Morphology Composition Research Articles

Preparation of C@CuNi/TiO2 with a local surface plasmon resonance for photocatalytic degradation of organic dyes and antibiotics under visible light irradiation

A composite photocatalyst with carbon-coated CuNi nanoparticles-loaded TiO2 nanotubes (C@CuNi/TiO2) was synthesized via a microwave hydrothermal alkali stripping method combined with subsequent in-situ carbothermal reduction. The structure, morphology, and surface chemical composition were investigated using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The findings demonstrate that the microwave hydrothermal alkali peeling enables the formation of a three-dimensional C@CuNi/TiO2 composite structure. The results of transient photocurrent response (i-t) and electrochemical impedance spectroscopy under visible light demonstrate that C@CuNi/TiO2 exhibits a reduced rate of electron-hole recombination and lower surface resistance compared to C@TiO2, C@Cu/TiO2, and C@Ni/TiO2. After a two-hour exposure to visible light, the composite photocatalyst C@CuNi/TiO2, featuring a molar ratio of 2 % CuNi nanoparticles to TiO2 nanotubes, exhibited remarkable degradation activity towards organic dyes (Rhodamine B (RhB), Methylene Blue (MB), Methyl Orange (MO)), as well as antibiotics (tetracycline (TC) and levofloxacin (LVFX)). After 5 cycles of photocatalytic reaction, the photodegradation activity of RhB remained above 79 %. It is indicated that CuNi nanoparticles effectively trap and enrich photoelectrons through the photoexcitation of TiO2 nanotubes. Additionally, the local surface plasmonic resonance (LSPR) effect of CuNi nanoparticles reduces the recombination rate of photogenerated electron/hole and the electron transport resistance in the composite photocatalyst, thereby enhancing its overall photocatalytic activity.

Experimental investigation of fired clay bricks for gamma radiation shielding

In this study, the focus was on evaluating how the physical and structural attributes of red clay bricks influence their ability to shield γ-rays. The red clay brick samples' density (ρ, g/cm3) was measured using the MH-300A density meter. The minerals present in the selected clay were identified through the application of X-ray diffraction. Moreover, the material's morphology and chemical composition were studied using scanning electron microscopy. By increasing the pressure rate (PR) from 7.61 to 114.22 MPa, the density of the synthetic clay bricks was increased from 1.50 to 1.69 g/cm3. Subsequently, the gamma-ray shielding effectiveness of the clay bricks produced was investigated through experiments utilizing a NaI (Tl) detector with exposure to various gamma sources. The experimental data illustrated a rise in the linear attenuation coefficient (μ) of the proposed clay bricks, progressing from 1.352 ± 0.040 to 1.559 ± 0.068 cm−1, from 0.111 ± 0.003 to 0.123 ± 0.005 cm−1 and from 0.087 ± 0.002 to 0.099 ± 0.003 cm−1 at γ-ray energies of 0.033, 0.662, and 1.332 MeV, respectively. The rise in μ resulted in a reduction in the half-value thickness (Δ0.5), lead equivalent thickness (Δeq) and transmission factor (TF), in the synthetic bricks. Additionally, samples with increased thickness exhibited enhanced effectiveness in shielding gamma radiation, making them suitable for various applications requiring radiation protection. Moreover, the detection of pressure rate's influence on the physical and shielding characteristics of clay bricks was observed at specific gamma energies. (0.033, 0.662 and 1.332 MeV).

The role of predation and pesticides in shaping phytoplankton dynamics in a short microcosms experiment.

Aquatic organisms are subject to various forcing factors that affect their structure, some of which are natural, while others result from human activities, both having variable effects. This study aimed to determine the importance of a natural stressor (zooplankton) and an herbicide (atrazine) on phytoplankton density and morphological composition in a microcosm experiment. A natural phytoplankton assemblage was exposed to two zooplankton predators: a copepod (Argyrodiaptomus falcifer) and a cladoceran (Ceriodaphnia dubia), and to atrazine (27 µg L-1), in three combinations of factors (zooplankton treatments (Z), atrazine treatment (A), the combination of both (ZA)) plus a Control. The experiment lasted 48 h. Samples were taken at the beginning and the end of the experiment, and relevant limnological variables, including inorganic nutrient concentrations, were considered. Results indicated differences in phytoplankton densities when treatments were compared with Control. In this respect, Chlorophyceae, Euglenophyceae, and Bacillariophyceae exhibited more changes than other phytoplankton classes. Chlorophyceae densities tended to be higher in the Control than in the treatments; the combination of zooplankton and atrazine favored Euglenophyceae, while atrazine favored Bacillariophyceae densities. Regarding morphological groups, unicellular and small colonies (<35 µm), showed differences between the Control and particularly with Z treatment, colonial-cenobia forms were negatively affected by atrazine and silica forms were favored by both stressors combined. It is concluded that interactions among natural and anthropogenic stressors could be complex, influencing factors such as phytoplankton taxonomical affinities, morphological groups, and the nature of the stressor applied.

