Light Clay Research Articles

Peculiarities of clay soils research in the course of forensic soil examination

Methods of clay soils research that take into account the specifics of expert study of soil objects are defined. In order to classify a soil as clay, the mechanical composition is first examined. According to this indicator, clay soils are divided into loam, light clay, and heavy clay. Clay is classified as a mineral resource of national importance, while loam is classified as a mineral resource of local importance. These soils may be subject to illegal mining. The article analyses the possibilities of applying various methods for the expert study of clay soils, namely, the method of sedimentation analysis and the ‘field’ method. After establishing the mechanical composition and classification of samples as clay soils, it is recommended to determine the plasticity index, according to which the soils are classified as loams or clays. The analysis is described in accordance with the State Standard of Ukraine Б B.2.1-17:2009 “Bases and foundations of buildings and structures. Soils. Methods of laboratory determination of physical properties”. It is shown that in the course of forensic soil examination, the use of the “field” method in combination with the determination of the plasticity number allows soil samples to be classified as clay soils without the need for a long sedimentation analysis. The proposals presented in this article may be useful for selecting effective expert methods for the study of clay soils during the forensic examination of materials, substances and products in the expert speciality 8.8 “Soil Research”.

Getting a Face Brick of Light Shades Based on Marl

The article reflects the topic of the shortage of raw materials for the production of face bricks of light colors. This problem has particularly affected producers in the European part of Russia due to the cessation of clay supplies from the territory of Donbass. Therefore, one of the relevant directions is the search for alternative sources of raw materials. The accumulated experience and laboratory tests have shown the possibility of producing light bricks using marl. As components of the ceramic mass, clays from the Vladimirovsky deposit in the Rostov region of the East Kazakhstan region, charge and marl KO-2 were also accepted from deposits in the Rostov region. By changing the percentage of marl and refractory clay and the firing temperature, it is possible to adjust the color of the fired products, as well as water absorption, average density, strength of products and their shrinkage. Industrial tests conducted on the basis of two brick factories in Rostov-on-Don and the region showed positive results. The use of marl ranged from 40 to 70% of the total weight. Clay from the East Kazakhstan region Vladimirovskoye deposit in the amount of 30 to 60%, respectively, acted as a plastic component. The brick turned out to be light beige to light yellow in color. One of the factories launched the “Svetly” brick into mass production. The material fully meets the requirements of GOST 530–2012. Thus, the problem of the shortage of light clays can be solved by using alternative raw materials – marl. The introduction of 50 to 70% of the mass into the composition is particularly effective. Preliminary calculations show the profitability of the technology by saving raw materials up to 20–25%, while increasing the aesthetic characteristics of the front brick.

Prefab Light Clay-Timber Elements for Net Zero Whole-Life Carbon Buildings

"Net zero whole life carbon" is an ambitious climate target that refers to neutralizing and offsetting the entire LCA-based carbon footprint of a building, including both operational and embodied greenhouse gas emissions. Especially in the Northern climate, viable building envelope structures must, therefore, provide good thermal insulation and low embodied emissions. Carbon offset is typically based on excess on-site renewable energy or purchased carbon offsets disconnected from the building and the site. Viable strategies for carbon neutrality start by minimizing material-related and energy-related CO2e emissions. As a result, new kinds of building envelope structures have been recently introduced in the academic literature and experimental building projects. Traditional construction materials, such as timber and clay, have been sourced locally and processed manually, providing good results for the embodied emissions in life cycle assessment. Recent studies on clay-based construction materials have concluded that more research on clay as a construction material is needed, in particular considering its environmental performance. One specific concern in the Northern climate is that the weather conditions limit clay construction outdoors and prevent industrial-scale application of these solutions. The methods of prefabrication can address these issues. This study introduces the critical technical and environmental properties of a new prefabricated wall element based on a combination of light timber frame and light clay. In a hybrid light clay-timber structure, a mixture of clay and hemp shives is cast between the timber studs. On the one hand, the novelty of this wall structure is the prefabrication that enables industrial applications and upscaling without the limitations of weather conditions. On the other hand, the study assesses the climate impact of a light clay-timber wall element : cradle-to-gate emissions, thermal insulation, and the climate benefits outside the system boundary (carbon handprint) reported in the D-module of the LCA framework. The study also shows that natural materials require a different approach than synthetic materials from industrial processes. There may be variations in the properties of hemp and clay, especially when local sourcing is prioritized for better environmental performance. Moreover, the mixing and installation processes have a significant impact on the final properties and the performance. We show that constructing a light clay wall is a knowledge-intensive process that may result in very different technical properties.

