Sand Research Articles

Exploring Resistance Reduction of Subsoiling Through Sandfish (Scincus scincus) Inspired Sinusoidal Locomotion

Highlights Biomimetic design, inspired by sandfish locomotion, decreased subsoiling resistance. Penetration tests and simulations showed bioinspired tines outperforming traditional ones in resistance reduction. DEM-MBD co-simulation effectively modeled the sandfish's movement, revealing the mechanisms of soil interactions. Simulations confirmed that sinusoidal subsoiler movement significantly reduced soil resistance. Abstract. This study addresses the issue of high resistance and low efficiency in subsoiling operations by employing a novel method inspired by the unique locomotion of the sandfish (scincus scincus), aimed at reducing forward resistance. The unparalleled adaptability of the sandfish in navigating granular media, such as desert sand, offers valuable insights for enhancing agricultural machinery. This research employs sandfish’s movement principles to propose innovative strategies for improving subsoiling efficiency. A sandfish inspired prototype, created through reverse engineering, served as the basis for the analysis. The models of both traditional (T-S) and bioinspired (B-S) subsoiler tines for comparative assessment were developed. The EDEM simulation model’s performance was calibrated using soil penetration tests and integrated with multibody dynamics (MBD) to analyze the sandfish’s variable locomotion in sandy soil. The impact of linear and sinusoidal locomotion at velocities of 0.8 m/s, 1.0 m/s, and 1.2 m/s on resistance and soil disturbance were investigated and contrasted. The congruence between measured and simulated resistance-depth curves for T-S and B-S models was desirable, with maximum resistance errors of 2.54% and 2.47%, respectively, confirming the simulation model’s accuracy in predicting mechanical interactions. A comparison of characteristic angles validated the close correlation between simulated and actual sandfish locomotion in soil. Stress analysis during soil locomotion of the sandfish head indicated a 25.1% reduction in resistance with sinusoidal motion compared to linear motion. At the specified velocities, sinusoidal locomotion of the subsoiler tine showed resistance reductions of 6.75%, 7.39%, and 9.40%, respectively, relative to linear locomotion. The mechanism of resistance reduction in sinusoidal locomotion was further verified through soil compression force analysis, supporting the adoption of sandfish-inspired sinusoidal behavior as an innovative approach to enhance efficiency in agricultural practices. Keywords: Bioinspired design, DEM-MBD simulation, Sandfish (Scincus scincus), Sinusoidal locomotion, Subsoiling.

Methods for calculating basic parameters of machines for the distribution of chemical and mineral materials on highways

The article is devoted to determining the main parameters of the working body (an implement) of the machine for distributing chemical and mineral materials (sand) ensuring high-quality performance of works. Based on the ranking of forces acting on a sand grain located on the surface of the machine implement and eliminating forces that do not significantly affect its movement, differential equations of a particle motion are obtained. Based on the solution to the differential equation, the following parameters were obtained: the flight range of the grain, the time of movement of the grain on the disk, and the angle of its dumping. In addition, issues related to the requirements for such machines are considered. The methodology developed makes it possible to significantly reduce the time and money spent and the costs of calculating the main parameters and arrange a rational design of the machine for distributing chemical and mineral materials.

The morphological analysis and electrical properties of beach sand magnetic mineralbased nano silica gel synthesized via the sol-gel method

The morphological analysis and electrical properties of beach sand magnetic mineralbased nano silica gel synthesized via the sol-gel method

On predictive models for the equivalent sand grain roughness for wall-bounded turbulent flows

One of the long-standing goals of rough wall fluid dynamics research is to determine the drag penalty of surfaces based solely on their topographical parameters. The most important length scale or roughness parameter that best describes a surface in relation to friction drag has not been agreed upon yet, despite the many studies that, over the years, have attempted to identify the most appropriate surface parameter. The concept of an equivalent sand-grain roughness (ks) was introduced to standardize different types of roughness in wall-bounded turbulence, serving as an input parameter for predicting the roughness function ΔU+. To anticipate ΔU+ generated by a rough surface under turbulent flow conditions, experts use roughness correlations that establish a correspondence between the topographical characteristics of the surface and ks. Therefore, a chronological compilation of roughness correlations is presented, detailing the parameter ranges and types of roughness used in their development. This study evaluates the effectiveness of predictive correlation functions and aims to formulate a universal function by exploring a comprehensive assortment of three-dimensional (3D) surface textures available in the literature. The results suggest that a correlation based on surface height skewness (ksk) and streamwise effective slope (ESx) can predict the ratio (ks/kq), where kq is the root mean square roughness height for 3D roughness in the fully rough regime. Despite the fact that the correlation is restricted to 3D surface roughness, which is a more realistic representation, the model demonstrated a high level of accuracy in predicting ks for over 120 distinct rough surfaces.

