Search Results (50)

Using molecular dynamics (MDs) simulations with Materials Studio 8.0 software, we systematically investigated the adsorption and aggregation behaviors of silicon, tin, and copper atoms on the surface of (7,7) single-walled carbon nanotubes (SWCNTs). Silicon, tin, and copper were selected due to their distinct bonding characteristics—covalent (Si), semi-metallic (Sn), and metallic (Cu)—and their relevance in potential composite interface applications such as energy storage, thermal management, and electronics. The results indicate that silicon atoms form multi-layered concentric shells; however, the rigidity of their covalent bonds makes the resulting structures susceptible to disruption by local density fluctuations. Tin atoms form a limited number of stable concentric shells benefiting from the flexibility of their semi-metallic bonds. In contrast, copper atoms rapidly aggregate into disordered clusters due to their high diffusivity and metallic bonding. Within the confined geometry of the carbon nanotubes, all three types of atoms exhibit a tendency toward spiral growth, but their regularity depends on the properties of their chemical bonds, leading to distinct spiral features. These findings are further supported by linear density and radial distribution function (RDF) analyses. Full article

Germanium/tin-containing silicon oxide [SiO–(GeO/SnO)] nanoclusters have been designed with different Si/Ge/Sn particles and characterized as electrodes for magnesium-ion batteries (MIBs) due to forming MgBe [SiO–GeO], MgBe [SiO–SnO], MgCa [SiO–GeO], and MgCa [SiO–SnO] complexes. In this work, alkaline earth metals of magnesium (Mg), beryllium (Be), and calcium (Ca) have been studied in hybrid Mg-, Be-, and Ca-ion batteries. An expanded investigation on H capture by MgBe [SiO–(GeO/SnO)] or MgCa [SiO–(GeO/SnO)] complexes was probed using computational approaches due to density state analysis of charge density differences (CDD), total density of states (TDOS), and electron localization function (ELF) for hydrogenated hybrid clusters of MgBe [SiO–GeO], MgBe [SiO–SnO], MgCa [SiO–GeO], and MgCa [SiO–SnO]. Replacing Si by Ge/Sn content can increase battery capacity through MgBe [SiO–GeO], MgBe [SiO–SnO], MgCa [SiO–GeO], and MgCa [SiO–SnO] nanoclusters for hydrogen adsorption processes and could improve the rate performances by enhancing electrical conductivity. A small portion of Mg, Be, or Ca entering the Si–Ge or Si–Sn layer to replace the alkaline earth metal sites could improve the structural stability of the electrode material at high multiplicity, thereby improving the capacity retention rate. In fact, the MgBe [SiO–GeO] remarks a small enhancement in charge transfer before and after hydrogen adsorption, confirming the good structural stability. In addition, [SiO–(GeO/SnO)] anode material could augment the capacity owing to higher surface capacitive impacts. Full article

In this paper, we investigated fractal cluster structures of colloidal particles in tin dioxide films obtained from lyophilic film-forming systems SnCl₄/EtOH/NH₄OH with different pH levels. It was revealed that at the ratio Sn > Cl₂ > O₂, N₂ = 0, and pH = 1.42, the growth of cross-shaped and flower-shaped structures of various sizes from several μm to tens of μm is observed. At the ratio Cl₂ > Sn > O₂ > N₂ and pH = 1.44, triangular and hexagonal structures are observed, the sizes of which are on the order of several tens of micrometers. The growth of hexagonal structures is probably affected by the presence of nitrogen in the film, according to the elemental analysis data. At the ratio Sn > Cl₂ > O₂ > N₂ and solution pH of 1.49, the growth of hexagonal and cross-shaped structures is observed, whereas flower-shaped structures are not observed. Hierarchical flower-like and cross-shaped structures are fractal. The shape of microstructures is directly related to the shape of the elementary cells of SnO₂ and NH₄Cl. A direct dependence of the formation of hierarchical structures on the volume of ammonium hydroxide additive was found. This allows for controlling the shape and size of the synthesized structures when changing the ratio of the initial precursors and influencing the final physicochemical characteristics of the obtained samples. Full article

