Search Results (8,335)

The sulfur dioxide removal in thermoelectric plants occurs through flue gas desulfurization (FGD), which produces waste that needs to be correctly disposed of. This exploratory research aims to characterize waste obtained from an FGD plant in Candiota, Rio Grande do Sul, Brazil, and evaluate its potential as alternative mineral source in obtaining alkali-activated materials (AAM). The dried and processed waste was called FGD-D, and AAM was produced by mixing FGD-D with sodium-based alkaline activating solutions. The amounts of FGD at formulations ranged from 31.6 (F1) to 38.9 wt.% (F4), and the use of metakaolin was not necessary. The results show that the chemical composition of FGD-D is composed mainly of calcium oxides (38 wt.%), sulfur (22 wt.%), and silica (19 wt.%). Crystalline phases and a high amorphous fraction were identified in the residual samples. The use of FGD-D in AAM proved to be an alternative mineral source, showing an exothermic reaction with subsequent rapid hardening and increased compressive strength values ranged from 7.7 ± 1.3 Mpa for F1 to 14.4 ± 1.8 Mpa for F4 at seven days. The results demonstrate the potential of using FGD-D in AAM formulations, opening positive perspectives for a more sustainable destination for these residual materials. Full article

Integrating renewable energy requires robust, large-scale storage solutions to balance intermittent supply. Underground hydrogen storage (UHS) in geological formations, such as salt caverns, depleted hydrocarbon reservoirs, or aquifers, offers a promising way to store large volumes of energy for seasonal periods. This review focuses on the biological aspects of UHS, examining the biogeochemical interactions between H₂, reservoir minerals, and key hydrogenotrophic microorganisms such as sulfate-reducing bacteria, methanogens, acetogens, and iron-reducing bacteria within the gas–liquid–rock–microorganism system. These microbial groups use H₂ as an electron donor, triggering biogeochemical reactions that can affect storage efficiency through gas loss and mineral dissolution–precipitation cycles. This review discusses their metabolic pathways and the geochemical interactions driven by microbial byproducts such as H₂S, CH₄, acetate, and Fe²⁺ and considers biofilm formation by microbial consortia, which can further change the petrophysical reservoir properties. In addition, the review maps 76 ongoing European projects focused on UHS, showing 71% target salt caverns, 22% depleted hydrocarbon reservoirs, and 7% aquifers, with emphasis on potential biogeochemical interactions. It also identifies key knowledge gaps, including the lack of in situ kinetic data, limited field-scale monitoring of microbial activity, and insufficient understanding of mineral–microbe interactions that may affect gas purity. Finally, the review highlights the need to study microbial adaptation over time and the influence of mineralogy on tolerance thresholds. By analyzing these processes across different geological settings and integrating findings from European research initiatives, this work evaluates the impact of microbial and geochemical factors on the safety, efficiency, and long-term performance of UHS. Full article

Municipal sewage sludge represents a significant environmental challenge due to its large-scale production and limited disposal options. Pyrolysis, a thermal decomposition process, offers a promising approach for converting sewage sludge into biochar, a carbon-rich material with diverse environmental applications. Sewage sludge-derived biochars were prepared at pyrolysis temperatures of 300 °C, 500 °C, 700 °C, and 900 °C (denoted as B300 to B900) and evaluated for their structural, adsorption, and catalytic performance. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET), and energy dispersive X-ray spectrometry (EDS) analyses revealed a distinct temperature-dependent morphological evolution and mineral exposure. The B900 biochar exhibited a BET surface area of 83.8 m²/g and the highest pore volume of 0.101 cm³/g, indicating a well-developed mesoporous structure. In catalytic degradation tests using 20 mg/L persulfate and 500 mg/L B900, rapid oxidation was observed, achieving 91% methylene blue (MB) degradation in 30 min, highlighting its role in activating persulfate via surface-bound Fe and Al species. Optimization studies confirmed that MB removal efficiency was highest at 500 mg/L biochar and 40 mg/L persulfate, and the system was not significantly affected by the tap and synthetic wastewater matrices. This work demonstrates that biochar obtained from sewage sludge can serve as an eco-friendly and multifunctional material for resource recovery and environmental cleanup. Full article