Impact of damaged housing on the performance of field aged composite High Voltage Insulators

Composite High Voltage Insulators (HVIs) are lightweight, inexpensive, and offer superior pollution performance. Consequently, they have replaced ceramic HVIs in highly contaminating coastal and desert regions. However, they are prone to degradation in harsh environments. In this paper, we assess the performance of three identical field-aged 380 kV composite HVIs with a service life of twelve years near the western coastal region of the Kingdom of Saudi Arabia. The housing of all the HVIs showed widespread damage, including cracks on sheds and shanks, partially or fully broken sheds, and rusted end fittings. The changes in morphology and material composition were assessed through SEM and EDX. An electrical breakdown test in the presence of steam fog revealed lowered withstand strength. Electric field distribution, a key design criterion for an HVI, was studied using the Finite Element Model (FEM) of the insulator bearing physical defects. The results reveal localized electric field intensification caused by all types of defects, notably smaller and narrower ones. Our findings indicate that while physical defects in HVIs can cause localized electric field intensification, they are not a significant concern unless accompanied by severe hydrophobicity loss, compromised electrical withstand levels, or extensive erosion exposing the fiberglass rod and jeopardizing mechanical stability.

The Analysis of the Effect of Mischmetal Addition on the Formation of Non-Metallic Inclusions in Liquid Steel

The study focuses on the effect of rare earth elements (REM) in mischmetal on the morphology and chemical composition of non-metallic inclusions in pre-oxidised steel. Calculations were carried out using the WYK_STAL computer program according to two calculation models, considering/ignoring the sulphur partition coefficient at the liquid steel-liquid slag interfacial boundary. It was found that the chemical composition of the resulting precipitates is a consequence of the order in which deoxidising additives were admixed. Simulations confirmed the presence of Ce oxides and sulphides. This was also confirmed by the analysis of samples taken from the steel ingot after laboratory melting. Non-metallic inclusions Ce2O3 and CeS, and the complex of precipitates: La2O3-Ce2O3 was also identified in the steel. Introduction of mischmetal in the final stage refining is the most effective method. Therefore, the oxygen content is reduced below 0.001%, and the sulphfur content can be reduced to 0.004%.

Mosaic of biological soil crusts and vascular plants contributes to the spatial heterogeneity of key soil properties at different successional stages of restored inland sand dunes

Abstract Background and aims Inland sand dunes constitute Natura 2000 habitat that has become a priority to ensure biodiversity protection and habitat heterogeneity at the landscape scale; however, without proper management, spontaneous succession leads to overgrowing of trees and thus to habitat degradation. Understanding succession processes, relationships between biotic and abiotic components, and their changes over time after restoration, is the key to proper planning of future restoration activities. The aim was to determine the changes of biological soil crust (BSC), vascular plants and physicochemical parameters of BSC, below-crust, rhizosphere, and bare substrate types at different stages of succession in inland dunes of the Błędowska Desert (Poland). We also analyzed the interplay between these factors to further understand the mechanism of BSC development and recognize driving factors causing changes in the soil environment. Results Our results showed that BSCs contributed to increased organic C, total N, nutrients in soil, and acidification with the succession. The content of inorganic N forms was significantly higher in bare soil compared to below-crust soil. Rhizosphere soil was enriched in organic matter and nutrients, which improves soil conditions within plant patches. Moreover, below-crust soil pH, total N content and water holding capacity drive the patterns of BSC morphological groups and species composition of lichens, bryophytes, and vascular plants. Conclusion Our study shows that spatial structure of the inland dune ecosystem is a mosaic of BSCs and plants that contribute to the spatial heterogeneity of key soil properties. We concluded that it is necessary to consider the matter of BSC in restoration treatments.

