Deposition Area Research Articles

High-resolution soil erosion mapping in croplands via Sentinel-2 bare soil imaging and a two-step classification approach

Erosion-induced lateral soil redistribution leads to spatially heterogenous soil composition, which can be captured through the distinctive spectral reflectance of soils under varying levels of erosion influence. This points to the potential of using remotely sensed soil spectra to detect severe erosion and deposition hotspots in exposed croplands and, importantly, further differentiate the intra-class spectral variability of moderate erosion that often occupies the largest proportion. Here, we aim to develop a two-step erosion classification and mapping approach based on multitemporal compositing of Sentinel-2 bare soil images of a typical agricultural region (11,500 km2) of northeast China. A random forest classifier was firstly trained against the ground-truth data derived from very high resolution (VHR) imagery in Google Earth, with an overall accuracy of 91 % that allowed for clear delineation of severe erosion and deposition areas based on their distinct topographic and spectral features particularly in the red and red-edge bands. In the second step, the remaining area of moderate erosion (60.30 %) was further differentiated using Iterative Self-Organizing cluster unsupervised classification to yield a five-class soil erosion map at 10 m spatial resolution. The accuracy of the predicted map was successfully validated by independent Caesium-137 (137Cs) and soil organic carbon observations at catchment and regional scales, as revealed by significant inter-class differences in soil redistribution rates estimated from 137Cs inventory. The severe erosion class had a soil loss rate of 5.5 mm yr−1, suggesting that previous assessments have underestimated erosion severity. The spatial accordance of crop growth with soil erosion intensity, particularly in localized settings, further highlighted the potential of bare soil imaging for mapping the spatiotemporal development of soil erosion and its response to targeted sustainable cropland management efforts.

The ablation behavior and modification mechanism of SiC under different laser energy

The laser modification pretreatment method is an effective way to address the machining difficulties of silicon carbide (SiC), a typical hard-to-machine material. Therefore, the ablation behavior and modification mechanism of SiC under different laser energy were explored in this paper. A new multi-scale model of laser irradiation SiC that couples heat transfer and fluid motion is first established. Then, a series of experiments is carried out to evaluate the model's accuracy, and the interaction between laser and SiC is discussed in detail. The results show that the dominant modification mechanism changes from coulomb explosion to multiphoton absorption, incubation effect, and heat accumulation with the laser energy increase. This leads the surface topography of SiC to transition from nanoparticle formation to disorder to a melting state. In ablative state, micro/nano porous and humps are formed at the edge of ablation groove due to surface tension, generation and rupture of bubbles, respectively. Furthermore, the surface roughness is not proportional to the laser energy due to the plasma shielding effect, and the surface roughness can be reduced by enhancing the flow of the molten material. Amorphous Si–O–C, Si and spherical SiO2 exist in deposition area, leading to SiC elastic modulus decreases from 347 GPa to 103.82 GPa, and the shear strength decreases from 20.9 GPa to 17.25 GPa. The results of this study can provide references for parameters selection and theoretical support for improving the machinability of SiC.

Arthroscopic Decompression of Calcific Tendinitis of the Shoulder and Repair of Residual Rotator Cuff Defect