Polypropylene (PP) dielectric capacitors are crucial for electronics and electric power systems due to their high power density. However, their relatively low energy density limits their practical application in energy storage devices, presenting a long-standing challenge. Montmorillonite (MMT), a natural phyllosilicate mineral abundantly found on earth, features a two-dimensional nanosheet structure and excellent insulating properties. MMT nanosheets have shown promise in enhancing the breakdown strength and energy storage capability of PP dielectric, but compatibility issues with the PP matrix remain a challenge. In this study, we propose a novel surface modification strategy in which polystyrene (PS)-capped MMT (PCM) nanosheets are synthesized through a polymerization–dissolution process. The modified PCM nanosheets demonstrate improved compatibility and are well dispersed within the PP matrix. Optimal loading of the PCM nanosheets effectively dissipate charge energy and hinder the growth of electric trees in the PP matrix. As a result, the PP nanocomposite with 0.2 wt% PCM nanosheets exhibits an enhanced breakdown strength of 619 MV m⁻¹ and a discharged energy density of 4.23 J cm⁻³, with an energy storage efficiency exceeding 90%. These findings provide a promising strategy for the development of high-energy-density dielectric capacitors in an economical manner. Full article

Micronutrients and nutraceuticals play crucial roles in wound healing and tissue regeneration, supporting various physiological processes. This review aims to synthesize and evaluate the functions of various micronutrients and nutraceuticals, emphasizing the synergistic interactions among different nutrients that facilitate wound healing processes. A thorough literature review was performed using electronic databases, including PubMed, Scopus, Web of Science, Embase, Google Scholar, and Cochrane Library, to identify molecular studies, animal models, randomized controlled trials, and observational human studies published up to January 2000. Two independent reviewers screened the articles, extracted data, and evaluated the Risk of Bias using the Risk of Bias 2 (RoB 2) tool for the 190 studies that met the inclusion criteria. Evidence suggests that bioactive compounds found in functional foods and dietary supplements can help prevent chronic conditions and promote wellness beyond basic nutrition. Vitamins A, C, and E, as well as minerals such as zinc, selenium, and iron, are essential for cell proliferation and the formation of new tissues. Additionally, nutraceuticals, including omega-3 fatty acids, glutamine, arginine, and polyphenols, exhibit anti-inflammatory and antioxidant properties, which promote healing and reduce the risk of infection. Probiotics and other bioactive compounds in nutraceuticals contribute to maintaining the balance of microbiota, reducing inflammation, and stimulating cell regeneration. Significant variability was noted in study design, sample size, intervention dosage, and outcome measures. This evidence underscores the necessity for further well-designed clinical trials to determine the optimal dosages and combinations for specific wound types across diverse patient populations. This systematic review was prospectively registered in PROSPERO (ID: 1072091). Full article

Background/Objectives: Bones are essential components of the human body, providing structural support, enabling mobility, storing minerals, and protecting internal organs. Bone fractures (BFs) are common injuries that result from excessive physical force and can lead to serious complications, including bleeding, infection, impaired oxygenation, and long-term disability. Early and accurate identification of fractures through radiographic imaging is critical for effective treatment and improved patient outcomes. However, manual evaluation of X-rays is often time-consuming and prone to diagnostic errors due to human limitations. To address this, artificial intelligence (AI), particularly deep learning (DL), has emerged as a powerful tool for enhancing diagnostic precision in medical imaging. Methods: This research introduces a novel convolutional neural network (CNN) model, the Multi-Level Feature Fusion Network (MLFNet), designed to capture and integrate both low-level and high-level image features. The model was evaluated using the Bone Fracture Multi-Region X-ray (BFMRX) dataset. Preprocessing steps included image normalization, resizing, and contrast enhancement to ensure stable convergence, reduce sensitivity to lighting variations in radiographic images, and maintain consistency. Ablation studies were conducted to assess architectural variations, confirming the model’s robustness and generalizability across data distributions. MLFNet’s high accuracy, interpretability, and efficiency make it a promising solution for clinical deployment. Results: MLFNet achieved an impressive accuracy of 99.60% as a standalone model and 98.81% when integrated into hybrid ensemble architectures with five leading pre-trained DL models. Conclusions: The proposed approach supports timely and precise fracture detection, optimizing the diagnostic process and reducing healthcare costs. This approach offers significant potential to aid clinicians in fields such as orthopedics and radiology, contributing to more equitable and effective patient care. Full article

