Chromitites uniquely catalyse low‑temperature methane formation [1], motivating data‑driven exploration of naturally occurring catalysts for CO₂ methanation aligned with sustainable energy goals [2]. Using 12 Greek chromitite samples with quantified methane, petrographic point counting and grain‑size distributions were encoded via percentile ranks and modeled with a super‑ensemble that stacks Multinomial Naive Bayes with XGBoost, guided by automated model search and manual tuning. The selected classifier achieved 75% training and 71% test accuracy, outperforming alternative algorithms evaluated on these data. Model interpretability using SHAP [3] and partial dependence plots identified several key predictors of high methane levels. Large olivine crystals within chromitites emerged as the strongest positive predictor. Medium-sized veins showed a positive association, while large veins had adverse effects. Large spinel crystals acted as a secondary, though weaker, indicator. The workflow converts petrographic observations—often visible at hand‑specimen scale—into practical field criteria for targeting chromitites that host mineral catalysts, thereby reducing reliance on synthetic catalysts and mitigating pressure on noble and critical metal supply chains. This first application of machine learning to field exploration of mineral catalysts demonstrates how tree‑based, interpretable ensembles can capture complex relationships in multivariate petrographic data and enable precision exploration for carbon‑neutral energy materials.

Assessing the levels of oxidative stress markers and antioxidant enzymes in the brain is crucial in evaluating its antioxidant capacity and understanding the influence of various dietary patterns on brain well-being. This study aimed to investigate the antioxidant status and oxidative damage in the brain of bat species with different feeding habits to gain insights into their protective mechanisms against oxidative stress and their interspecific variation. The levels of oxidative damage markers and the activities of antioxidants were measured in the brain of four bat species with different feeding habits, namely insectivorous, frugivorous, nectarivorous, and hematophagous. Insectivorous bats showed higher levels of SOD and fumarase compared to the other groups, while hematophagous bats showed lower levels of these enzymes. On the other hand, the activities of glutathione peroxidase and glutathione S-transferase were higher in hematophagous bats and lower in insectivorous bats. The carbonyl groups and malondialdehyde levels were lower in frugivores, while they were similar in the other feeding guilds. Nitrite and nitrate levels were higher in the hematophagous group and relatively lower in all other groups. The GSSG/GSH ratio was higher in the hematophagous group and lower in frugivores. Overall, our results indicate that the levels of oxidative stress markers and the activities of antioxidant enzymes in the brain vary significantly among bat species with different feeding habitats. The findings suggest that the antioxidant status of the brain is influenced by diet and feeding habits.

The environmental impact of polymer waste, heightened during the pandemic, poses a significant 21st-century challenge. The growing market for eco-friendly materials, with an annual growth rate of 20-25%, underscores the urgency of this endeavor [1]. Aligned with Green Chemistry principles, the proposed research focuses on developing biodegradable materials using environmentally sustainable production methods.

The proposed work involves the preparation of eco-friendly, biodegradable polymers and the investigation of their properties. Among the relatively novel biomimetic polymers are those based on natural α-amino acids, known as biomimetic polymers, synthetic analogs of proteins. Particular interest is pseudo-proteins (PPs) within the poly(ester urea) (PEU) class — a family of biomimetic polymers developed by Prof. Katsarava et al [2]. Composed of non-toxic building blocks, PPs degrade into biocompatible products, ensuring their safety and suitability for biomedical applications  [2, 3]. 

The first PP-PEUs, synthesized from the flexible building block 1,6-hexanediol (HD), exhibited outstanding mechanical characteristics (Young's modulus, E = 6.0 ± 1.1 GPa) [3]. To further enhance the mechanical properties, a strategy involving rigid cyclic diols with limited intramolecular mobility was employed. This led to the synthesis of new key monomers through the direct thermal condensation of cyclic diols with α-amino acids, in the presence of p-toluenesulfonic acid in a refluxed organic solvent.

The research, supported by the Shota Rustaveli National Science Foundation of Georgia ("Creation of special-purpose, multifunctional composites, and determination of technological parameters," FR-23-9113), introduces a novel approach to synthesizing PP-PEUs with enhanced mechanical strength. Within this project, a total of six new polymers were synthesized using the Interfacial Polycondensation method, and their structures were studied using spectroscopic methods. All the synthesized polymers demonstrated film-forming abilities, and the mechanical properties of each polymer were thoroughly examined.

Among the newly synthesized polymers, the one based on L-leucine and 1,4-cyclohexanedimethanol stands out due to its favorable properties, cost-effectiveness, and low toxicity. It exhibits a Young’s modulus of approximately 7 GPa, significantly exceeding that of the previously developed polymer based on 1,6-hexanediol. This makes it a promising candidate for applications in engineering and the medical field, particularly in bone surgery. Ongoing research continues to explore the properties and biomedical potential of these novel PP-PEUs. Future studies aim to optimize the materials for specific engineering and biomedical uses, by evaluating their performance, durability, and biocompatibility under various conditions. 

Surface-grafted polymers, commonly known as polymer brushes, have gained prominence due to their ability to modify and functionalize surfaces.[1] In this research, a novel approach has emerged, combining dynamic covalent chemistry (DCC) with polymer brushes to achieve unprecedented versatility.

The method involves introducing initiators with cyclic triketone moieties onto amine-functionalized surfaces.[2] Polymer brushes are then grown from these surfaces. What sets this approach apart is the subsequent cleaving of the previously grafted polymer using small-molecule amines. By re-exposing amino groups on the surface, a second batch of initiators can initiate another polymer, leading to a cascade of grafting events. 

Unlike traditional copolymerization, which only varies composition along the polymer brush, this DCC-enabled technique allows for unlimited types of polymer brushes along the surface. Researchers can tailor the composition, molecular weight, and architecture of each brush, opening up exciting possibilities for customizable surface modifications.

This innovative strategy promises applications in fields such as biomedicine, materials science, and nanotechnology. By harnessing the stability of diketoenamine linkages, scientists can explore intricate multicomponent polymer brushes, paving the way for advanced functional materials.

Potassium ferrite was synthesized through the sol-gel auto-combustion [1] chemical route, aiming to evaluate the influence of calcination temperature on the formation of crystalline phases. The obtained samples were subjected to calcination temperatures of 0°C (post-combustion), 300°C, 550°C, 750°C, and 950°C. Structural characterizations were performed using X-Ray Diffraction (XRD), where the crystallite size was calculated from the most intense peak at each calcination temperature using the Scherrer equation [2]. Micrographs were also obtained to assess grain size, along with analyses by Mössbauer Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), and Raman Spectroscopy. The results demonstrated that the synthesis of potassium ferrite was successful; however, an increasing formation of additional phases of potassium ferrite and magnetite was observed with rising calcination temperatures. Therefore, it is concluded that the sol-gel auto-combustion method is not recommended for applications requiring a specific crystalline phase predominance, due to the simultaneous generation of secondary phases with higher thermal treatment temperatures [3]. Additionally, as the temperature increased, a reduction in grain size was observed, attributed to the combustion of residual fuel traces.

This study investigated the Cold Sintering Process (CSP) [1] of potassium ferrite, previously synthesized by the sol-gel auto-combustion method. To date, there have been no reported cases of potassium ferrite sintering; therefore, two solutions were tested for transient phase formation: acetic acid at a 5 molar concentration and pure ethanol, both applied at 5 wt% of the sample's weight. After consolidation of the specimens, an average material loss of 20 wt% was observed in both cases. Structural characterization by X-Ray Diffraction (XRD) indicated that the use of acetic acid resulted in a poorly defined crystalline phase, highlighting the inadequacy of this solvent for the studied method, despite achieving bulk formation. On the other hand, the use of ethanol revealed significant microstructural changes, confirmed by Scanning Electron Microscopy (SEM) images. It was observed that the initial microstructure, characterized by typical grains resulting from combustion synthesis, evolved into a lamellar (plate-like) structure [2,3], leading to an improvement in the mechanical strength of the material when compared to specimens produced with acetic acid. These results demonstrate that ethanol is an effective solvent for optimizing the microstructural and mechanical properties of potassium ferrite obtained through cold sintering process.

A growing demand for research about ballistic armor shields follows the increase of violence around the world. Ultimately, different composite materials with polymeric matrices have already presented the minimum performance as an individual protection required with cheaper and lower density, such as those reinforced with natural lignocellulosic fiber (NLF). The Cyperus malaccensis, a type of sedge fiber, is already used in simple items like ropes, furniture, and paper, but has not yet been investigated as composite reinforcement for possible ballistic protection applications. Therefore, composite plates were prepared for the ballistic tests, based on the condition of 30 vol% sedge fibers coated by graphene oxide. A total of seven plates have been subjected to seven test-shots  using 7.62 mm commercial ammunition. The fibers were embedded under pressure in the epoxy resin matrix and cured at room temperature for 24 hours. The tested specimens were examined by scanning electron microscopy. Besides, analysis of variance (ANOVA) was performed and the absorbed energy of all specimens were evaluated, based on a confidence level of 95%.

Given the growing demand for sustainable alternatives in pavement and geotechnical engineering, the use of agricultural residues as soil reinforcement materials has gained attention as a technically and environmentally viable approach. Among these residues, banana fiber stands out for its low cost, renewable nature, and wide availability in tropical regions. This study presents a preliminary investigation of the interaction between banana fiber and sandy soil through morphological and microanalytical characterization. The experimental procedure involved adapting the compacted soil molding process (MCT method) to prepare small-scale fiber–soil specimens under conditions representative of field compaction. After seven days of air curing, the fibers were carefully removed and analyzed using scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS) to observe the interface and identify possible physicochemical interactions. The results revealed similar surface compositions between the fiber portions embedded in and exposed from the soil, suggesting the occurrence of capillary sorption and moisture-induced ionic migration along the fiber structure. These findings indicate that banana fiber exhibits potential compatibility with sandy soils, supporting its future application as a sustainable reinforcement material. This methodological adaptation establishes the foundation for subsequent mechanical evaluations, such as pull-out and triaxial tests, aimed at quantifying the interfacial strength and overall contribution of natural fibers to soil improvement.

Solid solution strengthening is an essential process for increasing the strength of metals. It occurs when solute atoms are introduced into a crystalline matrix [1,4]. The interaction between dislocations and solute atoms — which may occupy interstitial sites or substitute lattice positions — generates distortions that hinder dislocation motion, thus enhancing mechanical resistance [2,5]. Substitutional solutes cause spherical distortions in the lattice, creating compressive or tensile stress fields, while interstitial solutes, due to their smaller size, produce more significant distortions and interact more effectively with dislocations [1,6]. The elastic misfit energy resulting from these distortions is a fundamental component of the strengthening mechanism [4,7]. The mathematical modeling of these interactions allows for the estimation of interaction energy based on elastic theory, taking into account parameters such as solute concentration, atomic radius mismatch, and modulus difference [3,8]. Recent studies emphasize the importance of optimizing the concentration and type of solute atoms, as well as processing conditions such as temperature and strain rate, to maximize the strengthening effect in advanced metallic alloys [5–7].

The growing global demand for product customization, coupled with the long lead times associated with traditional manufacturing processes, has driven the industry to adopt faster and more flexible production methods. In this context, additive manufacturing (AM) — particularly material extrusion-based 3D printing (FFF) — stands out as a technological advancement by enabling the fabrication of customized geometries and multi-material parts with minimal waste. Among the polymers used in AM, polyamides are widely recognized for their mechanical strength, thermal stability, rigidity, and wear resistance. When reinforced with carbon fibers, these properties are significantly enhanced, making nylon-based composites highly suitable for high-performance applications, including in the defense sector. However, the mechanical performance of parts produced via FFF depends directly on process parameters such as extrusion temperature, print speed, and layer thickness, which influence material flow and interlayer adhesion. This study investigates the effects of extrusion speed, nozzle temperature, and infill orientation on the mechanical and thermal behavior of a carbon fiber-reinforced polyamide processed on the Bambulab X1E printer. Tensile and Differential Scanning Calorimetry (DSC) tests were conducted to evaluate the influence of these parameters, and an Analysis of Variance (ANOVA) was applied to validate the statistical significance of the results and support the selection of optimal printing conditions.

This research investigates the radiological protection properties of composite materials comprising aramid and linen fabrics integrated within an epoxy matrix through advanced computational simulations. The study focuses on assessing the efficacy of these composites in attenuating gamma radiation, with specific emphasis on measuring the photon flux between layers and the energy deposition within the material structure. Utilizing Monte Carlo simulation techniques, the interaction of gamma photons with the composite layers was modeled, accounting for variations in layer thickness, material density, and stacking configurations. The simulations provide detailed data on the attenuation coefficients and energy absorption profiles, enabling a comprehensive evaluation of the shielding performance. The choice of aramid and linen fabrics, combined with the epoxy matrix, aims to balance lightweight and flexible characteristics with robust radiation protection, offering potential applications in medical imaging, aerospace radiation shielding, and industrial safety equipment. Preliminary results indicate that the hybrid composite structure exhibits promising attenuation capabilities, with the layering sequence and material composition significantly influencing the reduction of photon flux and energy deposition. These findings contribute to the development of sustainable, high-performance radiological protection materials, paving the way for further experimental validation and optimization of composite designs for real-world applications.

