The shape of particles significantly influences their mechanical properties, making accurate shape modeling crucial in numerical simulations. This paper proposes a framework for generating particles by applying improved spherical harmonic reconstructions to convex hull surfaces. The framework integrates mesh refinement tech- niques to enhance mesh resolution, enabling the generation of finer surface details than 3D laser scanning. Three parameters are introduced: Delta K1, which controls roundness; Delta K2, which governs roughness; and Rd, which represents the boundary between roundness and roughness in spherical harmonic reconstructions. Introducing these parameters not only allows independent control over the three levels of shape (form, roundness, and roughness) but also enhances the flexibility of the method, enabling the generation of various particle shapes. Granular assemblies with varying roundness and roughness distributions are generated and applied in discrete element method (DEM) simulations of triaxial shear. The results show that roundness is negatively correlated with the peak friction angle, while roughness is positively correlated. The proposed method enhances the ability to generate complex particle shapes, offering a practical tool for modeling and simulating granular materials.

A sustainable use of croplands should utilize beneficial services provided by their resident soil microbiome. To identify potentially adverse environmental effects on soil microbiomes in the future, a better understanding of their natural variability is fundamental. Here, we characterized the abundance and diversity of soil microbial communities over 2 years at two-week intervals on three neighboring fields at an operational farm in Northern Germany. Field soils differed in texture (clay, loam) and tillage (soil conservation vs. conventional). PCRamplicon analyses of soil DNA revealed distinct temporal variations of bacteria, archaea, fungi, and protists (Cercozoa and Endomyxa). Annual differences and seasonal effects on all microbial groups were detected. In addition to soil pH, prokaryotic communities varied with total soil C and N, but fungi with temperature and precipitation. The C/N ratio had contrasting effects on prokaryotic phyla and protistan classes, but all fungal phyla responded positively. Irrespective of the sampling date, prokaryotic and fungal but not protistan community compositions from the three soils were distinct. Compositional turnover rates were higher for fungi and protists than for prokaryotes and, for all, lower in clay. Conventional tillage had the strongest effect on protist diversity. In co-occurrence networks, most nodes were provided by prokaryotes, but highly connected nodes by predatory protists in the first, and by saprotrophic fungi in the second year. The temporal variation established here can provide insights of what is natural and thus below the limits of concern in detecting adverse effects on the soil microbiome.

To assess the stability of coral sand foundation in complex environments, the undrained monotonic and cyclic shear tests were conducted in the laboratory. The test results indicate that the coral sand exhibits pronounced inherent anisotropy in the vertical direction. Under complex consolidation conditions, significant stress-induced anisotropy can also be observed. With increasing generalized shear strain (gamma g), both the generalized monotonic and cyclic shear modulus (Ggm, Ggd) exhibit a decreasing trend irrespective of consolidation ratio (kc) and inclinations of major principal stress (alpha c). Additionally, a strong linear relationship is evident between Ggm and Ggd, suggesting a consistent reduction pattern of Gg for various loading modes. The investigation on the inclination of the failure line (phi FL) for monotonic and cyclic shear is also conducted. The test results show that consolidation conditions have minimal influence on phi FL during monotonic shear, but exert a significant impact on phi FL during cyclic shear. A novel index called the consolidation parameter (eta) is proposed to quantitatively assess the relationship between kc, alpha c and phi FL. The average values of phi FL for cyclic shear increase with increasing eta, indicating the non-failure zone of coral sand during undrained cyclic shear will shrink with higher values of kc and alpha c.

The effective separation of ore is based on two fundamental processes: liberation and separability. Liberation involves the reduction of size, yielding smaller particles with enhanced compositional homogeneity. Understanding liberation requires an understanding of rock breakage, as it impacts mineral liberation and helps identify ores suitable for pre-concentration. Non-random breakage, influenced by textural and mineral properties, introduces heterogeneity in mineral distribution across size fractions. Physical attributes, including ore and gangue mineralogy and texture, influence fractionation tendencies during breakage. Notably, the presence of mineralization in veins substantially assists early-stage liberation in mineral processing. The aim of this study is to develop a methodology that allows the prediction of natural fractionation tendencies based on geological, mineralogical, and textural data using Discrete Element Method (DEM) modeling. DEM simulations provide insights into granular material behavior, capturing phenomena such as crack initiation and propagation. The use of DEM, particularly with models such as the Flat Joint Model (FJM), enhances our understanding of rock damage mechanisms. In this paper, DEM is used to predict preferential grade by size deportment, and a numerical model is developed to reflect grade distributions across size fractions. A fragmentation analysis is conducted after rock breakage simulations using DEM to analyze the fragment sizes and grades and calculate the Response Rankings of synthetic specimens.

