Search Results (501)

Polylactide (PLA) composites were prepared and doped with starch (10% by weight), and mineral salts used as mineral fertilisers (MgSO₄, KNO₃, Ca(NO₃)₂ and Ca₃(PO₄)₂) were prepared. The content of the added fertilisers was 2% by mass in the composites. The tensile strength properties of the obtained composites were tested. The effect of the addition of fertilisers on the structure of polylactide was analysed using spectroscopic methods (FTIR and FTRaman). The thermal properties of the obtained composites were tested using thermogravimetry (TG/DTG) and differential scanning calorimetry (DSC). PLA composites with fertilisers were tested for biodegradability in two types of soil—field soil and horticultural soil—and in compost. Biodegradability was assessed based on the mass loss of biodegraded composites, spectroscopic tests and visual assessment of changes occurring in the composites. Tests were performed on the respiratory activity of microorganisms in the compost extract in which the tested composites were placed. The addition of mineral salts used in the tested composites significantly influenced the biodegradation rate of the composites. Mineral compounds (MgSO₄, KNO₃ and Ca(NO₃)₂) added to the PLA–starch composite improve its mechanical properties. It should also be noted that the addition of mineral salts to the prepared composites did not affect the chemical structure of polylactide. The addition of mineral salts to PLA also did not significantly affect its thermal properties, as demonstrated by DSC and TG thermal analysis. Full article

This study evaluates the role of groundwater in the dynamics of the Slano blato landslide using hydrogeochemical and stable isotope data. Results show that deep groundwater inflow significantly affected the landslide behavior, as demonstrated by pronounced hydrogeochemical and isotopic differences among springs. Springs within the landslide differ markedly from those in similar geological settings of the Vipava Valley, indicating a distinct local groundwater system. Groundwater is present within the landslide body even during dry periods. Waters originate mainly from a higher karstic recharge area and flow through deep flysch strata, particularly fractured sandstones, where they become enriched in dissolved ions, especially K⁺ and SO₄²⁻, and show increased mineralization in the lower parts of the landslide. Saturation indices indicate slight oversaturation with calcite and dolomite and equilibrium with quartz for most samples, reflecting interaction with carbonates and flysch sandstones. Elevated sulphate concentrations and near-equilibrium conditions for mirabilite and thenardite suggest salt-related deterioration of landslide material, enhanced by evaporation. Stable isotope data (δ¹³C_DIC, δ¹⁸O, δ²H) indicate dominant carbonate recharge, meteoric origin, evaporation effects, and long-term water–rock interaction. This study highlights the need for additional isotope tracers, groundwater age indicators, seasonal monitoring, and on-site meteorological measurements to improve interpretation. Full article

The homogeneity of methane hydrates in marine sediments plays a significant role in determining the efficiency of gas production during exploitation processes. Revealing their distribution mechanisms is crucial for optimizing the development of gas hydrates. This work systematically investigates the evolution patterns of effective thermal conductivity (ETC) during the formation and dissociation of methane hydrate in marine sediments, focusing on their major mineral components, such as quartz sand, illite, and montmorillonite. The results reveal the influence of thermal conductivity (TC) characteristics in porous media on hydrate phase transition behavior and spatial distribution. Key findings demonstrate that the TC characteristics of porous media are one of the dominant factors controlling hydrate formation rates. High-conductivity porous media significantly accelerate hydrate formation through efficient heat transfer. The swelling characteristics of montmorillonite and its coupling effects with salt ions impair heat transfer pathways, thereby inhibiting hydrate formation. Further analysis reveals that the spatial heterogeneity in reservoir TC is the primary intrinsic mechanism responsible for the macroscopic heterogeneous distribution of hydrates. Additionally, the hydrate dissociation process disrupts solid-state thermal bridging and generates gaseous thermal barriers, causing irreversible attenuation of reservoir TC. This phenomenon exacerbates the non-uniformity of the front during dissociation and increases the risk of secondary formation during exploitation. From a novel perspective of reservoir TC heterogeneity, this study establishes mechanistic links between the thermophysical properties of porous media and the spatial distribution patterns of hydrates. This provides significant theoretical guidance for resource exploration and the safe, efficient exploitation of marine gas hydrate reservoirs. Full article