Background: Calcific tendinitis is a common source of shoulder pain and represents pathologic deposition of calcium hydroxyapatite within rotator cuff tendon tissue, most commonly the supraspinatus tendon. Indications: Arthroscopic decompression of calcific tendinitis with possible rotator cuff repair is indicated in patients with persistent, debilitating symptoms of pain and/or dysfunction who are recalcitrant to nonoperative treatments, including corticosteroid administration, ultrasound-guided needle barbotage, and/or extracorporeal shockwave therapy. Technique Description: With the patient in a beach chair position, a standard diagnostic shoulder arthroscopy is performed to evaluate for concomitant pathologies. Within the subacromial space, a thorough bursectomy is performed and the area of calcium deposition is localized with a spinal needle. A scalpel may be used to create a small incision through the rotator cuff tendon in line with its fibers to promote egress of calcific debris. Surrounding tissue and loose debris are removed with an arthroscopic shaver. Following decompression, the rotator cuff repair is inspected, and if a bursal-sided or full-thickness tear is identified, an arthroscopic repair is performed with a construct individualized to the specific tear pattern. Results: Surgical treatment conferred greater functional improvement and comparable pain reduction to nonoperative treatments in a systematic review comprised of 27 randomized trials. While the addition of a rotator cuff repair remains controversial, combined excision of calcific tendinitis with concomitant rotator cuff repair led to greater functional outcomes and pain reduction at 2-year minimum follow-up compared with isolated decompression. Conclusion: Calcific tendinitis within the shoulder may be treated successfully with arthroscopic decompression and subsequent repair of a residual rotator cuff defect, followed by a graduated physical rehabilitation program. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Structure-Function Relationship of Respiratory Muscles in the mdx Mouse Model of Duchenne Muscular Dystrophy

Duchenne muscular dystrophy (DMD) is a genetic neuromuscular disorder, characterized by severe and progressive skeletal muscle weakness, which extends to the respiratory muscles. We have determined that peak inspiratory pressure-generating capacity is preserved in early dystrophic disease in the mdx mouse model of muscular dystrophy, but this early compensation is lost as disease progressesa. We sought to examine the structure-function relationship of obligatory and accessory respiratory muscles in early (4-month) and advanced (16-month) disease. Ex vivo muscle function of obligatory (diaphragm and parasternal) and accessory (sternomastoid, cleidomastoid and scalene) respiratory muscles was assessed in wild-type and mdx mice in early dystrophic disease (n = 8-15 per group). Diaphragm and scalene ex vivo muscle function was assessed in advanced dystrophic disease (n = 10-14 per group). Histology (sirius red, and haematoxylin and eosin) and immunofluorescence (laminin) were used to assess the form of obligatory (diaphragm, parasternal and intercostal) and accessory (sternomastoid, cleidomastoid, scalene and trapezius) respiratory muscles (n=6 per group). Pro-inflammatory cytokine concentrations were examined in muscle homogenates of obligatory and accessory respiratory muscles of wild-type and mdx mice in early and advanced dystrophic disease (n=10 per group). Our study revealed obligatory (diaphragm and parasternal) and accessory (sternomastoid and cleidomastoid) muscle weakness evident in early dystrophic disease. Scalene muscle function is preserved in mdx mice in early disease but is weak in mdx mice in advanced dystrophic disease. Structural remodelling by way of increased collagen deposition (fibrosis), increased central nucleation, increased area of inflammatory cell infiltrate and reduced mean minimal Feret’s diameter (relative atrophy) was evident in obligatory and accessory respiratory muscles in early dystrophic disease. The relative area of collagen deposition in obligatory and accessory respiratory muscles increased with disease progression, but interestingly the increase was most pronounced in the diaphragm muscle. Increased concentration of pro-inflammatory cytokines (IFN-γ, IL-1β, IL-6, KC/GRO, TNF-α, MCP-1, IL-33, MIP-1α, IP-10, MIP-2) was observed in mdx obligatory and accessory muscle homogenates compared to wild-type in early and advanced dystrophic disease. These data widen characterisation of the respiratory control system in mdx mice, potentially revealing novel therapeutic targets. References a O'Halloran KD, Maxwell MN, Marullo AL, Hamilton CP, Ó Murchú SC, Burns DP, Mahony CM, Slyne AD, Drummond SE (2023). Loss of compensation afforded by accessory muscles of breathing leads to respiratory system compromise in the mdx mouse model of Duchenne muscular dystrophy. J Physiol. 601(19):4441-4467. Eli Lilly & Science Foundation Ireland (19/FFP/6628). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Prediction of the mineral components spatial distribution in tailings ferruginous quartzite enrichments