Characterizing anthropogenic litter pollutants in African freshwater ecosystems: A case study of Dunga Beach in Lake Victoria, Kenya

AbstractAnthropogenic litter (AL) in world's aquatic ecosystems presents critical ecological threats to environmental quality, aquatic biodiversity and human welfare. However, most studies on AL have been conducted in marine ecosystems with very little focus being given to freshwater systems like Lake Victoria. This study characterized AL pollutants in Dunga beach in Lake Victoria, Kenya, where sampling was done in the beach, riparian and benthic zones along a 100 m reach for 6 days. Across the sampled reaches, the AL associated with packaging, consumer products, building and construction, transport, electronic wastes, textile, fishery and medical materials were collected, counted, sun‐dried and weighed. AL were more abundant in the beach and riparian zone than in the benthic reaches with plastics being the dominant litter in all reaches. Based on Kruskal–Wallis rank sum test the density of AL associated with packaging and consumer products was significantly higher than other AL in all the reaches. Plastics, polystyrene and glass wastes dominated the beach zone at 31.19%, 12.14% and 11.14%, respectively. In the benthic area, the dominant wastes were plastics, fishery and polystyrene items at 22.14%, 16.34% and 12.14%, respectively. The top 10 AL pollutants in Dunga beach were as follows: bags/food wrappers, bottle caps, diapers, plastic and glass beverage bottles, plastic plates, forks, knives, spoons, straws and e‐wastes. Based on data from literature, several clear patterns emerged when comparing relative AL abundance across other aquatic habitats. In the Lake Michigan Beach, the AL were dominated by plastics (41.2%) followed by cigarettes at 29.3%. In contrast, Chicago River Beach contained more glass wastes (42.1%) while Chicago River Riparian had more plastics (57.8%). At the South Sea of Korea, fishing gear wastes were the majority AL (61.1%). AL consisting of fishing items was restricted to benthic and riparian settings, in which the benthic zone had the most items recorded. It is therefore evident that a large amount of AL waste accumulates at Dunga, Hippo point and other beaches in the world, thus justifying the need for beach cleaning and maintenance strategies. This study presents baseline data that is useful to environmental ecologists, aquatic scientists and management authorities to formulate policies, evaluate guidelines and recommend beach management strategies to conserve aquatic biodiversity, human health and aesthetic value of the freshwater habitats.

Impact of differential settlement on leakage through geomembranes in waste covers: A field and numerical investigation

This study evaluates the impact of differential settlement on leakage through geomembrane holes in landfill and mine tailings covers. Conducted at the Queen’s University Experimental Liner Test Site, the research spanned two sections with 4H:1V slopes over 13 months. Section B, featuring a 3 m x 2 m depression (0.12 - 0.17 m deep), exhibited a 51- fold increase in leakage compared to the uniform Section A without depression (493L vs 11.1 L). Intriguingly, during colder months with lower precipitation, leakage in Section B surged by 43%, contrary to the lesser leakage observed during warmer, wetter months. 3D numerical models corroborate these findings, attributing the increased leakage during cold periods to reduced temperature-induced hydraulic conductivity of the cover sand. The research provides insights for design and inspection to effectively manage contaminant leakage in waste covers.