Військовий табір Коблеве та західний кордон хори Ольвії римського часу

In the article the results of the first archaeological investigations of the Roman military camp near Kobleve village on the left bank of the Tylihul estuary are highlighted. According to the extensive analysis of narrative and cartographic sources of the 19th century, it was possible to clearly determine the location of this camp and introduce it into the system of Roman period field fortifications on the territory between the Buh and Tylihul estuaries. The analysis of the obtained materials made it possible to partially reproduce the construction of the camp’s fortifications and outline the period of its operation in the second half of the 1st century AD. Considering the chronology of amphorae finds (light clay with double-barreled handles) and historical events, namely the combined campaign of T. Plautius Silvanus' troops to Chersonesos, it can be stated that the Kobleve camp, like other similar monuments in the region, was built in the third quarter of the 1st century AD. It should be noted that this object was part of the general system of protection of the Olbian chora during Roman times, which did not consist of linear defensive structures (ramparts with ditches, as it was previously believed), but of a system of fortifications of individual cities and settlements and military camps-forts erected near the most important highways. It should also be emphasised, that the Kobleve Roman fort and similar camps (Didova Khata III and Kamianka V) were located near high mounds with traces of fortifications on them. The camp with the mound formed a single observation and defense complex, which was responsible for the protection of certain sections and junctions of the main roads (in particular, the Road of the barbarians), crossings, as well as the northern borders of the Olbian polis of Roman times, at least from the third quarter of the 1st to the beginning of the 2nd centuries AD. After the stabilisation of the political and military situation in the region during the second half of the 1st century AD, the chora of Olbia had began to expand. In addition to other factors, the appearance of numerous plaques with dedications to Achilles Pontarchus, including along the Road of the barbarians in the area of Kobleve village, serve as markers of this. It testifies to the restoration of Olbia’s influence on these territories around the beginning of the 2nd century AD and the establishment of the western border of its chora along the left bank of the Tylihul estuary. Perhaps the influence of Olbia had spread further west. Finally, we emphasise that the field studies of the Kobleve Roman military camp are promising (to establish the planigraphy of the monument, the stratigraphy of the remains of the rampart and the ditch, as well as the identification of building remains inside its area).

Physical-chemical properties of the soils of the Ganja-Gazakh region

Field experiments were carried out on irrigated gray-brown (chestnut) soils in the territory of the Ampelographic collection garden of the Ministry of Agriculture Viticulture and Winemaking Research Institute of Ganja Viticulture and Winemaking Experimental Station. Total absorbed bases were 28.5 mg/eq in the 0-30 cm layer and decreased to 20.5 mg/eq in the 60-90 cm layer. The amount of silt along the profile was 25.1-23.6%, and the amount of physical clay was 25.1-23.6%. These soils are considered to be light clay with granulometric composition according to R.H. Mammadov.

Effect of mechanical impact on the microstructure and IR spectra of cohesive soil

The aim of the study is to determine the correlations between mechanical impacts on clay soil samples and resulting changes in the microstructure of the samples and their IR spectra. For research, soil from a railway subgrade under construction in the Azov-Black Sea region was used. The soil was examined by traditional and modern physical methods and classified as light clay. Clay properties were modified by adding alabaster to the soil, after which the samples with different amounts of alabaster were subjected to mechanical load. A cyclic mechanical impact by the compression method was applied to a clay sample without alabaster, an equivalent to the passage of 400 freight trains along the railway track. The microstructure of samples was studied by electron microscopy which allowed determining the microstructure parameters of the fragments of samples before and after the mechanical action. Samples of clay and clay with the addition of alabaster were subjected to a semi-quantitative express analysis by IR spectroscopy, as a result of which the concentrations of minerals were determined with an accuracy of no worse than 10%. Clay and clay samples with the addition of alabaster were subjected to static uniaxial compression, after which the samples were examined by IR spectroscopy. Comparison of the results of spectral and compression studies made it possible to investigate the correlations between changes in the peak intensities of the IR spectra bands and the concentration of alabaster, as well as the strength properties of the soil.