Photoluminescence properties of Eu3+ doped La(OH)3 phosphors: Fuel dependent combustion synthesis

In this study, we synthesized La(OH)3:Eu3+ phosphor using the combustion method with diverse fuels—urea, glycine, and dextrose. Through XRD patterns and Rietveld refinement, we confirmed a hexagonal crystal structure with a P63/m space group for all samples. Our analysis also delved into morphological properties and elemental composition, revealing intriguing differences in particle shapes despite similar sizes, depending on the fuel utilized. Interestingly, the PL excitation and emission characteristics remained consistent among the samples, displaying distinct bands. Spectroscopic investigation of Eu3+ activated La(OH)3 exhibits the strong red emission which indicated effective energy transfer among rare earth and host. Notably, when excited at 284/290 nm and 395 nm, the phosphor emitted multicolour bands spanning blue to red regions. However, some challenges and shortcomings were observed related to lanthanum hydroxide such as thermal stability, because at higher temperatures samples decompose easily which can limit their high-temperature applications. Additionally, some more issues are with this material i.e. complexity in synthesis, insolubility in water and ageing and exposure to atmospheric CO2 which can change its composition. Despite these challenges, our research focuses on optimizing and improving all these parameters. Addressing these shortcomings of lanthanum hydroxide can be beneficial for the advancement of applications. This impressive emission spectrum underscores the potential of this synthesized phosphor for lighting and display devices. The consistent photoluminescence features across different fuel variations suggest robustness and versatility, indicating promising avenues for future exploration in lighting technology research.

Molecular sieves hybrid metal–organic framework for efficient simultaneously capturing carbon dioxide and collecting water from air

Water scarcity and climate change associated with global warming are two common challenges facing humankind. The simultaneous removal of water and carbon dioxide (CO2) from the air has become a popular candidate strategy to address these challenges. In this paper, molecular sieve@MOF composites were synthesized in-situ for the first time by adding ZSM-5 and HZSM-5 during the preparation of Mg/DOBDC. A comprehensive review of the air capture CO2 and water harvesting properties of the novel composites was also presented. Primarily, the effects of molecular sieve category and ratio on the composite were systematically investigated. Subsequently, the crystal structure, morphological composition and textural properties of the composites were characterized. Finally, CO2/H2O co-adsorption performance, adsorption and desorption cycle stability and adsorption mechanism were investigated. The results demonstrated that the metal nodes of Mg/DOBDC interacted with the molecular sieve surface functional groups to increase the metal active sites and porosity. The obtained 0.5HZSM-5@Mg/DOBDC MOF showed the maximum CO2 uptake of 15.90 mmol/g (0.1 MPa, 25 °C), which was 3.66 times the amount of Mg/DOBDC.

Developing a novel calcium silver zeolite for caries management

ObjectiveTo develop a novel calcium silver zeolite (Ca-Ag-Zeo) and assess its biocompatibility, physiochemical properties and antimicrobial effects.MethodsCa-Ag-Zeo was synthesized using ion-exchange method with calcium chloride, silver nitrate and Zeolite X (Zeo). Silver zeolite X (Ag-Zeo) and Zeo were set as control. The chemical structure, morphology, crystal structure and elemental composition of Ca-Ag-Zeo was characterized by X-ray diffraction spectrum, scanning electron microscopy, transmission electron microscopy and energy dispersive spectroscopy, respectively. Its biocompatibility on the human gingival fibroblasts was assessed by cell counting kit-8 assay. Its physiochemical properties were determined by the released calcium and silver ion using Inductive Coupled Plasma Emission Spectrometry for up to 12 weeks. The antimicrobial properties on Streptococcus mutans, Lactobacillus acidophilus, Lactobacillus casei, and Candida albicans were assessed by minimum bactericidal concentration (MBC) or minimum fungicidal concentration (MFC) assay.ResultsCa-Ag-Zeo with a hexagonal cage structure was synthesized. As for biocompatibility, the half-maximal inhibitory concentration (± SD in mg/mL) of Ca-Ag-Zeo, Ag-Zeo and Zeo in human gingival fibroblasts were 0.52 ± 0.05, 0.15 ± 0.01 and 3.35 ± 0.58, respectively (Zeo > Ca-Ag-Zeo > Ag-Zeo; p < 0.05). As for physiochemical properties, the accumulated ion release (± SD in mg) of Ca-Ag-Zeo, Ag-Zeo and Zeo were 0.011 ± 0.003, 0 and 0 for calcium ion, respectively (Ca-Ag-Zeo > Ag-Zeo, Zeo; p < 0.001), and 0.213 ± 0.032, 0.209 ± 0.019 and 0 for silver ion, respectively (Ca-Ag-Zeo, Ag-Zeo > Zeo; p < 0.001). As for anti-microbial ability, the MBC/MFC (mg/mL) of Ca-Ag-Zeo, Ag-Zeo and Zeo were 32, 16 and > 256 against Streptococcus mutans; 32, 16, > 256 against Lactobacillus acidophilus; 16, 16, and 256 against Lactobacillus casei; 0.25, 0.125; and 2, 1, > 256 against Candida albicans, respectively.ConclusionA novel Ca-Ag-Zeo was developed. It presented better biocompatibility compared to Ag-Zeo. It released calcium and silver ions sustainably, and it could inhibit the growth of common cariogenic microorganisms.

