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.

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.

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.

The growing demand for sustainable solutions in civil construction, particularly in tropical regions facing a shortage of natural aggregates, has encouraged the use of mining waste as an alternative raw material for the production of artificial aggregates (Cabral et al., 2008). This study investigates the mineralogical interactions between sandy and silty textured soils and a clayey mining sludge, subjected to calcination processes aimed at forming reactive phases.

The methodology involved the formulation of mixtures with varying proportions of clayey sludge, subjected to calcination at temperature ranges defined based on mineralogical and thermal analyses. The samples were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA), following established practices for assessing the reactivity of calcined clays (Pinheiro et al., 2023; Monteiro et al., 2004).

Preliminary results indicated the formation of potentially pozzolanic phases, such as amorphous aluminosilicates, at temperatures above 700 °C, corroborating literature findings on the influence of firing temperature on clay activation (da Silva et al., 2015). The microstructure observed via SEM showed good integration between the constituents of the mixtures after calcination, suggesting the feasibility of combining soils and mining residues for pavement applications.        

The shortage of natural aggregates in tropical regions has driven the development of alternative materials for road infrastructure applications. Among these, artificial aggregates produced through clay calcination have been investigated for their mechanical properties and pozzolanic reactivity potential (Cabral, 2008; da Silva et al., 2015; Friber et al., 2023). This study proposes the production of artificial aggregates from soil–waste mixtures, incorporating a clay-rich mining sludge, aiming to add value to mineral waste and reduce reliance on conventional materials.

The formulations were defined based on preliminary mineralogical analyses using X-ray diffraction (XRD) and scanning electron microscopy (SEM), with the objective of identifying the phases formed and microstructural changes induced by calcination (Monteiro et al., 2004; Pinheiro et al., 2023). The calcination temperature was selected to maximize the formation of amorphous cementitious phases. After calcination, the aggregates were used to mold cylindrical specimens using split molds, which were then subjected to repeated load triaxial tests to determine the resilient modulus a key parameter for assessing the mechanical performance of materials used in pavement base and subbase layers.

Initial results indicated that the artificial aggregate exhibits elastic behavior compatible with that of traditional pavement materials, reinforcing its potential as a technically and environmentally sustainable solution.

Sustainable polymer matrix composites have gained prominence as an eco-friendly alternative to conventional materials, especially those based on biodegradable thermoplastics. Among them, thermoplastic starch (TPS) stands out for its abundance, low cost, and biodegradability, although its mechanical limitations require reinforcement for more demanding applications [1]. In this context, the use of natural fibers emerges as a viable and environmentally responsible solution. Ubim fiber, originating from the Amazon region and extracted from the leaves of the Geonoma baculifera palm, presents itself as a promising reinforcement due to its lightness, strength, and renewability [2,3]. This study investigates the potential of TPS composites reinforced with ubim fibers, aiming to improve mechanical properties and promote materials aligned with the bioeconomy and the valorization of sustainable Amazonian forest resources.

For composite production, commercial corn starch plasticized with 30% glycerol was used. Ubim fibers were sourced from the local market in Belém (PA) and subjected to peeling and milling processes to optimize adhesion to the polymer matrix. The composites were processed using a single-screw extruder in five TPS/fiber ratios (0, 5, 10 and 15 wt.%). Films and test specimens were molded by hot pressing under standardized parameters. The composites were characterized through density, hardness (ASTM D2240), tensile strength (ASTM D638), and impact tests, as well as microstructural analyses by scanning electron microscopy (SEM) and phase evaluation by X-ray diffraction (XRD).

The results showed that the addition of ubim fibers to the thermoplastic starch composites significantly increased tensile strength, demonstrating the effectiveness of natural reinforcement in enhancing the mechanical properties of the polymer matrix. SEM analyses revealed morphological changes, highlighting good interfacial adhesion between the ubim fibers and TPS, which is essential for efficient stress transfer. XRD indicated the presence of semi-crystalline structures influenced by fiber incorporation. These findings confirm that the use of natural fibers, such as ubim, is a promising strategy for developing biodegradable composites with improved performance. Such materials exhibit high potential for sustainable plastic packaging applications, combining mechanical performance with reduced environmental impact.