This study investigates how molecular weight, ionic strength, and ionic composition influence the performance of sodium lignosulfonate as a dispersant for titanium dioxide (TiO₂) suspensions. Adsorption behavior was quantified using a quartz crystal microbalance with dissipation monitoring (QCM-D), while dispersion efficiency was assessed in concentrated suspensions via particle analysis (LUMiSizer) and in pastes through rheological measurements. In salt-free conditions, no adsorption occurs; however, the observed low particle size and viscosity can be attributed to depletion stabilization by non-adsorbing lignosulfonates. Both low- and high-molecular-weight fractions exhibit dispersing performance, but high-molecular-weight lignosulfonate provides the greatest stability across electrolyte variations. Increasing ionic strength enhances adsorption, leading to elastic particle network formation and higher viscosity due to reduced Debye length. With divalent ions, this effect is stronger and promoted by divalent cation bridging. These findings underscore the importance of tailoring lignosulfonate molecular weight and dosage to operating conditions, supporting formulation strategies for mineral-rich suspensions and industrial effluents. Future work should address long-term stability, temperature effects, and behavior on hydrophobic surfaces. Full article

This study investigates a 26th Dynasty Ptah–Sokar–Osiris wooden statuette excavated from the Tari cemetery, Giza Pyramids area, to decode ancient Egyptian manufacturing techniques and establish evidence-based conservation strategies of such wooden objects. Using minimal sampling (1.0–2.0 mm²), integrated XRF, synchrotron-based X-ray diffraction, FTIR, and confocal microscopy distinguished original technological choices from burial-induced alterations. The 85 cm Vachellia nilotica sculpture exhibits moderate structural preservation (cellulose crystallinity index 62.9%) with partial chemical deterioration (carbonyl index 2.22). Complete pigment characterization identified carbon black, Egyptian Blue (cuprorivaite, 55 ± 5 wt %), atacamite-dominated green (65 ± 5 wt %) with residual malachite (10 ± 2 wt %), orpiment (60 ± 5 wt %), red ochre (hematite, 60% ± 5 wt %), white pigments (93 ± 5 wt % calcite), and metallic gold (40 ± 5 wt %). Confocal microscopy revealed sophisticated multi-pigment mixing strategies, with black carbon systematically blended with chromophores for nuanced color effects. Atacamite predominance over malachite provides evidence for chloride-mediated diagenetic transformation over 2600 years of burial. Consistent calcite detection (~ 20–45%) across colored layers confirms systematic ground layer application, establishing technological baseline data for 26th Dynasty Lower Egyptian workshops. Near-complete organic binder loss, severe lignin oxidation, and ongoing salt-mediated mineral transformations indicate urgent conservation needs requiring specialized consolidants, paint layer stabilization, and controlled environmental storage. This investigation demonstrates synchrotron methods’ advantages while establishing a minimally invasive framework for studying polychrome wooden artifacts. Full article