In Ukraine, a significant mass of potential man-made deposits is represented by waste from ferruginous quartzite enrichment. The mineral mass of such deposits is mixture of iron-containing minerals (magnetite, ilmenite) and quartz. The M.S. Poliakov Institute of Geotechnical Mechanics has developed a new methodology for the mineral components spatial distribution predicting in tailings of ferruginous quartzite enrichment. It includes the fractional and mineralogical composition of the samples study by optical method, and spatial useful components distribution of prognostication in waste and predictive plans construction for the useful components spatial placement. A previously unknown pattern of changes in mineral composition of wastes from mining ore production was revealed which caused by the turbulent transportation mode and waste deposition on the tailing (potential man-made deposit) area. This regularity arises from the fact that with decrease in the size of the mineral components particles with size of 0-200 microns, the share of the magnetic mineral magnetite increases linearly and, accordingly, the share of the non-magnetic mineral quartz decreases. The obtained new properties of man-made deposits from the waste (tailings) can be used in creation of resource-saving technology for the iron ore man-made raw materials processing and to determine their suitability for mining.

Effects of slope topography on rock avalanche mobility and deposition: A 2-D discrete element method investigation

The impact of rock avalanches is a major concern in mountain areas. However, fundamental understanding and reliable prediction of the depositional area of rock avalanches remains inadequate. Here, an idealized numerical study of granular materials flowing down a slope is carried out using two-dimensional (2-D) discrete element method simulations. The effects of the slope geometry on the mobility and deposit morphology of the granular flow are studied in detail. It is found that the granular flow mobility increases with the curvature radius of the circular ramp, leading to a longer runout distance, which is explained from the viewpoint of energy transfer and dissipation. The results are expected to enhance understanding of the travel and deposition mechanisms of rock avalanches and other related geophysical flows.

Effects of Empagliflozin on Vascular and Skeletal Mineralization in Hyperlipidemic Mice

Cardiovascular disease and osteoporosis, major causes of morbidity and mortality, are associated with hyperlipidemia. Recent studies show that empagliflozin (EMPA), an inhibitor of sodium-glucose cotransporter-2 (SGLT2), improves cardiovascular health. In preclinical animal studies, EMPA mitigates vascular calcification in the males but its effects in the females are not known. Thus, we used female mice to test the effects of EMPA on calcification in the artery wall, cardiac function, and skeletal bone. By serial in vivo microCT imaging, we followed the progression of aortic calcification and bone mineral density in young and older female Apoe−/− mice fed a high-fat diet with or without EMPA. The two different age groups were used to compare early vs. advanced stages of aortic calcification. Results show that EMPA treatment increased urine glucose levels. Aortic calcium content increased in both the controls and the EMPA-treated mice, and EMPA did not affect progression of aortic calcium content in both young and older mice. However, 3-D segmentation analysis of aortic calcium deposits on microCT images revealed that EMPA-treated mice had significantly less surface area and volume of calcified deposits as well as fewer numbers of deposits than the control mice. To test for direct effects on vascular cell calcification, we treated murine aortic smooth muscle cells with EMPA, and results showed a slight inhibition of alkaline phosphatase activity and inflammatory matrix calcification. As for skeletal bone, EMPA-treated mice had significantly lower BMD than the controls in both the lumbar vertebrae and femoral bones in both young and older mice. The findings suggest that, in hyperlipidemic female mice, unlike males, SGLT2 inhibition with empagliflozin does not mitigate progression of aortic calcification and may even lower skeletal bone density.

Effect of changes in the fuel type of thermal power plants on the spatial distribution and levels of PAH pollution in the Vorkuta agglomeration beyond the Arctic Circle