Solar technology for the production of Bi/Pb superconducting ceramics and its properties

Based on the experience of isostoichiometric and isostructural oxides production using solar energy, the prospects for synthesizing of Bi/Pb superconducting ceramics are shown. The principle of technology in the Large Solar Furnace (Parkent), the influence of gradient conditions on the formation of the oriented structure of crystallites-nuclei, and the connection of the innate properties of precursors with the lamellar morphology and phase composition of massive ceramics are described. The homophase composition of Bi/Pb ceramics was determined. Graphs of resistance and voltage of BSCCO in the temperature range 80-320K are presented. Anomalous of resistance and magnetic susceptibility in bismuth cuprates synthesized by solar energy were observed. Experimental graphs in resistance and magnetic susceptibility changes represent dependencies characteristic of the potential superconducting transitions. The manifestation of the Meissner effect at room temperature and normal atmospheric pressure and daylight, and under the influence of light is shown. The properties of Bi/Pb ceramics are explained by the connection with the innate properties of precursors obtained by concentrated solar energy.

Transformation of waste thermocol into activated carbon for electrochemical detection of ammonia in an aqueous solution

In this study, waste thermocol sheets are used to synthesize activated carbon (AC) for the electrochemical detection of ammonia in an aqueous solution. The AC is characterized for its morphology, structure, and chemical composition via standard characterization techniques. AC shows promise for detecting ammonia in aqueous solutions due to its high adsorption capacity from large surface area and porosity. The electrochemical approach used to detect ammonia (NH3) in electrolyte solutions uses an AC electrode and is based mostly on the electro-oxidative conversion of ammonia species at the electrode's interface. AC electrodes fabricated on flexible conductive fabric (CF) are used for the electrochemical detection of ammonia at pH 6. The electrochemical sensing of ammonia in aqueous solutions involves its oxidation on the electrode's surface. Cyclic Voltammetry (CV) experiments were conducted over a pH range of 5 to 8, revealing optimal current responses at pH 6. Therefore, phosphate-buffered saline (PBS) at pH 6.0 was employed for all electrochemical analyses. Various concentrations of ammonia (10–100 ppm) were investigated within a voltage window of −0.3 V to 0.3 V, with current signals increasing proportionally with ammonia concentration. The limits of detection (LOD) and quantification (LOQ) were determined to be 28.55 ppm and 86.54 ppm, respectively. An incubation period of 3 min was observed for ammonia concentrations ranging from 0 to 40 ppm. Selectivity evaluations were conducted by assessing interference effects from ethanol (E), methanol (M), toluene (T), and uric acid (UA), revealing ammonia's distinctive peak, indicative of superior selectivity. Notably, the electrode exhibited remarkable stability, retaining approximately 95 % of the original signal over a 5-week duration. The reproducibility of the fabricated electrodes shows significant results. The repeatability was performed at room temperature in a buffer solution of pH 6 and at a 40-ppm concentration of ammonia and has shown almost similar results. Therefore, the fabricated AC sensing electrode has shown prominent stability, reproducibility, and repeatability. These sensing electrodes can be very beneficial for sensing applications.