Salinization is a growing global problem, particularly in arid and semi-arid areas, where salt concentration interferes with the soil structure, altering natural cycling, decreasing agricultural outputs, and threatening food security. Although many soil amendments have been studied, there is still a limited understanding of their interaction with soil after mixture application and the geochemical processes and long-term sustainability that govern their effects. To address this knowledge gap, this review elucidated the effectiveness and sustainability of soil amendments, biochar, humic substances, and mineral additives in restoring saline and sodic soils of arid and semi-arid region to explore the geochemical processes that underlie their impact. A systematic search of 174 peer-reviewed studies was conducted across multiple databases (Web of Science, Google Scholar, and Scopus) using relevant keywords and the findings were converted into quantitative values to evaluate the effects of biochar, gypsum, zeolite, and humic substances on key soil properties. Biochar significantly improved cation exchange capacity, nutrient retention, microbial activity, and water retention by enhancing soil porosity and capillarity, thereby increasing plant-available water. Gypsum improved phosphorus availability, while zeolite facilitated the removal of sodium and supported microbial activity. Humic substances enhanced soil porosity, water retention, and aggregate stability. When applied together, these amendments improved soil health by regulating salinity, enhancing nutrient cycling, while also stabilizing soil conditions and ensuring long-term sustainability through improved geochemical balance and reduced environmental impacts. The findings highlight the critical role of multi-functional amendments in promoting climate-resilient agriculture and long-term soil health restoration in saline-degraded regions. Further research and field implementation are crucial to optimize their effectiveness and ensure sustainable soil management across diverse agricultural environments. Full article

Two genetically engineered Bacillus subtilis strains, BMV9 and BsB6, were evaluated in terms of culture medium (effect of nutrients on surfactin yield) and potential biotechnological applications of surfactin in agriculture and the petrochemical industry. BMV9 (spo0A3; abrB*; ΔmanPA; sfp+) is, to date, the highest surfactin producer reported scientifically, and BsB6 is a sfp+ laboratory derivative strain that has also demonstrated considerable production potential. To assess their performance, fermentation experiments were conducted in shake flasks using two different culture media, a mineral salt medium and a complex medium, each supplemented with 2% (w/v) glucose. Lipopeptides (surfactin and fengycin) were extracted and quantified at multiple time points (up to 48 h) via high-performance thin-layer chromatography (HPTLC). Optical density, residual glucose, and pH were monitored throughout the cultivation. In parallel, microbial growth in both media were also validated in small-scale cultivation approaches. Antifungal activity of culture supernatants and lipopeptide extracts was tested against two Diaporthe species, key phytopathogens in soybean crops. Given the agricultural relevance of these pathogens, the biocontrol potential of lipopeptides represents a sustainable alternative to conventional chemical fungicides. Additionally, oil displacement tests were performed to evaluate the efficacy of surfactin in enhanced oil recovery (EOR), bioremediation, and related petrochemical processes. High-resolution LC-MS/MS analysis enabled structural characterization and relative quantification of the lipopeptides. Overall, these investigations provide a comprehensive comparison of strain production performance and the associated impact of cultivation media, aiming to define the optimal conditions for economically viable surfactin production and to explore its broader biotechnological applications in agriculture and the petrochemical industry. Full article

This study evaluated the effects of varying dietary salt and boric acid addition doses on the milk quality of Savak Akkaraman sheep. A total of 120 animals were as-signed to six treatment groups (n = 20): control (C), rock salt (S; 10 g/day), boric acid 20 mg/day (B20), boric acid 40 mg/day (B40), BS20 (20 mg boric acid + 10 g/day rock salt), and BS40 (40 mg boric acid + 10 g/day rock salt). All analyses were performed in duplicate on six samples, taken on days 30 and 35 following the administration of the additives. Physicochemical analyses only showed significant variation in milk pH (p = 0.006), while acidity, dry matter, and ash remained unaffected. Strong positive correlations were found among protein, lactose, salt, and density (r > 0.95; p < 0.001). Coagulation times differed widely, with the longest being observed in BS20 (995.03 s) and the shortest in BS40 (141.73 s). Among mineral parameters, only selenium levels differed significantly between the treatment groups (p < 0.05). No significant differences were found for fat, solids-not-fat, lactose, freezing point, or electrical conductivity. Importantly, boron addition had a significant influence on total casein content (p < 0.001). Overall, dietary rock salt and boric acid did not markedly alter the basic milk composition but produced notable physicochemical changes, particularly in coagulation behavior and casein levels, which may influence the technological properties of sheep milk. Full article

