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Article
Chemistry and Materials Science
Materials Science and Technology

Rezky Anggakusuma,

Gemilang Lara Utama,

Dadan Sumiarsa,

Permata Apriliani Dewi Muslimah,

Ali Asgar

Abstract: A nuclear facility undergoes decommissioning when it is no longer in use. Hazardous sites get decontaminated during decommissioning to protect workers, communities, and the environment. One decontamination technique involves peel-off gels made from polyvinyl alcohol (PVA). Cassava starch is a natural polymer. Cassava starch is a natural ingredient that is readily available, non-toxic, and environmentally friendly. Cassava starch, which is abundant in Indonesia in the form of processed flour, was used in this study as a peel-off gel material for metal ion decontamination. Cassava starch was synthesized and became denser and tighter upon the addition of glycerol. The starch-glycerol gel interacted with material add-ins like glass, metal plates, aluminum, and ceramics. A starch-glycerol gel can form a 24-27°C film for 24 hours. The analysis revealed that starch-glycerol gel could create a film and bind metal ions. The type of metal and the contaminated substance had a substantial impact on the metal ion binding outcomes. Extracting all metal ions from the contaminated material media was possible based on the concentration measurements. Therefore, starch-glycerol gel is a suitable alternative for cleaning surfaces and reducing the presence of heavy metal-contaminated materials. By directly testing the gel's application on radioactively contaminated objects, it is possible to gain a deeper understanding of how effectively starch-glycerol gel reduces surface contamination from radioactive compounds.
Article
Chemistry and Materials Science
Materials Science and Technology

A. Márquez-Herrera

Abstract: This work presents a compact, easy-to-manufacture, low-cost, and friendly mechanism capable of producing samples encapsulated in a polymeric material of the same quality as those obtained from commercial equipment. The device is easy to manufacture, has efficient maintenance, is low-cost, and can also be used in any commercially available hydraulic press. It was designed considering factors such as the requirements of the system, the geometry of the sample, and the dissipation of heat. The House of Quality (HoQ), a key tool within the Quality Function Deployment (QFD) methodology, was utilized in the design of a this device to ensure it met both customer needs and technical requirements effectively. The HoQ matrix was then used to ensure that the operation of the device was safe, which included a prioritized list of customer requirements, their relative importance, and their correlation with technical specifications, as well as benchmarks comparing the device’s performance against competitors. It affirms that the designed devices are capable of mounting a metallography specimen, allowing easy handling and conditioning of the surface of interest. It also adapts to any commercial hydraulic press, making it a versatile and accessible solution.
Article
Chemistry and Materials Science
Inorganic and Nuclear Chemistry

Ian R. Butler,

Peter Neil Horton,

Simon J. Coles,

William Clegg,

Kevin M. Fortune,

Michael G. B. Drew,

Kamil Suwada

Abstract: The reaction of the bulky ligand 1,2-bis-(di-tert-butylphosphinomethyl)benzene,1 with [Ni(DME)Cl2], 3, DME = 1,2-dimethoxyethane, at room temperature over extended periods, affords the new blue Zwitterionic complex [(1,2-C6H4-CH2PtBu2-2-C6H4-CH2P(H)tBu2)2NiCl3], 4, which contains a phosphonium group and an anionic nickel trichloride. This complex decomposes in alcohols such as methanol and the solution turn yellow. A discussion of the possible mechanism leading to the observed product is presented. Key to this is identification of the source of the phosphonium proton, which we speculated to arise from trace water in the initial nickel complex. To prove that trace water was present in [Ni(DME)Cl2] a sample of this precursor was reacted under similar condition with anhydrous DMF alone. In addition to the known complex [Ni(DMF)6)]2+[NiCl4]2-, 5, we identified the trans-diaqua complex [Ni(Cl)2(H2O)2(DMF)2], 6, which proved the presence of trace water. Interestingly in dimethylformamide [(1,2-C6H4-CH2PtBu2-2-C6H4-CH2P(H)tBu2)2NiCl3] exhibits thermochromic properties: an ambient temperature pale blue solution changes colour reversibly to yellow on cooling. This behaviour is specific to DMF and is related to the solvato-chromic behaviour exhibited by related DMF nickel complexes. A discussion of the NMR spectra of compound 4 in a range of solvents is presented. The structures of the previously prepared molybdenum complex, [1,2-(C6H4-CH2PtBu2)2Mo(CO)4] and the bis-(phosphine sulfide) of the ligand, [1,2-(C6H4-H2P(S)tBu2)2], 5, are described for structural comparative purposes.
Article
Chemistry and Materials Science
Inorganic and Nuclear Chemistry