Beach Sand-derived Mesoporous Silica by Hydrothermal Process for Hydrocracking Waste Coconut Oil to Biofuel

<p>Hydrocracking, a key process for converting waste coconut oil into biofuel, requires efficient catalysts. This study investigates the synthesis of mesoporous silica catalysts using a hydrothermal process. Dodecyl amine, sourced from beach sand, serves as a template. The hydrothermal synthesis involved durations (12, 15, 18, 21, and 24 hours) and dodecyl amine concentrations (0.25 M, 0.5 M, 0.1 M), conducted at 40 °C for 30 minutes. The synthesized catalysts were then characterized for their surface area, pore volume, and diameter. Among the synthesized samples, those treated for 15 hours displayed optimal total acidity at 0.88 mmol/g. The catalysts synthesized with a dodecyl amine concentration of 0.025 M exhibited superior characteristics, including a specific surface area of 233 m²/g, a pore volume of 0.47 cc/g, and an average pore diameter of 2.10 nm. These findings underscore the efficacy of mesoporous silica catalysts in hydrocracking, particularly in converting large hydrocarbon molecules into smaller, more valuable biofuel molecules. Comparative analysis with similar research highlights the significance of these findings in the field of sustainable energy. The optimal catalyst conditions yielded a liquid fraction of over 70% for 0.25 M dodecyl amine. This efficiency in converting waste coconut oil into biofuel signifies the potential of mesoporous silica catalysts in advancing environmentally friendly energy sources. This research contributes to the growing knowledge of renewable energy, offering promising avenues for developing sustainable and eco-friendly energy solutions.</p>

Evaluation of Coral Reef Health Status in the Fish Sanctuary of San Esteban, Ilocos Sur

Studies on corals are lacking in Ilocos Sur’s marine protected areas (MPAs), hindering management effort development. This study evaluated the health status of coral reefs in the San Esteban Fish Sanctuary. Hard coral cover, hard coral diversity in terms of Taxonomic Amalgamation Units (TAUs), and coral reef health status in terms of live coral coverage, algae coverage, sand coverage, and coral mortality index were measured in two sampling stations inside an over-a-decade-old fish sanctuary that does not have previous data on its coral reef health status. The Underwater Photo Transect (UPT) method was employed to take image samples subjected to the Coral Point Count with Excel extensions (CPCe) software for analysis. The study revealed that the coral reef in San Esteban Fish Sanctuary is in good condition with a hard coral cover of 30.0%, falls under Hard Coral Cover Category C, and a hard coral diversity of 16.8TAUs that falls under Diversity Category D. The fish sanctuary is also in a healthy condition based on excellent live coral coverage, algae coverage, sand coverage, and low coral mortality index. The two stations are more or less the same in terms of the aforementioned parameters. Overall, it is recommended to continuously strengthen the enforcement of the fish sanctuary to protect its coral reefs, measure other parameters that might impact and indicate coral reef health status, employ evaluations inside and outside MPAs in the province, and use high-resolution cameras during image sampling for more efficient analysis.

Education on the use of compost blocks for chili cultivation for coastal sand farming groups

High temperatures in the land are one of the obstacles faced in cultivating chilies on coastal sand, resulting in nutrients being easily lost and not lasting long. An alternative solution to overcome this problem is to use compost block planting media. This service activity aims to provide knowledge and skills in utilizing agricultural waste for compost as a medium for planting chilies in beach sand. The service methods used are (1) Counseling and Focus Group Discussions about compost blocks; (2) training and demonstration on making block compost; (3) demonstration plot for the use of compost blocks for chili plants, and (4) monitoring and evaluation before, during, and after the activity takes place. The results of service activities show that partners are very enthusiastic about participating in all activities, as shown by an increase in partners' knowledge about compost blocks by 47%. There are 12% of chili plants that die when planted using compost blocks. Meanwhile, chili plants planted conventionally without compost blocks produced more dead plants, namely 30%.