This study evaluates the radiological shielding performance of hybrid composites comprising aramid and fique fabrics embedded in an epoxy polymer matrix, reinforced with silicon carbide (SiC), through Monte Carlo N-Particle (MCNP) simulations. The research focuses on assessing the attenuation of both gamma radiation and neutrons by analyzing photon and neutron flux across composite layers and energy deposition within the material structure. The MCNP code was employed to model the interactions of gamma photons and neutrons with the composite, exploring variations in SiC concentration, layer thickness, and fabric stacking configurations. SiC, valued for its high density and neutron absorption capabilities, enhances the composite’s shielding efficiency while maintaining mechanical robustness. The results demonstrate significant reductions in gamma photon and neutron flux, with optimized energy absorption driven by the synergistic effects of aramid’s tensile strength, fique’s sustainable properties, and SiC’s superior radiation interaction characteristics. The simulations reveal the influence of composite design on dual-protection effectiveness, offering insights into lightweight, eco-friendly materials for radiological shielding in medical, nuclear, and aerospace applications. This work establishes a foundation for experimental validation and further optimization of SiC-reinforced hybrid composites, advancing sustainable, high-performance solutions for comprehensive radiation protection.

This study investigates the interaction of radiation with two-dimensional (2D) materials, including graphene, graphene oxide (GO), hexagonal boron nitride (hBN), and molybdenum diselenide (MoSe₂), to assess their potential in radiation sensor development. Using Monte Carlo N-Particle (MCNP5) simulations with 10⁷ to 10⁸ events, the research evaluates the materials’ responses to photons, neutrons, and charged particles, focusing on energy deposition and interaction efficiency. For photons, MoSe₂ exhibited superior interaction at low energies, while graphene showed limited absorption, particularly at higher energies. GO displayed moderate efficiency at intermediate energies, and hBN’s interaction increased with photon energy. In stacked configurations, MoSe₂ maintained high energy deposition, with other materials showing distinct low-energy behaviors. For neutrons, graphene exhibited minimal response across all energies, whereas MoSe₂ and hBN demonstrated robust interactions, especially at medium to high energies. hBN excelled in thermal neutron absorption, while MoSe₂ was more effective at higher neutron energies. Charged particle interactions mirrored these trends, with MoSe₂ leading in high-energy absorption and graphene, GO, and hBN offering balanced responses at lower energies. These findings highlight MoSe₂ and hBN as promising candidates for radiation sensors in neutron-rich and high-energy environments, while graphene and GO are better suited for moderate-energy applications, paving the way for tailored sensor designs.

The search for renewable resources has recently intensified. In this context, Amazonian fibers are gaining attention for their potential use as sustainable materials in construction due to their natural abundance, renewability, and eco-friendly properties. However, their application often depends on understanding their intrinsic properties and how treatments can modify them. This study focuses on the characterization of a specific Amazonian fiber, evaluating its physical, chemical, and mechanical properties and assessing the effects of different treatments. The untreated fiber and its treated counterparts underwent a series of analyses, including thermal, structural, and morphological evaluations. The results demonstrated that it was possible to characterize several key properties, such as tensile strength, thermal stability, and water absorption. Moreover, significant changes were observed in the fiber's structure and behavior after each treatment, highlighting the influence of the applied processes. These findings provide valuable insights into optimizing natural fibers for construction applications, promoting their broader use in sustainable engineering practices.

Mining activities generate large volumes of tailings with significant environmen- 13 tal impact, but also with potential for sustainable reuse in construction materials. This 14 study evaluates the production of ceramic aggregates from mixture of clay, sand and iron 15 ore waste subjected to thermal treatment at temperatures ranging from 600 to 1100°C. The 16 influence of calcination temperature on mineralogical transformations and mechanical 17 integrity was investigated using X-ray diffraction (XRD) and the α-Treton parameter, de- 18 rived from standardized impact resistance testing. The results indicate that the formation 19 of metakaolinite between 700 and 900°C enhances mechanical resistance, while higher 20 temperatures (>900°C) lead to structural degradation, followed by partial recovery due 21 to mullite crystallization. The α-Treton curve exhibited clear correlation with the phase 22 changes identified by XRD, demonstrating its applicability as a low-cost, sensitive proxy 23 for optimizing thermal activation. A simplified methodology is proposed to optimize the 24 thermal activation of such materials by correlating firing temperature with mineralogical 25 evolution and mechanical integrity, contributing to the development of sustainable ceramic 26 aggregates for pavement applications

The growing impacts of climate change, combined with the high demand for environmentally responsible practices, have encouraged the scientific community and the industrial sector to seek sustainable alternatives for the development of new materials [1]. In this context, natural fiber-reinforced composite materials have emerged as a promising alternative to synthetic composites, not only due to their lower environmental impact but also because they offer economic and functional advantages in various applications [2]. The Amazônica region, rich in plant biodiversity, holds significant potential for the use of fibers extracted from native species in the development of sustainable composites. This contributes to reducing dependence on synthetic materials while also promoting the appreciation of the forest’s natural resources through responsible extractive practices [3]. The incorporation of these natural fibers into materials—especially in the construction sector—represents a significant step forward in the development of sustainable cities, while also promoting the growth of the regional bioeconomy, technological innovation, and local infrastructure [4]. In this study, polyester matrix composite materials reinforced with guaruman fibers were analyzed for their flexural mechanical properties. Test specimens were produced using silicone molds and sanded to meet the specifications of ASTM D790 for flexural strength testing. Specimens were fabricated with 10%, 20%, and 30% guaruman fiber volume fractions in polyester resin. The results were validated through ANOVA statistical variance analysis. The flexural mechanical results indicated a slight increase in the average strength. Regarding the flexural modulus, there was an increase in material stiffness as the fiber content increased. ANOVA indicated no statistically significant differences in the strength results among the composites. Although no significant differences in strength were observed, it is important to highlight the reduction in resin content required to produce composites with 30% fiber volume, without compromising strength.

Hybrid composites composed of carbon and sisal fibers are gaining prominence due to their ability to balance mechanical performance with sustainability. These materials are particularly promising in structural applications where fracture resistance is a critical design factor. Fracture toughness, which reflects a material’s ability to resist crack propagation, is influenced by the fiber-matrix interface, fiber hybridization strategy, and microstructural parameters. This study presents a review of current methods for characterizing fracture toughness in hybrid composites and explores modelling techniques that predict fracture behavior. Emphasis is placed on the interaction between synthetic (carbon) and natural (sisal) fibers, including how their contrasting properties influence crack deflection, fiber pull-out, and energy absorption mechanisms [1]. Modelling approaches such as finite element analysis and cohesive zone modelling are also discussed, offering insights into the prediction of fracture response under different loading conditions [2]. This work provides a framework for optimizing hybrid fiber composites in applications requiring high fracture resistance with environmental considerations [3].

Recent reports on the giant electric-field-induced strain of Bi0.5Na0.5TiO3 [BNT] based lead-free ceramics have highlighted their potential value for large-stroke actuator applications, as well as environmental benefits. While there are still several problems that have yet to be resolved, the large strain of > 0.4%, which is even larger than those reported for Pb(Zr,Ti)O3 [PZT] ceramics, is quite attractive to researchers and manufacturers.

In this study, (1-x)Bi0.5Na0.5TiO3-xABO3(LaYO3, YAlO3, YMnO3, YFeO3) ferroelectric ceramics were synthesized with a conventional solid state reaction method. The structures and morphologies of these ceramics were characterized by XRD (X-ray diffraction) and FE-SEM (field emission scanning electron microscopy). Analysing the electric polarization, electric-field-induced strain and temperature-dependence dielectric constant, the effects of rare earth metal compounds, such as LaYO3, YAlO3, YMnO3, and YFeO3, on the ferroelectric properties of (Bi0.5Na0.5)TiO3 based lead-free ceramics were investigated.

The large strain and low hysteresis of ceramics sintered at 1150℃ for 2h were obtained at an applied electric field of 2kV/mm.

The internalization of carbon materials has emerged as a critical strategic objective in response to the global demand for advanced functional materials in high-tech sectors such as secondary batteries, semiconductors, and aerospace [1]. Carbon-based materials, such as artificial graphite and graphene, are essential components in these industries. Although South Korea is heavily reliant on imported carbon materials, it possesses abundant anthracite reserves, especially in Gangwon Province. However, the domestic coal industry has declined since the 1989 coal rationalization policy, resulting in many abandoned mines. This situation underscores the urgent need to develop technologies that can convert underutilized domestic resources into high-value carbon materials.

This study investigates the feasibility of producing high-purity graphite from low-grade domestic anthracite through an integrated process combining froth flotation, chemical purification, and thermal plasma-based graphitization. This approach aims not only to reduce dependence on imported carbon sources but also to revitalize regional economies by utilizing abandoned coal resources.

High-grade and uniform refined anthracite was obtained through a floating process. As the result, the ash content was successfully reduced from 30% to 7%. The floated product was further refined through acid treatment, specifically using sodium hydroxide and hydrochloric acid, to remove residual mineral impurities such as silicates and metal oxides. This purification process yielded a high-purity carbon concentrate with a fixed carbon content of 99%, indicating that nearly all inorganic contaminants had been eliminated.

The purified anthracite was then graphitized using a dry thermal plasma process. X-ray diffraction (XRD) analysis revealed that the resulting material exhibited a graphitization degree of approximately 97%, characterized by sharp (002) peaks and decreased d-spacing, consistent with prior findings on anthracite-derived graphite structures [2]. Additionally, scanning electron microscopy (SEM) analysis confirmed the structural transformation into graphitic carbon. These findings align with previous studies that demonstrated anthracite's ability to undergo structural reordering and crystallization into graphite under high-temperature conditions [3].

This research demonstrates that domestic anthracite, previously considered economically unviable, can be converted into a high-performance carbon material suitable for advanced industrial applications. The proposed approach offers a promising strategy for securing domestic carbon material supply chains and supports national goals of resource self-sufficiency and industrial innovation.

 In addition to conventional applications in the printing of electrodes or antenna patterns on low-cost polymer substrates, the application of low-temperature sinterable Ag pastes is now also being explored for electrode fabrication in perovskite solar cells. In this study, a particle-free Ag ink was synthesized based on an Ag-organic complex, and a printable paste capable of sintering at 120 °C was formulated by adding Ag flakes. The corresponding properties were systematically evaluated. For the optimization of ink formulation, the optimal combination of Ag salt and amine-based complexing agents was determined, and a solvent exhibiting both rapid evaporation at low temperatures and synergistic compatibility with the complex system was selected, enabling film formation at 120 °C. Subsequently, after the optimal amount of Ag flakes was incorporated, the resistivity of the film decreased with increasing annealing time at 120 °C, ultimately achieving an excellent electrical resistivity of 1.13 × 10⁻⁵ Ω·cm after 90 min. However, after 120 minof annealing, the resistivity increased to 1.19 × 10⁻⁴ Ω·cm, which was attributed to the formation of large pores in the microstructure during the grain growth process [1].

Due to their unique characteristics, nanocomposite materials are a promising alternative to existing sensor materials, capable of providing high sensitivity, extremely low detection levels of gases (at the ppb and ppm level) and chemical vapors (at ~1 ppb), high selectivity and low energy consumption, as well as operating in ambient conditions. Therefore, the study of such materials, along with the fundamental, has enormous applied significance. It should be noted that the interest of researchers in multicomponent metal-containing nanocomposite materials has noticeably increased recently [1-3]. 

The general method for the synthesis of unsaturated mono- and dicarboxylates of calcium and strontium is based on the direct interaction of aqueous solutions of metal salts and the corresponding unsaturated acid with the addition of sodium hydroxide to increase the yield of the final product. The main methods used in the study of controlled thermolysis of metal-containing monomers were DSC, DTA, and TGA. The composition and structure of the obtained metal-polymer nanocomposites were studied using the methods of elemental analysis, IR spectroscopy, X-ray phase analysis, energy-dispersive analysis, scanning and transmission electron microscopy, and atomic force microscopy.

New methods have been developed and known ones have been modified for the synthesis of metal-containing calcium and strontium monomers based on unsaturated mono- and dicarboxylic acids: acrylic, maleic, itaconic, cinnamic, fumaric, trans, trans-muconic, propargyl, acetylenedicarboxylic, 4-pentynic. The composition and structure of the obtained compounds have been characterized using various physicochemical methods (elemental analysis, IR, Raman, XPS spectroscopy, EXAFS, XRF, SEM, TEM, AFM). For the first time, new types of functional two-component (metal oxide/graphene oxide) nanocomposites with a wide variation in weight composition (1, 5, 10 and 20% graphene oxide) have been obtained. 

The proposed method for producing calcium- and strontium-containing nanocomposites is simple and inexpensive, making it suitable for large-scale production.