Surface characterization of biochar from agricultural residues for environmental applications

Bio-waste materials banana (Musa ealbisiana) leaves, cassava (Manihot esculenta) peels, mango (Mangifera indica) leaves, plantain (Plantago lanceolata) leaves and peels were pyrolyzed at different temperatures; 300, 400, 450, 500 and 600 oC using a muffle furnace. The biochar samples obtained were characterized and properties evaluated for their potential application in soil for agronomic and environmental benefits. The measured physico-chemical properties; pH, bulk density, percentage yield and electrical conductivity varied with temperature of pyrolysis and somewhat with the source of the bio-waste. Surface morphology and elemental composition were determined from Scanning Electron Microscopic (SEM) and Energy Dispersive X-ray (EDX) measurements and showed variations in texture, porosity and elemental composition with pyrolysis temperature. The produced biochar yields were in the range 16.1 to 84.6% and highest for banana leaves (BL) pyrolysed at 300 oC. The scanned images showed a remarkable surface morphology for all the biochar samples obtained at temperatures ≥ 450 oC. The pH obtained indicate the alkaline nature of the biochars with mean values &gt; 7.5 except for cassava peels (CP) pyrolysed at 300 oC having a value of 5.5. From the elemental analysis, the high carbon content (&gt; 60%) at higher temperatures (&gt; 450 oC) of the biochars and the molar O/C ratios may suggest the suitability of the biochars in applications for long-term carbon sequestration and also promising candidates for soil amendment due to increase in macro porosity.

Bamboo durability: Understanding the combined effect of weathering and mildew infection

Bamboo has been widely used in outdoor applications and heat treatment is a typical industrial technique for improving its durability. Weathering and mildew are the two main types of deterioration that occur on bamboo. However, there are few studies on the deterioration of bamboo properties and degradation mechanism under such combined effect. Therefore, in this study, the effect of weathering on the mildew infection value (MIV) of natural bamboo (NB) and heat-treated bamboo (HB) were compared. The changes in surface color, morphology, and chemical composition of NB and HB during accelerated UV weathering were characterized. Meanwhile, the MIV of bamboo samples after different weathering durations was evaluated and the influencing mechanism was explored. The results revealed that the decomposition of starch and hemicellulose during heat treatment resulted in the generation of levoglucosan and acids, thereby providing a new nutrient source and a more suitable environment for mildew growth. HB exhibited superior color stability and anti-weathering characteristics compared to NB. Moreover, certain photodegradation products from HB demonstrated anti-fungal and anti-weathering properties, which resulted in a temporary resistance to mildew in weathered samples. However, after long-term exposure, the cracks on the surface of HB caused by weathering facilitated the colonization of mildew hypha by releasing inner nutrients, leading to severer mildew infection.

Simulated Gastrointestinal Digestion and Fecal Fermentation Characteristics of Exopolysaccharides Synthesized by Schleiferilactobacillus harbinensis Z171.

Exopolysaccharides (EPSs) produced by Lactobacillus have important physiological activities and are commonly used as novel prebiotics. A strain of Lactobacillus with high EPS yield was identified as Schleiferilactobacillus harbinensis (S. harbinensis Z171), which was isolated from Chinese sauerkraut. The objective of this study was to investigate the in vitro simulated digestion and fecal fermentation behavior of the purified exopolysaccharide fraction F-EPS1A from S. harbinensis Z171 and its influence on the human intestinal flora composition. The in vitro digestion results showed that the primary structural characteristics of F-EPS1A, such as morphology, molecular weight, and monosaccharide composition remained stable after saliva and gastrointestinal digestion. Compared with the blank group, the fermentation of F-SPS1A by fecal microbiota decreased the diversity of the bacterial communities, significantly promoted the relative abundance of Bifidobacterium and Faecalibacterium, and decreased the relative abundance of Lachnospiraceae_Clostridium, Fusobacterium, and Oscillospira. Reverse transcription polymerase chain reaction (RT-PCR) analysis also showed that the population of Bifidobacterium markedly increased. Furthermore, the total short-chain fatty acid levels increased significantly, especially for butyric acid. Gas chromatography-mass spectrometry (GC-MS) results showed that F-EPS1A could be fermented by the human gut microbiota to synthesize organic acids and derivative metabolites that are beneficial to gut health. Therefore, these findings suggest that F-EPS1A could be exploited as a potential prebiotic.

