A Note on the Influence of Smectite Coating on the Coefficient of Restitution of Natural Sand Particles Impacting Granitic Blocks

The study of the collision behavior of solid objects has received a significant amount of research in various fields such as industrial applications of powders and grains, impacts of proppants and between proppant and rocks during hydraulic fracturing, and the study of debris flows and avalanches and the interactions of landslide materials with protective barriers. This problem has predominantly been studied through the coefficient of restitution (COR), which is computed from the dropping and rebound paths of particles; its value corresponds to 1 for perfectly elastic impacts and 0 for perfectly plastic impacts (i.e., at the collision there is no rebound of the particle). Often, the colliding particles (or particle–block systems) are not perfectly clean, and there is debris (or dust) on their surfaces, forming a coating, which is a highly possible scenario in the debris flows of natural particles and fragments; however, the topic of the influence of natural coatings on the surfaces of particles on the collision behavior of particle–block systems has been largely overlooked. Thus, the present study attempts to provide preliminary results with respect to the influence of natural coating on the surfaces of sand grains in the COR values of grain–block systems using a stiff granitic block as an analogue wall. Montmorillonite powder, which belongs to the smectite clay group, was used and a sample preparation method was standardized to provide a specific amount of clay coating on the surfaces of the sand grains. The results from the study showed a significant influence of the smectite coating in the COR values of the grain–block systems, which was predominantly attributed to the dissipation of energy at the collision moment because of the compression of the soft coating of microparticles. Additionally, the method of analysis for calculating the COR values based on one and two high-speed cameras was explored, as the impacts of natural grains involve deviations from the vertical, which influences the rebound paths. Thus, a sensitivity analysis was performed investigating the differences in the COR values in two-dimensional and three-dimensional analysis of the impact tests.

Bronze-casting workshops of the Vengerovo-2 settlement (Baraba forest steppe)

The formation of the early bronze-casting production in Baraba and the appearance of products of the Seima-Turbino type were completed within the 3rd — early 2nd mil. BC — during the existence of the Krotovo Cul-ture. Plenty of work has been devoted to its characterization; the presence of bronze-casting on the sites has been noted, but special studies of this type of sources are extremely few. The purpose of this paper is to present the characteristics of the production areas associated with the processing of non-ferrous metals, based on mate-rials of the Vengerovo-2 settlement of the Krotovo Culture. Production sites were studied in six dwellings of the settlement. The uniformity of the workshops has been revealed in terms of site planning and principles of organi-zation of the production, although differences in scale have been noted. The use of two types of the forges has been recorded. In all these workshops and in other sites of the culture, a multifunctional sub-rectangular hearth buried in the ground with the walls and floor lined with fragments of ceramics or clay coating was found (with di-mensions of 1.65×0.87–2.3×0.9×0.21–0.52 m). The second type of the forges is less common — a small round or oval pit (0.4–0.5 m in diameter) with the bottom and walls lined with baked clay or fragments. The smelting was carried out with forced air supply. The casting of the metal was taking place next to the forge. Crushed bones were used as fuel. The production complex demonstrates extensive external economic and commercial ties. This is manifested by penetration of significant volumes of non-ferrous metal into the ore-barren areas of the Central Baraba, as well as by the presence of imported foundry equipment (molds made of marl and talc). The simultaneous presence inside the casters’ dwellings of bones of taiga-zone animals and those living in the southern, steppe regions indicates significant length of the supply routes. The specific features and unification of the production of the manufacturing equipment, nature of the work carried out, volume of heats, and a large number of similar-type forms suggest specialization of the village in the bronze casting production.

Reservoir facies mapping, depositional environment, and implication for hydrocarbon occurrence: A case study from Ariyalur-Pondicherry subbasin, Cauvery Basin, India

Commercial gaseous hydrocarbon has been established from multilayered reservoirs within the Bhuvanagiri Formation in the Ariyalur-Pondicherry subbasin, but sustained production is obtained from only a few wells of the Bhuvanagiri Field. This has necessitated developing an integrated depositional model dovetailing distribution of favorable reservoir areas of the Bhuvanagiri Formation within the subbasin. Root-mean-square amplitude attributes and spectral decomposition attributes, along with RGB blending of spectral slices at different frequencies, have revealed a conspicuously northeast-southwest-trending channel within the Bhuvanagiri Formation. From well, sedimentological, and biostratigraphic data analysis, a deepwater turbidity channel model for the Bhuvanagiri Formation has been postulated. Deciphering the facies distribution pattern vertically and laterally within the turbidity channel is often complex and challenging. Integrated analysis of available laboratory data, petrographic, and scanning electron microscopy studies indicate poor porosity and permeability because of clay coating on grains, occurrence of authigenic clay as pore fill, cementation, and other diagenetic changes that have made reservoir characterization increasingly challenging. Four major lithofacies assemblages have been identified: basal lags, slumps and debris flows, arenaceous coarse-grained stacked channels, and fine-grained channel levee with characteristic log and seismic responses. To characterize the lithofacies, various crossplots have been generated by using processed logs to derive interrelationships between reservoir facies and log impedance. A model-based inversion has been attempted, which resulted in fairly satisfactory output with likely discrimination of reservoir and nonreservoir in an unexplored area within the field. The outcome would facilitate further exploration and delineation activities within the Bhuvanagiri Formation in the Ariyalur-Pondicherry subbasin.

Abrasion protection of silicate enamel coating of engineering network nodes in field conditions

The paper proposes methods for protecting the internal silicate-enamel coating of pipes in field conditions. It is shown that the proposed methods are highly efficient for manual mechanical cutting, chamfering, cutting edges with abrasive tools with vulcanite cutting discs for welding, in manufacturing and assembling the engineering systems, transportation of aggressive products, and fire fighting systems.It is shown that the most appropriate method for preservation of the internal silicate-enamel coating is its preliminary annular incision and sizing of the cut place with a thin cloth (calico) impregnated with quick-drying glue, and clay coating protection from hot metal particles. This method is recommended to be used when cutting pipes, fittings, segments, processing their chamfers and cutting edges, in manufacturing of network nodes (fire-fighting systems) in field conditions.The proposed methods will significantly increase the operating life and reliability of engineering networks with silicate-enamel coating for the transportation of aggressive products and, as a result, technical safety of trouble-free facilities.

‘Palmer’ Mango Yield as Affected by Soil Class and Pedon Physicochemical Characteristics

To evaluate the variation in ‘Palmer’ mango yield related to soil formation and soil physical and chemical properties, we studied a transect with 11 soil profiles, selected according to the altitude in a commercial orchard. Surface and subsurface diagnostic horizons were described up to two meters in depth. Soil depth, texture, structure, consistency, clay coating, cementation, and color of each horizon were morphologically determined. Undisturbed and disturbed samples were used to determine the soil total porosity, macroporosity, microporosity, density, saturated hydraulic conductivity, granulometry, total organic carbon, pH, sum of bases, and the contents of P, S, K, Na, Ca, Mg, Al, Fe, Mn, Cu, and Zn. The number of fruits (for production estimates), stem diameter, canopy area, and plant height were determined in four plants around each soil profile. Three classes of soil showed good suitability for mango cultivation: Argisol Red-Yellow Eutrophic typic, Cambisol Haplic Eutrophic Tb, and Latosol Red Yellow Eutrophic typic. The ‘Palmer’ mango yield was correlated with the K contents, sum of bases, and pH. The low yield was a result of the low K content associated with the presence of gravel.