Elena S. Zhitova,

Andrey A. Zolotarev,

Rezeda M. Sheveleva,

Roman Yu. Shendrik,

Frank C. Hawthorne,

Anton A. Nuzhdaev,

Natalia S. Vlasenko,

Ekaterina V. Kaneva,

Victor N. Yakovenchuk

Abstract: The crystal-chemical behavior of two layered titanosilicate minerals with porous crystal structures: kupletskite, K2NaMn72+Ti2(Si4O12)2O2(OH)4F, and kupletskite-(Cs), Cs2NaMn72+Ti2(Si4O12)2O2(OH)4F, was investigated under high-temperature conditions using single-crystal and powder X-ray diffraction; infrared, optical absorption and Mössbauer spectroscopy and electron-microprobe analysis. Both minerals undergo topotactic transformation to dehydroxylated and oxidized high-temperature (HT) modifications at temperature above 500 °C while maintaining the basic bond topology of the astrophyllite structure-type. The high-temperature structures show contraction of the unit-cell parameters similar to that of Fe2+-dominant astrophyllite, indicating that Mn2+ oxidizes along with Fe2+. The oxidation of Mn2+ is confirmed by the increase of the Mn3+-related absorption (in optical spectra) that is inversely correlated with the intensity of O‒H bands in the infrared spectra. The Fe,Mn-oxidation is also evident by the contraction of the M(2), M(3) and M(4)O6 octahedra. The M(1)‒O bond length increases slightly, indicating a preference for mono- and divalent cations to occupy the M(1) site in the heated structure; this may be due to site-selective oxidation and/or migration of unoxidized cations (as previously shown for lobanovite) to this site. The role of extra framework A-site cations (K, Cs) in thermal expansion of these minerals is discussed.
Article
Chemistry and Materials Science
Food Chemistry

Nicola Culeddu,

Archimede Rotondo,

Federico Nastasi,

Giovanni Bartolomeo,

Pierfrancesco Deiana,

Mario Santona,

Petros A. Tarantilis,

Giuseppe Pellicane,

Giovanna Loredana La Torre

Abstract: The paper describes the application of four different Nuclear Magnetic Resonance (NMR) experiments on the same olive oil sample to extract, in our best extent, the oil chemical composition reasonably featured by the specific genotype (cultivar) and de-tailed environmental conditions (terroir). The acquisition of three different 1H-NMR experiments was set to extract the combined information about a) main components, b) less represented components, and c) very tiny represented but key-ruling secoridoid species, respectively. To enclose the main chemical information within a unique da-taset, a single 1H NMR spectrum was reconstructed by customized crops from the three mentioned experiments (RICC-NMR). The robust setup of four experiments, namely I) standard 1H{13C}, II) multiple pre-saturated 1H{13C}; III) 1H selective excita-tion at 9.25 ppm, and IV) 13C{1H} acquisition, allowed to process the 1H-RICC-NMR and the 13C-NMR profiles so that any sample chemometrics was chemo-metrically characterized with an enhanced precision over several key minor species important for the remarkable analytical conclusions. In this paper, some specific EVOOs from Sicily and Sardinia are compared and discussed.
Article
Chemistry and Materials Science
Food Chemistry