Stone cultural relics are primarily composed of sandstone, a water-sensitive rock that is highly susceptible to deterioration from environmental solutions and dry-wet cycles. Sandstone pagodas are often directly exposed to natural elements, posing significant risks to their preservation. Therefore, it is crucial to investigate the performance of sandstone towers in complex solution environments and understand the degradation mechanisms influenced by multiple environmental factors. This paper focuses on the twin towers of the Huachi Stone Statue in Qingyang City, Gansu Province, China, analyzing the changes in chemical composition, surface/microstructure, physical properties, and mechanical characteristics of sandstone under the combined effects of various solutions and dry-wet cycles. The results indicate that distilled water has the least effect on the mineral composition of sandstone, while a 5% Na₂SO₄ solution can induce the formation of gypsum (CaSO₄·2H₂O). An acidic solution, such as sulfuric acid, significantly dissolves calcite and diopside, leading to an increase in gypsum diffraction peaks. Additionally, an alkaline solution (sodium hydroxide) slightly hydrolyzes quartz and albite, promoting calcite precipitation. The composite solution demonstrates a synergistic ion effect when mixed with various single solutions. Microstructural examinations reveal that sandstone experiences only minor pulverization in distilled water. In contrast, the acidic solution causes micro-cracks and particle shedding, while the alkaline solution results in layered spalling of the sandstone surface. A salt solution leads to salt frost formation and pore crystallization, with the composite solution of sodium hydroxide and 5% Na₂SO₄ demonstrating the most severe deterioration. The sandstone is covered with salt frost and spalling, exhibiting honeycomb pores and interlaced crystal structures. From a physical and mechanical perspective, as dry-wet cycles increase, the water absorption and porosity of the sandstone initially decrease slightly before increasing, while the longitudinal wave velocity and uniaxial compressive strength continually decline. In summary, the composite solution of NaOH and 5% Na₂SO₄ results in the most significant deterioration of sandstone, whereas distilled water has the least impact. The combined effects of acidic/alkaline and salt solutions generally exacerbate sandstone damage more than individual solutions. This study offers insights into the regional deterioration characteristics of the Huachi Stone Statue Twin Towers and lays the groundwork for disease control and preventive preservation of sandstone cultural relics in similar climatic and geological contexts. Full article

Microseismic monitoring is extensively applied in hydraulic fracturing and mineral extraction, with accurate event localization being a critical component. Recently, deep learning approaches have shown promise for microseismic event localization; however, most of these supervised methods depend on large, labeled datasets, which are costly and challenging to acquire. To mitigate this issue, we propose a semi-supervised approach based on a residual convolutional autoencoder (RCAE) for automated microseismic localization, designed to leverage limited labeled data effectively and improve source localization accuracy even with small sample sizes. Our method employs pre-training by masking and reconstructing unlabeled seismic records, while integrating residual connections within the encoder to enhance feature extraction from seismic signals. This enables high localization accuracy with minimal labeled data, resulting in significant cost savings. Experimental results indicate that our method surpasses purely supervised approaches on both a 2D salt dome model and a 3D homogeneous half-space model, validating its effectiveness in microseismic localization. Further comparisons with baseline models highlight the method’s advantages, providing an innovative solution for improving cost-efficiency in practical applications. Full article