The structural and electronic properties of the obtained nanocomposites were studied using experimental (SEM, TEM, XRD, VSM, UV-visible spectroscopy, Raman spectroscopy, FTIR spectroscopy, NMR, AFM, J-V characteristics, dielectric studies, impedance analyzer, electrometers, etc.) and theoretical methods (quantum chemical calculations). The functional properties of the obtained nanocomposites were studied using the example of sensor characteristics. For the first time, methods for applying films based on the synthesized nanocomposites to Corning glass substrates were developed using spin-coating (SC), dip-coating (DC) and chemical vapor deposition (CVD) technologies to obtain homogeneous thin films. The physical parameters of the films and their sensor properties (speed, detection limit, range of detectable contents, selectivity, long-term stability and calibration, response and recovery time of the sensor, reproducibility, interfering effects, such as the effect of CO₂, temperature and humidity) were studied. The obtained films were used in sensors of ammonia, nitrogen oxide, carbon dioxide, volatile organic compounds (VOCs), such as benzene and acetone.

Comparison of the proposed sensors with other sensors described in the literature shows that they have good analytical characteristics. This indicates the prospects of the proposed approach based on the use of the obtained metal-containing nanocomposites as sensitive elements for solving the problem of gas detection.

Thus, new two-component nanocomposite materials including metal oxides and graphene oxide have been found. Films based on the synthesized nanocomposites have been obtained and studied, exhibiting improved sensor properties. Sensors for ammonia, nitrogen oxide, carbon dioxide, volatile organic compounds (VOCs) such as benzene and acetone have been developed.

Silicon carbide (SiC) is a ceramic material characterized by highly covalent bonds between silicon and carbon, which give it unique properties such as high hardness, excellent resistance to oxidation, wear, corrosion, and abrasion, as well as high thermal conductivity, low thermal expansion coefficient, and good thermal shock resistance¹. Due to its high stability and performance at extreme temperatures, SiC has been widely applied in the production of refractories for several sectors, mainly metallurgy², with its first recorded use in refractory bricks for blast furnace torpedo cars³. Currently, it is found in various refractories used in mining and metallurgical equipment, such as torpedo cars, steel ladles, and hot metal pre-treatment vessels⁴. Refractory applications may require different mechanical and thermal demands depending on the process, region, and type of stress involved. Therefore, the selection of each refractory must be adapted to the process in order to maximize equipment service life, considering factors such as mechanical wear, chemical compatibility with metal, slag and process gases, as well as internal thermomechanical stresses from heating and cooling cycles⁵. In this context, this study aims to review the main applications of SiC in refractories, discussing its physical and chemical properties, as well as approaches that promote more sustainable processes and the benefits of its use, such as cost reduction, process optimization, lower consumption of primary raw materials, and mitigation of environmental impacts.

Solid waste management in Brazil faces structural and institutional challenges, especially at the municipal level, which ownership and responsibility for organizing and providing urban cleaning and waste management services. Despite legal advances, such as the National Solid Waste Policy (Law No. 12.305/2010), the effective implementation of these guidelines is still hampered by factors such as budget restrictions, lack of specialized technical staff and low political appeal for environmental projects. In the school context, the adoption of waste management practices, such as selective collection, composting and the integration of environmental education into the curriculum, is proving to be strategic for the formation of conscious citizens and the dissemination of sustainable habits. Experiences from schools that have adhered to the "zero waste" concept show positive results, such as a significant reduction in the volume of waste and an increase in community engagement. In addition, the link with the Sustainable Development Goals of the 2030 Agenda reinforces the importance of educational and participatory actions, capable of transforming the school into a sustainability benchmark and replicating good practices in other social contexts. Therefore, investing in solid waste policies in the school environment is fundamental to promoting environmental citizenship and contributing to a more balanced future.

During storage, transport, dilution and intravenous (i.v.) administration, mAbs are exposed to different stressors, including artificial and indoor ambient light, which can compromise their efficacy and safety. Light can induce concentration-dependent aggregation, leading to a measurable reduction in the drug's ability to bind its target The surface tensiometry properties of monoclonal antibodies (mAbs) were recently characterized using the Solid-like Methodology (SLM) [1] applying the Contact Angle Method (CA) [2]. The SLM consists in the deposition of a hydrophobic, lipophobic and self-repellent “liquid film”, called polyperfluorometylisopropyl ether (PFPE) [3] used as “solid substrate” for the characterization of liquid systems droplets [4]. This SLM consents the determination of Surface Tension (ST; mN/m), Dispersion Component (DC; mN/m) and Polar Component (PC; mN/m) of liquids without the influence of friction forces and surface roughness and was largely applied in the field of pharmaceutical technology [5]. The Well methodology (WM) [5] derives from the concept of Solid-like Methodology (SLM); unlike the SLM, the WM consists in the deposition of an amount of PFPE (PFPEw) leaved in a ceramic concave support (well). When a drop of liquid comes in contact with the surface of the PFPEw, a characteristic meniscus is formed caused by the hydrophilic/lipophilic ratio of the liquid (corresponds to its surface chemistry) in relation to the hydrophobic, lipophobic and self-repellent properties of PFPEw at the interface. The WM was here used to determine the surface tensiometry properties of human blood (Hb, G.M. droplets) and its variations after the addition with Nivolumab/Opdivo® (Opdivo samples/Hb complex system) as such and diluted in glucose and NaCl before and after light treatment with 720.0 and 10.460 KJ/m². The surface tensiometry parameter used here is the Vertical Drop Speed (VDS: dSA/dt) which measures the rate at which a drop of mAb sample spreads vertically at the interface with PFPEw. As first result, the VDS Opdivoâ formulation values (6.3E-05±4.8E-05) tend to decrease strongly after treatment with 720.0 KJ/m² (2.9E-05±7.9E-06) and more at 10460 KJ/m² (2.2E-05±8E-06) due to the degradation of Opdivoâ under the light stressor. Differently, the Hb/Opdivoâ complex system VDS values (9.7E-05±5.3E-05) are quite the same after 720.0 KJ/m² (1.0E-04±4.0E-05) and slightly decrease only after 10460 KJ/m² (7.3E-05±3.6E-05). This result appears to be correlated with the presence of blood components in the system, which maintains  high VDS values due to the strong affinity between mAb and blood components. The presence of 5% glucose (Opdivoâ-glu) as cosolvent reveals the equilibrium between Opdivoâ-glu (3.4E-05±9.1E-06) and blood (9.6E-05±4.6E-05) in the Hb/Opdivoâ-glu complex system (7.5E-05±3.1E-05). The treatment of Opdivoâ-glu with 720.0 KJ/m² and 10460 KJ/m² causes, respectively, slight (Opdivoâ-glu; 2.8E-05±5.2E-06, Hb/Opdivoâ-glu; 8.7E-05±3.8E-05, blood; 9.6E-05±4.6E-05) and strong (Opdivoâ-glu; 5.5E-05±1.6E-05, Hb/Opdivoâ-glu; 1.7E-04±8.1E-05, blood; 9.6E-05±4.6E-05) equilibrium decreases due to the great increase of VDS of Hb/Opdivoâ-glu (10460 KJ/m²). This seems due to the increase of aggregates in Opdivoâ-glu after light treatments amplified by the presence of blood components. The presence of 0.9% NaCl demonstrates a disequilibrium between Opdivoâ-NaCl (6.2E-05±2.1E-05) and blood (9.6E-05±4.6E-05) due to lower VDS value of Hb/Opdivoâ-NaCl.(1.4E-05±1.0E-06). That equilibrium is reached after treatment of Opdivoâ-NaCl with 720.0 KJ/m² (Opdivoâ-NaCl; 4.8E-05±1.4E-05, Hb/Opdivoâ-glu; 7.1E-05±2.7E-05, blood; 9.6E-05±4.6E-05) and marked decreased after treatment with 10460 KJ/m² (Opdivoâ-NaCl; 4.7E-05±1.2E-05, Hb/Opdivoâ-glu; 1.2E-04±5E-05, blood; 9.6E-05±4.6E-05). However, the increase of Hb/Hb/Opdivoâ-glu as aggregates in NaCl irradiated Opdivo are formed in less amount. With this work we demonstrate the different behaviour of dark and irradiated samples and the difference between undiluted and diluted (NaCl and glucose) Opdivo samples when come in contact with blood. Therefore, we try to mimic the i.v. administration of this drug: when aggregation takes place, mostly under the light exposure and even more in glucose solution, the WM can promptly detect the physical differences among the samples. Our findings indicate that mAbs should be protected from light, especially during prolonged i.v. administration periods, to avoid aggregate formation and potentially reduction of their therapeutic activity.

Printing defects produced during additive manufacturing (AM) processes can have a significant detrimental effect on functional properties. This mainly relates to their influence on mechanical properties and corrosion performance. The present study aims to evaluate the effect of printing defects created during AM using direct energy deposition (DED) process. The raw material selected for this examination was 316L stainless steel in the form of welding wires. The printing defects were examined by micro-tomography (CT) analysis while the microstructure assessment was carried out using optical and scanning electron microscopy along with X-ray diffraction analysis. The mechanical properties were examined in terms of tensile strength, hardness measurements and fatigue endurance. The corrosion performance was tested by potentiodynamic polarization analysis, while stress corrosion resistance was examined by means of slow strain rate testing (SSRT). The results obtained emphasize the relatively reduced mechanical properties, fatigue endurance, corrosion resistance and stress corrosion performance of the AM alloy compared to its counterpart wrought alloy AISI 316L produced by conventional processes. This was mainly attributed to typical AM printing defects such as porosity and lack of fusion as well as dissimilarities in terms of phase compositions. The pure austenitic structure of the conventional wrought alloy was converted to duplex microstructure that encountered an austenitic matrix and a secondary delta-ferrite phase in the AM alloy which have a detrimental effect on the inherent passivity.      

Closed-cell aluminum foams are increasingly gaining attention as lightweight structural materials due to their excellent energy absorption capabilities, low density, and favorable strength-to-weight ratio. However, their endurance under cyclic loading conditions (fatigue behavior) is yet to be fully understood [1], which is a critical limitation to make them relevant to aerospace, automotive, and structural applications. To address this challenge, our research explores the mechanical enhancement of closed-cell aluminum foams through carbon nanotube (CNT) reinforcement, focusing particularly on their fatigue life and failure mechanisms. 

The primary objective of this study is to evaluate how CNT integration affects the fatigue performance of aluminum foams under varying stress amplitudes and cyclic loading conditions. The potential of reinforcements to improve the mechanical properties of closed cell Aluminum foam under high strain rate loading conditions has been documented in our previous studies [2, 3], this motivated us to investigate local stiffness, crack propagation, and redistribution of stress at the cell wallsunder fatigue loading in the presence of CNT reinforcement. This work aims not only to extend the operational life of foams but also to understand the underlying reinforcement mechanisms at both the macroscopic and microscopic levels.

Fatigue testing are being conducted on both unreinforced and CNT-reinforced foam specimens using a servo-hydraulic MTS testing system under load-controlled conditions. Foam specimens with a relative density of ~0.30 +/- 5% are fabricated via liquid metallurgy route, with 0.5wt% CNTs uniformly dispersed into the aluminum matrix through mechanical stirring. The specimens are subjected to high-cycle fatigue (HCF) regimes, with stress ratio of R = 0.1 as is commonly used in other studies and at a frequency of 1 Hz, mimicking service-level loads. In addition, microscopic evaluations are being carried out using micro-CT to investigate the internal pore structure, deformation patterns and crack initiation and propagation patterns. Results of fatigue life curve of CNT reinforced aluminum foam will be presented along with deformation and failure mechanisms. 

As a new class of semiconducting materials with excellent optoelectronic properties, metal halide perovskites have been applied in various fields such as solar cells, photodetectors, and electroluminescence. However, the toxicity of the lead element contained in these materials limits their application scenarios. Tin, a low-toxic element in the same main group as lead, is considered the most suitable alternative to lead. However, the performance of tin perovskite materials is currently far inferior to lead-containing materials, especially in terms of the short carrier lives and low open-circuit voltages of photovoltaic devices. Current research community generally attribute these phenomena to the material defects of tin perovskites, but the nature and regulation of these defects remain obscure. Under the guidance of theory, we have systematically studied this issue for tin perovskites from both aspects of bulk and surfaces, and prepared a series of high-quality single crystal and thin film samples. We directly characterized the types of defects, their concentrations and influence on semiconductor properties, revealing that the dominant defects in tin perovskites are not directly caused by oxidation of Sn2+. We found that substituted thiourea molecules as Lewis-base ligands can deactivate the Sn2+ 5s electron pair and create an appropriate intermediate phase structure, thereby slowing down the crystallization rate, inhibiting surface and bulk defects of the crystal, and obtaining high-quality thin films. On the other hand, by decorating the thin-film surfaces with molecular dipoles but not changing the bandgap of perovskite layer, we elevated its conduction band minimum (CBM) to better match the energy level of the electron transport material (ETM). The above measures have rendered thin films of tin perovskite with charge carrier lifetimes longer than 0.5 μs and diffusion lengths on the micrometer scale, and boosted the open-circuit voltage of solar cell devices to 1.0 V (only ~0.1 V loss), approaching the level of lead-containing materials. The energy conversion efficiency reached 16%, setting a new performance record for lead-free perovskite solar cells. Their stabilities are also significantly enhanced, demonstrating a promising application prospect.

