Search Results (47,241)

Rare earth elements (REEs), including yttrium, scandium and lanthanides, are essential for advanced technologies, particularly in electronics, defense and renewable energy systems. The main primary REE sources include bastnaesite, monazite and ion-adsorption clays, while secondary sources comprise permanent magnets, phosphors, LEDs and other technological waste. The growing demand, together with China’s dominant position in the global REE market and export restrictions, has increased concerns regarding the security of the REE supply in the European Union. This study evaluates selected primary REE resources and their processing possibilities using hydrometallurgical methods, with an emphasis on the thermodynamic aspects of REE leaching. The research focuses on the construction and analysis of Eh–pH diagrams generated using HSC Chemistry software to predict the stability of dissolved and solid species under different leaching conditions. These diagrams help identify suitable conditions for selective REE extraction and improve the understanding of the mechanisms governing hydrometallurgical processing. The results provide insight into the stability regions of REE species and indicate favorable conditions for selective leaching and recovery. Full article

The growing volume of agro-industrial and food-processing residues has intensified interest in their use as low-cost substrates for microbial bioprocessing. Coffee-derived waste streams, including spent coffee grounds (SCGs), wastewater, pulp, husk, and silverskin, represent abundant but still underutilized biomass resources. This narrative review evaluates their potential as liquid or solid substrates or as components of cultivation media for selected microbial systems, including microalgae, bioremediation- and bioprocess-related bacteria, edible fungi such as Pleurotus spp., and yeasts in the genera Pichia, Kluyveromyces, Saccharomyces, and Yarrowia. The review compares the suitability of individual coffee residues based on substrate composition, pretreatment requirements, inhibitory compounds, process limitations, and reported outputs. Coffee-derived residues can reduce substrate costs, support waste valorization, and partially replace conventional nutrients in microbial processes. However, their broader application is limited by compositional variability, conditioning or hydrolysis requirements, difficulties in process standardization, and downstream processing costs. Current evidence most strongly supports fungal cultivation on SCG-containing substrates, bacterial treatment of caffeine-rich wastewaters, yeast fermentation of hydrolyzed residues, and microalgal use of conditioned liquid streams. The review identifies key research gaps and outlines realistic directions for developing coffee-based microbial bioprocesses within a circular bioeconomy framework. Full article

Foodborne diseases remain a major global public health concern. According to the World Health Organization (WHO), contaminated food causes nearly 500,000 deaths annually. Consequently, the development of novel strategies to control foodborne pathogens and prevent microorganism-induced plant diseases remains an important research priority, attracting considerable scientific attention worldwide. This study describes the design and synthesis of novel dihydropyrazolines containing an ethylpiperazine moiety as potential antimicrobial agents. The antibacterial activity of the newly synthesized heterocyclic compounds, along with their corresponding chalcone precursors, was evaluated against Gram-positive and Gram-negative foodborne pathogens and phytopathogenic bacteria. The assessment was performed using a two-step protocol comprising an initial qualitative screening of selected bacterial species, followed by a quantitative evaluation of the inhibitory effects of individual compounds and their combinations. Among the tested compounds, pyrazolines 4a and 4b and chalcone 3b exhibited notable strain-dependent antibacterial activity, particularly against phytopathogenic strains of Pseudomonas syringae, while compound 4a demonstrated the highest efficacy against the Gram-negative foodborne pathogens Escherichia coli, Salmonella enterica and Listeria monocytogenes. Thus, the potential of the N-ethylpiperazine moiety as a key structural feature contributing to the antimicrobial activity of the studied compounds is revealed. Full article

When a large language model (LLM) answers a question using retrieved documents, retrieval-augmented generation (RAG) is the standard approach. Retrieving more documents improves answer accuracy but increases cost and response time; retrieving fewer documents saves resources but may miss critical information. Most existing RAG systems sidestep this dilemma by applying the same retrieval setting to every query, regardless of how simple or complex the question is. This wastes budget allocation on easy questions and under-serves hard ones. This paper introduces Cost-Aware RAG (CA-RAG), a routing framework that solves this problem by treating each query individually. For every incoming question, CA-RAG selects the most suitable retrieval strategy from a fixed menu of four options, ranging from no retrieval to fetching the top $k=10$ most-relevant documents. The selection is driven by a scoring formula that balances expected answer quality against predicted cost and response time. The weights in this formula act as dials: adjusting them shifts the system toward speed, savings, or quality without any retraining. CA-RAG is built on Facebook AI Similarity Search (FAISS) for document retrieval, OpenAI gpt-4o-mini for generation, and text-embedding-3-small for dense retrieval embeddings. We evaluate CA-RAG on a benchmark of 28 queries. The router assigns different strategies to different queries, achieving 26% fewer billed tokens compared to always using heavy retrieval and 34% lower response time compared to always answering without retrieval, while maintaining answer-quality parity in both cases. Further analysis shows that most savings come from simpler queries, where heavy retrieval was unnecessary. All results are reproducible from logged comma-separated value (CSV) files. CA-RAG demonstrates that a small but well-designed set of retrieval strategies combined with lightweight per-query routing can meaningfully reduce the cost and latency of LLM deployments without compromising answer quality. Full article