Data-driven irrigation scheduling increases the crop water use efficiency of Cabernet Sauvignon grapevines

In the context of water management in agriculture, irrigation scheduling is critically important as it optimises water application to crops and can also target specific production goals. However, there is no consensus on the ideal irrigation scheduling strategy regarding crop water use efficiency (WUEc). In a premium Cabernet Sauvignon vineyard in Coonawarra, South Australia, over three growing seasons, irrigation scheduling strategies based on experience or historical knowledge (‘GROW’ treatment) were compared to data-driven strategies including crop evapotranspiration, and plant and soil water status thresholds to evaluate their effects on leaf- and vine-level WUEs. A final treatment, GROW + , that doubled the GROW level of irrigation was also evaluated in the third season. The WUE metrics were determined at the leaf, vine, and fruit scales as intrinsic WUE (WUEi), crop WUE (WUEc), and carbon isotope ratio (δ13C), respectively. Furthermore, the irrigation strategies were evaluated in the background of two contrasting soil types: Terra Rossa (light clay, well-drained) and Rendzina (heavier clay, poorly drained). Seasonal soil and vine water status, leaf gas exchange, and light interception were measured, and yield components and pruning weights were obtained following harvest. The amount of seasonal irrigation water based on the data-driven strategies was up to 65% lower across both soil types compared with the GROW or GROW + approaches. WUEi and δ13C were largely similar between treatments. However, for vines grown on Terra Rossa soil, little to no yield penalty was observed when data-driven irrigation scheduling was applied, in addition to increased WUEc values of up to 41%. It can be concluded that irrigation scheduling decisions based on data were superior to the conventional irrigation scheduling method on account of reducing irrigation water volume and increasing WUE, particularly in Terra Rossa soils.

Rekonstrukce oligocenního prostředí na severním okraji středohorského vulkanického komplexu – kombinace vulkanologie a paleontologie

Fossilised remains of plants and animals can be found at many sites of volcaniclastic deposits and intravolcanic sediments (limestones, diatomites, lignite) of the České středohoří Volcanic Complex. Many of these localities have been known and studied since the 19th century. Some of these localities even gained international recognition due to abnormal abundance of fossil material. Collected and carefully stored paleontological material is still intensively studied with an aim to better understand the evolution of life but also environmental changes in Central Europe during Cenozoic. Combination of paleontology and volcanology has a potential to better constrain the paleo-environmental interpretations, as the two geological branches use different methods and gathered results can be confirmed by independent techniques. For this reason, our research focused on less-known paleontological locality at Starý Šachov, which provides interesting exposure documenting relations between volcanic activity, surrounding environment and biosphere during early stage of the České středohoří Volcanic Complex formation. The site Starý Šachov, also referred to as Malý Šachov (Radoň 2001), belongs to the basanitic Lower Oligocene Ústí Fm. of the České středohoří Volcanic Complex (sensu Cajz 2000) and is located at the northern margin of the České středohoří Mts. (Fig 1a). The Starý Šachov gorge exposes a sequence of pyroclastic rocks, capped with basanite lava (Fig. 1b), which was dated to 30.70 ± 0.45 Ma (K-Ar, bulk- rock). The pyroclastic sequence overlays redeposited volcaniclastic and intravolcanic sedimentary rocks (Fig. 1c). The volcaniclastic layers in the lower part of the sequence, where they alternate with intravolcanic sediments, consist of a mixture of basaltic epiclasts, and redeposited pyroclasts mixed with quartz and K-feldspar grains (Fig. 2a). This association suggests a short fluvial transport of volcaniclastic material from the growing volcanic complex, mixed with clastic material of the poorly solidified Merboltice Fm. sandstones representing the intimate bedrock of the locality. The pyroclastic sequence starts with deposits dominated by glassy non-vesiculated lapilli (Figs 1e and 2b, c) later replaced by deposits dominated by highly vesiculated lapilli (Figs 1d and 2d). The light-coloured sediments from the lower part of the succession contain abundant paleontological material. Clusters of white strongly flattened and crushed mollusc shells (Figs 3a, d, f, g) occur in whitish to light grey thinly bedded claystones. Together with molluscs, small cracked ostracod shells (Figs 4a–c) and caddisfly (Trichoptera) larval cases (Figs 4e, f ) are very abundant. Very rarely, twigs of plants from the Taxodiaceae family (Radoň 2001) and indeterminable leaf fragments were found. In dark coaly clays, undercut ostracod valves are abundant as well as in light coloured clays. Small rounded seeds of water lily-like plants (Fig. 4h) and fragments of frog bones (Fig. 4i) occur in larger numbers in the coaly clays. Gyrogonites of charophytes (Figs 4d, g) and only three shells of freshwater gastropods were found in the redeposited volcaniclastic layer underlaying the light clays. Unlike the compressed and crushed gastropod shells of the overlying clays, these three shells are spatially preserved. They belong to the species Planorbarius blazkai (Klika 1891) and Stagnicola sp.Based on the described taphocenosis, sedimentary and pyroclastic deposits we may reconstruct the paleoenvironment of this locality in Early Oligocene (Fig. 5). The landscape prior to the volcanic activity can be characterized as alluvial plain on the northern periphery of a growing volcanic complex. In this plain, braiding rivers were transporting and depositing volcaniclastic material as well as quartz grains of the poorly solidified Merboltice Fm. sandstones. Numerous oxbow lakes from abandoned meanders represented static water bodies. Such environment explains the observed biotic assemblages, dominated by flowing water preferring like trichoptera, with sporadic finds of static water elements like water lily-like plants, which may be either redeposited or reflect presence of minor static water bodies (oxbow lakes). The water rich environment is reflected also in the character of the subsequent volcanic activity. The phreatomagmatic pyroclastic deposits suggest that the eruption started in water- saturated environment (Surtseyan style eruption in a shallow lake or marsh) and later turned into the drier style (Strombolian) as the volcano emerged above the water body. The volcanic activity was terminated by lava emission.

