Abstract: Original compositions of electrical ceramics have been developed and tested using marshallite and wollastonite as raw materials. An analysis of the equilibrium states of the created porcelain masses at different temperatures in the Na2O-Al2O3-SiO2 and K2O-Al2O3-SiO2 systems has been carried out. The amount of melt in these systems has been calculated based on the equilibrium flux curves. The characteristics of the sintering process of the masses have been identified. A scheme for the formation of the very important secondary needle-like mullite during thermal treatment of the mass has been outlined, and the temperature intervals for the formation of intermediate compounds have been found. X-ray diffraction patterns and micrographs of the synthesized samples have been decoded, and the phase composition and microstructure of the samples have been analyzed. The effective influence of the dispersion of the silica component on the mineral formation processes during the sintering of porcelain masses on model samples of compositions of feldspar with quartz sand and marshallite has been noted. The optimal firing temperatures for full mineral formation and structure formation have been determined, as well as the physical-mechanical and dielectric properties of the obtained ceramic samples.

Abstract: The research context of this study focuses on optimizing the use of C60 steel in industrial applications where durability and fatigue resistance are critical. C60 steel is known for its combination of strength and hardness, but it is essential to evaluate how thermal and thermo-chemical treatments affect its performance under fatigue condi-tions. The objectives of the study include: Investigating the crack formation process and the early stages of fatigue in C60 steel, comparing the effects of thermal treatments (hardening and tempering) with those of thermo-chemical treatments (oxidation) on the steel's micro-structure, evaluating the performance of C60 steel under fatigue conditions based on the applied treatments, providing insights that can help optimize the use of this steel in in-dustries requiring high resistance and durability. The methodology of the study included: fatigue tests performed on a four-point bending machine to determine the exact time of microcracking. The C60 steel samples were pro-cessed according to SR ISO 1099:2017 "Fatigue testing. Axial load method". To ensure consistency and comparability of results, the samples were made from the same material charge and machined under the same conditions. A total of 26 specimens were used, 13 for each type of treatment: thermal treatment by hardening and tempering and thermo-chemical treatment by oxidation. Due to the different mechanical properties obtained from the thermal and thermo-chemical treatment processes, the sets of specimens were tested at varying forces. In these tests, frequency changes were monitored to evaluate the behaviour of the materials under repeated stresses. Finally, the frequency changes were correlated with the number of cycles to identify when microcracks appeared and their evolution. The main results from this study show: significant differences between the lifetimes of thermally and thermochemically treated samples and the time of microcracks appear-ance in the material.

Abstract: This study aimed to develop a mathematical model describing the thermal dissipation kinetics during the post-processing cooling phase of flat-pressed wood–polymer composites (FPWPC). The model elucidates the relationship between the composite's cooling time and the spatiotemporal temperature distribution across its thickness, as influenced by wood particle content, initial surface temperature, and bulk density. Analysis of the thermal profile in the core layer revealed three distinct phases: an initial temperature increase, a thermal peak, and a convective cooling phase. The results demonstrate that both the wood particle content and the initial surface temperature significantly affect the thermal dissipation rate. Higher initial surface temperatures (e.g., 200 °C) led to an initially accelerated cooling rate, followed by a deceleration phase. Composites with higher wood particle content (60%) exhibited slower cooling rates, which is attributed to the lower thermal conductivity of wood relative to the thermoplastic polymer matrix, resulting in greater thermal retention. Bulk density was also found to play a critical role in thermal management by influencing the composite’s specific heat capacity, thermal conductivity, and convective heat transfer efficiency. The proposed mathematical model offers potential for optimizing FPWPC manufacturing processes by enabling more precise control over cooling dynamics.