Concerns have increased significantly in recent years due to the presence of microplastics in different environmental compartments given that this pollutant can cause adverse effects on the environment and human health. The present review integrates representative studies of Mexican researchers proposing solutions to these concerns, addressing ecological risk and the human food chain, microplastic ingestion by animals, water and sediment pollution, physical/chemical methods for microplastic removal from water, and chemical recycling as a research direction in plastic waste management. Several publications from Mexican institutions are limited to the occurrence and identification of polymers, and a smaller number of documents are focused on solutions to microplastic pollution. Fibers, fragments, spheres, films, and foams have been found in aquatic compartments, sediment, and animals. High ecological risk has been documented in some aquatic compartments. There is a lack of standardized protocols for sampling, extraction, identification, and reporting. Flocculation is a cost-effective approach and may be one of the most promising options for removing microplastics from fresh water. Bioremediation using microorganisms and chemical recycling appear to be the two most widely considered approaches to reverse plastic pollution. National databases, permissible limits, and mandatory monitoring programs should be developed, as these are essential components of an effective regulatory framework. Full article

Tuberculosis (TB) remains a leading cause of death from a single infectious agent, and its outcome is shaped not only by Mycobacterium tuberculosis (Mtb) itself, but also by the host’s metabolic state. This review synthesises current understanding of how Mtb reprograms macrophage immunometabolism and how this reprogramming propagates to a systemic level, culminating in skeletal muscle dysregulation and TB-associated cachexia. We describe the molecular mechanisms by which Mtb subverts phagosomal maturation, the glycolytic (Warburg-like) switch governed by HIF-1α and accumulation of immunomodulatory tricarboxylic acid cycle intermediates, and the M1/M2 polarisation balance that dictates bacterial containment versus persistence. We then trace the cytokine- and metabolite-mediated circuits (TNF-α, IL-6, IL-1β, lactate, ketone bodies, free fatty acids) that link infected macrophages to ubiquitin–proteasome and autophagy–lysosome-driven muscle proteolysis, mitochondrial dysfunction and oxidative stress. Building on these mechanisms, we propose an immunometabolic and muscle-derived biomarker framework that, although still requiring clinical validation, may offer value for diagnosis, host-response stratification and treatment monitoring, and we discuss host-directed therapeutic strategies that target macrophage metabolism and muscle preservation. By integrating immunity, metabolism and systemic pathology at the molecular level, this work highlights translational opportunities relevant to the host immunity, diagnosis and treatment of tuberculosis. Full article

Viticulture, winemaking, and distillation industries produce substantial quantities of organic by-products (grape prunings, stems, marc-pomace, spent yeast, wine lees, distillation heads and tails, stillage), presenting both environmental challenges and promising opportunities for sustainable valorization. This narrative review offers a comprehensive analysis of the viticulture, winemaking, and distillation processes, along with the characterization of their solid and liquid by-products. Furthermore, it examines the chemical composition and mentions main valorization strategies for these residues, emphasizing their potential both as feedstocks for biochar production and as sources of valuable solvents. Additionally, various applications of biochars are explored, with particular focus on biochar derived from grape pruning and grape pomace-marc biomass, highlighting its effectiveness as a sorbent for environmental contaminants. Moreover, a broad range of biochar activation and modification methods that enhance physicochemical properties and expand functional applications is reviewed. Solvent-based biochar modification is also examined in order to introduce a novel concept: employing grape distillation liquid by-products (heads and tails fractions) to activate biochars made from grape prunings and pomace, creating a high-value sorbent while simultaneously valorizing two major waste streams. This dual-use strategy offers a new pathway for circular resource management within the viticulture and winemaking sectors. Full article