Increase in Productivity of Chestnut Soils on Irrigated Lands of Northern and Central Kazakhstan

Natural conditions in North and Central Kazakhstan and the energy potential of chestnut soil testify to the efficiency of agriculture, especially on irrigated lands. The humus horizon of chestnut soils is 35–50 cm, and the humus content is 3.0–3.5%. The majority of the humus (75%) is contained in a half-meter layer, which emphasizes the short humus level. The phosphorus content, both gross and mobile, is very low at 0.98–0.031%. Potassium is in elevated amounts. Soils are most susceptible to the application of nitrogen–phosphorus fertilizers. According to the mechanical composition, chestnut soils are predominantly lightly loamy, light clays with substrates of souses. Salinization is low, with a salt content in the 0–100 cm soil layer of 0.10–0.20%. The mass of the arable soil layer is 1.3–1.4 g/cm3. Deep plowing and loosening of soils improve the water and nutrition regime, creating good conditions for arid agriculture. With deep autumn plowing up to 30 cm, the accumulation of sediment and spring meltwater reaches 1200–1500 m3/ha more than in spring disposal. Deep plowing ensures absorption of irrigation water, eliminates run-off during irrigation, and reduces the number of crops requiring extra irrigation. In an average dry year, at 50% water availability and 70% soil moisture content (MC), the number of irrigations is 4, and the irrigation rate is 300–470 m3/ha; at 60% MC, 2 irrigations are performed, and the irrigation rate is 600–650 m3/ha. On irrigated land, the yield of cereals is 2.8–2.6 t/ha; perennial grasses, 3.0–4.5 t/ha; potatoes, 23.2–24.1 t/ha; carrots, 35.0–40.0 t/ha; and cabbage, 50.0–75.0 t/ha.

Морфолого-генетична та агрономічна характеристики контрастних за засоленням ґрунтів солонцевого комплексу Приорілля