The continuous increase in energy demand, combined with the finiteness of fossil reserves, highlights the need for sustainable energy alternatives capable of reducing carbon emissions and mitigating environmental impacts. In this context, biomass stands out as a clean and renewable source, representing about 24% of Brazil’s domestic energy supply. However, the efficient use of biomass still faces challenges related to economic feasibility, cost reduction, mitigation of environmental impacts, and the preservation of natural resources such as water and soil. A large share of agro-industrial residues remains underutilized, generating environmental liabilities. The water consumption is one of the most critical concerns, as Brazilian industry consumes vast amounts of water annually, approximately 67.3 trillion liters of water per year, including the human supply, animal supply, manufacturing, mining, irrigated agriculture, and thermoelectricity sectors [1]. Thus, it becomes essential to develop sustainable processes and studies that evaluate the entire biomass production chain, ensuring that the environmental benefits obtained from its use are not compromised by negative effects in other areas, especially regarding water consumption, given the context of increasing water scarcity. Given this, a detailed study analyzed water usage across four key sectors in Brazil - mining, steelmaking, agriculture, and cattle ranching - based on corporate financial reports and government documents on water consumption. The data were processed, and the water consumption associated with the production of each evaluated sector was calculated. The study revealed significant differences in water volumes used relative to input tonnage in each sector. Cattle ranching and agriculture were especially water-intensive, with bovine input showing exceptionally high consumption. In contrast, the mining and steelmaking sectors demonstrated comparatively high-water reuse rates, with steel mills achieving an average reuse rate of 90%. 

The efficiency and stability of organic solar cells (OSCs) can be further enhanced through meticulous control of the nanoscale morphology, particularly by employing solvent additive treatments that influence molecular organization and phase behavior. In this work, we introduce a tri-halogenated benzene derivative, 4-chloro-2-fluoroiodobenzene (CFIB), as a multifunctional solvent additive to regulate the active-layer morphology of D18-Cl:N3-based OSCs. The rational design of CFIB—featuring chlorine, fluorine, and iodine substituents—offers a delicate balance of volatility and intermolecular interactions with both donor and acceptor components. This dual functionality allows CFIB to extend the drying time during film formation and to promote favorable crystallization and phase segregation through specific halogen-induced interactions. As a result, CFIB treatment enables the formation of a more ordered and vertically optimized morphology, facilitating efficient charge transport and suppressed nonradiative recombination. The CFIB-treated devices achieve an impressive power conversion efficiency (PCE) of 18.5% and exhibit enhanced operational stability, maintaining a higher fraction of their initial performance compared to the untreated devices. Overall, this study demonstrates that CFIB serves as a simple yet highly effective additive to direct film formation dynamics, providing critical insights into the interplay between volatility, halogenation, and intermolecular interactions in morphological engineering for efficient and stable OSCs.

Plastic pollution poses a significant environmental threat, with single-use plastics like PET bottles playing a major role in the degradation of ecosystems. Conventional recycling methods, although aimed at reducing this impact, often lead to the creation of microplastics—tiny, persistent particles that endanger both biodiversity and human health. In contrast, upcycling offers a more sustainable and innovative alternative by converting plastic waste into high-value materials, thereby avoiding microplastic formation altogether. This approach not only mitigates environmental harm but also contributes to technological progress, particularly in areas such as energy storage.

In this study, waste PET bottles were upcycled into phosphorus-doped hard carbon (P-HC) via a one-step pyrolysis process using orthophosphoric acid (H₃PO₄), with the goal of enhancing the electrochemical performance of the resulting carbon material. Electrochemical analyses demonstrated that the 3P-HC anode delivered outstanding lithium storage performance, achieving a high specific capacity of 765 mAh g⁻¹ after 100 cycles at 0.2 A g⁻¹ and 531 mAh g⁻¹ after 200 cycles at 2 A g⁻¹. These results significantly surpass those of undoped PET-derived carbon anodes.

The performance improvements are attributed to phosphorus doping, which enhances electrical conductivity and induces beneficial structural modifications, including expanded interlayer spacing, increased surface area, and greater structural disorder.

Overall, this work offers a promising dual solution to both plastic waste management and the development of high-performance anode materials for next-generation lithium-ion batteries.

The process of pyrolysis to produce biochar also produces pyrolysis gasses that need to be delt with.  Burning the gasses is one option.  A burner which can burn these gasses at near 100% efficiency without needing electronics, fans, or electrical power, but is totally natural draft would be of benefit in many situations.

This paper describes such a burner, highly efficient, natural draft, inexpensive, and easy to use.

This burning technique was designed over 10 years of experiments.  Most of these experiments could be defined as back yard experimenting.  Promising designs were tested under the testing hood at Aprovecho Woodstove Research Center in Cottage Grove, Oregon.  One early design was tested at Lawrence Berkley National Labs Burn Lab on the UC Berkley campus about 7 years ago.  It tested at nearly 100% efficiency using a TLUD type pyrolysis gas generator.  Newer models are more capable, reaching very high-power levels with very high burning efficiency.  Placing such a burner atop a biochar kiln would efficiently burn the produced pyrolysis gas, without expensive sensors, electronics, or power supplies.

The process uses the Venturi effect and so could be classified as a Venturi mixer/burner.  It uses the Venturi effect to lower the pressure of the gas, increasing the pressure gradient with the atmospheric air, and so increasing the force pushing the air into the gas. It also increases the surface area between the air and gas and reduces the depth the air must penetrate into the gas, both of which speed mixing and burning.  It automatically adjusts the secondary air to match the amount of pyrolysis gas, keeping the burn efficient at all power levels.

Using burners of this type on biochar kilns could reduce polluting combustion emissions where processing the gas into useful products is not possible.

No published works.  The staff at Aprovecho WSRC are familiar with me.  I have presented at ETHOS wood stove conference on this topic, and displayed the burners there, so they are familiar with me.

The rapid proliferation of lithium-ion batteries (LIBs), driven by the global transition toward electric mobility and renewable energy storage, is projected to accumulate approximately 11 million tonnes of end-of-life LIBs by 2030 (Safarzadeh & Maria, 2025). Disposing such large volumes poses significant environmental and resource management challenges due to hazardous metals, including lithium, cobalt, and nickel, and the underutilization of valuable materials such as graphite (Winslow et al., 2018). A comprehensive assessment of current LIB recycling technologies reveals the dominance of pyrometallurgical and hydrometallurgical methods, both energy-intensive and associated with considerable environmental footprints (Roy et al., 2021). In contrast, biological approaches, particularly bioleaching, have emerged as promising alternatives due to their lower energy requirements and reduced environmental impact. Bioleaching employs acidophilic chemolithotrophic microorganisms, notably Acidithiobacillus spp. and Leptospirillum spp., to facilitate the solubilization of metals through biogenic acid production and redox-mediated dissolution mechanisms (Pathak et al., 2017). This process enables the selective recovery of lithium and associated metals from spent LIBs under mild operating conditions. Current research indicates that microbial metal recovery strategies can support the development of circular economy frameworks by offering cost-effective and environmentally sustainable alternatives to traditional recycling technologies. Life cycle assessment (LCA) and techno-economic analysis (TEA) further demonstrate the advantages of biologically driven processes in terms of reduced greenhouse gas emissions and lower operational costs (Fu et al., 2023). Despite these benefits, key challenges remain, including microbial tolerance to elevated metal concentrations, slow kinetics, and limitations in process scalability. Addressing these constraints through bioprocess optimization and integration into existing waste management systems could enhance the industrial viability of bioleaching technologies. Overall, microbially mediated bioextraction represents a transformative approach for the sustainable recovery of critical metals from end-of-life LIBs, aligning with global objectives for environmental protection, resource circularity, and economic resilience.

Bile acids are increasingly recognized as critical mediators of host-microbiome interactions, influencing a wide range of physiological processes including glucose and lipid metabolism, inflammation, and cardiovascular function. Beyond their classical role in dietary fat emulsification, bile acids act as signaling molecules through receptors such as FXR and TGR5, linking gut microbial activity to systemic health. While the microbial conversion of primary to secondary bile acids—primarily via bile salt hydrolase (BSH) and 7α-dehydroxylase pathways—is well established, the dynamic responsiveness of this system to acute dietary changes, particularly fasting, remains incompletely understood.

In this study, we investigated how a five-day 250 kcal vegetable juice-only fasting intervention affects gut microbiota composition and secondary bile acid metabolism in humans. Thirty-six healthy adults underwent supervised fasting, with fecal and plasma samples collected immediately before and after the intervention. To assess shifts in key microbial taxa associated with bile acid metabolism and gut barrier integrity, we performed quantitative PCR (qPCR) targeting Akkermansia muciniphila, Bacteroides ovatus, Bacteroides fragilis, and Prevotella copri. These taxa were selected based on their known involvement in mucin degradation, bile acid modification, and metabolic disease associations. However, qPCR analysis revealed no statistically significant changes in their relative abundance following fasting. Despite the absence of significant taxonomic shifts, previous studies suggest that microbial functions can adapt independently of community structure. To explore this further, shotgun metagenomic sequencing is currently underway to identify potential changes in the functional capacity of the microbiome, particularly in genes involved in bile acid metabolism such as the bile acid-inducible (bai) operon and BSH-related pathways. These preliminary findings highlight the complexity and potential disconnect between microbial composition and function, emphasizing the importance of multi-omic approaches in microbiome research. Functional changes in bile acid metabolism during short-term fasting may have important implications for metabolic flexibility and gut-liver axis signaling, even in the absence of major taxonomic shifts. Ultimately, this work contributes to a more nuanced understanding of how acute nutritional interventions influence host-microbiome dynamics and opens new avenues for targeting bile acid pathways in the context of metabolic and cardiovascular health.

steel production is one of the main pillars of modern society and, although different technological routes can be used, much of the world's production depends on metallurgical coke as a strategic input for the blast furnace process. Its manufacture, however, is based on the use of coal, a non-renewable resource that is in the process of depletion. In this context, control measures and strategies for the rational use of coal are indispensable, both for the sustainability of the process and for reducing environmental impacts. The objective of this article is to conduct a bibliographic survey of publications related to machine learning techniques applied to the prediction of coke quality indices: CRI (Coke Reactivity Index), CSR (Coke Strength after Reaction), DI (Drum Index), ash, sulfur, and moisture content. The study identified a gap in research specifically focused on moisture, ash, and sulfur content indices, despite their relevance to coke quality, pointing to the need to expand studies on these parameters, which are fundamental not only to process performance but also to energy efficiency, reducing greenhouse gas (GHG) emissions, and the sustainability of steel production. In addition, this work suggests the development of coke quality prediction models based on machine learning techniques, supported by interpretability tools such as SHAP (SHapley Additive exPlanations). Complementarily, it points to the exploration of mathematical optimizations aimed at reducing the cost of the coal mix, which can be integrated with the use of genetic algorithms. These, in turn, stand out for their ability to deal with nonlinear constraints and multiple objectives, offering robust solutions for the formulation of more economical mixtures with better operational performance.

Titanium alloy (Ti-6Al-4V) has been widely used in medical field due to its good biocompatibility and machinability. However, Ti-6Al-4V lacks antibacterial ability, which can be easy to lead the surgical infection by bacteria. At the same time, the release of the toxic ions such as Al or V in Ti-6Al-4V to the human body under the physiological environment is also easy to cause harm to the human body. Therefore, in order to solve the above problems, this study first used magnetron sputtering technique to prepare TiN-Cu composite coatings on the surface of Ti-6Al-4V, which is expected to take advantage of Cu antibacterial properties to achieve long-term antibacterial effects while preventing the release of toxic ions. Second, in order to enhance cell adhesion of the TiN-Cu composite coatings, plasma immersion ion implantation (PIII) was used to implant Mg ions into the surface of the composite coatings respectively. A series of measurements (such as XRD, XPS, SEM, etc.) were used to analyze the structure, composition and mechanical properties of TiN-Cu composite coatings before and after doping with different ion doses. L929 cells and MC3T3-E1 cells were used to analyze the cell proliferation and adhesion on the sample surfaces. The survival of Escherichia coli by using the coating plate method. The results showed that the surface of Mg⁺ implanted TiN-Cu composite film had the best antibacterial property and cell proliferation ability with the highest protein adsorption ability. Cu trapped electrons on the bacteria's surface and destroyed their membranes. In addition, the bonding of Cu and respiratory enzymes in the bacteria also caused bacterial dysfunction. The implanted Mg⁺ on the surface stimulated protein adsorption, the cell adhesion and proliferation.

The surface tensiometry technique leads to determine skin hydration status [1], using the contact angle method [2] with water as the liquid test, and surface tension of a liquid,  using pendant drop method [3, 4], in a quick and non-invasive way. Bioenergy Field Treatments represent an approach to treating chronic diseases by assessing an individual's physiological and emotional responses through their own bioenergetic body, and is an integration into traditional medicine [5]. Our first objective was to measure the bio-informational fields applied at mineral and sparkling water drops to evaluate differences in their volume. 

Our second objective was to provide the bio-informational field treatment with a tool capable of measuring effectiveness through analytics capable of determining changes in skin hydration levels and surface tensiometry. Two Prano Surface Tensiometry Units were implemented in Milan and Maserada Sul Piave (Italy) to realize our research aims.