The paper is a study of the composition of 15 polycyclic aromatic hydrocarbons (PAHs) in the snow cover of Vorkuta (Komi Republic) in the impact zone of the fuel and energy complex in 2017 and 2023. We have identified high aerotechnogenic pollution of the Vorkuta city and adjacent territories with PAHs during heating with fuel oil and coal, with a mean concentration of 301.6 ng/L (meltwater plus particles) and spatial distribution of 85.2 μg/m2. There is a significant decrease in PAH levels when the fuel for thermal power plants has been changed to natural gas, with a mean concentration of 26.1 ng/L (meltwater plus particulates) and spatial distribution of 4.9 μg/m2. The deposition areas of different PAH fractions are identified in the impact zones of Thermal Power Plants 1 and 2, the Central Boiler House and the urbanised areas of the Vorkuta agglomeration. 2-4-ring PAHs dominate in the emissions, accounting for 92–100 % of the sum of PAHs from coal/oil combustion and 66–93 % from natural gas combustion. The indicator ratios of PAHs in the snow cover of Vorkuta in both 2017 and 2023 indicate their predominantly pyrogenic genesis. The environmental risk coefficients of PAHs in the snow cover and their change from 2017 to 2023 are calculated. TEQ changed from 2.1 ng/L (mean) in the 2017 season to 1.7 ng/L (mean) in the 2023 season. The risk quotients have been reduced from moderate risk to low risk. Reconstruction of thermal power plants when replaced by more environmentally friendly fuel (natural gas) reduces the amount of atmospheric emissions of organic pollutants.

Fibroblast matrix implants—a better alternative for incisional hernia repair?

The standard surgical procedure for abdominal hernia repair with conventional prosthetic mesh still results in a high recurrence rate. In the present study, we propose a fibroblast matrix implant (FMI), which is a three-dimensional (3D) poly-L-lactic acid scaffold coated with collagen (matrix) and seeded with fibroblasts, as an alternative mesh for hernia repair. The matrix was seeded with fibroblasts (cellularized) and treated with a conditioned medium (CM) of human Umbilical Cord Mesenchymal Stem Cells (hUC-MSC). Fibroblast proliferation and function were assessed and compared between treated with CM hUC-MSC and untreated group, 24 h after seeding onto the matrix (n = 3). To study the matrices in vivo, the hernia was surgically created on male Sprague Dawley rats and repaired with four different grafts (n = 3), including a commercial mesh (mesh group), a matrix without cells (cell-free group), a matrix seeded with fibroblasts (FMI group), and a matrix seeded with fibroblasts and cultured in medium treated with 1% CM hUC-MSC (FMI-CM group). In vitro examination showed that the fibroblasts’ proliferation on the matrices (treated group) did not differ significantly compared to the untreated group. CM hUC-MSC was able to promote the collagen synthesis of the fibroblasts, resulting in a higher collagen concentration compared to the untreated group. Furthermore, the in vivo study showed that the matrices allowed fibroblast growth and supported cell functionality for at least 1 month after implantation. The highest number of fibroblasts was observed in the FMI group at the 14 d endpoint, but at the 28 d endpoint, the FMI-CM group had the highest. Collagen deposition area and neovascularization at the implantation site were observed in all groups without any significant difference between the groups. FMI combined with CM hUC-MSC may serve as a better option for hernia repair, providing additional reinforcement which in turn should reduce hernia recurrence.

Hydropedological Characterization of a Coal Mining Waste Deposition Area Affected by Self-Burning

Coal mining often produces severe environmental effects, including impacts on the soil system and, specifically, on hydropedological conditions that control the leaching of significant ions and Potentially Toxic Elements (PTEs). The research objective is to assess changes in the hydropedological conditions in an area with a coal mining waste pile that underwent self-burning. An integrative approach was implemented, starting with the definition of hydropedological zoning based on field observations of soil formation factors (namely, parent material, relief, biological activity, anthropic influence, and time). The soil profile in each hydropedological zone was characterized regarding morphological features. The upper mineral horizons were sampled and characterized in terms of mineralogy and PTE geochemistry. Field measurements of unsaturated hydraulic conductivity, soil water content, and hydrophobicity were performed. Afterwards, the hydrogeochemistry of leachates was determined, and the soil leaching potential was evaluated. The research outcomes express substantial differences regarding the hydropedological zones: development of different soil profiles, diverse mineralogy and PTE geochemistry, higher unsaturated hydraulic conductivity and leaching of major ions, and PTEs in soils affected by coal mining activities. Finally, a Principal Component Analysis confirmed the existence of significant contrasts according to hydropedological zoning.