The article presents the results of field and laboratory studies on the determination of the morphological, genetic and agronomic characteristics of the soils of the Solon complex of Prioril, contrasting in terms of salinity - the establishment of the peculiarities of the morphological structure of the profiles, the granulometric composition, and the parameters of the main agrochemical, salt and physicochemical parameters of the salt marsh of the meadow-black earth shallow salt marsh and black earth-meadow soil - as typical components of the salt complex of the Oril river valley. Standardized field survey and laboratory-analytical methods were used. It has been established that manifestations of halogenation increase with depth in the Luchno-chernozem salt marsh. Alkalinity in the humus-iluvial horizon increases to a strong degree, in deeper horizons - to a very strong one; the degree of salinity increases to medium, strong, and finally to very strong in the bedrock. According to the depth of the upper horizon of salt accumulation, this soil is classified as saline. The content of absorbed sodium in the humus-iluvial and illuvial horizons corresponds to the "saline" gradation. The chernozem-meadow soil is non-saline according to the content of toxic salts in the entire profile, there are no signs of physical and physico-chemical salinity. The content of the silt fraction in the salt marsh profile increases with depth and reaches its maximum value in the illuvial horizon, which is typical for salt marshes and is explained by the redistribution of soil colloids in the profile, the granulometric composition of the salt marsh in the humus-eluvial and illuvial horizons is light clay, in the humus-illuvial - medium clay. The profile of the chernozem-meadow soil is also heterogeneous in granulometric composition, which is heavier from medium loam in the humus horizon to heavy loam in the transitional horizons. The reason for this may be ancient alluvial processes that formed the soil-forming rock of the single-forest terrace. The content of humus in the salt pan in humus-eluvial and humus-iluvial horizons is average, the content of mineral (nitrate and ammonia) nitrogen is very low. The content of mobile potassium turned out to be elevated, and the content of mobile phosphorus was very high. In the chernozem-meadow soil, the content of humus in the humus arable horizon is high, in the first transitional one, it is average. The content of mineral nitrogen is low. The content of mobile phosphorus exceeds the upper limit of the high level by 3.5 times, and mobile potassium by 3.1 times, which is typical for the soils of closed depressions and is a consequence of long-term accumulation of surface runoff waters. Conclusions. The salt marsh complex of Priorillya with the number of salt marshes in the soil cover of about 50% is typical for the southern part of the Middle Forest Steppe in terms of the structure of soil profiles and soil halogenation. A characteristic feature of the studied salt marsh complex is the significant contrast of its components in terms of halogenation manifestations: at a short distance there are salt marsh highly saline salt marsh and leached chernozem-meadow soil without physical and physico-chemical signs of salinity.

О трансформации контуров капельного увлажнения почвы в постполивной период

Purpose: to determine special features of changes in the geometric and moisture parameters of the soil drip moisture contours after irrigation. Materials and methods. The basis for generalizations on the dynamics of moisture contours transformation was the results of field studies conducted on three experimental plots, the top soil of which is represented by medium-thick southern chernozem, characterized by the content of physical clay Wг equal to 45.0; 52.5 and 70.2 % by dry soil weight. Measurements of contour parameters were carried out in 0, 12, 24, 36, 48, 72 and 96 hours after completion of drip irrigation during post-irrigation period. Results and discussion. An analysis of the shape and geometric dimensions of the contours and internal contour isopleths, recorded in post-irrigation periods of different duration, made it possible to determine the qualitative features of their change over time. An increase of the linear, areal and volumetric dimensions of moisture contours over a certain time period, stabilization and their subsequent decrease, up to the complete contour drawdown, has been defined. Of all the variety of factors influencing the process of contour transformation, soil conditions determined by soil granulometry are considered as the main ones. An empirical dependence that describes the functional relationship between the linear parameters of the contours, the content of physical clay in the moistened soil profile, and the duration of the post-irrigation period has been obtained. Conclusions. Based on the field study data, the qualitative-quantitative parameters of transformation of the drip soil moisture contours in the post-irrigation period, typical for southern chernozems of medium-thick light clay, medium and heavy loam, were determined. The predicted parameters of drip soil moisture contours were compared with the known data, allowing to make a conclusion about their acceptability for practical application in the development of drip irrigation regimes for agricultural lands.