Adriana Gámbaro,

Marcelo Miraballes,

Nahir Urruzola,

Maximiliano Kniazev,

Cecilia Dauber,

Melissa Romero,

Adriana Maite Fernández-Fernández,

Alejandra Medrano,

Estela Santos,

Ignacio Vieitez

Abstract: Bee pollen is widely recognized for its health benefits, with its nutritional and bioactive properties varying by botanical origin. This study analyzed twelve bee pollen samples collected from six different apiaries in Uruguay during two seasons (spring and autumn) to determine their botanical composition; nutritional profile (protein, lipids, carbohydrates, dietary fiber, ash, and fatty acid profile); bioactive compound content (total phenols, vitamin C, tocopherols, and carotenoids); antioxidant activity (ABTS and ORAC); color, and its ability to inhibit enzymes involved in carbohydrate and fat digestion. Among the samples collected in autumn, three were monofloral (one from Casuarina and two from Eucalyptus). The spring samples, however, were all multifloral, except for one monofloral Rapeseed sample. Monofloral samples had higher protein, fiber, tocopherol, and total phenol content, along with higher ABTS and ORAC values, but lower carotenoid levels. In contrast, autumn samples had lower protein and lipid content but higher fiber and vitamin C levels. The predominant fatty acids were palmitic, linolenic, linoleic, and oleic acids, with most samples showing a higher proportion of polyunsaturated fatty acids (40.7–57.9%). Compared to other food matrices, the α-glucosidase inhibition values of Uruguayan bee pollen are similar to those found in raw citrus pomace. This is the first report on bee pollen's ability to inhibit pancreatic lipase in relation to its anti-obesity properties. Uruguayan bee pollen shows significant potential for combating metabolic syndrome, obesity, and type 2 diabetes.
Article
Chemistry and Materials Science
Metals, Alloys and Metallurgy

Mingqi Shi,

Ruiduo Chen,

Chengsong Zhang,

Zhenzhao Xu,

Hanke Hu,

Xiaolong Zhou,

Guodong Cui

Abstract: A novel Ti-N-O composite was prepared by powder nitriding/ oxynitriding combined with Spark-plasma Sintering(SPS)method. The effects of N/O on the microstructure and mechanical properties of Ti-N-O alloy were systematically studied. The results showed that the addition of N/O elements significantly improved the yield strength and the hardness of commercially pure titanium(cp-Ti). And the O element played a leading role in regulating the microstructure and morphology of Ti-N-O alloy. With the addition of O element, the microstructure showed equiaxed structure, and the characterization showed that this region is O-enriched region, and a small amount of nano-TiO2 particles appeared in the alloy, which together led to the change of the microstructure. At the same time, more large-angle grain boundaries were generated in the Ti-N-O alloy.
Article
Chemistry and Materials Science
Materials Science and Technology

Sergio Patricio Moraga-Bustos,

Yessica Rivas,

Ricardo Villalobos-Carvajal,

Marcela Jarpa-Parra

Abstract: (1) Grape stalks and aquafaba (Aq) from chickpeas are promising agricultural by-products with potential applications in the development of sustainable biomaterials due to their ligno-cellulose and protein content. (2) This study aimed to evaluate the incorporation of Aq and cinnamon essential oil (CEO) into grape stalk-based materials to enhance me-chanical properties and prevent microbial contamination. Four formulations were pre-pared, and their mechanical, physicochemical, and antifungal properties were assessed. (3) The incorporation of CEO significantly reduced water absorption, while formulations containing Aq exhibited the highest mechanical resistance, likely due to synergistic interactions between proteins and polysaccharides that modified the microstructure of cellulose fibers. Scanning electron microscopy (SEM) images supported these findings. Additionally, CEO-treated samples showed resistance to fungal contamination by Botrytis cinerea, unlike untreated samples, which were colonized by the fungus. Biodegradability tests indicated slower degradation for CEO-treated samples (10 weeks) compared to those without CEO (5-7 weeks). (4) The results suggest that the combination of Aq and CEO creates a promising material for use in food packaging, though further research is needed to fully understand the reinforcement mechanisms.
Article
Chemistry and Materials Science
Paper, Wood and Textiles