The bio informational fields were applied in vivo by placing the hands at a 5 cm distance for 3' from the test subject's skin and pendant natural and sparkling water drops [response X, Xs]. An expert pranopractic (true before [O] and after [X] treatment) applied the bio informational fields and a non pranopratic (sham before [Os] and after [Xs] treatment) as reference which responses were respectively [X] and [Xs]. The data were compared with correspondent controls [O] and [Os].

The results demonstrated that the effect of the action of true and sham pranopractics on the pendant drop volume variations have statistical differences (P-value = 0.00000 for both kind of waters for [O], [X] and [O,X], while for [Os] natural with [15]=23.32 and sparkling with t[15]=39.48 waters showed both p (>|t|) <.0001, [Xs] natural with t[15]=-68.75 and sparkling with t[15]=-77.95 waters showed both p (>|t|) <.0001, and for [Os, Xs] natural with t[15]=-7.90 and sparkling with t[15]=18.58 waters showed both p (>|t|) <.0.0001). 

The effect of the action of true and sham pranopractics on the water contact angle variations measured on forehead skin demonstrated statistical differences confirming that skin hydration change after the application of bio-informational fields by the true pranopractic to each test subjects involved in PTSU2 (p (>|t|) <.0001* for sham with t[8]=25.82 and true with t[8]=19.77 pranopractic both, p (>|t|)=0.6886 for sham with t[8]=-0.41 and p (>|t|) =0.8599 for true with  t[8]=-0.18 pranopractics). The analysis of variance of water contact angles measured in PTSU 2 also showed 95% subject CI [4.1013633, 163.12], 95% residue CI [23.08, 107.13], and p (Wald)=0.0303 confirming both the existence of trend variations of water contact angle between the true and sham pranopractics however the differences are not statistically significant. 

Results open the hypothesis of skin hydration variations trends and water pendant drop volume concerning control measurements after the bio informational fields application.

Our work combined non-invasive bio-informational field treatment with non-invasive surface tensiometry analytical approach using the contact angle method and water as a biocompatible liquid test. The results are preliminary and open new perspectives in a large-scale bio informational fields application to perform deep statistical analysis.

The contact angle method [1] quickly and noninvasively evaluates skin wettability with water to determine the skin hydration state [2]. Athletes' body hydration state influences their skills and performance, affecting the outcome of a game [3].

Our objective was to measure in vivo the changes in skin hydration of 12 basketball boys (age 13- to 15 years) before and after (called here “response”) a game about basal hydration conditions (called here “normal conditions”) and after oral assumption of mineral water 2L per week (called here “hydro conditions”) before a second game. Basal and response skin hydration measurements were performed on the right (dx) and left (sx) forearms skin. The response measurements were done 10’ after the end of the game and on the skin without sweat.

The skin hydration state was assessed using the contact angle (CA; deg) method with a mobile Tenskinmeter®. Personalized evaluations of epidermal moisture changes were conducted utilizing the Skin Hydration Debt (SHD) parameter, introduced by Davide Rossi in 2018, following the “Basketskin protocol”. A positive SHD indicates that the skin is experiencing “water debt,” whereas a negative value suggests “water credit”. The initial findings revealed a noticeable increase in skin hydration state after the first game, which correlated with a decrease in the average water contact angles observed at the interface of the right (dx) forearm skin (N=24) (basal CA: 106.7±18.3 deg, response CA: 78.8±21.1 deg) and left (sx) (N=24) forearm skin (basal CA: 111.5±15.7 deg, response CA: 79.0±17.0 deg). 

As regards the hydro conditions, the results showed a trend increase in skin hydration state before and after the second game corresponding to a trend decrease of droplet average water CAs at the interface with dx (N=24) forearm skin (basal CA: 104.0±17.7 deg, response CA: 62.7±20.1 deg) and sx (N=24) forearm skin (basal CA: 103.8±20.5 deg, response CA: 62.4±18.0 deg). 

The negative difference (Δ) between the basal (b) average CAs absolute values (|CAs|) measurements performed in hydro (h) conditions and that performed in normal (n) conditions on dx and sx forearms and the negative difference between the average response (r) average CAs absolute values (|CAs|) measurements performed in hydro (h) conditions and that performed in normal (n) conditions on dx and sx forearms were respectively Δ|CA|_b^dx=2.65 deg, Δ|CA|_r^dx=16.1 deg, Δ|CA|_b^sx=7.68 deg, and Δ|CA|_r^sx=16.45 deg. 

These data demonstrated that 2L water administration per week causes an overall a trend decrease of skin wettability with water drop, however the major trend increase of hydration state was revealed from the CAs measured after the two games (responses).

The second result demonstrated the capability of Skin Hydration Debt (SHD) in the evaluation of the hydration state of each boy before and after the two games, and in “normal” and “hydro” conditions. In the case of normal conditions (first game), basal average SHD related at dx  forearm skin (basal SHD: -1.15±8.00, response SHD: -11.45±13.7) and left (sx) forearm skin (basal SHD: +1.23±5.00, response SHD: -10.20±9.2) showed average water debt only in the case of basal (sx) forearms. For all other cases, the skins demonstrated be in “water credit”.  As regard hydro conditions (second game), basal average SHD related at dx forearm skin (basal SHD: -1.22±8.4, response SHD: -21.73±14.4) and left (sx) forearm skin (basal SHD: -1.36±8,4, response SHD: -21.76±12.5) demonstrated an increase “water credit” respect to “normal condition”

The difference (Δ) between the average |SHD| values of basal (b) and response (r) in hydro and normal conditions are respectively Δ^b(dx) _|SHD|=0.08, Δ^r(dx)_|SHD|=10.3, Δ^b(sx) _|SHD|= 0.14, and Δ^r(sx)_|SHD|=11.6.

Results demonstrated that the CA method is capable to determining in non-invasive and rapid way the real effect of water oral administration on the skin hydration state of basketball boys before and after the game. 

The SHD demonstrated its usefulness in the evaluation of the increase in skin hydration followed by the oral water administration performed by basketball boys one week before the second game mostly in the response evaluation.

This appears in accordance with the increase of body hydration following one week of water oral administration and improvement of skin moisturize that seems to promote the migration of water from the body inside to outside during the game. 

Our work is open to the possibility of using the tenskinmeterâ for control of the hydration state of sportsmen in relation to their real body hydration before the game.

The results open new perspectives in a large-scale application of the CA method to evaluate the increase of body hydration after oral assumption of water added with carbohydrate-electrolyte solution (CES) [3] and perform deep statistical analysis.

The measurement of contact angle (CA) on skin allows a simple and rapid test on the different pharmaceutical and cosmetic compounds [1]. Several studies evaluated the wettability of the skin surface as a function of the diffusion processes of the active ingredient through the skin [2]. The CA method can also be applied to evaluate skin hydration (SH) that is essential for body thermoregulation. Various investigations demonstrated correlations between water intake and variations in the SH status using the corneometric (H) approach and the variation in the Transepidermal Water Loss (TEWL) degree, respectively [3, 4], highlighting the influence of the intake of 2L per day on the SH. Our work aimed the assessing SH status by measuring the water CA and H, evaluating the influence of water intake and urination on SH status over time under controlled conditions involving four subjects (S1, S2, S3, and S4) aged between 24 and 26 between at environmental temperature of 24°C±0.5. 

As example, (a) S1 demonstrated a basal CA (°) of 83.3°, after 500 ml intake 75.4°(t₀), 65.4°(t₁₀), 82.4°(t₂₀), 80.1°(t₃₀), 88.4°(t₄₀), after urination (-200 ml) is 83.2°(t₀) and 83.7°(t₁₀), after 500 ml intake 77.6°(t₀), 76.6°(t₁₀), 79.4°(t₂₀), 77.7°(t₃₀), 79.9°(t₄₀), after urination (-300 ml) is 84.9°(t₀) and 91.9°(t₁₀), after 500 ml intake is 74.9°(t₀), 87.2°(t₁₀), 72,6°(t₂₀), 75.8°(t₃₀), 77.2°(t₄₀), after urination (-475 ml) is 67.0°(t₀) and 80.3°(t₁₀), (b) S2 demonstrated a basal CA (°) of 83.6°, after 500 ml intake 72.9°(t₀), 72.6°(t₁₀), 84.7°(t₂₀), 86.9°(t₃₀), 89.5°(t₄₀), after urination (-220 ml) is 85.4°(t₀) and 89.9°(t₁₀), after 500 ml intake 85.8°(t₀), 76.6°(t₁₀), 89.9°(t₂₀), 94.5°(t₃₀), 91.5°(t₄₀), after urination (-470 ml) is 96.7°(t₀) and 87.4°(t₁₀), after 500 ml intake is 89.0°(t₀), 83.1°(t₁₀), 90,6°(t₂₀), 92.5°(t₃₀), 91.2°(t₄₀), after urination (-400 ml) is 91.1°(t₀) and 88.4°(t₁₀), (c) S3 demonstrated a basal CA (°) of 83.8°, after 500 ml intake 78.1°(t₀), 83.0°(t₁₀), 84.4°(t₂₀), 84.2°(t₃₀), 88.3°(t₄₀), after urination (-210 ml) is 79.8°(t₀) and 82.9°(t₁₀), after 500 ml intake 82.1°(t₀), 82.6°(t₁₀), 79.1°(t₂₀), 84.4°(t₃₀), 83.2°(t₄₀), after urination (-580 ml) is 81.9°(t₀) and 84.9°(t₁₀), after 500 ml intake is 75.4°(t₀), 79.5°(t₁₀), 79,6°(t₂₀), 78.4°(t₃₀), 79.5°(t₄₀), after urination (-470 ml) is 85.9°(t₀) and 84.9°(t₁₀), and (d) demonstrated a basal CA (°) of 88.6°, after 500 ml intake 84.5°(t₀), 93.3°(t₁₀), 87.9°(t₂₀), 89.7°(t₃₀), 80.4°(t₄₀), after urination (-450 ml) is 78.3°(t₀) and 85.2°(t₁₀), after 500 ml intake 87.6°(t₀), 86.8°(t₁₀), 89.0°(t₂₀), 85.2°(t₃₀), 83.0°(t₄₀), after urination (-420 ml) is 86.7°(t₀) and 94.9°(t₁₀), after 500 ml intake is 85.9°(t₀), 87.8°(t₁₀), 89,5°(t₂₀), 85.9°(t₃₀), 84.5°(t₄₀), after urination (-500 ml) is 85.4°(t₀) and 86.6°(t₁₀). 

S1 showed a total average Hydration Index (HI) of 52.5±4.07 (Meas.1), 54.3±5.02 (Meas.2), 55.2±5.3 (Meas.3), S2 showed a total average HI of 35.1±1 (Meas.1), 37.2±5.1 (Meas.2), 37.2±4.9 (Meas.3), S3 showed a total average HI of 32.7±5.9 (Meas.1), 33.9±7.0 (Meas.2), 34.2±5.7 (Meas.3), and S4 showed a total average HI of 67.8±6.6 (Meas.1), 65.7±6.3 (Meas.2), 61.0±5.9 (Meas.3). In S1, the water intake caused increase in SH and decrease water CA. In the 1° period, CAs increase until the moment of urination because linked to the rapid hydrating effect due to the 1° water intake, and this phenomenon repeats at 2° water intake. 

In S2 the 1° and 2° water intake follow the same behaviour of S1, however the influence of water intake on SH appears more evident in S2 than in subject S1 because the difference between the volume ingested and excreted for the first two periods considered (1 Δ=280 mL, 2 Δ=30 mL) appears lower than that observed in S1 (1 Δ=300 mL, 2 Δ=200 mL). 

In S3, the 1° and 3° intake of water follow the same behaviour as S1 and S2, while after the 2° intake, the CAs showed less variability than what was observed in S1 and S2 in period 2. 

The S4 presents an anomalous CAs trend with respect to S1, S2 and S3 due to a poor ability to maintain body hydration levels over time and doesn’t appear suitable for the in vivo absorption test of a drug because it is closely linked to the maintenance of the SH status over time. 

Our work demonstrated that the CA method is capable of determining the influence of repeated water intake on the SH in relation to urination by measuring the CAs of a water droplet at different times. 

Our results open new perspectives in the evaluation of the effect of SH on the in vivo absorption of an active ingredient, developing a correlation model between CAs data obtained from static conditions and those obtained under kinetic conditions after application of the formulation loaded with the active ingredient.

Titanium alloys are widely used as aerospace structural materials because of their low density, high strength and excellent corrosion resistance at low-to-moderate temperatures. However, when the working temperature is over 400°C, titanium alloys usually show a poor oxidation resistance because of the fast diffusion of oxygen through the nascent TiO_2–X surface oxide layer[1]. On the other hand, SiO₂ shows considerable promise as a protective oxide layer, for both high temperature oxidation corrosion; however, the most successful application so far of Si–based oxides to Ti–alloys is the preprocessed amorphous (or ‘enamel’) SiO₂ coating [2]. Ti–based Multi-Principal Element Alloys with added Si potentially provide a novel opportunity to find new alloy compositions which could form an SiO₂–based layer spontaneously at elevated temperatures [3]. Boron has also been suggested as a further alloying addition, that could avoid the possible issue of pesting of formed silicide compounds in such MPEAs at intermediate temperatures [4].