Preparation process and performance study of desert sand autoclaved bricks

Desert Sand Autoclaved Brick(DSAB) represents a novel type of building wall material. To investigate the performance of this wall material in the high-intensity cold regions of Xinjiang, this study, based on the(GB/T 11945–2019) "Autoclaved sand-lime solid brick and solid block" standard, explores the impact of varying lime content, forming pressure, autoclaving time, and autoclaving temperature on compressive strength. The aim was to determine an appropriate preparation process for DSAB that meets meets MU15-grade requirements. Additionally, experimental research was conducted on the micro-pore structure, freeze-thaw durability, and carbonation performance of the manufactured MU15-grade DSAB. Furthermore, microscopic analysis methods were employed to analyze the mechanisms behind the changes in the strength of the DSAB throughout the various experiments. The research findings are as follows: The optimal preparation parameters for producing MU15-grade DSAB are a forming pressure of 20 MPa, an autoclaving time of 8 h, and an autoclaving temperature of 180 ℃. Mercury intrusion porosimetry(MIP) revealed that DSAB has a total porosity of 38.19%, an average pore diameter of 55.86 nm, total pore volume of 0.175 mL/g, and total pore area of 12.56 m2/g. The majority of pore spaces consist of harmful and more harmful pores. DSAB exhibits favorable freeze-thaw durability. After 30 freeze-thaw cycles, the strength loss rate is only 7.0%, and the mass loss remains within 1%. After carbonation, the newly formed CaCO3 and SiO2 fill the brick's pores, transforming pre-existing harmful large pores into harmless tiny pores. After complete carbonation, the carbonation coefficient reaches 1.17.

Вплив механохімічної активації композиційного цементу на міцність будівельного розчину

The article discusses issues related to the use of technology for the production of mortar mixtures and mortars based on high-speed mixers, the operation of which causes mechanochemical activation of the binder. The rotary counterflow mill used in the work acts as an activator of the surface zone of both Portland cement grains and quartz sand grains and, thus, contributes to the intensification of the processes of structure formation of cement paste and mortar based on it. Based on the fact that one of the promising ways to reduce the cost of cement activation is to reduce the energy intensity of the dispersion process itself, the use of relatively low-energy rotary mills can be considered as an effective way to increase the activity of the binder. After the joint activation of Portland cement and unground quartz sand (the amount of which was adjusted from 0 to 50 % of the cement mass; activation period - 300 seconds), samples were made from equal-viscosity cement paste. It was experimentally established that the maximum strength of cement stone at 28 days of age was achieved when using composite cement with a 20 % content of activated sand. To determine the influence of the studied factors, such as the consumption of mechanically activated composite binder, the concentration of superplasticizer C-3 (0...1,5 %) and the consumption of microsilica (0...10 %) on the strength of the mortar in 2 and 28-day old, a 3-factor experiment was conducted. It was established that in the studied hardening period, the content of mechanically activated composite cement has the greatest influence on the compressive strength for the studied mortar compositions (from 1:3 to 1:1). The next most important influence on the strength of the mortar is the consumption of superplasticizer C-3. The increase in compressive strength of a mortar from the introduction of microsilica into its composition does not exceed 10-15 %. The combined effect of mechanical activation of the binder and the use of the C-3 additive ensures an increase in the strength of the mortar (mortar composition 1:1) at 28 days of age from 43,5 MPa (non-activated binder; no C-3 additive) to 63 MPa, that is, almost by 45 %. For a mortar of similar age with a lower consumption of composite cement (mortar composition 1:3), mechanical activation of the binder in the presence of 1,5 % C-3 additive ensures an increase in the compressive strength of the mortar from 21 MPa (non-mechanically activated binder; C-3 = 0 %) to 39 MPa.

Spatial distribution and habitat relationship of sea urchin assemblages (Echinodermata: Echinoidea) in Hong Kong waters

Sea urchins are important components of marine ecosystems and can act as bioindicators, reflecting the health of reefs. The spatial patterns of sea urchins are largely shaped by the type of habitat. In Hong Kong, coral communities are divided into two distinct types: reef-building coral habitats and non-reef-building coral habitats. In summer 2020, a qualitative survey was conducted using SCUBA at 56 sites across eastern and western waters, recording a total of 11 species from 6 families of sea urchins. Out of these 56 sites, 14 were selected for a quantitative survey to investigate the relationship between sea urchin assemblages and the two types of coral habitat. We found that the species composition of sea urchins differed significantly between the two habitats, and the presence of sand was a critical factor influencing the species composition of sea urchins. Sand coverage had a positive effect on Salmasic sphaeroides abundance but a negative effect on the abundance of Diadema setosum and Heliocidaris crassispina. The distribution of sea urchins across different degrees of sand coverage may be associated with food availability or species-specific adaptive behaviour, likely due to niche preferences.