Gustavo E. Rodríguez,

Rosilei Garcia,

Alain Cloutier

Abstract: Acid hydrolysis can be more efficient than water hydrolysis, particularly in breaking down cured adhesives found in waste panels within a shorter reaction time that could benefit large-scale industrial processes. This study evaluates the effects of various acid hydrolysis conditions on the thermal, physical, and chemical properties of recycled particles intended for particleboard production. Particleboards were recycled using oxalic acid and ammonium chloride at different concentrations and reaction times at 122 °C. The thermal stability of the particles was determined by thermogravimetric analysis. Particle size distribution, particle morphology, nitrogen content, pH and acid/base buffer capacity were analyzed. The effect of the recycled particles on the urea-formaldehyde (UF) curing was assessed using differential scanning calorimetry and the gel time method. The recycled particles exhibited a higher thermal degradation beyond 200 °C, indicating their thermal stability for manufacturing new panels. The acid treatments did not damage the anatomical structure of the particles. The nitrogen content of recycled particles decreased by up to 90% when oxalic acid was used, compared to raw board particles. Recycled particles had a lower pH, a lower acid buffer capacity, and a higher base buffer capacity than those of raw board particles. The recycled particles did not significantly affect the peak polymerization temperature of the UF adhesive. However, some treatments affected the gel time of the adhesive. The results indicate that particleboards can be effectively recycled through acid hydrolysis, mainly with oxalic acid, which gives better results than hydrolysis using water alone. Oxalic acid showed increased selectivity in eliminating the cured UF adhesive, resulting in recycled particles suitable for manufacturing new panels.
Article
Chemistry and Materials Science
Organic Chemistry

Jyotsna Pandit

Abstract: The growing concerns of rapid population expansion, depletion of fossil fuels, climate change, and escalating environmental degradation pose significant challenges to the sustainable development of modern society. In response, the scientific community has increasingly focused on the development of green and sustainable chemical methodologies. Within this context, metal-free synthetic strategies have gained prominence due to their ability to eliminate the dependence on toxic, heavy, and non-renewable transition metals. These methodologies offer a cleaner alternative for the chemo-selective transformation of inexpensive starting materials into high-value products. Recent advances have led to the development of metal-free oxidation, reduction, hydrogenation, and condensation reactions that align with the principles of green chemistry. However, the replacement of transition-metal-catalyzed carbon–carbon (C–C) bond-forming reactions remains a critical challenge. Innovative approaches involving the nucleophilic addition of organometallic species to carbonyl or imine compounds, as well as radical-mediated C–C couplings in the presence of aryl halides, are paving the way for sustainable alternatives. This abstract highlights the recent progress and ongoing efforts toward achieving environmentally benign synthetic methodologies, emphasizing the pivotal role of metal-free reactions in shaping a greener chemical future.
Article
Chemistry and Materials Science
Ceramics and Composites

Mukhtar Yendibaevich Kurbanbayev,

Begen Omarovich Yesimov,

Vladimir Ivanovich Vereschagin,

Tatyana Amanovna Adyrbayeva,

Yelena Sergeevna Dubinina

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.
Article
Chemistry and Materials Science
Materials Science and Technology

Tudorache (Nistor) Iuliana,

Cornel Samoila,

Doru Ursutiu

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.
Article
Chemistry and Materials Science
Paper, Wood and Textiles

Pavlo Lyutyy,

Pavlo Bekhta,

Ján Sedliačik

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.
Article
Chemistry and Materials Science
Theoretical Chemistry

Williams García-Argote,

Erika Medel,

Diego Inostroza,

Alejandro Vásquez-Espinal,

José Solar-Encinas,

Luis Leyva-Parra,

Lina Ruiz,

Osvaldo Yañez,

William Tiznado

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.
Article
Chemistry and Materials Science
Nanotechnology

Lorenzo Manunza,

Riccardo Dettori,

Antonio Cappai,

Claudio Melis

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.
Review
Chemistry and Materials Science
Ceramics and Composites

Abir Saha,

Nicola M Pugno,

Lakshminath Kundanati

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.
Article
Chemistry and Materials Science
Polymers and Plastics

Riccardo Dettori,

Sahar Aghapour Ghourichay,

Stefania Porcu,

Claudio Melis,

Luciano Colombo,

Pier Carlo Ricci

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.
Article
Chemistry and Materials Science
Surfaces, Coatings and Films

Dezheng Wu,

Canyu Ding,

Ming-Der Jean

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 .
Article
Chemistry and Materials Science
Metals, Alloys and Metallurgy

Zhenyu Wei,

Yongjie Sun,

Yeshang Hu,

Lei Peng,

Jingyi Shi,

Yifan Shi,

Shangming Chen,

Yiyi Ma

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.
Article
Chemistry and Materials Science
Materials Science and Technology

Michał Czerwiński,

Mateusz Filipow,

Klaudia Łuczak,

Dorota Węgłowska

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.

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