A detailed characterization of metal clusters bound at the surface of crystalline metal oxide supports is crucial for identifying their structure–property relationships relevant to practical applications. Theoretical investigations based on first-principles calculations have proven to be helpful in characterizing supported metal clusters. In this work, the adsorption of an Sn dimer on the regular and defective (100) surfaces of MgO crystal was studied by means of density functional theory (DFT) calculations. The investigated defects included ${\mathrm{F}}_{\mathrm{s}}^0$, ${\mathrm{F}}_{\mathrm{s}}^{+}$, and ${\mathrm{F}}_{\mathrm{s}}^{2+}$ oxygen vacancies on MgO(100). From the results of the calculations, it is clear that the adsorption of Sn₂ at the ${\mathrm{F}}_{\mathrm{s}}^0$ and ${\mathrm{F}}_{\mathrm{s}}^{+}$ centers is stronger than that occurring on the defect-free MgO(100) surface. While the triplet spin multiplicity of a free Sn dimer tends to be preserved upon its adsorption at the ${\mathrm{F}}_{\mathrm{s}}^{2+}$ center, spin quenching is favored for the dimer adsorbed at the regular O²⁻ and defective ${\mathrm{F}}_{\mathrm{s}}^0$ and ${\mathrm{F}}_{\mathrm{s}}^{+}$ centers. The topological analysis of the electron density for the adsorbed dimer was carried out within the quantum theory of atoms in molecules (QTAIM). The calculated values of QTAIM parameters for the Sn-Sn bond of the adsorbed dimer do not differ radically from the corresponding values for the dimer in the gas phase. Full article

This study investigates the electrochemical conversion of methane to methanol using fuel-cell-type reactors with palladium- and lanthanum-based catalysts supported on antimony-doped tin oxide (ATO). The combination of these elements demonstrated promising characteristics for selective methanol production. Transmission electron microscopy (TEM) analysis revealed the impact of lanthanum addition on palladium nanoparticles, influencing size distribution and clusters. Polarization curves and power density plots highlighted the Pd₅₀La₅₀/ATO catalyst, indicating an optimal palladium/lanthanum ratio for methanol optimization. FTIR analysis confirmed the presence of methanol in the reaction products, while the methanol production rate showcased the superior performance of the Pd₅₀La₅₀/ATO catalyst compared to other compositions. The synergistic effects between lanthanum’s water activation capability and the carbophilic nature of PdO emerged as crucial factors for the catalyst’s success. Full article

Background/Objectives: Although physical activity and balanced diet may increase peripheral brain-derived neurotrophic factor (BDNF) concentration, little is known about whether these factors modify BDNF content in physically active individuals and whether the serum fatty acid (FA) profile is related. This study aimed to evaluate quality of diet, identify specific dietary patterns and assess their influence on BDNF and FA levels in serum. It is hypothesized that there is a correlation between diet quality and the concentrations of BDNF and FA in the serum of physically active male individuals. Methods: Physically active young adult male students at Jozef Pilsudski University of Physical Education in Warsaw (Poland) were enrolled. Dietary patterns were identified with cluster analysis and linear discriminant analysis (LDA) based on responses to a validated food frequency questionnaire, KomPAN^® version 1.1. Results: Consumption of beverages, vegetables, milk, wholemeal bread/rolls, fruit and vegetable juices, butter, tinned vegetables and fruits were significant in the LDA model, in which three clusters were distinguished. Cluster 1 was characterized by more frequent consumption of wholemeal bread/rolls, milk, fruits, vegetables, fruit and vegetable juices and sweetened hot beverages and by significantly greater values for the pro-healthy diet index (p < 0.0001) and diet quality index (p < 0.0001) compared to Clusters 2 and 3. The diet of Cluster 2 was of the worst quality, as indicated by the higher values of the not-healthy diet index. Cluster 1 had the tendency for the highest BDNF levels (of the best quality of diet), and a tendency for decreased BDNF concentration with an increased physical activity level was observed. Conclusions: Physical activity, diet quality and BDNF level depend, correlate and interact with each other to provide both optimal physical and mental health. Full article