Transitioning Wintering Shorebirds to Agroecosystem: A Thorough Evaluation of Habitat Selection and Conservation Concern

Habitat fragmentation and degradation in natural wetlands has resulted in declines in the populations of shorebirds in the Indian subcontinent. Shorebirds rely on these wetlands as wintering or stop-over sites along the southern extent of the Central Asian Flyway. Shorebirds are known to utilize agroecosystems as alternate foraging habitats. The suitability of agroecosystems as foraging areas for overwintering migratory shorebirds has not been well studied in the Indian subcontinent. We conducted a comprehensive assessment of published literature and compiled field observations to investigate the importance of inland and coastal agroecosystems for shorebirds in India. We assessed the shorebird populations at natural wetlands: mudflats and mangroves of Kadalundi Vallikkunnu Community Reserve (KVCR) and Puthuvypu sand beach, as well as adjacent agroecosystems on the west coast of India, including Sanketham Wetlands, Manthalakkadavu, Vazhakkad, Elamaram, Kodinhi, and Kooriyad. On the east coast, we assessed the natural wetland habitats of Valinokkam, Point Calimere, and Pichavaram and evaluated inland agroecosystems in regions, such as Jammu and Kashmir, Punjab, Rajasthan, Gujarat, Uttar Pradesh, Tamil Nadu, and Kerala. Fifty-three shorebird species utilize diverse agroecosystems from various parts of India. While studies on the use of agroecosystems by shorebirds are limited on the east coast, evidence suggests that major wintering sites are adjacent to paddy fields, fostering substantial shorebird diversity. In Pichavaram, Point Calimere, and Gulf of Mannar regions, 22 shorebird species utilize agroecosystems, including the notable near-threatened Eurasian Curlew. Seventeen of these species are winter arrivals, highlighting the crucial role agroecosystems play as stopover areas. On the west coast, 19 shorebird species appear to utilize agroecosystems in Kooriyad, Manthalakkadavu, Vazhakkad, Sanketham Wetlands, Elamaram, and Kodinhi. Few species use agricultural fields in the north (Jammu and Kashmir). Paddy fields, that are flooded as part of the cropping cycle, support diverse prey species, such as macroinvertebrates, amphibians, and small fish, that could attract and support migratory shorebirds. Agricultural practices like fallowing, flooding, and ploughing could further increase the abundance and accessibility of prey for shorebirds, drawing them in greater numbers. It is crucial to recognize that unsustainable and unethical agricultural methods could detrimentally affect shorebird numbers. The accumulation of pesticide residues and the contamination from heavy metals could also threaten shorebirds. As a result, there is an urgent need for detailed research to better evaluate the importance of agroecosystems in supporting resident or migratory shorebirds. Systematic studies that explain the population dynamics, habitat selection trends, habitat utilization, and the over-summering behavior of the migratory birds at agroecosystems are needed. Implementing sustainable conservation strategies and adopting environmentally friendly agricultural practices are essential to support the rich biodiversity of the region.

Beach sand plastispheres are hotspots for antibiotic resistance genes and potentially pathogenic bacteria even in beaches with good water quality

Massive amounts of microplastics are transported daily from the oceans and rivers onto beaches. The ocean plastisphere is a hotspot and a vector for antibiotic resistance genes (ARGs) and potentially pathogenic bacteria. However, very little is known about the plastisphere in beach sand. Thus, to describe whether the microplastics from beach sand represent a risk to human health, we evaluated the bacteriome and abundance of ARGs on microplastic and sand sampled at the drift line and supralittoral zones of four beaches of poor and good water quality. The bacteriome was evaluated by sequencing of 16S rRNA gene, and the ARGs and bacterial abundances were evaluated by high-throughput real-time PCR. The results revealed that the microplastic harbored a bacterial community that is more abundant and distinct from that of beach sand, as well as a greater abundance of potential human and marine pathogens, especially the microplastics deposited closer to seawater. Microplastics also harbored a greater number and abundance of ARGs. All antibiotic classes evaluated were found in the microplastic samples, but not in the beach sand ones. Additionally, 16 ARGs were found on the microplastic alone, including genes related to multidrug resistance (blaKPC, blaCTX-M, tetM, mdtE and acrB_1), genes that have the potential to rapidly and horizontally spread (blaKPC, blaCTX-M, and tetM), and the gene that confers resistance to antibiotics that are typically regarded as the ultimate line of defense against severe multi-resistant bacterial infections (blaKPC). Lastly, microplastic harbored a similar bacterial community and ARGs regardless of beach water quality. Our findings suggest that the accumulation of microplastics in beach sand worldwide may constitute a potential threat to human health, even in beaches where the water quality is deemed satisfactory. This phenomenon may facilitate the emergence and dissemination of bacteria that are resistant to multiple drugs.