Abstract: Silicon–lithium clusters are promising candidates for hydrogen storage due to their lightweight composition, high gravimetric capacities, and favorable non-covalent binding characteristics. In this study, we employ density functional theory (DFT), global optimization (AUTOMATON and Kick-MEP), and Born–Oppenheimer molecular dynamics (BOMD) simulations to evaluate the structural stability and hydrogen storage performance of key Li–Si systems. Potential energy surface (PES) exploration reveals that the true global minima of Li6Si6 and Li10Si10 differ markedly from previously proposed aromatic analogs based on benzene and naphthalene motifs. Instead, these clusters adopt compact geometries composed of one or two Si4 (Td) units and a Si2 dimer, all stabilized by surrounding Li atoms. Motivated by the recurrence of the Si4–Td motif—previously shown to exhibit three-dimensional σ-aromaticity—we explore oligomers of Li4Si4, confirming additive H2 uptake across dimer, trimer, and tetramer assemblies. Within the series of Si–Li clusters evaluated the Li12Si5 sandwich complex, featuring a σ-aromatic Si5 ring encapsulated by two Li6 units, achieves the highest hydrogen capacity, adsorbing 34 H2 molecules with a gravimetric density of 23.45 wt%. Its enhanced performance arises from the high density of accessible Li⁺ adsorption sites and the electronic stabilization afforded by delocalized σ-bonding. BOMD simulations at 300 and 400 K confirm dynamic stability and reversible storage behavior, while analysis of the interaction regions confirms that hydrogen adsorption proceeds via weak, dispersion-driven physisorption. These findings clarify structure-property relationships in Si–Li clusters and provide a basis for designing modular, lightweight, and thermally stable hydrogen storage materials.

Abstract: We investigate the thermal conductivity of graphene Moiré superlattices formed by twisting bilayer graphene (TBG) at small angles, employing approach-to-equilibrium molecular dynamics and lattice dynamics calculations based on the Boltzmann Transport Equation. Our simulations reveal a non-monotonic dependence of the thermal conductivity on the twisting angle, with a local minimum near the first magic angle (θ∼1.1∘). This behavior is attributed to the evolution of local stacking configurations—AA, AB, and saddle-point (SP)—across the Moiré superlattice, which strongly affect phonon transport. A detailed analysis of phonon mean free paths and mode-resolved thermal conductivity shows that AA stacking suppresses thermal transport while, AB and SP stackings exhibit enhanced conductivity owing to more efficient low-frequency phonon transport. Furthermore, we establish a direct correlation between the thermal conductivity of twisted structures and the relative abundance of stacking domains within the Moiré supercell. Our results demonstrate that even very small changes in twisting angle (<2∘) can lead to thermal conductivity variations of over 30%, emphasizing the high tunability of thermal transport in TBG.

Abstract: With the global shift toward greener transportation, the automotive industry is rapidly adopting lightweight materials to enhance fuel efficiency and reduce greenhouse gas emissions. Weight reduction not only improves recyclability but also enhances vehicle performance, including driving dynamics, braking efficiency, and crash safety. A key enabler of this transition is the integration of lightweight, high-performance materials such as advanced polymer composites as sustainable alternatives to conventional automotive components. As the future of mobility increasingly leans toward electric vehicles (EVs), the demand for eco-friendly materials has never been greater. This review provides an extensive analysis of natural fibers and fillers derived from agro/food waste—such as banana, coir, corncob, date palm, pineapple leaf fiber (PALF), and sugar bagasse—as potential reinforcements for biocomposites in EV interior applications. It explores the extraction processes, as well as the physical, chemical, mechanical, and thermal characterization of these fibers and their reinforced composites. Additionally, the article presents a comprehensive review of automotive interior requirements, evolving market trends, and key considerations for adopting biocomposites in vehicle interiors. Finally, this review highlights the future research scope and challenges associated with integrating agriculture waste-based biocomposites into electric vehicle applications, paving the way for a more sustainable and environmentally responsible automotive industry.

