AlO(OH)), brucite (Mg(OH)2), and magnesium- and aluminum-layered double hydroxide-like phase ([Mg6Al2(OH)18 4.5H2O]) were formed via hydrothermal synthesis in the MgO-Al2O3-H2O system. Chrysotile (Mg3[Si2−xO5](OH)4−4x) was detected in the MgO-SiO2-H2O binder system as a main phase and in the MgO(rich)-Al2O3-SiO2-H2O binder system as secondary phase. For the sample with the Al2O3 excess, two magnesium aluminum silicate hydroxides ((Mg,Al)6(Si,Al)4O10(OH)8, Mg5Al2Si3O10(OH)8), together with MgAl(OH)14 xH2O, Mg(OH)2, and AlO(OH), were formed in the MgO-Al2O3(rich)-SiO2-H2O binder system. Since the type of hydrates contributed to the thermal stability of the binder matrixes, the valuable practical results concern mainly on the optimization of heat treatment process of state-of-the-art CaO-free matrixes being considered as precursors in the low-temperature synthesis of high refractory phases like spinel and forsterite.

Preparation and Properties of Zr-Bearing Sorption Materials Based on Coal Fly Ash Microspheres

The influence of hydrothermal conditions on synthesis of analcime and a composite material ZrO2- analcime as well as zirconomolybdate coverings with ion exchange properties was studied using narrow fractions of aluminosilicate microspheres with a high content of a glass phase (91-95 wt. %). The possibility to synthesize ZrO2-analcime composites of narrow particle size distributions with maximum of about 40 μm and 6 μm under hydrothermal treatment at 150 °С was demonstrated starting from microspheres with Si/Al=2.7 and applying different regimes of a reaction mixture agitation. A microsphere material of a “core-shell” type such as ZrMo2O7(OH)2(H2O)2@(SiO2-Al2O3)glass with the nanostructured covering was prepared. Sorption properties of the materials regarding Nd3+, Sr2+ and Cs+ were studied under equilibrium conditions by means of determination of sorption isotherms and their fitting by the Langmuir model. Sorption parameters were determined including distribution coefficients which reach the values of 104−105 mL/g

Yielding properties of bread winter wheat seeds depending on morphotypes of embryos and the influence of hydrothermal conditions and preceding crops on them

Yielding properties of bread winter wheat seeds depending on morphotypes of embryos and the influence of hydrothermal conditions and preceding crops on them