Provenance of Coastal and Seabed Sediments Relative to Mining and Processing Wastes: The Case of Lavrion, Attiki Peninsula, Greece

A detailed textural, mineralogical, and geochemical investigation of beach sands and seabed sediments from Thorikos and Oxygono bays of the eastern coast of Lavrion is performed, with the objective the provenance of the ore types exploited, the processing and beneficiation types employed, and the respective exploitation periods. The Oxygono Bay beach and seabed sands are highly heterogeneous, predominated by lithic clasts originating from surrounding lithologies. Examination of the fine-grained fraction from the seabed core revealed that only the upper 50 cm was affected by recent and ancient mining activity. Combining the mineralogy and geochemistry of Oxygono Bay sands with the radiochronological model of Pappa et al. (2018), four periods of recent exploitation (mid-19th—late 20th century) are distinguished: (1) The “1860–1875 A.D.”, involving exploitation of the ancient smelter slags, (2) the “1875–1900 A.D.”, with ongoing ancient smelter slag processing and the commencement of underground sulfide ore exploitation, (3) the “1900–1930 A.D.”, where heavy mining of the carbonate-hosted Pb–Zn–Ag ore occurs, (4) the “1930–1980”), where the implementation of flotation-type processing assisted in the exploitation of the poor skarn and porphyry-type ores. The latest “1980 A.D.—to date” period depicts the cessation of all mining and processing activities. The southern Thorikos Bay beach sands are homogeneous and fine-grained, are mainly composed of gangue and pyrite, and show elevated Fe, As, Pb, Zn, and Mn content. The southern Thorikos Bay beach sands clearly point to exploitation and processing by flotation of the carbonate-hosted Pb–Zn–Ag sulfide ore, and the tailings were disposed of from the nearby facilities to southern Thorikos Bay without any environmental concern during the “1930–1980 A.D.” period.

Sex Ratio Estimation of Green Turtle Hatchlings in Kazanlı Beach, Türkiye

Sea turtles are distributed worldwide, mostly in the tropical and subtropical waters. All seven species of sea turtles in the world have temperature-dependent sex determination. The pivotal temperature for hatchlings with a female:male ratio of 1:1 is usually around 29°C. Female hatchlings are observed at values higher than the pivotal temperature and male hatchlings at lower values. It is expected that wildlife threatened by global warming will be more severely affected, especially species that sex is determined by temperature. This study was carried out by measuring air, sand and nest temperatures during two nesting seasons at Kazanlı Beach, one of the largest nesting sites of Chelonia mydas (Green turtle) in the Mediterranean. Sand grain size was also measured, and gonads of dead hatchlings were examined histologically. Both sand (n=4) and nest (n=6) temperatures were above the pivotal temperature (between 29.1-31.6°C) in the study area. According to the estimation based on temperatures, hatchlings were female (♀>50%) biased. Of the hatchling samples, 75 were examined histologically. According to histological examination, the female:male ratio was 2:1. According to the direct examination and indirect estimation; the sex ratio of green turtle hatchlings in Kazanlı Beach, one of the highest hatchling producing nesting sites of the Mediterranean, was reported for the first time in this study. There is a need to fill the data gaps regarding sex ratios, especially for major beaches with high hatchling production. Knowing the temperature profiles in and around the nest and sex ratios of hatchlings is critical for the development of conservation measures for endangered sea turtles.