Facing the severe environmental challenge of massive red mud (RM) stockpiles, iron extraction research is accelerating from traditional pyrometallurgy and other conventional processes toward green low-carbon, multi-source synergistic, and total-component high-value utilization approaches—a transition that continues to evolve. This review systematically examines three frontiers: green reduction technologies, synergistic valorization via waste-treating-waste, and integrated cascading strategies for total-component high-value utilization. Evaluation focuses on the principles, advantages, and challenges of biomass reduction, hydrogen metallurgy, selective flocculation, advanced heating techniques, co-processing with other solid wastes, and multi-metal cascading extraction. Evidence suggests that future RM iron extraction technology lies in establishing cross-industry circular economy networks, transforming RM from a singular waste into a resource hub linking aluminum, steel, and construction industries to maximize environmental and economic benefits. Full article

Hydraulic nozzles are widely utilized for dust removal, cooling, and waste heat recovery in mining production. Nevertheless, the influence of co-flow disturbance on the atomization characteristics within the downstream region of droplet fields remains inadequately understood. In this study, three typical hydraulic nozzles were selected, and the atomization characteristics of the downstream region under different co-flow disturbance intensities were experimentally investigated. The results reveal that increasing co-flow disturbance velocity does not intensify the reduction in sauter mean diameter (SMD), but markedly reduces the dispersed phase fraction (DPF). Under four co-flow disturbance velocities (1.5, 3.0, 4.5, and 6.0 m/s), the relative reduction rates of mean SMD are 6.77%, 3.27%, 4.42% and 2.60%, while those of mean DPF are 13.86%, 35.85%, 52.88%, and 61.86% (e.g., hollow-cone nozzle), respectively. The variation in SMD is achieved through the redistribution of cumulative volume among CV₁, CV₂, CV₃, and CV₄. As the velocity increases from 0 to 3 m/s, the mean SMD of the three hydraulic nozzles exhibits a decreasing trend, which can be directly attributed to the continuous increase in the total cumulative volume of CV₁ and CV₂, and the continuous decrease in those of CV₃ and CV₄. For the hollow-cone and solid square-cone nozzles, the SMD first decreases and then increases, with the turning point occurring at 3.0 m/s, consistent with the variation trend of cumulative volume fractions. In contrast, for the solid-cone nozzle, the SMD continues to decrease at velocities exceeding 3.0 m/s. This work provides both a fundamental understanding of atomization characteristics in the downstream region of hydraulic nozzles under co-flow disturbance and practical guidance for velocity control in mine spray systems. Full article

This paper proposes a practical heuristic engineering strategy for automated capacity allocation in a multifunctional parallel active power filter (PAPF) that simultaneously provides harmonic and reactive power compensation. Unlike theoretically optimal methods, our approach prioritizes real-time feasibility and ease of implementation. The key features are: (1) an event-triggered, closed-loop THD-feedback mechanism that dynamically recalculates the minimum active power required for harmonic compensation only when the load harmonic content changes, avoiding periodic computational waste; (2) a strict priority handling that guarantees grid current THD below 5% (IEEE-519 compliant) under all operating conditions, even when capacity is severely insufficient; (3) a closed-loop transition mechanism that uses measured grid current THD and remaining capacity as feedback inputs to continuously adapt power distribution. The proposed rule-based strategy does not claim theoretical optimality but provides a verifiable, ready-to-implement solution with experimental evidence. Simulation and experimental results on a three-level NPC PAPF prototype demonstrate that the strategy maintains grid current THD below 5% while keeping the apparent power within the rated capacity, achieving near-optimal reactive compensation (92–96% of the optimum) without iterative optimization. The experimental validation includes efficiency measurements, switching-loss estimation, DSP timing analysis, and robustness tests under grid disturbances. Future work will extend the concept to multi-inverter systems using multi-objective optimization and AI-based allocation. Full article

The persistence of refractory organic pollutants (e.g., antibiotics) in aquatic environments necessitates efficient and sustainable remediation strategies. In this study, a circular economy approach was adopted to convert iron sludge into a value-added carbon residue (CR) composite via one-step co-pyrolysis. The resulting material was designed as dual-functional, enabling synergistic pollutant removal through adsorption and catalytic oxidation. Experimental results demonstrated that the CR composite effectively adsorbed and degraded organic pollutants. The primary adsorption sites were attributed to surface functional groups, porous structure, and electrostatic interactions. Meanwhile, iron species, surface functional groups, and persistent free radicals facilitated the generation of singlet oxygen (¹O₂) and hydroxyl radicals (·OH), which in turn promoted pollutant degradation. The CR/PDS system exhibited excellent performance in real wastewater remediation, which was attributed to the high interference resistance of ¹O₂. Furthermore, the application of CR did not pose any significant environmental risk in aqueous solutions. Taken together, these findings present a novel material for pollutant removal and provide a cost-effective strategy for the valorization of waste iron sludge. Full article