Abstract: We combined atomistic simulations and experiments to assess the photocatalytic potential of the rutile phase of TiO2 combined with phenyl-modified carbon nitride (PhCN). Density Functional Tight Binding calculations are employed to investigate the electronic properties, band alignment, and adsorption behavior of TiO2/PhCN heterostructures. The results show a favorable adhesion and band alignment indicating strong potential for photocatalytic applications. XRD measurements, optical characterization, and photocatalytic degradation experiments provide insight on the beneficial integration of the organic and inorganic components, identifying the PhCN/rutile heterostructure as a promising green photocatalyst.

Abstract: The present work, optimization of ceramic-based composite WC (Co, Ni) welds by laser cladding through the response surface methodology based on finite element analysis. The heat distribution and temperature field of laser melted WC(Co,Ni) ceramic coatings were simulated using ANSYS software which allowed the computation of the distribution of residual stresses. The results show that the isotherms in the simulation of the temperature field are elliptical in shape, and the isotherms in front of the moving heat source are dense with a larger temperature gradient, and the isotherms behind the heat source are sparse with a smaller temperature gradient. In addition, the observed microstructural evolution shows that the domains of the melting zone of WC(Co,Ni) are mainly composed of unmelted carbides, dendritic, rod-like, leaf-like, net-like, and smaller agglomerates of carbides in which the W content of unmelted carbides exceeds more than 80%, and the C content is about 1.5-3.0%, while the grey areas are composed of WC, Co, and Ni compounds. Based on the regression model, a quadratic model was successfully constructed. A three-dimensional profile model of the residual stress behavior was further explored. The predicted values of RSM-based FEA model for residual stress are very close to the experimental data, which proves the effectiveness of model in improving the residual stress by laser cladding .

Abstract: Oxide dispersion strengthened (ODS) steels are among the most promising candidate structural materials for fusion and Generation-IV (Gen-IV) fission reactors, but the ductility of ODS steels is inferior to its strength properties. Therefore, we investigate void nucleation, considered as the first step of ductile damage in metal, using molecular dynamics simulations. Given that the materials are subjected to extremely complex stress states within the reactor, we present the void nucleation process of 1-4 nm Y2O3 nanoclusters in bcc iron during uniaxial, biaxial, and triaxial tensile deformation. We find that the void nucleation process is divided into two stages depending on whether the dislocations are emitted. Void nucleation occurs at smaller strain in biaxial and triaxial tensile deformation in comparation to uniaxial tensile deformation. Increasing the size of clusters results in a smaller strain for void nucleation. The influence of 1nm clusters on the process of void nucleation is slight, and the void nucleation process of 1nm cluster cases is similar to that of pure iron. In addition, void nucleation is affected by both stress and strain concentration around the clusters, and the voids grow firstly in the areas of high stress triaxiality.

Abstract: Ferroelectric liquid crystals (FLCs) are key materials for high-speed electro-optical applications, yet achieving optimal properties over a broad temperature range down below room temperature remains a challenge. This study presents a novel series of systematically designed FLC mixtures, incorporating achiral, monochiral, and bichiral components to optimize the mesomorphic stability, electro-optical response, and physicochemical properties. The strategic doping by chiral components up to a 0.2 weight fraction extends the temperature range of the ferroelectric phase while lowering the melting temperature. Notably, mixtures containing two chiral centers exhibit shorter helical pitches, while increasing chirality enhances the tilt angle of the director and spontaneous polarization. However, in the complex chiral mixture (CchM), spontaneous polarization decreases due to opposing vector contributions. Switching time analysis reveals that achiral–bichiral systems exhibit the fastest response, while CchM demonstrates only intermediary behaviour, caused by its high rotational viscosity. Among all formulations, mixtures containing bichiral compounds display the most favorable balance of functional properties for deformed helix ferroelectric liquid crystal (DHFLC) applications. One such composition achieves the lowest melting temperature reported for DHFLC-compatible FLCs, enabling operation at sub-zero temperatures. These findings pave the way for next-generation electro-optical devices with enhanced performance and appropriate environmental stability.