Migration of Fupingopollenites in the Cenozoic: Contribution from Turkish palynoflora and paleoclimatic implications

Fupingopollenites, an extinct plant, has been suggested to belong to a family that originated in eastern Asia, where it was recovered from the early middle Eocene. It developed throughout the Oligocene in eastern Asia, expanding its geographical range and reaching maximum distribution and probably species diversity in the Miocene. In this study, we present the Fupingopollenites occurrences from different regions and ages in Türkiye: the middle-late Eocene transition from the Hatıldağ area (NW Türkiye), the middle-late Eocene transition from the Niğde-Ulukışla area (central Türkiye), the early Oligocene from the Ankara-Şereflikoçhisar area (central Türkiye), the Miocene from the Muğla area (SW Anatolia), and the Pliocene from the Isparta-Şarkikaraağaç area (southern Anatolia). Based on all new findings and published records, we suggest that the migratory route of this plant into Europe is across Türkiye. Furthermore, we can conclude that the suitable palaeoclimatic and palaeoenvironmental conditions for the flourishment of this pollen existed in Türkiye during the Eocene-early Oligocene. According to the numerical climatic estimates, the favorable mean annual temperature and the mean annual prepitation was ∼16 °C and 1000–1100 mm respectively. In addition, we suggest that the microclimatic conditions driven by the intense local tectonics in different depositional areas exerted a significant role in the distribution of this plant. In this study, the botanical relationship of Podocarpium podocarpum with Fupingopollenites has not been fully determined. However, it is noteworthy that both plants were identified in the macro- and micro-flora of Muğla and its surroundings in the Middle Miocene.

Hydroxyapatite/polyamide 12 composite membrane as implant in intracorporeal sites

To evaluate the angiogenic and osteoinductive ability of implant consisting of hydroxyapatite powder incorporated into polyamide 12 membrane, thirty rats had this implant concomitantly placed at three intracorporeal sites (subcutaneous, omentum, and femur periosteum). Dosages of liver enzymes, urea, and creatinine serics demonstrated absence of hepatotoxicity and nephrotoxicity. Bone marrow samples, analyzed by the micronucleus test, demonstrated absence of toxicogenetic potential. The intracorporeal sites were assessed by light microscopy, indicating that the polymorphonuclear cells decreased in the omentum and femur periosteum, but not in the subcutaneous. The implants adhered to the femur periosteum between the 7th and 30th postoperative days. The periosteum thickness decreased on the 7th postoperative day. The vascularization decreased on all the postoperative days. In the femur periosteum, vascularization increased between the 7th and 21st. Calcium deposition in the omentum and femur periosteum was verified from the 7th day, without difference on later days. Subcutaneously, calcium deposition areas increased along time. By scanning electron microscopy was detected calcium and phosphorus deposition from the 7th day. Subcutaneous aggregation of these minerals became more evident on the 15th and 30th day, but the difference was not significant in the other intracorporeal sites. Subcutaneously, mineral organization was greater on the 15th postoperative day. In the omentum and femur periosteum, there was no difference along time. In conclusion, the implant did not display hepatotoxicity, nephrotoxicity, or genotoxicity, and stimulated deposition, aggregation, and organization of bone precursors from the very 7th postoperative day, which suggested that they have osteogenic and osteoinductive potential.

A novel membrane-free electrochemical separation-filtering crystallization coupling process for treating circulating cooling water