This research builds an equimolar TiCrAlNb MPEA alloy system with different ratios of Si and/or B content and characterizes their microstructure, before and after oxidation, to study the influence of the addition of silicon and boron. The oxidation resistance of such alloys shows in general a significant improvement compared with a typical Ti-6Al-4V Ti–alloy. Furthermore, Niobium shows a higher tendency to form compounds with silicon/boron. In addition to such silicide/boride compounds, some laves phases were also observed and the addition of silicon showed a significant influence on the microstructure, the addition of B refines the lamellar microstructure while the addition of Si transfers the structure into an equiaxed dendritic structure.
 

Corrosion is a natural phenomenon that degrades the properties of materials when they are exposed to environmental elements. This issue is especially prevalent in steel structures, where it can result in substantial economic losses, structural failures, and even pose risks to human safety. The corrosion of steel can be triggered by various factors, including environmental conditions, mechanical stress, and the presence of impurities. This study investigates the macroscopic corrosion of steel under potentiostatic conditions through a combination of electrochemical experiments and probabilistic modeling. A probabilistic cellular automata (PCA) model was developed in MATLAB to predict the propagation and penetration of corrosive material in steel. The model was refined using experimental data obtained from a three-electrode corrosion cell. Various steel specimens were subjected to corrosion under different environmental conditions, and their mechanical strengths were assessed. The refined model's predictions were validated using finite element analysis (FEA) and tensile testing of the corroded specimens. The FEA results showed a strong correlation with the tensile testing outcomes across three different specimen designs. This thesis enhances the understanding of steel corrosion under potentiostatic conditions and offers a predictive tool for assessing the corrosion behavior and mechanical properties of steel in such environments.

As interest in environmental issues grows, regulations on the Global Warming Potential (GWP) of refrigerants are becoming increasingly stringent [1], driving the demand for Low GWP alternatives. [2] Engine-driven heat pumps are also gaining attention as an effective technology to mitigate winter power peaks due to their lower electricity consumption compared to electricity-driven heat pumps. [3]

This study analyzes the performance improvement of an engine-driven heat pump using low-GWP refrigerants by adopting waste heat recovery mode and evaluates the applicability of alternative refrigerants. A cycle simulation program was developed to obtain the performance characteristic data of the engine-driven heat pump. R32, R452B and R466A were selected as Low GWP refrigerants for comparison with R410A, which was used as the baseline refrigerant.

The design parameters of engine-driven heat pump were determined to deliver the same heating capacity at identical evaporating and condensing temperature conditions without waste heat utilization. Performance simulations were conducted by varying the amount of waste heat recovered from the engine, while maintaining a constant heating capacity.

As the amount of waste heat increased, compressor power consumption decreased. The power consumption decrease was most significant in the order of R466A, R452B, R410A,and R32A. Furthermore, with 10 kW of waste heat, the coefficient of performance (COP) of engine driven heat pumps were improved by 1.2% and 2.3% using R452B and R466A compared to the COP using R410A. On the other hand, the COP using R32 was decreased by 2.6%.

Energy saving has become an important issue due to the limited energy resources and the increasing demands. Many studies have been carried out to improve energy efficiency. In this perspective, the vapor compression cycle (VCC) systems equipped with an ejector as an expansion device are considered to improve the COP by reducing the expansion loss and compressor work. This paper presents simulation results on the performance of the ejector vapor compression cycle (EVCC) using low-GWP refrigerants. The vapor compression cycle system equipped with an ejector as an expansion device is considered to improve the coefficient of performance (COP) by reducing expansion losses and compressor work. The EVCC was simulated using a model based on the conservation of mass, energy, and momentum in the ejector. Based on the simulation results, the COP improvement of the EVCC was analyzed under varying operating conditions and compared with that of the conventional vapor compression cycle (VCC). The EVCC showed greater performance improvements with increasing temperature differences between the condenser and evaporator for all refrigerants.

More than 190 nations have committed to limiting global warming to below 2°C by reducing greenhouse gas emissions (UNFCCC), signing the Paris Agreement. Recent conferences (COP28 and COP29) have focused on renewable energy transitions, carbon markets, and climate finance (WRI). Solar, wind and hydropower represent more than 30% of new global power capacity to reduce the dependence on fossil fuels (IEA) and advance in green hydrogen, carbon capture and battery storage, which offer promising cleaner energy solutions (WEF) with significant investment in fusion energy research to unlock unlimited clean energy. However, the actual technical solutions are still deficient in the social, business and effectiveness areas because respectively the populations perceive them as a burden imposed from above rather than a consumer-led change imposed at their expense, the shift to green energy remains unprofitable without government incentives and trigger geopolitical tensions to secure critical resources, and current technologies are only “half green” and do not achieve their intended goals. In the field of green energy, the H₂ technology still represents an obstacle in terms of competitiveness, lack of infrastructure, distribution and storage risks because of high pressure and low temperature conditions, uncompetitive price, investment risks and regulatory issues. In particular, the gray H₂ (95%) is obtained from steam methane reforming (SMR) with CO and CO₂ production without the possibility of carbon capture, while the blu H₂ (3-4%) is also obtained from SMR, but thanks to Carbon Capture Storage system, the emissions of CO₂ can be reduced (56-90%) however not completely cancelled. The green H₂ represent the only sustainable option because obtained exclusively from renewable sources such as wind, solar, and hydropower that support the electrolysis of water. The current global cost of green hydrogen ranges between 3 and 7 USD/kgH_2, is deemed acceptable only for certain applications, such as in the power-to-liquids (PtL) industry and transportation sector [2]. Thus, to be economically viable for commercial and residential use, the price per kilogram should be below approximately 2 USD/kgH₂ [2]. On this basis, Sedes H Company is successfully developing a new solution capable of producing massive green H₂ from renewable energy with low cost (1E/Kg) because using existing infrastructures and in a safe way, because green H₂ can be stored and distributed at 1 atm pressure and ambient temperature [4]. The so-called “Sedes H ecosystem” is mainly composed of an organic photovoltaic (OPV) paint, composed of conjugated polymers and/or molecules capable of generating electricity from the sun [3], whose excess could be used to power an electrolytic cell for green H₂ development [4]. The green H₂ so product could be stored and distributed in a versatile Inert Tank (IT) connected with a hydrogen station (Fuel Cells) for refuelling vehicles, placed outside any buildings or installed directly in existing and new vehicles, while it excess could be sold to other external users. In the end, the green H₂ production can also be performed with chemical reactions using a specific device, called Sedes H-POT (little and big), that can produce water vapour and high-value metallic compounds for industrial sectors starting from water, commonly used metals and specific molecules (called here XY Sedes H molecules) [4].  The Sedes H's purpose is aimed at a new integrated concept of H₂ low-cost production and could soon represent a great environmental and economic opportunity for human development. This target is well based on the estimated market size for energy production (2031) of 5.866 B and by the fact that in 2027 Sedes H will be listed on the NASDAQ.

Obtaining the best results in the processing of low-quality copper-containing raw materials requires comprehensive research, including the study of the bio-leaching process, as well as the influence of the composition of the culture fluid and the physico-mechanical characteristics of the starting material on this process. Based on the data obtained, more efficient methods of extracting copper from low-quality mineral and man-made materials will be developed. Bacterial biomass was built up using various amino acids such as meat peptone agar, meat peptone broth, adapted to the composition of the copper dump, in a bioreactor /fermenter in compliance with predefined parameters. The growth and development of A. Ferrooxidans bacteria is characterized by a change in the parameters of the biological solution, such as a significant decrease in the concentration of 〖Fe〗(2+) and an increase in the level of 〖Fe〗(3+) ions. In addition, some strains of A. Ferrooxidans, adapted to the presence of copper in solution, can effectively leach sulfides, including copper sulfides.

Plasma treatment of ores, and ore concentrates is used most often to improve the separation performance of ore minerals and non-metallic gangue, as well as for the “plasma grinding” (softening) of ores to reduce the time of subsequent mechanical grinding and energy costs. Non-equilibrium, low-temperature plasma of dielectric barrier discharge (LTP-DBD), characterized by high pressure (hundreds of Torr), high electron temperatures (electron temperatures can reach several electron volts), and low temperature of the process gas (close to the temperature of dielectric barriers) [1] is considered the most precise, efficient, and safe tool for modifying the composition, structure, and properties of the surfaces of various materials, including geomaterials [2–5]. A DBD occurs in a gas under the action of an alternating voltage applied to the conducting electrodes, provided that at least one electrode is covered with a dielectric layer on the side of the discharge gap. The discharge can be carried out in oxygen or air at atmospheric pressure, room temperature, and natural air humidity, i.e., under normal conditions and without the use of a special plasma gas. For practical applications, the problem of obtaining a diffuse discharge in air at atmospheric pressure is relevant, since in this case the effect of the DBD plasma spreads uniformly over the largest possible area [1,3]. During the our experiments, the mineral samples filled the gap between the active metal electrode and the dielectric barrier and were separated from the electrode by a small air gap. The mineral particles were affected by the following DBD factors: a high-strength pulsed electric field, ionic wind, and low-temperature plasma products in the form of chemically active compounds, such as ozone O₃, and other agents. When conducting experiments on the effect of DBD on the structural and physicochemical properties of minerals, the following rational parameters of pulses initiating a barrier discharge we established in [3]: duration of the leading edge of the pulse 250–300 ns, pulse duration 8µs, voltage on the electrodes in the barrier discharge cell 20 kV, repetition frequency of the pulses initiating the discharge ~15 kHz, time range of plasma minerals treatment was t_treat=10–150 s. The dimensions of the electrodes of the DBD discharge cell significantly exceeded the length of the interelectrode gap, which was 5mm. According to SEM, defects of a regular triangular shape formed on the surface of galena samples due to the removal of microcrystalline fragments due to ponderomotive forces in the region of a strong electric field. On the surface of chalcopyrite, the formation of irregularly shaped defects was observed, and on the surface of sphalerite, microchannels of electrical breakdown formed, bordered by the sinter formation material of oxide microphases. The change in the morphology of the surface of sulfides caused softening, and a significant decrease in the microhardness of minerals as a whole by 20–30%. Short (t_treat=10 s) treatment of pyrrhotite caused a shift in the electrode potential of the mineral to negative values (φ=−60mV, at pH 9.7–12) [4], which predetermines the effect of reducing the sorption activity of pyrrhotite with respect to xanthate, hence its flotation recovery reduction. In [5] rational conditions were determined for t_treat=30–40s) plasma pretreatment, in which the efficiency of pyrite and arsenopyrite separation in monomineral flotation increased considerably: an increase in pyrite recovery was 27% while the yield of arsenopyrite decreased by 10–12%. Thus, the method of plasma-chemical processing of geomaterials with using of DBD has great prospects for practical applications in the processes of selective separation of semiconductor ore minerals (sulfides, oxides). In rock-forming minerals, the following features of changes in surface properties when exposed to DBD were established [3]. With increasing plasma treatment time of the quartz samples t_treat=10–150s, smoothing of surface irregularities and the formation of microdefects of irregular shape (≤3µm) occurred This caused weakening and a monotonous decrease in the microhardness of the mineral from 1420 up to 1320 kgf/mm² in the original and modified at t_treat=150 s states, respectively. The maximum relative change (decrease) in microhardness ∆HVmax was ~7%. The contact angle of wetting the quartz surface with water changed nonmonotonically. As a result of short-term exposure (t_treat=10–30s), the contact angle increased from 44° to 53°, which indicates an increase in the hydrophobicity of the mineral’s surface, while with an increase in t_treat, a gradual decrease in the contact angle was observed to initial values. The possibility of modifying the hydrophobicity of quartz by energy impacts can be used in industrial processes for separating the mineral from impurities and selective (reverse) flotation of ferruginous quartzites.

The production of quality castings requires the use of modern computer programs that serve to simulate foundry processes as a tool for optimizing proposed production technologies. This paper focuses on the analysis of a computer simulation concerning the casting of a brake disc at a Slovak foundry. Notably, this brake disc has experienced issues such as shrinkages and micro shrinkages, which adversely affect the internal quality of the casting. Through this study, we aim to enhance our understanding of these challenges and explore solutions to improve the overall quality of cast components, making the process more efficient and cost-effective. Defects were identified in the ribs located in the upper section of the casting beneath the feeders. To address this issue, a comprehensive computer simulation was conducted, replicating the actual conditions of the casting and solidification process. The results revealed that the initially designed gating system, along with its feeder configuration, was inadequate in preventing the formation of these defects. 

In response, a new feeder layout was proposed, which successfully eliminated the defects based on the simulation outcomes. The input parameters for this simulation were meticulously set to reflect the actual requirements of the foundry closely. To facilitate this process, 3D models of the assemblies were created using SolidWorks CAD software, and filling and solidification simulations were carried out using the NovaFlow & Solid CV 4.6r42 simulation program. This approach ensured a thorough analysis and resolution of the issues at hand.