Titanium nitride and vanadium nitride–carbon-based composite systems, TiN/C and VN/C, were prepared using a new synthesis method based on the thermal decomposition of titanyl tetraphenyl porphyrin (TiOTPP) and vanadyl tetraphenyl porphyrin (VOTPP), respectively. The structure of the TiN/C and VN/C composite materials, as well as their precursors, were characterized using Fourier Transformed Infrared Spectroscopy, X-Ray diffraction (XRD), X-Ray energy dispersive (EDS) and X-Ray photoelectron spectroscopy (XPS). Morphologies of the TiN/C and VN/C composites were examined by means of scanning electron (SEM) and transmission electron (TEM) microscopy. The synthesis of the non-metalated tetraphenyl porphyrin, the titanium, and vanadium tetraphenyl porphyrin complexes were confirmed using FTIR. The thermal decomposition of the titanium and vanadium tetraphenyl porphyrin complexes produced the respective metal nitride encapsulated in a carbon matrix; this was confirmed by XRD, SEM, TEM, and XPS. From the XRD patterns, it was determined that the TiN and VN were presented in cubic form with expected space group FM-3M and 1:1 (metal:N) stoichiometry. The XPS results confirmed the presence of both TiN and VN in the carbon matrix without metal carbides. The SEM and TEM results showed that both TiN and VN nanoparticles formed small clusters throughout the carbon matrix; the EDS results revealed a uniform composition. The synthesis method presented in this work is novel and serves as an effective means to produce TiN and VN NPs with good structure and morphology embedded in a carbon matrix. Full article

This work presents the synthesis and characterization of materials that contain Sn metal clusters formed by ligands of trimesic acid (Sn-BTC) or 5-sulfobenzene-1,3-dicarboxylic acid (Sn-H₃-5-SIP). These catalysts were used to convert levulinic acid with ethanol to produce ethyl levulinate under mild reaction conditions. The characterization results confirmed that Sn is mainly present in the cassiterite crystalline phase with a tetragonal rutile structure in octahedral and tetrahedral coordination in the materials. The assembly of trimesic acid (a hard base) with metal species (Sn) results in the formation of acid and thermally stable metal–organic frameworks. The use of 5-sulfobenzene-1,3-dicarboxylic acid instead of trimesic acid in the synthesis incorporates sulfonic groups in the material, enhancing the total acidity of the Sn-H₃-5-SIP catalyst compared to the Sn-BTC material. The Sn-H₃-5-SIP catalyst exhibited the highest catalytic activity when converting levulinic acid with ethanol, resulting in a turnover frequency (TOF) of 0.0495 s⁻¹, which is a 50% increase compared to the TOF of the Sn-BTC catalyst (0.0329 s⁻¹). This result can be attributed to its higher concentration of acid sites (2.23 ± 0.05 mmol H⁺/g_cat) and specific area (139 m²/g). Thus, materials containing tin metal clusters and sulfonic groups are promising materials that could be used as catalysts for synthesizing ethyl levulinate under mild reaction conditions. Full article

The development of a suitable catalytic system for methane pyrolysis reactions requires a detailed investigation of the activation energy of C-H bonds on catalysts, as well as their stability against sintering and coke formation. In this work, both single-metal Ni atoms and small clusters of Ni atoms deposited on titanium nitride (TiN) plasmonic nanoparticles were characterized for the C-H bond activation of a methane pyrolysis reaction using ab initio spin-polarized density functional theory (DFT) calculations. The present work shows the complete reaction pathway, including energy barriers for C-H bond activation and dehydrogenated fragments, during the methane pyrolysis reaction on catalytic systems. Interestingly, the C-H bond activation barriers were low for both Ni single-atom and Ni-clusters, showing the energy barriers of ~1.10 eV and ~0.88 eV, respectively. Additionally, single-atom Ni-TiN showed weaker binding to adsorbates, and a net endothermic reaction pathway indicated that the single-atom Ni-TiN was expected to resist coke formation on its surface. However, these Ni single-atom catalysts can sinter, aggregate into a small cluster, and form a coke layer from the highly exothermic reaction pathway that the cluster takes despite the facile reaction pathway. Full article