Indian forests, having sixteen types of vegetation, provide various ecosystem services. Forests reduce water erosion of soil, reduce floods and conserve low river flow during dry seasons. Present study estimated annual sedimentation, texture, soil organic carbon control service of forests of India using the Revised Universal Soil Loss Equation (RUSLE) and Sediment Delivery Ratio (SDR) approach through GIS technique along with identifying important drivers responsible for erosion in forests. The soil erosion control service was based on five factors viz., rainfall erosivity, soil erodibility, slope, crop management, conservation practice factor and SDR across the various forest dominated river basins. Geo-detector modelling was performed to evaluate environmental drivers responsible for soil erosion. Valuation of soil control service of the India's forests was estimated based on damage and replacement cost method. Annual soil loss rate was maximum in Tropical Thorn Forest and in Ganga River basin. Maximum sediment control and SOC conservation against the soil erosion control service by India' forests were due to Tropical Dry Deciduous Forest with a total annual sedimentation control and SOC conservation of 33,056,560 tonnes and 3,31,115.06 tonnes, respectively. The conservative estimate of the economic value of soil conservation service by the forests of India was US$ 535.6 M with an average of 4.40 US$ ha-1 and a maximum share of value for Tropical Dry Deciduous Forest i.e. 294.18 million US$ and average maximum value for Littoral and Swamp Forest (28.91 US$ ha-1). The soil erosion in Tropical and Sub-tropical Forest was influenced by the interactive effects between NDVI and Bulk Density. In contrast, soil erosion in the temperate and alpine area was influenced by anthropogenic activity in combination with climatic factors. Present study accounts the role of India's forests for the soil conservation service and may provide inputs to implement forest and reservoir management strategies besides providing information for Integrated Watershed management and Catchment Treatment Plans.

Traditional geotechnical engineering is challenged in terms of sustainability, resilience, reliability and resources availability in the context of climate change and urbanization expansion. Abstracting inspiration from nature and adopting to geotechnical engineering, bio-inspired geotechnics can provide innovative solutions to address these challenges. This paper reviews the underlying mechanics of bio-inspired geotechnical engineering from three perspectives, i.e., bio-inspired burrowing strategies and mechanisms, bio-inspired surfaces with textures and bio-inspired underground structures. The results highlight that the bio-inspired burrowing strategies (i.e., particle removal, chiseling/grabbing-pushing, peristalsis, dual-anchor, pivot burrowing, undulatory propulsion, reciprocating, rotation and root growth) differ in their application scopes and burrowing efficacy, and the auxiliary burrowing, the principle of least impendence, as well as the multi-functional root growth presents promising solutions to burrowing challenges. Bio-inspired textured surfaces exhibit performance enhancement with regard to anisotropic friction, wear resistance and actuator initiation. In bio-inspired underground structures, snakeskin- and root-inspired geotechnical elements provide superior performance due to the frictional anisotropy and branching effects, respectively, and the potential implementation techniques are challenging current geotechnical engineering. Finally, transferring issues, potential research trends and future prospects are presented, and the significance of collaborative engagement of both engineers and scientists for promotion in bio-inspired geotechnics is emphasized. (c) 2024 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.

In the context of sustainable building development, Compressed Earth Blocks (CEBs) have garnered increasing attention in recent years owing to their minimal environmental and economic impact. However, owing to the inherent diversity of raw soil and the production process's reliance on expertise, the properties of these blocks are subjected to multifaceted influences. Among these, the significance of soil particle size variation often remains overlooked, leaving its impact ambiguous. This study endeavours to address this gap in existing research by delving into this aspect. Two distinct batches of CEBs were produced by adjusting the grain size curve of a single type of sieved soil with different maximum mesh openings: 2 mm for R1 CEBs and 12.5 mm for R2 CEBs. Experimental results reveal significant differences in thermophysical characteristics: on average, R1 blocks show superior thermal performance, boasting a 23% reduction in thermal conductivity compared to R2 blocks, and are lighter, with an 8% decrease in dry bulk density. Although no significant changes in mechanical parameters were observed, finer-structured R1 blocks showed a 25% greater tendency to absorb water due to changes in their porous structure. This study sheds light on the sensitivity of thermal parameters to changes in soil particle size and shows that blocks with finer particles exhibit poorer heat conduction and heat diffusion. Besides providing new insights into the literature, this research also provides a strategic approach to optimise the thermophysical properties of CEBs. By understanding the influence of particle size, researchers and practitioners can now develop strategies to enhance these properties and improve the overall performance of CEBs.