The traditional electrochemical descaling process exhibits drawbacks, including low OH− utilization efficiency, constrained cathode deposition area, and protracted homogeneous precipitation time. Consequently, this study introduces a novel membrane-free electrochemical separation-filtering crystallization (MFES-FC) coupling process to treat circulating cooling water (CCW). In the membrane-free electrochemical separation (MFES) system, OH− is rapidly extracted by pump suction from the porous cathode boundary layer solution, preventing neutralization with H+, thereby enhancing the removal of Ca2+ and Mg2+. Experimental results indicate that the pH of the pump suction water can swiftly increase from 8.13 to 11.42 within 10 min. Owing to the high supersaturation of the pump suction water, this study couples the MFES with a filtration crystallization (FC) system that employs activated carbon as the medium. This approach captures scale particles to enhance water quality and expedites the homogeneous precipitation of hardness ions, shortening the treatment time while further augmenting the removal rate. After the MFES-FC treatment, the single-pass removal rates for total hardness, Ca2+ hardness, Mg2+ hardness, and alkalinity in the effluent reached 92 %, 97 %, 64 %, and 67 %, respectively, with turbidity of 3 NTU, current efficiency of 86.6 %, and energy consumption of 7.19 kWh·kg−1 CaCO3. This coupling process facilitates an effective removal of hardness and alkalinity at a comparatively low cost, offering a new reference and inspiration for advancements in electrochemical descaling technology.

Sediment resuspension and transport due to synoptic winter winds in the Bohai Sea

The Bohai Sea is the receiving basin of the Yellow River (Huanghe), one of the largest contributors of global terrestrial materials to the sea. An area of fine-grained sediment deposition extends northeast of the Yellow River and its formation mechanism is still unclear. A calibrated, high-resolution coupled model of the Bohai and Yellow Seas was used to investigate sediment transport pathways in the region under the influence of strong and varying winds in winter. Numerical results highlight the importance of storm events in modifying the regional sediment resuspension and transport. During winter, the prevailing winds are typically from the northeast and northwest, interspersed by relaxation periods with weak winds. Winds influenced the currents and sediment movement in the Bohai Sea through several processes: local wind waves and resuspension, coastal-trapped waves in the Bohai Sea, and remotely forced coastal-trapped waves in the Yellow Sea. During northwesterly winds, sediment off the Yellow River Delta was mainly transported eastward along the south coast of Bohai Sea and escaped the Bohai Sea through the southern Bohai Strait. When northeasterly winds prevailed, sediment transport split into three branches: westward into the Bohai Bay, northeastward to the central Bohai Sea, and eastward along the south coast of Bohai Sea. Modeling results driven by synoptic winds indicate a more complex sediment transport pattern than previously understood with monthly average wind forcing. These findings challenge the traditional view of predominantly eastward sediment transport during winter and help to explain the observed grain size distribution in the Bohai Sea, in particular the accumulation of fine-grained sediments northeast of the Yellow River.

Comparative dose distribution profiles in a water-filled tube, jet, and tray treated with 1–5 MeV electrons

Accelerated electrons up to 5 MeV energy are relatively low-penetrating, and in the second half of the penetration length, the non-uniformity of energy deposition can increase by 20–50% per 1 mm of material depth. This feature of 1–5 MeV electrons, widely used in technology and research, as well as the high cost of beam power, requires the researcher to have the skills to identify areas of optimal energy deposition and develop measures to reduce energy loss. This work examines the dependence of the average absorbed dose and dose non-uniformity for three modes of electron beam treatment of water, taking into account the beam direction (horizontal or vertical, 1–5 MeV), beam window foil thickness (20–100 μm Al or Ti) and glass wall thickness (0.2–2 mm Pyrex). The dependencies are applicable to clarify, predict and analyze the dose distribution in a liquid irradiated in a tube, jet or tray.

Bioavailability and remineralization rates of sediment-derived dissolved organic carbon from a Baltic Sea depositional area

This pilot study investigated the bioavailability and remineralization kinetics of the sediment-derived dissolved organic carbon (DOC) from the Gdańsk Deep, a depositional area in the Baltic Sea. This was assessed in the long-lasting (126 d) incubation experiment, in which the mixture of DOC from sediment pore water and bottom water was exposed to oxic microbial respiration with incubation of bottom water as a control run. The obtained decay curves allowed us to distinguish three DOC fractions: labile (DOCL), semi-labile (DOCSL), and refractory (DOCR). In bottom water, the refractory fraction was predominant and amounted to almost 85% of total DOC, whereas about 15% of DOC was bioavailable: 6% labile and 9% semi-labile. In contrast, DOC from pore water was much more bioavailable DOC (~55% of total DOC) and contained 11% DOCL and 44% DOCSL. The remineralization rate constants recalculated to the in situ temperature of 6°C for labile and semi-labile DOC in pore water were 0.025 d−1 and 0.002 d−1, respectively, whereas, in bottom water, 0.026 d−1 and 0.004 d−1. The half-life times for DOCL were comparable for both bottom water and pore water and amounted to 26.2 d and 27.6 d, respectively. For DOCSL, the half-life time was shorter for bottom water (165.5 d) than for pore water (322.9 d).