Nine glazed porcelain artifacts bearing the coat of arms of France, from King Louis XV tableware orders, were analysed at the laboratory or in their conservation secure room. Based on the experience acquired in the study of 18th century European and Chinese porcelain using mobile XRF (pXRF) and Raman microspectroscopy, a comparison of the impurities in the paste (Y, Rb, and Sr), the elements associated with cobalt in the blue overglaze (Bi, Mn, Zn, and As) and those present in the tin yellow and Naples yellow pigments (Sn, Sb, and Zn) highlights the use of different raw materials for some of these objects. Differences regarding the Ag content in the gold decorations also provide information. Raman identification of the different types of yellow pigment confirms the categorization. The results obtained on the Louis XV tableware are compared to those of “Chine de commande”, attributed to the same places and periods of production or recognized copies. The clustering of the quantitative comparison pXRF signals of the abovementioned elements and a consideration of the Raman parameters of the yellow pigments appear to be effective tools for object categorization to confirm or refute questions about the authenticity of objects. Full article

Extreme ultraviolet lithography (EUVL) is a leading technology in semiconductor manufacturing, enabling the creation of high-resolution patterns essential for advanced microelectronics. This review highlights recent progress in inorganic metal-oxide-based photoresists, with a focus on their applications in EUVL. The unique properties of zinc-based, tin–oxygen, and IVB group inorganic photoresists are examined, showcasing their enhanced chemical reactivity and precise patterning capabilities. Key advancements include the development of zinc oxide and tin oxide nanoparticles, which demonstrate significant improvements in photon absorption and solubility under extreme ultraviolet exposure. Additionally, the review delves into the photochemical reactions of tin–oxygen clusters and the influence of various ligands on film density and cross-linking. The findings suggest that these inorganic photoresists not only improve photolithographic performance but also hold potential for broader applications, such as pyroelectric infrared sensors and 3D printing. Future research directions are outlined, including the optimization of process parameters, the exploration of new ligand and metal combinations, and the evaluation of the environmental benefits of inorganic photoresists over traditional organic ones. These advancements are poised to further enhance the resolution and patterning capabilities required for next-generation semiconductor devices. Full article

Aluminum and A356 alloy foam castings are produced using a melt-foaming method. Prior to foaming, the melt is modified with nano-sized particles (SiC, TiN, or Al₂O₃). The nano-sized particles are mixed with micro-sized Al particles, which are ultrasonically treated and hot-extruded. Thus, the so-called “modifying nano-composition” is obtained. The resulting compositions are introduced into the melt of the Al foam at the following mass concentrations of nanoparticles: SiC: 0.038 wt. %; TiN: 0.045 wt. %; and Al₂O₃: 0.046 wt. %. For the A356 foam, we use the following concentrations: SiC: 0.039 wt. %; TiN: 0.052 wt. %; and Al₂O₃: 0.086 wt. %. The macrostructure of the foam castings is investigated by CT scanning and 3D analysis. The pore size distributions and accumulative fraction dependencies are determined for all samples. The microstructure of the foam castings is investigated by SEM-EDS analysis. The results confirmed the presence of individual nano-sized particles, as well as clusters of particles in foam walls. The conducted compression tests show a significant increase in the plateau stress (up to 237%) of the modified aluminum foam castings compared to non-modified castings. However, a similar effect of the nano-compositions on A356 alloy foam castings is not observed. The obtained results show that the above-indicated concentrations of nanoparticles can positively influence the mechanical properties of aluminum foam castings. The novelty of the current study is two-fold: (1) such low concentrations of added nanoparticles have never been used before to alter Al foam’s properties, and (2) an original method of introducing the nanoparticles into the melt is applied in the form of nano-compositions. Full article