Long and continuous lacustrine sediments in Southwest China provide exceptional records of the Indian summer monsoon (ISM) evolution. Rock magnetic and environmental magnetic methods have significant roles in these lacustrine studies. However, lacustrine sedimentary environments are complex and magnetic mineral signatures can be altered by post-depositional processes. This study applies isothermal remanent magnetization (IRM) component unmixing methods to lacustrine sediments from the Heqing core, to identify and quantify magnetic mineral components. We analyzed 104 samples based on lithological variations and magnetic susceptibility (χ) to examine the composition of magnetic minerals and their relative contributions. Three distinct magnetic components were identified in IRM component unmixing results: a low-coercivity detrital component, a medium-coercivity authigenic component, and a hard magnetic component. Based on rock magnetic results, the medium-coercivity component was attributed to greigite. These components exhibit stratigraphic trends that reflect changes in paleoenvironmental conditions. The medium-coercivity component shows an upwards decrease, indicating a significant change in ISM science at about 1.8 Ma. The study highlights the importance of considering post-depositional processes when interpreting magnetic mineral signatures in lacustrine sediments. The CLG model, combined with conventional rock magnetic analyses, provides a rapid approach for characterizing magnetic assemblages in weakly magnetic sediments. Full article

This study conducts a detailed and systematic Life Cycle Assessment (LCA) of demineralized (DEMI) water production at the Al-Hilla Second Gas Power Plant in Iraq, employing the Open LCA-ReCiPe 8 Midpoint (H) method to evaluate potential environmental impacts across 18 midpoint categories. The analysis focuses on the production of 1 cubic meter of high-purity water, offering a comprehensive evaluation of the environmental burdens associated with chemical usage, energy consumption, and resource depletion. The results indicate that terrestrial ecotoxicity is the most dominant impact category (20.383 kg 1,4-DCB-eq), largely driven by the extensive use of treatment chemicals such as coagulants, disinfectants, and antiscalants. Climate change follows as the second highest impact category (3.496 kg CO₂-eq), primarily due to significant electricity consumption during energy-intensive stages, particularly reverse osmosis (RO) and electro-deionization (EDI). These stages also contribute notably to fossil resource depletion (1.097 kg oil-eq) and particulate matter formation, reflecting the heavy reliance on fossil fuel-based energy in the region. Additional environmental concerns identified include human toxicity (both carcinogenic and non-carcinogenic), freshwater and marine ecotoxicity, and metal/mineral resource depletion, all of which underscore the need for improved chemical and material management throughout the treatment process. While impacts from categories such as ozone layer depletion, ionizing radiation, and eutrophication are relatively low, their cumulative effect over time remains a concern for long-term sustainability. The energy assessment reveals that the RO and EDI units alone account for over 70% of the total energy consumption, estimated at 3.143 kWh/m³. This research provides insights into minimizing environmental burdens in water treatment systems, especially in regions facing energy and water stress. Full article

In the mining of deep mineral resources and tunnel engineering, the degradation of mechanical properties and the evolution of energy of through-double-joint sandy slate under triaxial loading and unloading conditions are key scientific issues affecting the stability design of the project. The existing research has insufficiently explored the joint inclination angle effect, damage evolution mechanism, and energy distribution characteristics of this type of rock mass under the path of increasing axial pressure and removing confining pressure. Based on this, in this study, uniaxial compression, conventional triaxial compression and increasing axial pressure, and removing confining pressure tests were conducted on four types of rock-like materials with prefabricated 0°, 30°, 60°, and 90° through-double-joint inclinations under different confining pressures. The axial stress/strain curve, failure characteristics, and energy evolution law were comprehensively analyzed, and damage variables based on dissipated energy were proposed. The test results show that the joint inclination angle significantly affects the bearing capacity of the specimen, and the peak strength shows a trend of first increasing and then decreasing with the increase in the inclination angle. In terms of failure modes, the specimens under conventional triaxial compression exhibit progressive compression/shear failure (accompanied by rock bridge fracture zones), while under increased axial compression and relief of confining pressure, a combined tensioning and shear failure is induced. Moreover, brittleness is more pronounced under high confining pressure, and the joint inclination angle also has a significant control effect on the failure path. In terms of energy, under the same confining pressure, as the joint inclination angle increases, the dissipated energy and total energy of the cemented filling body at the end of triaxial compression first decrease and then increase. The triaxial compression damage constitutive model of jointed rock mass established based on dissipated energy can divide the damage evolution into three stages: initial damage, damage development, and accelerated damage growth. Verified by experimental data, this model can well describe the damage evolution characteristics of rock masses with different joint inclination angles. Moreover, an increase in the joint inclination angle will lead to varying degrees of damage during the loading process of the rock mass. The research results can provide key theoretical support and design basis for the stability assessment of surrounding rock in deep and high-stress plateau tunnels, the optimization of support parameters for jointed rock masses, and early warning of rockburst disasters. Full article