Abstract: The kinetics of the Br-atom reactions with C2H4S and ClNO have been studied as a function of temperature at a total pressure of 2 Torr of Helium using a discharge-flow system combined with mass spectrometry: Br + C2H4S  SBr +C2H4 (1) and Br + ClNO  BrCl +NO (2). The rate constant of reaction (1) was determined at T = 340 - 920 K by absolute measurements under pseudo–first order conditions, either by monitoring the kinetics of Br-atom or C2H4S consumption in excess of C2H4S or of Br atoms, respectively, and by using a relative rate method: k1 = (6.6 ± 0.7)10-11 exp(-(2946 ± 60)/T) cm3molecule-1s-1 (where the uncertainties represent the precision at the 2σ level, the estimated total uncertainty on k1 being 15% at all temperatures). The rate coefficient of reaction (2), determined either from the kinetics of the formation of the reaction product, BrCl, or from the decays of Br-atom in an excess of ClNO, showed a non-Arrhenius behavior, being practically independent of temperature below 400 K and increasing significantly at temperatures above 500 K. The measured rate constant is well reproduced by a sum of two exponential functions: k2 = 1.2×10-11 exp(-19/T) + 8.0×10-11 exp(-1734/T) cm3 molecule-1 s-1 (with an estimated overall temperature-independent uncertainty of 15 %) at T = 225 – 960 K.

Abstract: Liquid fuels obtained from CO₂ and green hydrogen (i.e. e-fuels) are powerful tools for decarbonization of the economy. Improvements provided by Process Intensification in the existing conventional reactors aim toward a decrease in energy consumption, higher yield and more compact and sure processes. This review describes the advances in the production of methanol, dimethyl ether and hydrocarbons by Fischer-Tropsch using different tools of Process Intensification, mainly membrane reactors, sorption enhanced reactors and structured reactors. Due to the environmental interest, the review on methanol and dimethyl ether synthesis is mainly devoted to systems based in a feed with CO₂+H₂, while for Fischer-Tropsch the use of syngas (CO+H₂) is also considered. Both mathematical models and experimental results are discussed. Achievements in the improvement of catalytic reactor performance are described.

Abstract: Aim: Resin-based restorative materials have been the material of choice for direct dental restorations. However, the selection process remains multifaceted, while dentists often face the challenge of choosing the most suitable materials that not only meet clinical requirements but also align with their preferences, practice settings, and individual characteristics. This pilot study aimed to evaluate professional characteristics, knowledge levels, and selection criteria for resin-based restorative materials among dental clinicians at the National and Kapodistrian University of Athens.Materials and Methods: A cross-sectional questionnaire-based study was conducted between October 2023 and January 2025. A structured instrument comprising 23 closed-ended and 5 open-ended questions was administered to 87 dental clinicians. The questionnaire collected data on demographics, professional background, knowledge of resin materials, material selection preferences for anterior and posterior restorations, and influencing factors including economic and environmental considerations. Statistical analysis was performed using IBM SPSS version 29. Descriptive statistics, Spearman correlation coefficients, and Mann-Whitney tests were utilized to assess relationships between professional characteristics (e.g., clinical experience, age, postgraduate education) and material selection decisions.Results: Findings revealed that clinicians with over five years of experience demonstrated significantly higher knowledge of material composition (r = .230, p < .05) and shelf life (r = .223, p < .05). Less experienced practitioners prioritized anatomical and esthetic features, whereas experienced dentists favored specialized resin materials for anterior restorations. For posterior restorations, the majority (75.9%) selected packable composite resin for its superior mechanical properties and wear resistance. Additionally, procurement responsibility was associated with increased familiarity with industry specifications (r = .254, p < .05). Environmental considerations were noted as secondary factors, with notable gender-based differences observed.Conclusion: The study highlights that clinical experience and procurement involvement significantly influence the selection of restorative materials. While less experienced dentists focus on essential esthetic criteria, experienced clinicians incorporate a wider range of technical and regulatory factors. These insights report on the need for targeted educational interventions to bridge existing knowledge gaps and promote evidence-based decision-making in restorative dentistry.