Natural fiber-reinforced polymer composites have emerged as a sustainable alternative to conventional materials, particularly those utilizing biodegradable thermoplastics. Thermoplastic starch (TPS) is a notable candidate due to its renewability, low cost, and biodegradability; however, its limited mechanical strength necessitates reinforcement for broader applications [1]. Among natural reinforcements, guarumã fiber, derived from the Ischnosiphon koern plant native to the Amazon, offers excellent potential owing to its lightweight nature, mechanical resistance, and ecological appeal [2,3]. This research explores the development of TPS-based composites reinforced with guarumã fibers, aiming to enhance mechanical performance while fostering sustainable material solutions aligned with bioeconomic principles and the valorization of Amazonian biodiversity.

The composites were produced using commercial corn starch plasticized with 30% glycerol, incorporating guarumã fibers processed through peeling and milling to improve interfacial compatibility. Five formulations were prepared via single-screw extrusion, varying fiber content up to 30 wt.%. Standardized hot-pressing techniques were applied to obtain films and specimens, which were subsequently characterized by density, hardness (ASTM D2240), tensile (ASTM D638), and impact testing, alongside SEM and XRD analyses.

The incorporation of guarumã fibers led to notable improvements in tensile strength and modified the composite morphology, as evidenced by SEM, which also revealed satisfactory interfacial adhesion. XRD results indicated semi-crystalline structures influenced by fiber content. These outcomes highlight guarumã fiber as an effective reinforcement for biodegradable TPS composites, supporting their application in sustainable plastic packaging with enhanced mechanical properties and reduced environmental footprint.

In recent years, the use of lignocellulosic natural fibers (LNFs) as reinforcements in composites has increased significantly [1,2]. This trend is driven by environmental concerns and the need to reduce dependence on petroleum reserves [3]. Consequently, there is a growing interest in environmentally friendly materials aligned with the principles of sustainable development. LNFs are considered a promising alternative due to their low cost, renewability, biodegradability, and low specific weight [4,5]. As a result, these fibers have been employed across various technological sectors, particularly in engineering applications. Hybrid composites combining natural and synthetic fibers are being investigated to enhance mechanical performance while reducing weight and cost, balancing the advantages and disadvantages of each constituent. Thus, the present study investigates the influence of different stacking configurations involving aramid fabric and jute fibers, and separately, aramid fabric and sisal fibers, as reinforcement components in composite materials. These composite systems were subjected to ballistic testing using .22 caliber ammunition. Based on the measurements of impact and residual velocities, the absorbed energy and the ballistic limit velocity of the projectile were calculated. Preliminary results indicated that the incorporation of aramid layers into the sisal-based composites enhanced the energy absorption under projectile impact, likely due to modifications in the fracture mechanisms of the composites. In contrast, the jute-based composite did not exhibit significant changes.

Natural lignocellulosic fibers (NLFs) have been widely studied as sustainable alternatives to synthetic fibers, standing out for being renewable, biodegradable, economically viable and for presenting good specific mechanical properties [1-3]. In this context, the present study aimed to evaluate the flexural strength of polyester matrix composites reinforced with short jute and piassava fibers. The fibers were used in their natural form, without surface treatment, cut to a length of 15 mm, and incorporated into the matrix by manual molding (hand lay-up) using silicone molds, without the application of pressure. The specimens were produced with randomly distributed discontinuous fibers, with mass fractions adjusted to the mold volume. The bending tests indicated that the pure polyester composite presented a bending stress of 112.12 ± 17.58 MPa, while the composites reinforced with jute and piassava fibers reached 59.16 ± 8.37 MPa and 62.48 ± 5.89 MPa, respectively, representing reductions of approximately 47% and 44% in relation to the pure matrix. Fractographic analysis of the rupture surfaces revealed that the failure of the composites was predominantly governed by fiber pull-out and low interfacial adhesion between fiber and matrix, also associated with the presence of internal voids resulting from the manual molding process. These factors contributed to the reduction of the mechanical efficiency of the composites, highlighting the need for surface treatments of the fibers and improvements in processing to optimize structural performance.

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% alkali treated sedge fibers. 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%.

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%.

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, one for each condition of 10, 20 and 30 vol% sedge fibers. Each plate has been subjected to 5 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 was performed and the absorbed energy of all specimens were evaluated.