ENSURING THE EQUISTABILITY OF THE TILLAGE TOOLS WEAROUT

The paper considers the elaborated measures, aimed at ensuring the equistability of the wearout and reaching the effect of selforganization of the cutting elements of the reinforced V-shaped sweeps that leads to the reduction of the tractive resistance and decrease of the fuel consumption by the mobile energy facility. Soil environment, where V-shaped sweeps function, influence greatly the regularities of the wearout and formation. Wearout of the tillage tools occurs unevenly, that leads to their premature rejection. Solution of the problem of ensuring higher durability to abrasive wear is achieved due to the application of the reinforcing technologies. All the available methods of reinforcements are suggested for the specific operation conditions and do not take into consideration possible change of the conditions and operation models. For achieving the equistability of wearing- out it is necessary that the wear resistance of the tillage tools surfaces was proportional to the intensity of the abrasive wear in all the local zones. Uniform wearing-out of all the friction surfaces must provide long saving of the initial form and provide the effect of self-sharpening of the tillage tools. Determination of the character and peculiarities of the wearing process of the serial V-shaped sweeps was carried- out at three types of soils, using the cultivator «John Deere 2210»). For study serial V-shaped sweeps, made of the steel 28MnB5 and steel 65Г were used. As a result of the studies, carried out wear distribution line was established, on its base measures, aimed at ensuring wearing- out the equistability and achieving self-sharpening were determined. Reinforcement of the V-shaped sweeps was performed by means of the electrodes T-620, Т-590 and M-Fe 6 according to the elaborated schemes. As a result of the application of the suggested measures increase of the wearing-out equistability on sandy loam soils is observed within the limits of 6…9%, on clay loam soils – 42…49%, on light clay – 25…36%. Self organization of the cutting elements of the reinforced V-shaped sweeps results in the decrease of the tractive resistance and fuel consumption by the mobile energy facility on average by 11%. Application of the reinforcing technologies enables to increase wearing-out equistability of the V-shaped sweeps of the cultivators by 9…49%.

In Vitro Antimicrobial Activity Of Layered Silicate Materials

Objective — to assess the presence of a direct antimicrobial effect of natural minerals (ammonite; montmorillonite of the Azerbaijani deposit; calcium montmorillonite, or light clay, and sodium montmorillonite, or dark clay, of the Gerpegezh deposit in Kabardino-Balkaria; serpentinite) against strains of Staphylococcus aureus, Escherichia coli and yeast-like Candida fungi. Material and Methods — The antimicrobial activity was investigated by qualitative and quantitative methods; the methods of X-ray diffraction and X-ray fluorescence analysis were used to assess the chemical composition of samples of natural minerals. The results were statistically processed. Results — We established that ammonite, montmorillonite of Azerbaijani origin and serpentinite did not have a direct antimicrobial effect against the studied cultures of bacteria and fungi (S. aureus, E. coli, Candida albicans). The growth of S. aureus was suppressed by calcium and sodium montmorillonite from the Gerpegezh deposit. Sodium montmorillonite had the strongest antibacterial effect, and its dose-dependent effect was revealed. According to the data of X-ray fluorescence analysis, in the structure of, trivalent iron and oxides of manganese and titanium predominated in the samples of dark Gerpegezh clay with a more pronounced anti-staphylococcal effect. Conclusion — Our study demonstrated the possibilities and limitations of using various samples of layered silicate minerals for antibacterial solutions. The spectrum of antimicrobial activity largely depends on the unique composition of mineral complexes. Samples with a high content of iron(III) can be considered promising in the development of natural antimicrobial preparations.

Finite Element Method Analysis Applied to Different Foundations Structures Systems

In the conventional static analysis of building frames, the base is idealised on rigid supports and the building is subdivided into three parts namely, the superstructure, the foundation and the ground soil, before design. In real life situations, the soil underneath the building undergoes deformations which may alter the performance of the structure. In this paper, it is studied the effect of soil type and foundation type on the response of a building frame system with both fixed base and flexible base. The Winkler model of soil-structure interaction is adopted to study the influence of soil flexibility and foundation rigidity on a 4 storey RC building with a regular plan resting on three types of soils namely, the light peat marshy ground, wet clay and medium gravel with fine sand. Three types of foundations are considered in the study: isolated footings, tied foundation and the raft (with and without overhangs) foundations. Winkler model is developed using springs by Finite Element Method in SAP2000. The settlement, the bending moment, the shear force and the axial force are the parameters placed forth for the comparative study. Results obtained reveal an increase in the response of the structure with respect to the soil flexibility and foundation rigidity.

