Search Results (1,021)

Red mud, a by-product of aluminum production, leads to significant environmental challenges due to its alkalinity and presence of soluble compounds. This study explores its valorization through agglomeration with blast furnace sludge as a reducing agent to form self-reducing briquettes. Five C/Fe₂O₃ ratios (0.131, 0.262, 0.523, 0.840 and 1.000) were tested to determine the most effective reducing condition, with 0.840 emerging as optimal based on thermal analysis (mass loss of 27.44 wt.% at 1200 °C and iron formation specific energy of 450 J g⁻¹). Briquettes prepared with three agglomeration methods varying in water content (water/starch ratios of 6:1, 12:1 and 18:1) were evaluated through drop, compression and abrasion tests. The agglomeration method with a 12:1 water/solid ratio, involving both starch gelatinization and red mud water absorption, produced the most mechanically resistant briquettes (19.210 MPa). The mechanical and metallurgical properties of the 0.840-2W briquettes after reduction at 700, 950, 1200 and 1450 °C (temperature maintenance for 15 min) were assessed to define the best compromise between the reduction degree and mechanical strength. While reduction at 950 °C led to the weakest structure (0.449 MPa) but poor metallization, 1450 °C ensured the highest degree of reduction (94%) with adequate brittleness to facilitate a possible subsequent magnetic separation. Full article

Cobalt-doped iron disulfide (FeS₂) thin films were synthesized via chemical bath deposition (CBD) followed by annealing at 450 °C, yielding phase-pure pyrite structures with multifunctional properties. A deposition temperature of 95 °C is critical for promoting Co incorporation, suppressing sulphur vacancies, and achieving structural stabilization of the film. After annealing, the dendritic morphologies transformed into compact quasi-spherical nanoparticles (~100 nm), which enhanced the crystallinity and optoelectronic performance of the films. The films exhibited strong absorption (>50%) in the visible and near-infrared regions and tunable direct bandgaps (1.14 to 0.96 eV, within the optimal range for single-junction solar cells. Electrical characterization revealed a fourth-order increase in conductivity after annealing (up to 4.78 Ω⁻¹ cm⁻¹) and confirmed stable p-type behavior associated with Co²⁺-induced acceptor states and defect passivation. These results demonstrate that CBD enabled the fabrication of Co-doped FeS₂ thin films with synergistic structural, electrical, and optical properties. The integration of earth-abundant elements and tunable electronic properties makes these films promising absorber materials for the next-generation photovoltaic devices. Full article

Background: Iron is an essential nutrient for the proper development of infants. Iron deficiency, a common cause of anemia—affects nearly half children under four years of age in developing countries. The aim of the study was to assess the impact of an intensive nutritional education program on the iron status of infants. Material and methods: The parents of 115 infants were randomly assigned to two groups: the study group, which received intensive nutritional education up to 12 months of age, and the control group, which received basic infant nutrition guidelines. Serum concentrations of iron metabolism parameters—among others hemoglobin, iron, ferritin, ferroportin, and total iron-binding capacity (TIBC)—were assessed at both the beginning and end of the study. Additionally, at the final time point, dietary intake of iron and components influencing its absorption (e.g., vitamin C, fiber, etc.) was evaluated based on food diaries completed by the parents. Results: At the end of the study, the study group showed a significantly higher level of hemoglobin (p = 0.0499), ferritin (p = 0.0067) and lower levels of TIBC (p = 0.0478) and ferroportin (p = 0.0410) compared to the control group. Moreover, infants in the study group demonstrated significantly higher intake of both iron (p = 0.0252) and vitamin C (p = 0.0458). Conclusions: Parental nutritional education contributes to improvements in iron metabolism indicators in infants. Full article

One of the cytochrome b₅₆₁ family members in C. elegans, named Cecytb-2, was investigated. Purified recombinant Cecytb-2 showed typical visible absorption spectra, EPR signals, and redox midpoint potentials, very similar to those of human Dcytb, which is responsible for intestinal iron acquisition by its ferric reductase activity. Fast kinetic experiments using pulse radiolysis and stopped-flow techniques showed that Cecytb-2 donates electrons to monodehydroascorbate radicals with a much lower reactivity than other cytochrome b₅₆₁ members, but it can accept electrons from ascorbate (AsA) as rapidly as other members. DEPC treatment of Cecytb-2 caused significant inhibition of electron acceptance from AsA and lowered the midpoint potential of heme b_L. MS/MS MASCOT analyses verified that N-carbethoxylations of conserved Lys98 and heme b_L axial His101 residues on the cytosolic side were major causes of the inhibition. Reconstituted Cecytb-2 in sealed vesicle membranes, in which AsA was entrapped, showed significant transmembrane ferric reductase activity. In situ hybridization analysis revealed that Cecytb-2 mRNA was distributed in intestinal cells. Immunohistochemical analysis indicated that Cecytb-2 resided in intestinal lumens. Knockdown of the Cecytb-2 gene expression in N2 worms indicated a significant suppression of growth under ferrous ion-deficient conditions. Thus, the ferric reductase activity conferred by Cecytb-2 seems to participate in iron acquisition and is very important for normal growth in low-ferrous conditions, confirming that Cecytb-2 is a genuine Dcytb homolog in C. elegans. Full article