Temporal and spatial variations in dust activity in Australia based on remote sensing and reanalysis datasets

Abstract. Spatial and temporal variations in the level of dust activity can provide valuable information for policymaking and climate research. Recently, Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol products have been successfully used for retrieving dust aerosol optical depth (DAOD), especially over bright dust source areas, and Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) aerosol reanalysis provides DAOD and additionally other dust-aerosol-related parameters. In this study, spatial and temporal variations in dust activity in Australia were analyzed using MODIS and MERRA-2 combined (M&M) DAOD and MERRA-2 near-surface dust concentrations and estimated PM10 for the period 1980–2020. Validation results show that M&M DAOD has an expected error of ±(0.016+0.15τ) compared to the ground observations at the AErosol RObotic NETwork (AERONET) dust storms on populated areas sites. MERRA-2 near-surface dust concentrations show a power-law relationship with visibility data collected at meteorological stations with an r2 value from 0.18 to 0.44, and the estimated MERRA-2 PM10 shows similar temporal variations and correlates with ground-based PM10 data with an r2 value from 0.14 to 0.44 at six selected stations in Australia. Moreover, MERRA-2 horizontal dust flux shows the same major dust pathways as those in previous studies and similar dust emissions and deposition areas identified using ground-based observations. Dust events based on DAOD over eastern Australia are concentrated in the north in December, are concentrated in the south in February, and can occur anywhere in January. Near-surface dust concentration was found to be the highest (over 200 µg m−3) over the center of Lake Eyre basin in central Australia and radially decreased toward the coast to below 20 µg m−3 via the two main pathways in the southwest and northeast. The ratio of near-surface dust concentration to PM10 shows a similar spatial pattern. Total dust emission was estimated to be 40 Mt (megatonnes) per year over the period 1980–2020, of which nearly 50 % was deposited on land and the rest exported away from the Australian continent.

Lead ions detection using CVD-grown ReS2-FET with the facilitation of a passivation layer

Field-effect transistor (FET)-based heavy-metal detection is garnering attention due to its heightened sensitivity, affordability, convenient fabrication, and portability. Flower-like rhenium disulfide (ReS2) offers potential for high-performance FET sensors, but direct exposure of channel materials to the ionic solution without a passivation layer results in multiple signals arising from the ionic transmission, doping impact, and gating effect. Introducing a passivation layer to the channel surface enhances sensor sensitivity without compromising device performance, ensuring conductance changes are primarily due to the gating effect. Here, a large surface area of Chemical Vapor Deposition (CVD)-grown vertically aligned ReS2 is employed in the FET-based sensor, and the utilization of the HfO2 layer is to isolate analytes from the elements of the conducting channel. For real-time lead monitoring in a water environment, it exhibits strong electrical stability, an impressive LoD (≈2 nM), a rapid response time (≈1.1 sec), and notable selectivity. Additionally, sensing operations are characterized by developing a unique amplifier circuit by integrating the fabricated sensor, contributing to advancements in sensor integration to detect hazardous metals in industrial electronics. These results underscore the potential for enhancing the performance of ion-sensitive FETs through structural optimization and improvements to the fundamental sensor mechanism.