Cryopreservation of semen of initial forms and chimeras of birds of two breeds: Sussex light and Poltava clay

Purpose: evaluation of the quality of seed chimer and source forms before and after cryopreservation.Materials and methods. For research, the breed of Sussex chickens and Poltava clay. Using these rocks, chimeras were obtained by the method of transplantation of blastodermal cells. An assessment of the quality of sperm of the roosters was carried out under a microscope at a temperature of 42 degrees. At various times, the activity of native sperm and its concentration was determined. Cryoconservation was carried out in small granules. The defrosting of the granules was produced on a heated metal plate at a temperature of 60 ° C.Results. A comparative analysis of the volume of the ejaculate showed that Himer on average it was somewhat larger than that of the initial forms. The activity of sperms in native genital cells was sufficiently high in all studied samples, and was 80% or more. The concentration of sperm retained the same trend and practically did not differ from each other in all studied samples. The activity of frozen-fatty seed of the initial breeds and their chimer was significantly different. The maximum activity was observed in the Sussex breed and reliably below (p≤ 0.01) it has the remaining experimental groups. The activity of frozen-fatty seed turned out to be equal in chimeric organisms and Poltava clay, although Himer recipients were sussexes. It should be noted that the swing of oscillations according to the degree of activity of frozen-fatty seed in chimeric birds was significant (from 10 to 40 points), and the number of observations is small.Conclusion. The study assess the quality of seed chimer and the source forms before and after cryopreservation. It was demonstrated that after defrosting the activity of frozen-fatty seed of the initial rocks and their chimer was different.

Geometrical and statistical analysis of dynamic crack morphology in shrink-swell soils with addition of maize roots or salinity (NaCl)

Cracks generated in shrink-swell soils detrimentally affect hydraulic and mechanical properties of soils, and alter soil-water processes, such as gas diffusion, water flow, solute transport, and root penetration. Root additives and salinity beget physicochemical changes in soils, resulting in variations of crack morphology. Understanding these variations provides effective means of crack utilization or prevention. In this study, we investigated the effects of maize roots and sodium chloride (NaCl) on crack dynamics and morphology in shrink-swell light clays. Drying experiments were conducted in soils containing roots (root densities: 0, 0.5, 1.0 and 1.5 cm/cm3) or NaCl (mass contents: 0.03, 1.0, 1.5 and 2.0 %). Crack evolution patterns were photographed at regular intervals and crack parameters were calculated from the resulting images using morphological algorithms. We investigated the dynamic geometry, topology, and statistical behaviors of cracks. Results indicate that incorporating maize roots effectively restrained crack area and width, but increased crack length, tortuosity, and number of cracks. Crack networks in root-treated soils contained a vast number of dead-ends and displayed pronounced fragmentation and low connectivity. Distribution of crack intersection angle well approximate normality with a mean around 120°. The bonding and friction between roots and particles, the bridging effects, stiffness, and ductility of roots improved the soil tensile strength and altered the intrinsic release criteria of tensile stress. The NaCl treatments increased crack area and width but decreased total crack length and tortuosity. With a slight amount of NaCl, the crack network tended to be highly connected with no dead-ends. Distribution of crack intersection angle in sodic soils exhibited asymmetric bimodality and was well described by a mixture of two Gaussian distributions, with primary and secondary peaks around 105° and 165°, respectively. We proposed a statistical function that describes crack area probability distribution considering water content as a variable, which proved to be a good fit in modeling dynamic statistics of crack patterns. Our results provide compelling evidence of how roots and salinity alter crack evolution, dynamics, and morphology in shrink-swell soils, which will be beneficial in crack inhibition and utilization, and in hydrological use such as water management in saline-sodic soils and prevention of preferential flow. However, cracking behaviors are highly susceptible to sample size effects and basal boundary. We hypothesize cracking behaviors (in roots- or salinity-treated soils) in small scale and in-situ scale are dimensionally similar, and the validity of these conclusions being generalized to in-situ cracked soils should be further investigated.

A new low-density hydrogel-based matrix with hollow microsphere structure for weight reduction of microwave absorbing composites

A new low-density hydrogel-based composites matrix, super light clay (SLC), with a low density of 0.24 g/cm3, was prepared by mixing the hydrogel and hollow glass microspheres. The swelling-adsorption effect of hydrogel was used to adsorb carbonyl iron powder (CIP) on the surface of hollow microspheres. Benefitting from the existence of microporous structure and surface adsorption, the electromagnetic absorption performance of the obtained SLC/CIP composite microwave absorbing materials (MAMs) were greatly boosted. The results show that the composite filled with 11 vol% of the CIP had a minimum reflection loss (RL) of −45.3 dB and an effective absorption bandwidth (EAB, with a RL of less than −10 dB) of 4.81 GHz. In addition, the swelling-adsorption mechanism of the hydrogel-based SLC matrix and the high-frequency electromagnetic wave attenuation mechanisms have been also discussed. The environmentally friendly low-density matrix is of great significance for weight reduction of MAMs.