Abstract: Oxidative stress and its relation on the onset of several chronic diseases has been in-creasingly studied and highlighted in recent years. This fact has been concurrent with increased reports on the antioxidant properties of various phytochemicals derived from fruits, vegetables, herbs, or seaweed, which can be accessible by intake or obtained following chemical extraction from these sources. These phytochemicals are majorly the result of each plant’s secondary metabolism, out of which the main chemical groups include structural polysaccharides, unsaturated fatty acids (PUFAs), pigments (chlo-rophylls, carotenoids, anthocyanins) and chief among them, phenolic compounds. The structural features of each group allow them to act at different sites, levels, by different molecular mechanisms and display diverse effectiveness as chemo-preventive agents for various diseases. Beyond their antioxidant properties, these phytochemicals have been described to exert a plethora of chemo-preventive and therapeutic effects, in-cluding anti-inflammatory, antidiabetic, anti-obesity or neuroprotective, acting through various mechanisms and paths involved. This knowledge has led to the development of various nutraceuticals enriched in antioxidant phytochemicals to be used as functional ingredients in foods, or for their periodic separated intake, whether as enriched extracts, or isolated compounds of high efficacy. Overall, phytochemical antioxidants are attrac-tive biomolecules to be used as nutraceuticals of relevant chemo-preventive and ther-apeutic properties on the onset of various diseases related to antioxidant stress.

Abstract: Recently, graphene oxide (GO) has been largely investigated as potential adsorbent towards dyes. However, the major obstacle to its fully employment is linked to its nat-ural powder consistence, which greatly complexifies the operations of recovery and reuse. With the aim to overcome this issue, the present work reports the design of GO modified carbon nanotubes buckypapers (BPs), in which the main component, GO, is entirely entrapped in the BP grid generated by CNTs, for the double purpose of a) in-creasing adsorption performance of GO-BPs and b) ensure a fast process of regenera-tion and reuse. Adsorption experiments were performed towards several dyes: Acid Blue 29 (AB29), Crystal Violet (CV), Eosyn Y (EY), Malachite Green (MG), and Rhoda-mine B (RB) (Ci = 50 ppm, pH=6). Results demonstrated that adsorption is strictly de-pendent on the charge occurring both on GO-BP and dye surfaces, observing great ad-sorption capacities towards MG (493.44 mg g-1), RB (467.35 mg g-1) and CV (374.53 mg g-1), due to the best coupling of dye cationic form with negative GO-BP surface. Con-firmed also by kinetic constants, where higher values are those of MG, RB and CV, the following trend in GO-BP adsorption performance has been derived: MG ≈ RB > CV > AB29 > EY.

Abstract: The thermal behavior of a three-layer structure – glass/ITO/TAPC/CBP/BPhen – in an OLED system was investigated using in situ spectroscopic ellipsometry during controlled heating from room temperature to 120°C over 60 minutes, simulating the ageing process and analysing degradation kinetics. Variations in Ψ and Δ spectra were observed across the entire 0.7-5.9 eV spectral range, with five distinct anomalies, particularly in the UV region. An anomaly at approximately 66°C is attributed to the glass transition temperature Tg of BPhen, while another two at around 82°C and at around 112°C correspond to the first-order phase transition of TAPC, and Tg of CBP, respectively. The origins of the remaining anomalies at 91°C and 112°C are explored in this study, with a focus on interphase layer formation and morphological changes that emerges during heating. These findings provide insights into the stability of OLEDs under thermal stress.

Abstract: This review article provides an in-depth analysis of recent advancements in the fabrication, structural characterization, and magnetic properties of Heusler alloy glass-coated microwires, focusing on Co₂FeSi alloys. These microwires exhibit unique thermal stability, high Curie temperatures, and tunable magnetic properties, making them suitable for a wide range of applications in spintronics, magnetic sensing, and biomedical engineering. The review emphasizes the influence of geometric parameters, annealing conditions, and compositional variations on the microstructure and magnetic behavior of these materials. Detailed discussions on the Taylor-Ulitovsky fabrication technique, X-ray diffraction (XRD) analysis, and scanning electron microscopy (SEM) provide insights into the structural properties of the microwires. The magnetic properties, including room-temperature behavior, temperature dependence, and the effects of annealing, are thoroughly examined. The potential applications of these microwires in advanced spintronic devices, magnetic sensors, and biomedical technologies are explored. The review concludes with future research directions, highlighting the potential for further advancements in the field of Heusler alloy microwires.