Water resources are essential to human exploration in deep space or the establishment of long-term lunar habitation. Ice discovered on the Moon may be useful in future missions to the lunar surface, necessitating the consideration of in situ resource utilization if it is present in sufficient amounts. Extraction of ice can cause the regolith to settle, which can lead to unintended structural damage. Therefore, any settlement resulting from ice extraction should be understood from a geotechnical perspective. This work reports on experimental investigation of the potential settlement caused by the extraction of ice from lunar regolith simulant containing different textures of ice. The KLS-1 simulant was prepared with different water contents and ice textures. Significant settlement occurred in simulant-ice mixtures with initial water contents of 5-10%.

Important agricultural pests in the Canadian Prairies, wireworms are the soil-living larvae of click beetles. Several notable species are found within the Prairies, with Hypnoidus bicolor being the most ubiquitous in most parts of the region. Despite their prevalence, H. bicolor is often disregarded as a significant pest species due to their comparatively small larval sizes. However, few studies have directly assessed the capacity of wireworms to cause damage to particular crop(s), and thus far no such studies have been undertaken for H. bicolor. We therefore carried out laboratory experiments under controlled environmental conditions, with soil and wireworms transplanted from the field, to determine the capability of H. bicolor to damage soybean. As expected, wireworm damage was strongly associated with larval densities, with more severe soybean injury occurring in the presence of greater numbers of H. bicolor. Further, feeding damage to soybean by H. bicolor was greater at lower temperatures (10 degrees C and 20 degrees C) than at higher temperatures (30 degrees C). In terms of soil texture, soybean grown in loam and silt soils were the most susceptible to wireworm damage and those grown in clay soil were the least affected. Although the larvae are not capable of damaging soybean to the same extent as other Prairie pest species, Limonius californicus and Hypnoidus abbreviatus, in high enough densities and under ideal environmental conditions H. bicolor can significantly impact soybean growth. Overall, our study suggests that soybean is susceptible to considerable wireworm damage and H. bicolor is an under recognized pest species of this legume.

Over a period of 15 years, the influence of 12 different rootstock varieties on phenology, vigour, nutrient content of leaves, yield, must components and wine sensory characteristics was observed on a calcareous deep-loosened soil on marl in the high-precipitation wine- growing region Southern Styria. While the varieties 161-49C and B & ouml;rner were the earliest and 1103P the latest at budbreak, no difference was found in the time of flowering. The lowest vigour was shown by the varieties 161-49C, B & ouml;rner and Binova. Medium vigour was achieved with 8B, C3309, Ganzin 9 and 5C. The strongest growth was achieved by 5BB, 1103P, SO4, 420A and Fercal. Significant differences in leaf nutrient values were found for the elements phosphorus, calcium, magnesium and copper. The highest phosphorus levels were measured in Fercal, Ganzin 9 and 1103P and the lowest in B & ouml;rner and Binova. The highest calcium value was shown by the 420A variant, the lowest by Ganzin 9, B & ouml;rner and 8B. Magnesium was absorbed most efficiently by 1103P, Fercal and C3309. There were no significant differences in bunch texture and susceptibility to bunch rot. There were also no significant differences in drought resistance, especially in the dry vintages 2013 and 2017, although the varieties 420A, Fercal and 1103P tended to show fewer symptoms of drought damage and 8B, B & ouml;rner and Binova more. In terms of yield, the rootstock varieties 420A and 1103P were the most productive. The lowest grape weights and yields were produced by the varieties 161-49C and Ganzin 9. High must proline values were achieved by Ganzin 9, the lowest by 5BB and 1103P. The highest must magnesium values were achieved by C 3309, the lowest by 5C and SO4. Organoleptic wine evaluation of the 2018 vintage revealed no significant differences in the ,,body/density parameter. In the parameter taste, there was a preference for the rootstocks 5C, Ganzin 9 and 1103P over 420A, SO4 and C3309. Regarding the parameter bitter/tannin, only 5C and SO4 differed significantly, with the SO4 variant being rated as more bitter.