This study introduces a novel methodology for the dynamic extraction of information on cotton growth in terms of height utilizing the DJI Zenmuse L1 LiDAR sensor mounted onto a DJI Matrice 300 RTK Unmanned Aerial Vehicle (UAV), aimed at enhancing the precision and efficiency of growth monitoring within the realm of precision agriculture. Employing the Progressive TIN Densification (PTD) and Cloth Simulation Filter (CSF) algorithms, combined with Kriging interpolation, we generated Canopy Height Models (CHMs) to extract the cotton heights at two key agricultural sites: Zengcheng and Tumxuk. Our analysis reveals that the PTD algorithm significantly outperforms the CSF method in terms of accuracy, with its R² values indicating a superior model fit for height extraction across different growth stages (Zengcheng: 0.71, Tumxuk: 0.82). Through meticulous data processing and cluster analysis, this study not only identifies the most effective algorithm for accurate height extraction but also provides detailed insights into the dynamic growth patterns of cotton varieties across different geographical regions. The findings highlight the critical role of UAV remote sensing in enabling large-scale, high-precision monitoring of crop growth, which is essential for the optimization of agricultural practices such as precision fertilization and irrigation. Furthermore, the study demonstrates the potential of UAV technology to select superior cotton varieties by analyzing their growth dynamics, offering valuable guidance for cotton breeding and cultivation. Full article

This work focuses on the synthesis of titanium nitride–carbon (TiN–carbon) composites by the thermal decomposition of a titanyl phthalocyanine (TiN(TD)) precursor into TiN. The synthesis of TiN was also performed using the sol-gel method (TiN(SG)) of an alkoxide/urea. The structure and morphology of the TiN–carbon and its precursors were characterized by XRD, FTIR, SEM, TEM, EDS, and XPS. The FTIR results confirmed the presence of the titanium phthalocyanine (TiOPC) complex, while the XRD data corroborated the decomposition of TiOPC into TiN. The resultant TiN exhibited a cubic structure with the FM3-M lattice, aligning with the crystal system of the synthesized TiN via the alkoxide route. The XPS results indicated that the particles synthesized from the thermal decomposition of TiOPC resulted in the formation of TiN–carbon composites. The TiN particles were present as clusters of small spherical particles within the carbon matrix, displaying a porous sponge-like morphology. The proposed thermal decomposition method resulted in the formation of metal nitride composites with high carbon content, which were used as anodes for Li-ion half cells. The TiN–carbon composite anode showed a good specific capacity after 100 cycles at a current density of 100 mAg⁻¹. Full article

Planar tetracoordinate silicon, germanium, tin, and lead (ptSi/Ge/Sn/Pb) species are scarce and exotic. Here, we report a series of penta-atomic ptSi/Ge/Sn/Pb XB₂Bi₂ (X = Si, Ge, Sn, Pb) clusters with 20 valence electrons (VEs). Ternary XB₂Bi₂ (X = Si, Ge, Sn, Pb) clusters possess beautiful fan-shaped structures, with a Bi–B–B–Bi chain surrounding the central X core. The unbiased density functional theory (DFT) searches and high-level CCSD(T) calculations reveal that these ptSi/Ge/Sn/Pb species are the global minima on their potential energy surfaces. Born–Oppenheimer molecular dynamics (BOMD) simulations indicate that XB₂Bi₂ (X = Si, Ge, Sn, Pb) clusters are robust. Bonding analyses indicate that 20 VEs are perfect for the ptX XB₂Bi₂ (X = Si, Ge, Sn, Pb): two lone pairs of Bi atoms; one 5c–2e π, and three σ bonds (two Bi–X 2c–2e and one B–X–B 3c–2e bonds) between the ligands and X atom; three 2c–2e σ bonds and one delocalized 4c–2e π bond between the ligands. The ptSi/Ge/Sn/Pb XB₂Bi₂ (X = Si, Ge, Sn, Pb) clusters possess 2π/2σ double aromaticity, according to the (4n + 2) Hückel rule. Full article