The growing global population has increased energy and food demand, leading to a higher production of waste streams such as fly ash from the energy sector and wastewater from food and beverage industries. Without proper treatment, these wastes pose significant environmental concerns. One promising strategy is to repurpose industrial byproducts for wastewater treatment. Winery wastewater, for instance, contains acidic organic compounds and alcohol that are difficult to remove using conventional methods, while large amounts of fly ash remain underutilized. This study, therefore, examines a hybrid system that combines fly ash-assisted Fenton oxidation with membrane filtration for winery wastewater treatment. The process involved sequential Fenton pre-treatment followed by lab-scale nanofiltration using a 1 kg/mol ceramic membrane (13.1 cm²). A Design of Experiments approach was applied to evaluate system performance under varying H₂O₂ dosages (10–30 mL/L), fly ash loadings (1–3 g/L), and membrane fluxes (40–80 LMH). Filtration was performed through multiple constant-flux cycles, with energy requirements ranging from 400 to 800 kWh/m³ for the flux variations calculated from the lab-scale pump operating at a constant power supply. The hybrid method showed strong performance, achieving 70% TOC removal and 90% reduction of color and iron. However, considerable membrane fouling was observed, likely due to increased retention and deposition of organic matter, iron, and fly ash during filtration. Full article

A series of chlorinated chalcone derivatives containing oxazole and thiazole rings were synthesized via Claisen–Schmidt condensation of 6-acetyl-2(3H)-benzoxa(thia)zolone with substituted chlorobenzaldehydes. The synthesized compounds were evaluated for their antimicrobial activity against selected bacterial and fungal strains. Several compounds demonstrated moderate antimicrobial activity against the tested microorganisms. Full article

Waste biomass powders and waste oils are promising sustainable modifiers for asphalt binders, but solid-phase biomass powders and oil-phase modifiers often have competing effects on high-temperature stability and low-temperature relaxation. In this study, peanut shell powder (PSP) and waste cooking oil (WCO) were combined at a fixed mass ratio of 1:1 to modify No. 70 base asphalt binder, and the material characteristics, physical properties, rheological responses, and chemical interactions of unaged PSP/WCO-modified asphalt binders with total modifier dosages of 5%, 10%, and 15% were evaluated. The results showed that PSP had a rough, wrinkled, and locally porous lignocellulosic structure and showed no obvious thermal decomposition near the preparation temperature of approximately 150 °C. As the PSP/WCO dosage increased from 0% to 15%, the softening point increased from 50.2 °C to 53.9 °C, while penetration decreased from 66.2 to 62.6 (0.1 mm) and ductility decreased from 74.0 mm to 69.5 mm, indicating increased binder consistency and improved high-temperature flow resistance. DSR and MSCR results showed enhanced high-temperature deformation resistance; at 15% dosage, Jnr at 3.2 kPa decreased from 2.35 to 1.25 kPa⁻¹, while R increased from 0.51% to 1.36%. However, BBR results showed increased creep stiffness and decreased m-value, indicating reduced low-temperature relaxation capacity. FTIR spectra showed no new strong characteristic absorption peaks, suggesting that the modification was mainly associated with physical blending, compositional regulation, and weak intermolecular interactions. The main novelty of this work is that it demonstrates a fixed-ratio PSP/WCO composite modification strategy that combines biomass-powder reinforcement with oil-phase regulation to improve the unaged high-temperature rheological performance of asphalt binders while promoting the resource utilization of peanut shells and waste cooking oil. Full article

The electrification of the industrial sector is an important pathway to decarbonizing the industry and achieving a sustainable society. High-temperature heat pumps (HTHPs) are critical devices for providing industrial heat and consuming green electricity. The goal of the present work is the theoretical thermodynamic analysis of a reverse Brayton HTHP that operates with novel working fluids. Specifically, the idea of using mixtures of working fluids with CO₂ is studied for the first time with the aim of suggesting new candidates to increase the performance of industrial HTHPs. A model of an HTHP with an internal heat exchanger is developed and verified in the MATLAB programming language. Nine different mixtures are studied: CO₂/R152a, CO₂/R1234ze(E), CO₂/Propane, CO₂/Butane, CO₂/Isobutane, CO₂/Pentane, CO₂/Isopentane, CO₂/Hexane and CO₂/Heptane. The examined industrial heat production temperatures are 150 °C, 200 °C and 250 °C, while the waste heat stream temperatures that drive the heat pump are considered to be 80 °C and 100 °C. The results prove that the application of the mixtures can enhance the COP, especially in the case of lower temperature lifts. CO₂/R152a seems to be a promising choice compared to pure CO₂, presenting performance enhancements ranging from 4.12% to 64.02% among the studied scenarios. Full article