The present study investigated the effects of hierarchical molecular weights and iron chelation on the in vivo absorption and the inflammatory bioactivity of chondroitin sulfate (CS). Firstly, CS, chondroitin sulfate-iron complex (CS-Fe), and low-molecular-weight chondroitin sulfate-iron complex (LCS-Fe) were fluorescently labeled and characterized. Then, the plasma concentration–time profiles and fluorescence imaging results demonstrated that LCS-Fe was more efficiently absorbed into the bloodstream and showed a higher Cmax (415.16 ± 109.50 μg/mL) than CS-Fe (376.60 ± 214.10 μg/mL) and CS (135.27 ± 236.82 μg/mL), and it clearly accumulated in the liver. Furthermore, the anti-inflammatory effect of CS-Fe and LCS-Fe was assayed in LPS-induced macrophages, and LCS-Fe and CS-Fe both showed a better inhibitory effect on NO production, COX-2 and IL-1β gene expression levels compared to CS. Additionally, targeted metabolic analysis of macrophages using LC-MS/MS revealed that CS, CS-Fe, and LCS-Fe could reverse approximately one quarter of the LPS-induced differential metabolites, and the biosynthesis of valine, leucine, and isoleucine was the most significantly involved metabolic pathway. Notably, the molecular weight reduction and iron chelation could both enhance the bioavailability and anti-inflammatory efficacy of CS. Full article

Surface functionalization of magnetic nanoparticles, commonly used for their biocompatibility in biomedical applications, plays a critical role in optimizing iron oxide nanoparticles (IONPs) for magnetic hyperthermia (MH), a promising modality in cancer therapy. In this study, we provide the first comprehensive comparison of hyperbranched dendron coatings versus linear dicarboxylate ligands on IONPs, revealing their contrasting impacts on heating efficiency under varying magnetic field amplitudes (H). Dendron-coated IONPs outperform dicarboxylate-coated ones at low fields (H < 25 kA/m) due to reduced dipolar interactions and enhanced Brownian relaxation. Conversely, dicarboxylate coatings excel at high fields (H > 25 kA/m) by enabling magnetically aligned chains, which amplify hysteresis losses. Our work also introduces an approach to dynamically modulate the heating efficiency of IONPs by applying a static DC magnetic field (H_DC) in conjunction with the alternating magnetic field (AMF). We observed a coating-dependent response to H_DC in the parallel configuration (H_DC aligned with AMF), the specific absorption rate (SAR) increased by ~620 W/g_Fe for cubes and ~370 W/g_Fe for spheres at high AMF amplitudes (H > 30 kA/m) for dicarboxylate-coated IONPs. This enhancement arises from magnetically aligned chains (visualized via Transmission Electron Microscopy), which amplify extrinsic anisotropy and hysteresis losses; in contrast, for dendron-coated IONPs, their SAR values decreased under H_DC (up to ~665 W/g_Fe reduction for cubes in the perpendicular configuration), as the thick dendron shell prevents close interparticle contact, suppressing chain formation and fanning rotation modes. These findings underscore the significance of surface functionalization in enhancing the therapeutic efficacy of magnetic nanoparticles. Full article

The steel industry is a significant contributor to global CO₂ emissions due to the highly energy-intensive nature of its production processes. Specifically, steel production involves the conversion of iron ore into steel through processes such as the blast furnace method, which result in significant greenhouse gas emissions due to the combustion of fossil fuels and the chemical reactions involved. To address this challenge, Carbon Capture Utilization and Storage (CCUS) technologies are essential for reducing emissions by capturing CO₂ at its source, preventing its release into the atmosphere. This study focuses on a French steel plant with an annual production capacity of 6.6 million tons of steel and seeks to optimize the chemical absorption process by using a 30 wt.% MonoEthanolAmine (MEA) aqueous solution. To the authors’ knowledge, studies on this solvent, widely used for treating other types of flue gases, are still not present in the literature for the application to this gaseous stream. The goal is to minimize the thermal energy required for solvent regeneration by optimizing some key parameters. Additionally, an economic analysis is carried out, with a particular focus on different achievable CO₂ recovery ratios, with costs quantified as 102.48, 104.47, and 224.36 [$/t CO₂ removed] for 90%, 95%, and 99% CO₂ recovery, respectively. Full article