With the progressive depletion of conventional oil and gas resources and the increasing demand for alternative energy, organic-rich sedimentary rock—oil shale—has attracted widespread attention as a key unconventional hydrocarbon resource. Pyrolysis is the essential process for converting the organic matter in oil shale into recoverable hydrocarbons, and a detailed understanding of its behavior is crucial for improving development efficiency. This review systematically summarizes the research progress on the pyrolysis characteristics of oil shale under laboratory conditions. It focuses on the applications of thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) in identifying pyrolysis stages, extracting kinetic parameters, and analyzing thermal effects; the role of coupled spectroscopic techniques (e.g., TG-FTIR, TG-MS) in elucidating the evolution of gaseous products; and the effects of key parameters such as pyrolysis temperature, heating rate, particle size, and reaction atmosphere on product distribution and yield. Furthermore, the mechanisms and effects of three distinct heating strategies—conventional heating, microwave heating, and autothermic pyrolysis—are compared, and the influence of inherent minerals and external catalysts on reaction pathways is discussed. Despite significant advances, challenges remain in quantitatively describing reaction mechanisms, accurately predicting product yields, and generalizing kinetic models. Future research should integrate multiscale experiments, in situ characterization, and molecular simulations to construct pyrolysis mechanism models tailored to various oil shale types, thereby providing theoretical support for the development of efficient and environmentally friendly oil shale conversion technologies. Full article

As the primary method of obtaining metallic copper resources from copper ore, pyrometallurgical smelting usually produces a large amount of copper slag, which has good physical properties and contains many valuable metals. Therefore, how to fully recycle and utilize it has become a research direction that has received much attention in recent years. To better understand the ‘artificial’ ore of copper slag, this article reviews the copper smelting process, the sources and properties of copper slag, and its resource potential. It introduces the method of recovering valuable metals from copper slag, including pyrometallurgical impoverishment, hydrometallurgical recovery, mineral processing methods, etc. Furthermore, it lists some applications of copper slag in the field of materials, primarily in cement, concrete aggregates, and glass-ceramic materials. Finally, based on the sustainable development background, copper slag’s efficient recycling is prospected. However, scalable, eco-friendly recovery technologies remain limited and warrant further research. Full article

The challenges of climate change require in-depth attention and targeted strategies for specific sectors, such as energy and mining. Within the mining sector, climate change imposes constraints on the sustainable extraction of minerals, thereby heightening the importance of several minerals in addressing these challenges. Chile emerges as a pivotal nation due to its substantial reserves of copper, lithium, cobalt, nickel, and graphite, which are essential for energy transition and decarbonization processes. Consequently, Chile must foster gradual processes to establish competitive advantages based on technological and innovative capabilities, thus projecting a competitive and sustainable mining industry. This endeavor should be accompanied by enhancements in policies and instruments to guide development, expanding local value creation. This study examines the global challenges faced by the mining sector in the context of the energy transition and evaluates Chile’s response through an assessment of public policies for mining development. It provides an analysis of the scope of various public policy instruments to establish the link between international agreements and development opportunities, subsequently proposing a series of indicators to assess policy progress. To this end, the Environmental Observatory of Mining Projects is developing indicators to evaluate compliance with these policies. In addressing the nation’s challenges related to green and sustainable mining, 20 indicators have been developed in collaboration with civil society and public and private stakeholders through a design thinking process. These indicators enable the evaluation of aspects such as air quality, water quality, and the surface area affected by tailings, among others. The initial section of the document outlines the global challenges in achieving the carbon neutrality goals set by the IPCC. The subsequent section elaborates on the theoretical framework of the research, addressing theories of economic development and sustainability, public policy approaches considered in recent years, as well as the governance of mining development, with an emphasis on its capacity to articulate industrial policies, promote environmental sustainability, and foster technological innovation. The third section details the research methodology and framework of the study. This study examines how Chile’s mining policies align with the global energy transition. Amid growing demand for critical minerals, climate change, and decarbonization, Chile faces both opportunities and socio-environmental risks. Addressing these challenges requires integrated sustainability strategies and an active state role to ensure inclusive, environmentally responsible, and innovation-driven mining development. Full article