Abstract: Partial reduction of transition metal oxides via defect engineering is a promising strategy to enhance their electronic and photocatalytic properties. In this study, we systematically explore the mechanochemical reduction of Nb2O5 using LiBH4 and NaBH4 as reducing agents. Electron paramagnetic resonance (EPR) spectroscopy confirms a successful partial reduction of the oxide, as seen by the presence of unpaired electrons. Interestingly, larger hydride concentrations do not necessarily enable a higher degree of reduction as large amounts of the boron hydrides act as a buffer material and thus hinder the effective transfer of mechanical energy. Powder X-ray diffraction (PXRD) and 7Li solid-state NMR spectroscopy indicate the intercalation of Li+ into the Nb2O5 lattice. Raman spectroscopy further reveals the increased structural disorder, while optical measurements show a decreased band gap compared to pristine Nb2O5. The partially reduced samples show significantly enhanced photocatalytic performance for methylene blue degradation relative to the unmodified oxides.

Abstract: Organic dyes are pollutants that threaten aquatic life and human health. These dyes are used in various industries; therefore, recent research focuses on the problem of their removal from wastewater. This aim of this study is to examine the clay/Gum Arabic nanocomposite (CG/NC) as an adsorbent to adsorb methylene blue (MB) and crystal violet (CV) dyes from synthetic wastewater. The CG/NC was characterized using Fourier Transform Infrared spectroscopy (FTIR), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Brunaure-Emmett-Teller (BET). The effect of parameters that may influence the efficiency of removing MB and CV dyes was studied: (dosage of CG/NC, contact time, pH values, initial concentration, and temperature), and the optimal conditions for removal were determined. Furthermore, an Artificial Neural Network (ANN) model was adopted in this study. The results designated that the adsorption behavior adhered to the Langmuir model and conformed to pseudo-second-order kinetics. The results also indicated that the removal efficiency reached 99%, and qmax reached 66.7 mg/g and 52.9 mg/g for MB and CV, respectively. Results also proved that CG/NC can be reused up to four times with high efficiency. The ANN models have proven effective in predicting the process of the removal, with the low Mean Square Error (MSE = 1.824 and 1.001) and high Correlation Coefficient (R2 = 0.945 and 0.952) for the MB and CV dyes, respectively.

Abstract: The intramolecular Diels-Alder (IMDA) reactions of four substituted deca-1,3,9-trienes and one N-methyleneocta-5,7-dien-1-aminium with different electrophilic/nucleophilic activations have been studied within the Molecular Electron Density Theory (MEDT) and compared to their intermolecular processes. The topology analysis of the electron density and DFT-based reactivity indices reveal that substitution does not modify neither the electronic structure nor the reactivity of the reagents relative to those involved in the intermolecular processes. The analysis of the relative energies establishes that the accelerations found in the polar IMDA reactions follow the same trend as those found in the intermolecular processes. The geometries and the electronic structures of the five transition state structures involved in the IMDA reactions are highly similar to those found in the intermolecular processes. A relative interacting atomic energy (RIAE) analysis of Diels-Alder and IMDA reactions allows for the establishment of the substituent effects on the activation energies. Although the nucleophilic frameworks are destabilized, the electrophilic frameworks are further stabilized, resulting in a reduction in the activation energies. The present MEDT study demonstrates the remarkable electronic and energetic similarity between the intermolecular and intramolecular Diels-Alder reactions. Only the lower, unfavorable activation entropy associated with the latter renders it 104 times faster than the former.