Functional properties of coastal halophytes are important for development of salt-tolerant cash crop cultures. The study of salt tolerance in coastal dune-building grass Leymus arenarius holds significant importance for its application in land reclamation, soil stabilization, and enhancing crop resilience to salinity stress. We used two accessions (LA1 and LA2) of L. arenarius to compare effects of salinity caused by NaCl and NaNO₃ on growth, ion accumulation and mineral nutrition in controlled conditions. L. arenarius plants exhibited high tolerance to sodium salts, with distinct effects on growth and development observed between chloride and nitrate treatments. While both salts negatively impacted root biomass, nitrate treatment (50–100 mmol L⁻¹) increased leaf number and biomass in LA2 plants, whereas chloride treatment decreased tiller and leaf sheath biomass. Despite individual variations, salinity treatments showed comparable effects on traits like tiller and leaf count, as well as leaf blade and sheath biomass. Salinity increased water content in leaf blades, sheaths, and roots, with LA2 plants showing the most pronounced effects. Chlorophyll a fluorescence measurements indicated a positive impact of NaNO₃ treatment on photosynthesis at intermediate salt concentrations, but a decrease at high salinity, particularly in LA2 plants. The accumulation capacity for Na⁺ in nitrate-treated plants reached 30 and 20 g kg⁻¹ in leaves and roots, respectively. In contrast, the accumulation capacity in chloride-treated plants was significantly lower, approximately 10 g kg⁻¹, in both leaves and roots. Both treatments increased nitrogen, phosphorus, and manganese concentrations in leaves and roots, with varying effects on calcium, magnesium, iron, zinc, and copper concentrations depending on the type of salt and tissue. These findings highlight the potential of L. arenarius for restoring saline and nitrogen-contaminated environments and position it as a valuable model for advancing research on salt tolerance mechanisms to improve cereal crop resilience. Full article

Mineral extraction from brine solutions is a vital issue for resource recovery in many fields of industry, especially in desalination processes. Usually, the solubility limit is viewed as a key factor that plays a determinant role in the efficiency of a prescribed process. This paper suggests the investigation of the influence of ionic strength, which is a measure of the total concentration of all dissolved ions, on the solubility limits in brines that are extracted from desalination facilities in Kuwait before discharging them into the Persian Gulf. For this purpose, the solubility of two main minerals (CaSO₄ and Mg(OH)₂) was measured for several values of ionic strength achieved by adjusting the concentration of the brine solutions. Brine samples were characterized and concentrated to achieve ionic strength values that are in the range of 1.1–2.0 mol/L. An adapted supersaturation-equilibration method was applied to determine solubility limits. Results show a non-linear relationship between ionic strength and the solubility limit of the target minerals, with behavior similar to that which could be found in the literature. In the case of CaSO₄, it was found that the solubility exhibits an increase (salting in effect) at low ionic strength, followed by a decrease at higher ionic strength (>1.1 M) (salting-out effect). On the other hand, the solubility of Mg(OH)₂ in Kuwait brine water was shown to decrease as the ionic strength increased. These trends, validated against literature data, are attributed to non-ideal solution behavior and specific ion interactions in the complex brine matrix. The findings of this work provide crucial insights for process design, enabling more precise control over precipitation steps and enhancing the overall yield and economic viability of mineral extraction from complex brine resources. Full article

Qarhan Salt Lake, located in the Qaidam Basin of northwestern China, is a highland lake characterized by diverse surface features, including salt lakes, salt crusts, and saline-alkali lands. Investigating the distribution and dynamic variations of salt crusts is essential for mineral resource development and regional ecological monitoring. To this end, the surface of the study area was categorized into several types according to micro-geomorphological characteristics. Polarimetric synthetic aperture radar (PolSAR), which provides rich scattering information, is well suited for distinguishing these surface categories. To achieve more accurate classification of salt crust types, the scattering differences among various types were comparatively analyzed. Stable samples were further selected using unsupervised Wishart clustering with reference to field survey results. Besides, to address the weak inter-class separability among different salt crust types, this paper proposes a PolSAR classification method tailored for salt crust discrimination by integrating unsupervised feature learning, attention-based feature optimization, and global context modeling. In this method, convolutional autoencoder (CAE) is first employed to learn discriminative local scattering representations from original polarimetric features, enabling effective characterization of subtle scattering differences among salt crust types. Vision Transformer (ViT) is introduced to model global scattering relationships and spatial context at the image-patch level, thereby improving the overall consistency of classification results. Meanwhile, the attention mechanism is used to bridge local scattering representations and global contextual information, enabling joint optimization of key scattering features. Experiments on fully polarimetric Gaofen-3 and dual-polarimetric Sentinel-1 data show that the proposed method outperforms the best competing method by $2.34\%$ and $1.17\%$ in classification accuracy, respectively. In addition, using multi-temporal Sentinel-1 data, recent temporal changes in salt crust distribution are identified and analyzed. Full article