Morphology and chemical composition of mineral particles in a special dust storm with high relative humidity in North China

A special dust storm characterized by high PM10 mass concentrations (921.9 ± 632.3 μg m−3) and high relative humidity (RH; 60.1 % ± 11.1 %) was observed on March 22–24, 2023 at a coastal city of North China. Aerosol particles of PM10 were analyzed by a scanning electron microscope coupled with energy dispersive X-ray and an ion chromatograph. The results showed that individual mineral particles were dominated by clay minerals, followed by quartz, feldspar, and carbonate. Bulk water-soluble inorganic ions analysis showed that SO42- mass concentrations varied from 3.7 μg m−3 to 23.3 μg m−3 with an average value of 12.4 μg m−3. However, their mass ratios to PM10 were relatively stable, being 1.15–2.01 % with an average value of 1.49 % ± 0.25 %, similar to the value near the dust sources (Tengger Desert). Although S-containing individual mineral dust varied from 5.2 % to 70.7 %, the average weight ratio of S on individual mineral dust was 2.1 %, much lower than that of non-dust periods (11.0 %). The results suggested limited sulfate formation on mineral dust surfaces even under high RH. In contrast, NO3-, which was very limited in dust sources, varied from 0.21 % to 4.11 % of the total PM10 with an average value of 1.61 % ± 1.07 %. The research highlighted that nitrate formation has exceeded sulfate formation during severe dust storm episodes, which might because the atmospheric compositions in China have changed significantly with a high mass ratio of NO2/SO2 after the implementation of the strict emission control measures.

Elucidating the bacterial inactivation mechanism by argon cold atmospheric pressure plasma jet through spectroscopic and imaging techniques.

This study aims to assess the potential bacterial inactivation pathway triggered by argon (Ar) cold atmospheric pressure plasma jet (CAPJ) discharge using spectroscopic and imaging techniques. Electrical and reactive species of the Ar CAPJ discharge was characterized. The chemical composition and morphology of bacteria pre- and post-CAPJ exposure were assessed using Fourier transform infrared (FTIR), Raman micro-spectroscopy, and transmission electron microscopy (TEM). A greater than 6 log reduction of E. coli and S. aureus was achieved within 60 and 120 s of CAPJ exposure, respectively. Extremely low D- values (< 20 s) were recorded for both the isolates. The alterations in the FTIR spectra and Raman micro-spectra signals of post-CAPJ exposed bacteria revealed the degree of destruction at the molecular level, such as lipid peroxidation, protein oxidation, bond breakages, etc. Further, TEM images of exposed bacteria indicated the incurred damages on cell morphology by CAPJ reactive species. Also, the inactivation process varied for both isolates, as evidenced by the correlation between the inactivation curve and FTIR spectra. It was observed that the identified gas-phase reactive species, such as Ar I, O I, OH•, NO+, OH+, NO2-, NO3-, etc. played a significant role in bacterial inactivation. This study clearly demonstrated the effect of CAPJ exposure on bacterial cell morphology and molecular composition, illuminating potential bacterial inactivation mechanisms.

Structural, morphological, and chemical composition of ternary ZrHfN thin films deposited by reactive co-magnetron sputtering

This study focuses on a deposited ternary zirconium hafnium nitride (ZrHfN) thin film prepared using the reactive co-magnetron sputtering technique. The effect of the nitrogen (N2) flow rate on the films' structural, morphological, and chemical composition was investigated. The gracing-incidence X-ray diffraction (GIXRD) showed that all ZrHfN thin films exhibited a crystalline face-centered cubic structure with a strong (111) orientation. With increasing the N2 flow rate, the film's crystallography changed based on thermodynamic theory. The films demonstrated uniformity and homogeneity in their ternary nitride composition, as confirmed by transmission electron microscopy-energy dispersive X-ray spectroscopy (TEM-EDS) mapping and electron probe microanalyzer (EPMA). Chemical state analysis using X-ray photoelectron spectroscopy (XPS) indicated the presence of both nitride and oxynitride species in all samples. Notably, the atomic concentration of the main elements (Zr, Hf, and N) remained relatively stable over the controlled N2 flow rate range. However, the N2 flow rate played a crucial role in forming hafnium nitride and oxynitride chemical states, whereas it did not significantly influence the Zr phases, dominated by Zr oxides. Additionally, the hardness of the ternary ZrHfN thin films exhibited enhancement comparable to typical ternary nitrides.