The present study investigates post-emplacement zeolitization processes in two widespread pyroclastic units from Central Italy: the Cimina Ignimbrite and the Sorano Ignimbrite. A total of seventy-five samples from ten outcrops were analyzed using optical and environmental scanning electron microscopy, electron probe microanalysis, X-ray powder diffraction, and inductively coupled plasma optical emission spectrometry. Analytical results allow the mineral distribution, zeolite composition, textural relationships, and geochemical features of the zeolite-bearing rocks to be defined. In the Cimina Ignimbrite, zeolitization affects the glassy portion of the groundmass, where the glass transforms into a medium- to high-temperature mineral assemblage dominated by clinoptilolite-Ca and cristobalite. This transformation is restricted to the innermost parts of the deposit. In contrast, zeolitization in the Sorano Ignimbrite involves the entire glassy fraction of pumice clasts, with extensive alteration of the glass into medium- to low-temperature zeolites such as chabazite-K and phillipsite-K. The results reveal a significant correlation between the chemical composition of the juvenile material and that of the newly formed zeolites in both types of ignimbrites, particularly in the Sorano Ignimbrite. Zeolitization in Central Italy ignimbrites likely occurs in a natural autoclave-like setting, where hot fluids remain trapped in the deposit for a long time. Full article

The deep carbonate reservoirs in the Yingzhong Block of the Qaidam Basin exhibit strong vertical heterogeneity and complex natural fracture development. Conventional fracability evaluation methods struggle to accurately characterize formation features, thereby affecting the stimulation effectiveness. To enhance the evaluation accuracy of fracturing sweet spot intervals, automatic mineral scanning equipment is employed to obtain formation micro-physical property parameters at continuous depths. Considering the temperature-pressure coupling effect under deep conditions, a rock mechanics computational model based on mineral composition was established to derive macroscopic mechanical parameters such as brittleness index and in situ stress. Based on a combined algorithm of the improved Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) and Analytic Hierarchy Process (AHP), a fracturing sweet spot prediction model integrating micro- and macro-multi-factors is established, and sweet spot index levels are classified. The research results indicate that the rock mechanics computational model demonstrates high accuracy, the calculated macroscopic parameters are reliable, and the fracturing sweet spot index model can fracability and meticulously evaluate the characteristics of deep carbonate formations. The fracturing sweet spots can be classified into three levels: Level I with an index higher than 0.50, Level II with an index between 0.35 and 0.50, and Level III with an index lower than 0.35. After using this method for layer selection, the fracture pressure decreases by 11.6%, and the sand addition success rate increases by 24%. Applying this method to guide the optimization of fracturing intervals demonstrates good on-site practical value, providing an important reference for identifying fracturing sweet spots in deep carbonate reservoirs. Full article

To unravel the link between agate geochemistry, host volcanic rocks, and ore-forming processes, this study integrated elemental correlation analysis, interaction interpretation, and interpretable machine learning (LightGBM-SHAP framework with SMOTE and 5-fold cross-validation) using 203 in-situ element datasets from 16 global deposits. The framework achieved 99.01% test accuracy and 97.4% independent prediction accuracy in discriminating host volcanic rock types. Key findings reveal divergence between statistical elemental correlations and geological interactions. Synergies reflect co-migration/co-precipitation, while antagonisms stem from source competition or precipitation inhibition, unraveling processes like stepwise crystallization. Rhyolite-hosted agates form via a “crust-derived magmatic hydrothermal fluid—medium-low salinity complexation—multi-stage precipitation” model, driven by high-silica fluids enriching Sb/Zn. Andesite-hosted agates follow a “contaminated fluid—hydrothermal alteration—precipitation window differentiation” model, controlled by crustal contamination. Basalt-hosted agates form through a “low-temperature hydrothermal fluid—basic alteration—progressive mineral decomposition” model, with meteoric water regulating Na-Zn relationships. Zn acts as a cross-lithology indicator, tracing crust-derived fluid processes in rhyolites, feldspar alteration intensity in andesites, and alteration timing in basalts. This work advances volcanic-agate genetic studies via “correlation—interaction—mineralization model” coupling, with future directions focusing on large-scale micro-area elemental analysis. Full article