Evaluation of soil texture classification from orthodox interpolation and machine learning techniques

The current investigation examines the effectiveness of various approaches in predicting the soil texture class (clay, silt, and sand contents) of the Rawalpindi district, Punjab province, Pakistan. The employed techniques included artificial neural networks (ANNs), kriging, co-kriging, and inverse distance weighting (IDW). A total of 44 soil specimens from depths of 10–15 cm were gathered, and then the hydrometer method was adopted to measure their texture. The map of soil grain sets was formulated in the ArcGIS environment, utilizing distinct interpolation approaches. The MATLAB software was used to evaluate soil texture. The gradient fraction, latitude and longitude, elevation, and soil texture fragments of points were proposed to an ANN. Several statistical values, such as correlation coefficient (R), geometric mean error ratios (GMER), and root mean square error (RMSE), were utilized to evaluate the precision of the intended techniques. In assessing grain size and spatial dissemination of clay, silt, and sand, the effectiveness and precision of ANN were superior compared to kriging, co-kriging, and inverse distance weighting. Still, less than a 50% correlation was observed using the ANN. In this examination, the IDW had inferior precision compared to the other approaches. The results demonstrated that the practices produced acceptable results and can be used for future research. Soil texture is among the most central variables that can manipulate agriculture plans. The prepared maps exhibiting the soil texture groups are imperative for crop yield and pastoral scheduling.

Natural Radioactivity Levels of the Beach Sands of Cleopatra Beach and Damlatas Beach (Türkiye) and Their Impact on Human Health.

HPGe γ spectrometry method was used to measure the natural radioactivity levels (40K, 232Th, and 226Ra) of the beach sand samples from Cleopatra Beach and Damlatas Beach in Antalya (Türkiye). The mean 40K, 232Th, and 226Ra radioactivity levels of the studied samples were calculated as 276.88 ± 17.24, 25.04 ± 2.88, and 17.06 ± 1.68 Bq/kg, respectively. Being below the radiation limits, these values indicate no risk in terms of public health. Moreover, the radiological risk parameters, such as excess lifetime cancer risk, radium equivalent activity (Raeq), absorbed γ dose rate (D), annual effective dose equivalent (Eaed), γ index (Iγ), internal radiation hazard index (Hin), and external radiation hazard index (Hex), were calculated. The values of all of these parameters were found to be below the internationally accepted radiation limit values. In addition, distribution maps showing the radiological situation of the region were generated although they did not pose a hazard to public health. No results were found in the analysis processes related to artificial radioactivity.

Komparasi Perubahan Tutupan Lahan di Gili Meno, Gili Trawangan dan Gili Air (Gili Matra)

This research aims to determine changes in land cover on Gili Meno, Gili Trawangan, and Gili Air as small islands in West Nusa Tenggara Province. The method used in this research is a qualitative descriptive method in comparing land cover changes on each island and also spatial analysis using Google Earth satellite image data in 2013 and 2022. The research results show seven land cover classifications consisting of built-up land, open land, stretches of beach sand, water bodies, plantations, bushes, and mangroves. Based on the analysis of land cover changes in Gili Trawangan, Gili Meno, and Gili Air, a trend of increasing built-up land area for ten years from 2013 to 2022. The most significant increase in built-up land occurred on Gili Trawangan, namely 48.14 Ha. It was followed by Gili Air and Gili Meno, respectively 24.86 ha and 23.71 ha. The driving factor for changes in land cover on Gili Matra is policies from the central, provincial, and regional governments regarding the promotion and establishment of Gili Matra as a tourism destination in NTB Province. Furthermore, this policy impacts the growth of tourists and the number of residents. It causes an increase in the need for tourism-supporting facilities. Therefore, there is a change in land cover, which gradually reduces the area of undeveloped land on Gili Matra.

A micropolar model accounting for asymmetric behavior of cold‐box sand in relation to tensile and compression tests

AbstractCold‐box sand (CBS) belongs to the granular materials and consists of sand and a binder. The behavior of CBS is simulated with a micropolar model, whereby the additional degree of freedom of the model describes the rotation of the sand grains. The model is used to generate a shear band under pressure for three different meshes, where the force‐displacement curves of the three meshes converge so that no mesh dependence occurs. Another requirement of the model is the consideration of asymmetric behavior for compression and tension. Due to the additional degree of freedom the implicit implementation of the micropolar continuum is very time‐consuming. Therefore, an explicit implementation is considered as an alternative possibility. This paper compares the advantages and disadvantages of both methods and the results for both calculations.