Multiple sclerosis (MS) is a chronic neuroinflammatory and autoimmune disorder of the central nervous system (CNS) whose cause remains unknown. Disease-modifying therapies (DMTs) are the current standard of care, yet growing evidence highlights the importance of complementary lifestyle-based interventions, including nutrition, in modulating disease activity. Given the influence of diet on immune function, several studies have examined its effects in MS, with particular attention to specific dietary patterns and macronutrients. However, fewer studies have focused on micronutrients, bioactive compounds, and minerals and their influence in MS. In this narrative review, we report the latest evidence on micronutrients such as vitamins and essential metals, along with polyphenols and minerals like salt, in both experimental autoimmune encephalomyelitis (EAE) and MS. We also discuss how these dietary components may influence the gut microbiota, which is considered a contributor to disease onset due to its interaction with the immune system in the gut–brain axis. While findings for vitamins B, C, E, and K remain heterogeneous, vitamins A and D show the most consistent immunological and clinical effects, with immunomodulatory, antioxidative, and neuroprotective effects in both EAE and MS. Polyphenols also display anti-inflammatory and neuroprotective properties in EAE and, to a lesser extent, in clinical studies. Lastly, evidence suggests the importance of balanced salt intake and adequate levels of essential metals, as dysregulation may contribute to comorbidities or enhance inflammatory pathways relevant to MS. Although only a limited number of studies have explored these aspects, the gut microbiota appears to be differentially affected by these dietary factors. Overall, advancing our understanding of how these components interact with immune and microbial pathways may support the development of personalized nutritional strategies to complement current therapies and improve patient outcomes. Full article

To address the problem of wellbore instability in the development of deep coalbed methane reservoirs in Daniudi gas field, this study takes the coal seam cores from Member 1 of the Taiyuan Formation at a depth of approximately 2880 m as the research object. Through CT scanning, scanning electron microscopy (SEM), mineralogical analysis, laboratory mechanical tests, and drilling fluid interaction experiments, the study investigated the coal seam fabric characteristics, mechanical response, anisotropy, and the interaction between drilling fluids and the formation. Based on the double-weak-plane criterion, a wellbore collapse prediction model was established, and instability risk assessment under multi-factor coupling conditions was carried out. Experimental and computational results indicate that the deep coal seam exhibits significant heterogeneity in fabric structure, the clay minerals show low swelling potential, and the bright coal and semi-bright coal are prone to instability due to their dual pore structures. The average uniaxial compressive strength (UCS) of the coal cores is 16.3 MPa, which is weaker than that of the roof, floor, and dirt band. The coal also exhibits anisotropy, with the lowest strength occurring when the loading direction forms an angle of 30–60° with the weak planes, corresponding to 67.5% of the intrinsic compressive strength. Immersion in drilling fluid causes the coal rock strength to decay in a pattern of “rapid decline in the initial stage—gradual decrease in the middle stage—stabilization in the later stage.” After 24 h, the strength is only 55–65% of that in the dry state. Due to its excellent plugging and inhibition performance, HX-Coalmud drilling fluid delays strength loss more effectively than the strongly inhibitive composite salt drilling fluid. The wellbore instability risk assessment indicates that as the drilling time is extended, the collapse pressure rises significantly. After 7 and 20 days of contact between the wellbore and drilling fluid, the equivalent collapse pressure density increases by 0.08–0.15 g/cm³ and 0.13–0.20 g/cm³, respectively. Therefore, homogeneous isotropic models tend to underestimate the risk of wellbore collapse. The findings can provide theoretical and technical support for the safe drilling of deep coalbed methane in Daniudi gas field. Full article