The Triassic Buntsandstein sedimentary basins of Sardinia (Italy) and their transition to the Brianzonese Ridge (W Alps): crossroads through the W-Tethys areas

Sardinia represented a key area during the Western Tethys opening in late Early-early Middle Triassic times since it was located at the nodal point of several paleogeographic domains. New and revised sedimentological data and petrographical investigations evidence that the Sardinian Buntsandstein Group formational units differ from each other and were deposited in different alluvial to transitional depositional systems related to Alpine rifting basins. Petrographic analysis revealed directional NS and EW compositional differences: they hint at morphotectonic rises separating the diverse depositional areas through lasting barriers related to paleoeuropean ridges in progressive dismantling. The data suggest that 1) the dominating environmental and (micro)climate conditions were diverse from area to area, 2) the sedimentary basins evolved differently through time, and 3) were diachronous in timing. Moreover, the sources of debris were variable, both in morphology and substrate composition, with reliefs from articulated to smoothed. A stratigraphic and sedimentological framework for the Sardinian Buntsandstein is suggested. Comparison analysis with close coeval successions of the Western Tethydian area, particularly regarding the Upper Permian? - Lower Middle Triassic deposits of the Brianconnais ridge have been attempted, as well as their palaeogeographic localization, to frame the Sardinian Buntsandstein Group with the coeval units of SW Europe.

Advancements in on-site heavy metal detection: Characterizing and sensitive Hg2+ sensing of silver spheroid nanoparticles obtained by laser ablation synthesis in solution

Heavy metal detection in water bodies is crucial to prevent potential harm to the environment, animals and humans. While powerful techniques such as atomic absorption spectrometry exist, they often require extensive sample preparation and are typically confined to laboratory settings. As a result, alternative detection methods such as optical sensors, are under development to provide a simpler, faster, and on-site detection solution. In the present work spheroidal silver nanoparticles (AgNPs) with a mean size of 14.7 ± 0.6 nm were synthesized by laser ablation in a sodium citrate solution. These nanoparticles exhibit a localized surface plasmon resonance (LSPR), which is profoundly dependent on the size, morphology and composition of the nanoparticles and the refractive index of the surrounding media. The detection capabilities of these nanoparticles were assessed by exposing them to various metal ions, revealing a distinctive sensitivity to Hg2+ ions. Notably, this particular ion had a significant impact on the extinction curve of the AgNPs. The impact of synthesis parameters, including sodium citrate and NaCl concentration, as well as pH, on the efficacy of Hg2+ detection was systematically studied. Characterization techniques such as Dynamic Light Scattering (DLS), Transmission Electron Microscopy (TEM), High-Resolution TEM (HRTEM), and Scanning Transmission Electron Microscopy (STEM) were employed to determine the size, morphology, distribution, crystalline structure, and elemental composition of the AgNPs. The results indicated that AgNPs synthesized through laser ablation in a sodium citrate solution exhibited sensitive detection capabilities for Hg2+ ions, reaching an LOD and LOQ of 0.9355 μM and 2.8350 μM respectively.

Investigation of in-vitro bioactivity, electrochemical corrosion, wettability and adhesion properties of bioglass-based coatings modified with Y2O3 and Zr on novel β-type Ti-30Zr-5Mo alloys

In this study, the in-vitro bioactivity, electrochemical corrosion resistance, wettability, and adhesion properties of bioglass-based coatings modified with Y2O3 and ZrO2 on Ti-30Zr-5Mo alloy were investigated. The coatings were prepared using the sol-gel method and applied to the alloy substrates through dip-coating. The surface morphology and elemental composition of the coatings were analyzed using SEM/EDS and XRD techniques. Potentiodynamic polarization (PDS) and electrochemical impedance spectroscopy (EIS) were employed to assess the electrochemical behavior of the coatings under in-vitro conditions. Contact angle measurements were conducted to evaluate the wettability of the surfaces. Adhesion strength was measured using tensile testing in accordance with ISO 13779-2 standards. Bioactivity tests were performed by immersing the samples in simulated body fluid (SBF). The results demonstrate that the addition of Y2O3 and ZrO2 improves adhesion strength and corrosion potential, but introducing localized galvanic effects that increase the corrosion current density. Besides, the coatings maintained their structural integrity after the bioactivity tests, and promoted new apatite formation.