Soil fertility, enzyme activity, and microbial community structure diversity among different soil textures under different land use types in coastal saline soil

This investigation assessed the responses of soil fertility, enzyme activity, and microbial community diversity to soil texture and land use type. The tested soils included five soil textures (sandy loam, medium loam, heavy loam, light clay, and medium clay soils) with two land use types (uncultivated and paddy soils) in the coastal zone of Zhejiang Province, China. Soil texture had a significant effect on soil pH, electrical conductivity (EC), organic carbon (OC), total nitrogen (TN), available nitrogen (AN), phosphorus (AP) and potassium (AK), catalase and protease activities, total phospholipid fatty acids (PLFAs), bacterial and actinomycetes PLFAs, and microbial diversity (MD). The clay content was significantly positively correlated to soil EC, OC, TN, AN, AP, AK, catalase activity, total PLFAs, bacterial and actinomycetes PLFAs, and MD but significantly negatively associated with soil pH and protease activity. Land use type also had significantly influenced soil pH, EC, OC, TN, AN, AP, AK, catalase, protease and urease activities, total PLFAs, bacterial, actinomycetes, and fungal PLFAs, and MD. The paddy soil had higher OC, TN, AN, AP, catalase, protease and urease activities, total PLFAs, bacterial and actinomycetes PLFAs, and MD but lower soil pH, EC, and AK than the uncultivated soil. The interaction with soil texture and land use type had significantly affected soil pH, EC, OC, TN, AN, AP, AK, catalase and protease activities, total PLFAs, bacterial and actinomycetes PLFAs, and MD. Soil texture and land use type could be considered important factors in improving soil fertility, enzyme activity, and microbial diversity in coastal saline soils.

Optimal doses of fertilizer application against the background of resource-saving soil cultivation technologies in the Steppe zone of Russia

A stationary experiment presented the data on the effect of optimal and increased doses of organic and mineral fertilizers against the background of various tillage systems on productivity, quality and soil fertility of the southern chernozems of the steppe zone of Russia. The rotation of crops was as follows: complete fallow - winter wheat - winter barley - corn for green fodder - winter wheat - fallow occupied (Vika panonskaya + winter wheat) - winter wheat - spring barley - sunflower. The soil of the experimental plot is represented by southern low humus chernozem on loess like light clays, the humus horizon is up to 40–50 cm. The optimal fertilizer doses, irrespective of the method of cultivating the soil, increased the yield of grain crops of the crop rotation from 4.2 to 9.7 centners per hectare, green mass of corn and Wiko-wheat mixture by 15.2 and 48.5 centners per hectare, respectively. The glassiness of the grain in the control on average was 44.8%, the generally accepted dose of fertilizing increased it by 7%. Accordingly, the amount of raw gluten also increased with control—23.9%, 28.7, and 30%. Therefore, the optimal fertilizer doses affected the quality indicators, and a 1.5-fold increase in the dose increased the wheat grain quality indicators by only 0.7–0.9 times. The amount of protein in the grain of winter wheat and winter barley, spring barley increased with fertilizer from 10.1 to 12.7%. According to the fallow precursor (complete and seeded), higher quality indicators were obtained in comparison with non-steam precursors.

Transition Between Constitutive Equations and the Mechanics of Water Flow in Unsaturated Soil: Numerical Simulations

Richards’ partial differential equation normally governs water flows in soil. It can be utilized to investigate water infiltration in the soil. A case study of the Haverkamp’s water infiltration simulation into Yolo Light Clay was carried out. A common practice to change between the hydraulic functions (from Haverkamp to van Genuchten) could cause a discrepancy in the simulation results. Hence, the first objective is to modify van Genuchten’s equations to reproduce the water infiltration result that was obtained using the Haverkamp constitutive functions. The method used was able to recreate water infiltration by increasing the fitting parameters of the van Genuchten constitutive functions. The second objective is to identify the mechanism governing the flow of water. The soil water diffusivity and the hydraulic conductivity were responsible for the flux of water in the soil. The Richards’ equation was discretized using a finite difference method, and the algebraic solution was coded into Simply Fortran 2008.