Copper oxide (CuO) has emerged as a promising candidate for chemiresistive gas sensors due to its intrinsic p-type semiconducting nature, cost-effectiveness, and strong interaction with a wide range of toxic and volatile organic compounds. In this study, density functional theory (DFT) was employed to investigate the adsorption behavior of various gas molecules, including NO, NO₂, CO, CH₂O, ethanol, and acetone, on the CuO (111) surface.The adsorption energies revealed a clear trend in gas-surface interactions: NO exhibited the strongest binding (-2.96 eV), followed by CO (-2.34 eV), acetone (-1.90 eV), ethanol (-1.755 eV), formaldehyde (-0.471 eV), and NO₂ (-0.107 eV). Structural analysis of adsorption configurations indicated distinct bonding motifs and charge redistribution pathways that correlate with adsorption strength. Strong chemisorption was observed for NO and CO, while weaker physisorption dominated for NO₂ and formaldehyde.These findings provide fundamental insights into the selectivity and sensitivity of CuO-based gas sensors, highlighting NO and CO as the most responsive analytes. The study demonstrates that theoretical modeling can serve as a predictive tool for screening gas–sensor interactions, guiding the rational design of next-generation CuO-based sensing devices for environmental and health monitoring.

In this work, we have studied the possibility of the electrochemical synthesis of titanium borides from ionic-organic melt based on imidazole: C₃H₄N₂ (t_m = 91°C) [1]. The solubility of (NH₄)₂TiF₆ and NH₄BF₄ in imidazole melts at 120°С reaches 5 and 10 wt.%, which makes it possible to carry out voltammetric studies and electrolysis experiments. In the binary system: C₃H₄N₂ (t_m = 91°C)–(NH₄)₂TiF₆ a new process, which is more electropositive than the decomposition of imidazole as been observed. The scan rate independence of potential characterizes the observed processes as reversible charge transfer. This process corresponds to the one-electron irreversible charge exchange: Ti(IV)/Ti(III). In the binary system C₃H₄N₂ –NH₄BF₄ only the decomposition of imidazole has been observed. In the ternary system C₃H₄N₂–(NH₄)₂TiF₆–NH₄BF₄ a new process, which is more electropositive than the decomposition of imidazole and more electronegative than the one-electron charge exchange: Ti(IV)/Ti(III) has been observed. 10 micron coatings have been obtained on nickel and stainless steel by the electrolysis from a C₃H₄N₂–(NH₄)₂TiF₆–NH₄BF₄ melt at 120°C at current densities of 20-40 mA/cm². The X-ray phase analysis of samples after the electrolysis ofan ionic-organic melt did not allow us to determine the composition of the coating because it was very fine-crystalline. In order to coarsen the crystal structure of the coating, the samples were annealed in a furnace at 600°C in Ar stream. The research has established that the XRD patterns of the products obtained by electrolysis C₃H₄N₂–(NH₄)₂TiF₆–NH₄BF₄ to nickel cathode at 120°C and after annealing at 600°С in an Ar stream exhibits peaks corresponds to the Ni (COD - 96-901-3025) and TiB (COD - 96-151-1333) [2]. TiB crystallizes in the orthorhombic Pnma space group. The sample was obtained without extraneous phases inclusions. On the basis of XRD analyses it may be assumed that the stoichiometry of the compound deposited from ionic-organic melts is TiB.

The (LiCl-KCl)_eut.- PbCl₂ melts can be used as a reaction medium for “soft chlorination” during pyrochemical reprocessing of spent nuclear fuel, as well as for electrolytic extraction and refining of metallic lead and its alloys.

Previously, we measured the specific electrical conductivity of molten (LiCl-KCl)_eut.- PbCl₂ mixtures in the entire concentration range and in the temperature range from the liquidus to 994 K. In this work we calculated the density and molar volumes of the quasi-ternary (LiCl−KCl)_eut. − PbCl₂ system in the entire range of PbCl₂ concentrations. This system may be used in a vast number of technological operations. The calculation was performed by an original method using experimental data [1]. Based on the obtained results, the molar electrical conductivity and its activation energy were also calculated.

It was found that the specific electrical conductivity of molten (LiCl-KCl)_eut. – PbCl₂ mixtures decreases with the addition of PbCl₂, while the molar electrical conductivity, on the contrary, increases. The molar electrical conductivity (Λ) of molten PbCl₂ is higher than the electrical conductivity of the LiCl-KCl eutectic by approximately 30%. For all molten mixtures, the ln Λ vs. 1/T dependence is not linear. For example, at 773 K, the molar conductivity has positive deviations from additive values (~ +1.6%). However, with increasing temperature, the deviations decrease, become negative and further increase in the negative direction with the increasing temperature (-5.3 % at 973K). This indicates different predominant mechanisms of electrical transport at different temperatures.

In general, the isotherms of molar conductivity in the (LiCl-KCl)_eut. - PbCl₂ system are close to linear. This indicates weak interaction in the system. The data on electrical conductivity and molar volumes of the (3LiCl-2KCl) - PbCl₂ melts are compared with those earlier obtained in our studies on the (3LiCl-2KCl) - CdCl₂ [2] and (3LiCl-2KCl) - SrCl₂ molten mixtures [3].

When adding PbCl₂, the activation energy of molar electrical conductivity decreases until the PbCl₂ concentration of 30-40% is reached and then increases. The available data on the structure of the melts [4] indicate that, along with simple ions, complex chloride anion groups of various compositions are present. These groups were also considered for the analysis of the results. A relatively complex behavior of deviations of molar electrical conductivity depending on the temperature, activation energy and the PbCl₂ concentration is associated with the presence of two complex-forming ions with almost equal ionic potentials (Li⁺ and Pb²⁺) in the system.

According to the obtained electrical conductivity data, the liquidus line of this system has been built. It is in good agreement with the literature data. 

Molten salts containing ZrCl₄ generally have a high vapor pressure. However, there are concentration ranges with a relatively low vapor pressure. And such melts are quite suitable for industrial use. In this work we have considered molten of MCl – ZrCl₄ mixtures (where M is an alkali metal) with a relatively low saturated vapor pressure (P ⩽ 1 atm) of highly volatile ZrCl₄. These mixtures can be divided into high-temperature regions with a ZrCl₄ concentration of 0–30 mol. % and low-temperature regions with a ZrCl₄ concentration of 50–75 mol. %. 

The aim of this work is to review the available experimental data on the electrical conductivity of ZrCl₄-containing salt melts with vapor pressures below atmospheric ones [1–6].

It was found that the electrical conductivity of all molten ZrCl₄ - containing mixtures increases as the temperature increases, zirconium tetrachloride concentration decreases, and the molten salt-solvent is replaced in a series from CsCl to LiCl.

As the concentration of zirconium tetrachloride in melts increases, the concentration of its relatively low-mobility complex anion groups, (in solutions with ZrCl₄ concentrations up to 33 mol.%) or and (in solutions with higher ZrCl₄ concentrations) also increases. This leads to a decrease in the concentration of the main current carriers: alkaline cations and mobile Cl^- ions, which are gradually replaced by bulky complex Zr(IV) groups that make a small contribution to the transfer of electricity. As a result, the electrical conductivity of molten mixtures decreases as the ZrCl₄ concentration increases.

The electrical conductivity of all studied molten mixtures decreases not only with an increase in the concentration of ZrCl₄, but also with a decrease in temperature as a result of a decrease in the mobility of ions (both simple and complex) and an increase in the viscosity of the melt. As a result, the electrical conductivity of high-temperature MCl - ZrCl₄ melts (M is an alkali metal, with 0 - 30 mol. % ZrCl₄) is in the range of 0.6 - 3.1 S/cm, is significantly higher than that of low-melting molten mixtures of the same chlorides (0.1 - 0.5 S/cm) with a high ZrCl₄ content (55 - 75 mol. %).

It was found that the use of low-melting salt solvents such as the LiCl - KCl eutectic allows for a significant (by hundreds of degrees) expansion of the existence range of ZrCl₄ - containing melts towards lower temperatures and saturated vapor pressures at sufficiently high electrical conductivity values ​​(0.9 - 2.8 S/cm), which provides additional advantages for various technological processes.

The electrical conductivity of the majority of molten salts increases with temperature. However, the rate of conductivity growth decreases with temperature. It is hypothesized that the electrical conductivity polytherms of all molten salts pass through their maximums in the temperature range from the melting point to the critical point [1–3]. For the majority of molten salts, the maximum of electric conductivity is difficult to achieve experimentally, because, as a rule, it is reached at the temperature when the value of the salt vapor pressure is equal to tens of atmospheres. 

It is known that there is a very small number of halides that have negative temperature coefficients of electrical conductivity, starting from the melting point of salt [1–4]. One such salt is InCl₃. According to Klemm et al. [4], the electrical conductivity of molten InCl₃ decreases with increasing temperature in the studied range of 867–967 K (i.e., immediately after melting). Our experimental data on the electrical conductivity of molten InCl₃, obtained using a specially designed hermetically sealed quartz cell of capillary type [5], in the temperature range of 862–1009 K confirm the Klemm’s information [4] on the negative temperature coefficient conductivity of the melt, but deviate by 2–7% at higher values:

k(S·cm^–1) = –5.408 + 5.2114·10^–2∙T – 5.6407·10^–5∙T² + 2.0028·10^–8·T³.

In addition to InCl₃, we have measured the electrical conductivity of molten ZrCl₄ and HfCl₄ for the first time. These salts exist in a liquid state only in narrow temperature ranges (68 or 17 K, respectively, from their melting points to the critical points):

ZrCl₄:   k·10⁴/S·cm^–1 = –2.0970·10³ + 8.7463∙T – 1.2119·10^–2∙T² + 5.5819·10^–6·T³

(in the temperature range studied 710–744.5 K the electrical conductivity decreases 1.8 times),

HfCl₄:   k·10⁶/S·cm^–1 = 735.06 – 1.9473∙T + 1.2966·10^–3∙T²

(in the temperature range studied 704.5–713.5 K the electrical conductivity decreases by about 1.17 times).

The following InCl₃, ZrCl₄ and HfCl₄ chlorides have a high vapor pressure already at the melting point (13–46 atm). These three salts form melts, which electrical conductivity falls on the descending branch of the general curve of electrical conductivity immediately after the melting [1, 2]. Possible causes of the anomalous dependence of electrical conductivity of molten salts on temperature are discussed.

Several studies have demonstrated the antioxidant and anti-inflammatory effects of plant polyphenols (PP) [1, 2]. However, despite their biological potential, the clinical application of PP is limited primarily by their poor water solubility, which results in low bioavailability when administered orally. Micro- and nanoparticles loaded with plant polyphenols have shown high pharmacological activity, making the development of such delivery systems and the investigation of their biological effects highly relevant [3]. The objective of this study was to compare the protective effects of native and nanostructured quercetin on the initiation of oxidative stress in human keratinocytes exposed to tert-butyl hydroperoxide (tBHP). Quercetin was encapsulated within gelatin-based microcontainers, forming nanoparticles with diameters ranging from 160 to 190 nm. Two formulations were used: uncoated gelatin nanoparticles (nano 1) and  gelatin nanoparticles coated with a  shell composed of dextran sulfate and a chitosan-dextran copolymer (nano 2). Cell viability was assessed using PrestoBlue™ reagent. Keratinocyte damage was evaluated via lactate dehydrogenase (LDH) release. Apoptotic and necrotic cells were identified through flow cytometry using an Annexin V-FITC/PI staining kit. DNA damage was analyzed using the comet assay. The results demonstrate that gelatin nanoparticles effectively encapsulate quercetin, and the nanostructured form enables its application in aqueous suspensions without compromising its antioxidant, gene-protective, and cytoprotective effects under conditions of cellular oxidative stress. Both free and nanoparticle-loaded quercetin significantly protected keratinocytes from oxidative DNA damage and apoptosis induced by tBHP. These findings suggest that gelatin nanoparticles are effective carriers for quercetin, exhibiting high efficiency in its release.

Conclusion: The use of gelatin nanoparticles represents a promising strategy for enhancing the bioavailability and therapeutic efficacy of phytochemicals.

Flexible and wearable technologies in environmental monitoring, healthcare, and industrial safety have been made possible by the advancement of chemiresistive sensors. Ammonia is an important sign of food going bad and kidney problems, so we need detection systems that are sensitive, stable, and can work at room temperature, which many traditional metal oxide sensors can't provide. In this study, we present a flexible ammonia sensor based on a Ti-doped ZnO/polymer composite, fabricated via a cost-effective electrospinning method. This approach enabled uniform integration of Ti-doped ZnO nanoparticles into polymeric fibers, improving electron transport and enhancing sensing performance under mechanical deformation. Obtained material also showed good flexible properties. The sensor exhibited strong mechanical stability and maintained high sensitivity across various bending conditions, showing the same response at both 0° and 90° angles. The synergistic effects between the doped metal oxide and the flexible substrate offer a reliable, non-invasive platform for real-time ammonia monitoring in wearable applications. 

Acknowledgments. This research has been funded by the Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan (Grant No. AP23489498, Development of advanced polymer-based sensor containing biowaste-derived carbon for detection of NH3).