Niobium is a strategic material for Brazil, a country that holds the largest global reserves of this element. However, its sintering presents significant challenges, mainly due to the high reactivity of the metal, which promotes oxide formation and hinders consolidation. This study aimed to investigate the feasibility of cold sintering of niobium at different temperatures, seeking to minimize oxidative effects and enable new technological applications. The material used was supplied by CBMM (Companhia Brasileira de Metalurgia e Mineração), and experiments were conducted at temperatures of 125 °C, 150 °C, and 175 °C. To promote the formation of a transient liquid phase, niobium powders were mixed with 10 wt.% of absolute ethanol. Sintering was performed under a simultaneous pressure of 300 MPa, with a holding time of 30 minutes at each specified temperature. After processing, the samples were characterized through density measurements, scanning electron microscopy (SEM), and X-ray diffraction (XRD) analyses. The results indicated that cold sintering of niobium was effective even at the relatively low temperatures employed. XRD analysis revealed only minor peaks corresponding to the NbO phase, indicating a low incidence of oxidation during the process. These findings demonstrate the feasibility of cold sintering pure niobium, paving the way for the development of new components and applications, with advantages in reducing processing temperatures and preserving metallic properties. The use of cold sintering techniques thus represents a promising alternative for processing highly reactive metals such as niobium.

Given the growing demand for sustainable solutions in pavement engineering, the use of agricultural waste as soil reinforcement material has emerged as a technically and environmentally viable alternative. Among these residues, banana fiber shows high potential due to its low cost and wide availability in tropical regions. This study investigates the feasibility of using banana fiber as a reinforcement material for pavement subgrades by adapting the pull-out test methodology traditionally used in cementitious matrices. Small-scale specimens were developed with controlled fiber embedment lengths in a compacted soil matrix to assess the mechanical interaction at the fiber–soil interface. Physicochemical analyses, including X-ray diffraction (XRD) and scanning electron microscopy (SEM), were conducted on untreated and chemically treated fibers to evaluate surface modifications and determine the effectiveness of the treatments in enhancing interfacial bonding. The adapted pull-out tests enabled the quantification of interfacial shear strength and provided insights into the failure mechanisms governing fiber mobilization. Results indicate that banana fiber can enhance soil resistance to pull-out forces when an optimal fiber content is used and surface treatment is applied, improving bonding at the fiber–soil interface. These findings are consistent with previous studies that highlight the positive effects of natural fibers on the mechanical behavior of clayey soils (Finu John et al., 2018; Bawadi et al., 2020; Guimarães et al., 2024). The proposed testing approach contributes to the development of more sustainable and practical soil reinforcement techniques for pavement infrastructure.

Hydroxyapatite is a mineral composed of hydrated calcium phosphates. As it is the main mineral component of human bone, it is widely used in the fabrication of alloplasts for bone tissue regeneration treatments, known as scaffolds [1][2]. Scaffolds serve as a cellular matrix for the development of new bone tissue; therefore, they must have a porous structure, adequate mechanical strength, and be composed of biocompatible material [3]. To meet these criteria, additive manufacturing techniques, such as fused deposition modeling (FDM) 3D printing, are employed as an alternative for controlling structure and mechanical strength. However, if the printer operates by extruding thermoplastic material, it is necessary to synthesize polylactic acid (PLA) filament loaded with hydroxyapatite to incorporate the bioceramic into the scaffold [4]. Hydroxyapatite can be obtained through various synthesis routes or from synthetic or natural resources. In this study, hydroxyapatite was extracted from the byproduct of the Arapaima gigas fish and used to produce filaments for 3D printing. The scales were subjected to chemical treatment with NaOH and thermal treatment with sintering at 600 ºC in an oxygen-rich environment. The characterizations performed were TG, DTG, DSC, FTIR, and SEM. After these characterizations, the sample was subjected to a thermal treatment at 700 ºC, followed by the same analyses. The filaments were produced by extrusion and were loaded with 1% w/w of hydroxyapatite extracted from the scales of Arapaima gigas. The filaments were subjected to tensile testing according to ASTM C1557-20. Thermal analysis revealed that the sample sintered at 600 ºC did not undergo complete removal of organic volatiles, with mass losses of 3.6% in the range of 75 ºC – 100 ºC due to residual water; 1.1% in the range of 280 ºC – 700 ºC due to collagen residue; and 2.93% between 600 ºC – 742 ºC due to the loss of structural water from hydroxyapatite. The sample sintered at 700 ºC showed little mass loss, with a total loss of 1.68%, and a maximum degradation temperature at 619 ºC, related to the structural water present in hydroxyapatite. In both samples, FTIR analyses revealed the characteristic bands of PO₄³⁻ anions at 1091 cm⁻¹; 1022–1018 cm⁻¹; 602–563 cm⁻¹, and the presence of CO₃²⁻ ions at 1450 cm⁻¹, 1411 cm⁻¹, and 871 cm⁻¹. Scanning electron microscopy (SEM) micrographs showed that the samples sintered at 600 ºC presented agglomerates of inorganic particulates without a defined morphology. Sintering at 700 ºC promoted the growth of particulates larger than 200 µm with polygonal shapes, tending toward hexagonal formation.