Анализ устойчивости откосов горной дороги месторождения Camarioca Este компании Comandante Ernesto Che Guevara

In the framework of the study, numerical modelling has been conducted to calculate the slope stability of the mining road of the Camarioca Este deposit developed by the Empresa Comandante Ernesto Che Guevara Company. A geotechnical analysis of the deposit area has been carried out, as well as geological surveys to detect the areas prone to stability degradation. A geotechnical model including soil layers, properties of materials, and loading conditions was developed by using software. In order to assess the mining road slope stability, the limit equilibrium methods, in particular, the Morgenstern-Price method have been applied. This method is based on the limit equilibrium principle and the rock shear strength theory. Using the Slide software, the reserve factor has been calculated for different conditions. Modelling and calculation of the reserve factor have been conducted for two conditions: not considering factors reducing stability and considering such factors, namely the seismic level impact and rainfall effects. To determine the parameters of seismic acceleration in the region, the Cuban standard NC 46—2017 of the National Center of Seismological Research of Cuba has been applied. Three sectors with the potential level of stability reduction corresponding to stations with marks 0+250.00 m — 0+306.70 m, 0+380.00 m — 0+420.00 m, and 2+280.00 m — 2+291.68 m have been studied as the fundamental results; the reserve factors have been calculated considering seismic acceleration and intensive precipitation and are equal to 0.80, 1.45, and и 0.91, respectively.

Геохимическая оценка системы «поверхностная вода – донные отложения» в зоне горнопромышленного техногенеза

Introduction. Tailings dumps are the most common by-product of the process of extracting valuable minerals and metals from mined ore. Their placement is accompanied by a violation of the natural properties of natural landscapes, changes in the geochemistry of soils and the hydrochemistry of the aquatic environment, the accumulation of heavy metals and toxicants in depositing media. The issues of geochemistry and stability of landscapes, the safety of natural and technical systems, the identification, study, assessment and forecast of their development in the conditions of increasing techno genesis is an urgent global problem. One of the most important directions in the geochemistry of mountain landscapes and mining and industrial ecology is the purposeful study of the relationship and interdependence of the processes of technogenic geochemical migration of the main and associated ore-forming elements into the environment with the technological processes of ore extraction and processing. The development of scientifically-based principles for the organization of control and monitoring of disturbed geo-systems in the conditions of techno genesis is not only an important fundamental research task, but has practical significance in order to preserve natural landscapes and mountain geo-systems. Purpose of research. Geochemical assessment of the “surface water-bottom sediments” system in the area of a copper-molybdenum deposit. Materials and methods. The research methodology is based on the theoretical foundations of landscape geochemistry. The object of the study is the system “surface water-bottom sediments” in the zone of technogenic influence of the tailings dump of a copper-molybdenum deposit. Field and standard physical-chemical methods, Excel graphics, geo-information analysis, 3D modeling Statistica were used. Discussion. Geochemical testing of the surface river in the tailings storage area revealed a significant enrichment of the aquatic environment with salt ions, which enter the surface water in the form of dam filtrate. The violation of the ratio of alkali metal ions, as well as the ratio of alkali-earth metal ions to alkali metal ions, which is a geochemical anomaly for fresh surface natural waters, is shown. As a result of constant filtration through the body of the tailings dam, heavy metals also enter the river water, primarily Cu, Mo, Fe, which, under conditions of an alkaline water environment, accumulate mainly at the bottom of the watercourse in the form of insoluble deposits. The coefficients of accumulation of metals in bottom sediments relative to clerks are obtained. The spatial dynamics of their distribution and variability along the riverbed are revealed, which makes it possible to predict the development of the situation in the zone of mining and industrial techno genesis. 3D models of the distribution of the analyzed metals from the properties of the pH medium, the main regulating factor of the formation of various forms of heavy metals, are obtained. Conclusion. It is shown that the hydro-geochemical features in the “surface water – bottom sediments” system of the river in the area of the tailings dam inherit chemical ore occurrence during Cu, Mo, Fe extraction. This indicates a technogenic transformation of the hydrosphere in a zone with a predominance of mining and industrial specialization of the deposit. The results obtained are of scientific interest as an empirical model for studying the process of formation of sedimentary ores, which, in turn, represents a fundamental aspect for the development of the theory of subsoil development design and studying the processes of formation of technogenic deposits.