Deep slag recovery is a critical process in the metallurgical industry to extract valuable metals from slag waste. Current literature indicates a significant knowledge gap regarding the deep reduction of slags under extremely low partial pressures of oxygen, approximately P_O2<10^-10 atm [1-3].

This study aims to explore the factors influencing the efficiency of metal recovery from slag, particularly focusing on the chemical composition of slag, temperature, and oxygen partial pressure [4-5]. The goal is to optimize recovery processes to enhance efficiency and reduce costs.

The research involved experimental melting of slag samples under controlled conditions, simulating autogenous melting and purging with oxygen-containing mixtures. Various analytical techniques, including X-ray phase analysis, thermal analysis, and SEM analysis, were employed to evaluate the composition and properties of the slag.

The findings demonstrate that achieving deeply reducing conditions significantly impacts the recovery of metals, particularly copper, from slag. The study reveals that the copper content can decrease from 0,93-1,54% to 0.43-0.80% after reduction treatment, highlighting the importance of controlling oxygen partial pressure and temperature during the process. Optimal conditions for reducing depletion of slags were identified, indicating a temperature of 1300 °C and a need for substantial heat input to facilitate effective reduction reactions.

The exothermic mixture for lining high-temperature metallurgical units was developed using plant-derived waste. The composition of the mixture includes refractory clay, aluminum powder, magnesium sulfate (MgSO₄), and a silicon–carbohydrate ingredient as a source of amorphous silica and a burnout additive (PW) [1], as well as an organic binder OC-PW. The purpose of this study was to investigate the phase transformations of this mixture when heated up to 1200 ^оC using the thermal analysis (DTA/TG) method.

The studies were carried out on a synchronous thermal analyzer STA 449 F3 Jupiter (NETZSCH, Selb, Germany).  The results obtained using the STA 449 F3 Jupiter were processed using NETZSCH Proteus software.

For interpretation of thermal effects, thermal analysis of the novel (experimental) exothermic mixture (sample 1) was performed in comparison with a control mixture (without PW and OC-PW additives) (sample 2), and with samples based on the experimental and control compositions but without Al and MgSO₄ (samples 3 and 4, respectively). On the DTA curves of all four samples, a sharp endothermic effect with an extremum at 560 ^oC and a rather intense exothermic effect in the region (depending on sample composition) of 910–950 ^oC were observed. The combination of these effects can be interpreted as the manifestation of aluminosilicate. In the region near 560 ^oC, dehydration associated with hydroxyl groups and amorphization of the substance occur, while the peak at 910–950 ^oC corresponds to crystallization of amorphous phases.

In the DTA curve of sample 3, an endothermic effect with an extremum at 120 ^oC and an exothermic effect at 397 ^oC were observed. The first is related to the loss of free water, while the exothermic effect is due to the formation of new compounds and condensation processes in the carbonaceous material formed. Both effects are accompanied by mass loss on the TG curve.

A series of weaker thermal effects was recorded on the dDTA curves of all studied samples. Among these, two exothermic effects were notable, appearing only in samples 1 (at 649 and 932 ^oC) and 2 (at 649 and 802 ^oC), i.e., those containing Al and MgSO₄. These effects should apparently be considered together with a small endothermic effect on the DTA curve at 648 ^oC, also characteristic only of these samples. Although this temperature is close to the melting point of aluminum (660 ^oC), the effect most likely indicates a prereaction rearrangement between Al and MgSO₄. Local chemical interaction at the interface of these components requires energy absorption prior to the onset of the main exothermic reaction (effect at 649 ^oC). The endothermic effect at 648 ^oC may result from the formation of a transient complex phase (Al–Mg–O–S) or the melting/softening of MgSO₄ in the presence of Al. The second exothermic effect (at 802/932 ^oC) is associated with the formation of a mineral with an olivine structure (forsterite) [2]. Upon further heating, spinel (MgAl₂O₄) is formed [2]. Formation of spinel was also observed by the authors [3–4] during the production of refractories using rice husk silica at firing temperatures of 1050–1170 ^oC. This indicates that the products of the previous reactions continue to interact chemically at high temperatures. However, in samples 1 and 2, this process occurs at different temperatures (932 ^oC and 802 ^оC, respectively), likely due to the presence of organic components in the experimental mixture (sample 1). The combustion of organic components leads to the formation of a porous structure (the residual mass of sample 1 at 1174 ^oC was 80.4%, almost 11.5% lower than that of sample 2 at the same temperature). Since, as shown in [5], plant additives do not affect the phase composition during the production of thermal insulation materials based on clay, the presence of pores in the experimental sample 1 can be considered the reason for the shift of the spinel formation reaction to higher temperatures.

Thus, according to thermal analysis data, the developed composite mixture is exothermic. The shift of the main exothermic reaction to a higher temperature range during heating is caused by the retardation of heat transfer and reactivity due to microstructural changes. In other words, a weakly expressed (retarded) self-propagating high-temperature synthesis (SHS) occurs, making the process more controllable and reducing the risk of explosive behavior. Due to the high porosity, thermal stresses and cracking risks are reduced. As confirmed by corresponding experiments, the thermal shock resistance of the refractory material increases as a result.

This research was funded by the Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan (grant number AP 19677767).

The largest amount of input raw materials in the foundry is silica sand, which constitutes more than 90% of the molding mixture, which is necessary for the production of molds necessary for the production of castings. Almost all silica sand that enters the foundry ends its material cycle in a landfill, either after a single use (molding mixture with an organic binder) or after a certain period of time. Three types of waste with a high SiO₂ content are generated in the foundry: dust from handling the molding mixture (preparation of the molding mixture, molding and framing of castings), dust from blasting of castings, the non-magnetic part of which contains a high proportion of SiO₂, and the used molding mixture. The paper proposes methods for treating and utilizing these wastes containing SiO₂ either directly in the foundry or in other industrial sectors. Dust extracted from the molding mixture preparation workplace can be returned to the process in limited quantities without impairing the properties of the molding mixtures. Dust obtained from blasting castings can be separated by magnetic separation into a non-magnetic component containing a high proportion of SiO₂ and can be returned to the process, and the used molding mixture was added as a substitute for building sand in the preparation of concrete.

In technological and analytical practice, in preparative chemistry, halogenide complexes of platinum group metals play an important role. Available information concerning Pd(IV) chloride complexes is limited due to the instability of PdCl₄ [1-3], which exists in an individual state only as dichloride. Chlorination of metallic palladium in molten alkali metal chlorides at high temperatures (630-980 °C) and at elevated chlorine pressures (8-10 atm) allows, according to our data, obtaining palladium in rapidly cooled and solidified salt melts based on CsCl mainly in the tetravalent state in the form of Cs₂PdCl₆. However, in RbCl- and KCl-based solidified melts there are complex compounds both of Pd(II) and of Pd(IV), and in solidified melts containing NaCl and LiCl only divalent palladium is present in the form of M₂PdCl₄ compounds.

The ratio of valence forms (II, IV) of palladium chlorides in salt melts and in solidified fusions at different stages and process regimes can be conveniently and quickly monitored by changing the ratio of intensities of the bands of the groupings [PdCl₆]^2- (O_h): n₁(A_1g) ~ 315, n₂(E_g) 290, n₅(F_2g) ~ 170 cm^-1 and [PdCl₄]^2- (D_4h): n₁(A_1g) ~ 300, n₂(B_1g) ~ 270, n₄(B_2g) ~ 200 cm^-1 of the chloride complexes of M₂[PdCl₆] and M₂[PdCl₄] in the Raman spectra, recorded using a Renishaw U1000 spectrometer [4]. 

The use of low-temperature chlorination of Pd(II) compounds in solidified fusions with alkali and alkaline earth metal chlorides (exposed in liquid chlorine for several days at room temperature and for 10-12 hours at 100 °C) made it possible to obtain known hexachloropalladates(IV): M₂[PdCl₆] with M=Cs, Rb, K and new low-stability compounds Na₂[PdCl₆], Li₂[PdCl₆] and Ba[PdCl₆]. The experimental vibration frequencies are within the ranges of 309-323 - n₁(A_1g), 283-295 - n₂(E_g) and 169-176 cm^-1- n₅(F_2g), with a tendency to increase in a series from Cs₂[PdCl₆] to Li₂[PdCl₆] and to Ba[PdCl₆].

Pd(IV) chloride complexes with chlorides of other alkaline earth metals did not form under the conditions of this study.

Low-melting molten mixtures of sulfur chlorides with chlorides of other elements are promising for use in power sources and environmentally friendly processes for obtaining noble and rare metals [1]. Sulfur in compounds with chlorine may have different valences. The higher (IV, for chlorides) valence state of sulfur is unstable already at room temperature, at which SCl₄ dissociates into SCl₂ and Cl₂ even in the presence of the strongest oxidizer - liquid chlorine. The higher valence state of sulfur can be stabilized by the inclusion of sulfur in the composition of outer-sphere cations SCl₃⁺ in compounds of the [SCl₃]_k·[M_mCl_n] type, where M = Al, Sb, Zr, Nb, Fe, Au, Ir  and some other [1-3].

In the present work, a search for new chloride complexes was carried out. Sulfur together with the corresponding element (Be, In, Ga, V, Ti, Sn, Ge), red phosphorus or some chlorides (ZnCl₂, PbCl₂, GaCl₃, AlCl₃, HfCl₄) were kept for several days at 18–150 °C in sealed quartz ampoules with anhydrous liquid or gaseous Cl₂ at elevated pressures (up to 60 atm). Under these conditions, the indicated elements were chlorinated. Some of the chlorides formed (SCl₂, GaCl₃, VCl₄, TiCl₄, SnCl₄, and GeCl₄) are highly soluble in liquid chlorine. 

The formation of ionic compounds of the [SCl₃]_k·[M_mCl_n] type, which have low solubility in liquefied chlorine and therefore crystallize from solutions, was recorded by the appearance of characteristic bands of their SCl₃⁺ complex cations and M_mCl_n^k– anions in the Raman spectra of solid samples [4]. They were recorded using a Renishaw U1000 spectrometer microscope (laser power 25 mW, λ = 514.5 nm) directly through the glass walls of sealed reactionary ampoules with liquid Cl₂. 

Several new and known compounds have been synthesized according to the described method, for example [SCl₃]^.[BeCl₃],  [SCl₃]^.[AlCl₄], [SCl₃]^.[GaCl₄], [SCl₃]^.[Ga₂Cl₇], [SCl₃]^.[InCl₄], [SCl₃]^.[Ti₂Cl₉], [SCl₃]₂^.[SnCl₆], [SCl₃]₂^.[HfCl₆], [SCl₃]^.[Hf₂Cl₉], containing the pyramidal group SCl₃⁺ [4]. It was established, in particular, that sulfur chlorides do not form complex compounds with germanium and vanadium tetrachlorides, since the Raman spectra of solutions at room temperature only show bands of chlorides of these metals, sulfur dichloride and chlorine. Accordingly, crystalline deposits were also not observed. 

The spectroscopic characteristics of all synthesized chloride complexes, in which the highest valence state (IV) of sulfur is stabilized as a result of complex formation, have been systematized.

Aluminum trichloride is one of the strongest complexing agents. In a medium of molten alkali metal chlorides, it forms strong complex anions AlCl₄⁻ (T_d) and Al₂Cl₇⁻ (D_3d or C_2v). In the solid state, binary compounds of only one composition are known: M[AlCl₄] with M = Cs–Li [1–3]. However, compounds of the M[Al₂Cl₇] type, where M is a large organic cation, are well known. The existence of solid complexes M[A₂Г₇], where A denotes Al, Ga; Г denotes halogen, was found in the related systems MBr–AlBr₃ and MCl–GaCl₃ (M = Cs, Rb, K), for which the AlBr₄⁻, Al₂Br₇⁻, GaCl₄⁻, and Ga₂Cl₇⁻ ions are also present in molten mixtures. This prompted us to study further the products of the interaction between AlCl₃ and alkali metal chlorides obtained in two different ways. 

High-purity AlCl₃ was fused with alkali metal chlorides in sealed quartz ampoules and then cooled. A new method was also tested. Aluminum trichloride together with CsCl, RbCl, KCl or NaCl powders were exposed from two to three weeks at 20–25 °C in sealed quartz ampoules in an anhydrous liquefied hydrogen chloride environment, in which AlCl₃ is quite soluble. The ampoules were then opened and HCl evaporated. The solid reaction products were examined under a microscope of a Renishaw U1000 spectrometer (Ar⁺ laser) through the walls of glass reaction ampoules. 

In the Raman spectra of solid samples obtained by both methods, only the bands of the complex anions [AlCl₄]^– (~ 488, 355, 190, 129 cm^–1) of the compounds Cs[AlCl₄], Rb[AlCl₄], K[AlCl₄] and Na[AlCl₄] were recorded. Under the described conditions, complex compounds of the composition M[Al₂Cl₇] did not form, since the bands of the anions [Al₂Cl₇]^– (~ 430, 310, 160, 100 cm^–1 [1, 2]) were absent in the spectra. 

Our data, obtained using a new preparative method and Raman spectroscopy, confirm the existing information on the type of chlorocomplexes and supplement the information on the conditions of their formation during the interaction of components in binary systems AlCl₃–MCl (M is an alkali metal).