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.

Hydroxyapatite (HA), an inorganic ceramic biomaterial, presents itself as a promising and active bone substitute in this scenario, as it presents characteristics similar to the mineral apatite, found in human bones and teeth. Thus, the aim of this work is to synthesize and characterize synthetic hydroxyapatite, using chicken eggshell residue as a source of calcium. The analysis of the egg shell was carried out using X-ray Diffraction (XRD) and Fourier Transform Spectroscopy (FTIR) techniques. The characterization of the hydroxyapatite powder was performed by X-Ray Diffraction (XRD), Fourier Transform Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). The results for eggshell revealed the presence of absorption bands of hydroxyl groups and carbonates and phases corresponding to calcium hydroxide and calcium oxide. The HA sample showed vibration bands of hydroxyl, carbonate and phosphate groups, and hydroxyapatite and calcium oxide phases. SEM analysis indicated irregular morphological formations with dimensional variations. The EDS semiquantitatively revealed percentages of Oxygen, Phosphorus and Calcium. According to the results, type B hydroxyapatite was obtained using eggshell residue, which was also a good source of calcium in this study.

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.

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].

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 promotingenvironmental 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 (9.4E-05±5.3E-05) tend to decrease strongly after treatment with 720.0 KJ/m² (3.5E-05±6.4E-06) and more at 10460 KJ/m² (2.8E-06±7.3E-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.      

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.

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.

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.

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 R410A, R32, R452B and R466A. Furthermore, with 10 kW of waste heat, the coefficient of performance (COP) of engine driven heat pumps were improved by 1.7% and 2.3% using R32 and R452B compared to the COP using R410A. On the other hand, the COP using R466A was decreased by 3.2%.

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.

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. 

Present study determines conditions for titanium magnetite concentrate processing with fairly complete titanium conversion to the slag and iron and vanadium separation in the hot metal. It is quite difficult to process titanium magnetite concentrate in the blast furnaces due to low fusibility of charge and direct electrical melting causes process instability. Present work is devoted to development of concentrate double stage smelting process with little soda additions, including solid-phase recovery at the first stage using specific coke as a reductant, avoiding concentrate oxidation and including its preliminary thermooxidation.

Mix charge made of concentrate, soda and specific coke was granulated in water, dried at 130°C, pellets were placed in graphite crucible, and later on it was set up in the centre of the furnace in alundum crucible. Temperature regimen was fixed under following parameters: temperature at the first stage is 1250^оС; soaking time is 50 min; temperature at the second stage is 1500 - 1650^оС; soaking time is 35 min. It is established that little soda additive (estimated 3-4% Na₂O) to the charge of titanium magnetite concentrate recovery smelting performs as coagulant during briquetting, as catalyst in course of solid-phase recovery, as inhibitor of DRI briquettes secondary oxidation as slag thinner during smelting. In course of titanium magnetite concentrate reduction smelting process soda interacts to SiO₂, Al₂O₃, TiO₂ oxides forming sodium silicates and titanates.

Double-stage technology of titanium magnetite concentrate reduction smelting both with soda addition and without oxidation and preliminary iron oxidation of titanium magnetite concentrates till hematite was developed. Optimal process parameters were determined. Following parameters were obtained: hot metal yield was ~55% out of concentrate weight, slag yield – 23,3-25,8%, carbon-free slag content, wt. %: Fe=1,0-1,6; TiO₂=62,7-61,9. TiO₂ yield in the slag is 89,6-94,1%. Hot metal contains, %: 5,51 С; 0,36 Ti; 0,35 Mn; 0,04 Si; 0,23 V.  Vanadium yield in iron was 53,0%.

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 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).