This study aimed to elucidate the physiological, biochemical, and transcriptional regulatory responses of potato plants to iron deficiency stress. Two potato varieties were selected for analysis: 05P (high tuber iron content) and CI5 (low tuber iron content). Tissue culture seedlings of both varieties were subjected to iron deficiency, and the effects on stem length, root length, fresh weight, soluble sugar and protein contents, as well as the activities of superoxide dismutase (SOD), peroxidase (POD), malondialdehyde (MDA), and leaf chlorophyll content (SPAD) values were evaluated. Additionally, the impact of iron deficiency on zinc (Zn), magnesium (Mg), calcium (Ca), manganese (Mn), and copper (Cu) concentrations in different tissues were analyzed. Transcriptomic sequencing and quantitative real-time PCR (qRT-PCR) were performed on various seedling tissues. The results showed that iron deficiency significantly inhibited seedling growth and development, resulting in reduced plant height and fresh weight, increased root length, decreased leaf SPAD content, and elevated soluble sugar and protein concentration. SOD, POD, and MDA activities were also significantly increased. Elemental analysis revealed that iron deficiency enhanced the uptake and accumulation of Zn, Mg, Ca, Mn, and Cu across different tissues. Transcriptomic analysis identified differentially expressed genes (DEGs) significantly enriched in pathways related to photosynthesis, carbon metabolism, and ribosome function in roots, stems, and leaves. Iron deficiency induced the upregulation of H⁺-ATPase genes in roots (PGSC0003DMG400004101, PGSC0003DMG400033034), acidifying the rhizosphere to increase active iron availability. Subsequently, this was followed by the upregulation of FRO genes (PGSC0003DMG400000184, PGSC0003DMG400010125, PGSC0003DMG401009494, PGSC0003DMG401018223), which reduce Fe³⁺ to Fe²⁺, and activation of IRT genes, facilitating Fe²⁺ transport to various tissues. Iron deficiency also reduced SPAD content in leaves, negatively impacting photosynthesis and overall plant growth. In response, the osmotic regulation and antioxidant defense systems were activated, enabling the plant to mitigate iron deficiency stress. Additionally, the absorption and accumulation of other metal ions were enhanced, likely as a compensatory mechanism for iron scarcity. At the transcriptional level, iron deficiency induced the expression of genes involved in metal absorption and transport, as well as those related to photosynthesis, carbon metabolism, and ribosomal function, thereby supporting iron homeostasis and maintaining metabolic balance under stress conditions. Full article

To address the limitations of microwave healing and the repair capabilities of conventional asphalt mixtures, this paper employs carbonyl iron powder as a filler to replace 20% of the mineral powder in asphalt mixtures, thereby enhancing their microwave absorption and healing properties. The study uses carbonyl iron powder mixtures as the experimental group and conventional asphalt mixtures as the control group. Using digital image correlation (DIC) technology, the semi-circular bending healing test and microwave heating test were conducted to determine the optimal conditions for microwave-induced healing and to investigate the effects of multiple healing factors on the healing outcomes. The test results show that the carbonyl iron powder asphalt mixture has the advantage of heating healing, and the intermittent heating method further improves the heating uniformity. The fracture energy healing index (HI_U) and the crack initiation time healing index (HI_t) are 83.1% and 34.9% higher than the ordinary asphalt mixture (microwave heating 100 s). Among the external healing factors, the microwave heating time has the greatest influence on the healing rate, followed by the degree of damage and the standing time. The optimal healing scheme is to stand for 4 h after microwave heating for 100 s, and the curing effect is the best at the initial stage of damage (before crack initiation). Full article

The integration of nanotechnology with green chemistry presents sustainable strategies for developing multifunctional cosmeceutical formulations. In this study, iron oxide nanoparticles (IONPs) were successfully synthesized using antioxidant-rich green tea extract via an eco-friendly method. The nanoparticles were incorporated into a novel Pickering emulsion comprising coconut oil and green tea extract, targeting UV protection and antimicrobial performance. The green-synthesized IONPs displayed strong UV absorption properties, achieving an SPF of 6.20 at 1.0 M concentration, outperforming standard TiO₂ nanoparticles (SPF 3.98). The optimized Pickering emulsion formulation showed stability and skin-friendly pH. Antimicrobial studies revealed significant inhibition of Cutibacterium acnes and Staphylococcus aureus, with over 97% microbial reduction observed within 2 h of exposure. This dual-functional system, combining UV protection and antimicrobial effects, demonstrates the potential of green nanomaterials for developing safe, effective, and sustainable skincare formulations. The study provides new insight into the application of iron-based green nanotechnology in surfactant-free emulsions, supporting further innovation in the field of natural photoprotective cosmeceuticals. Full article

Molecular geometry, infrared (IR) vibrational frequencies, and ultraviolet–visible (UV-Vis) electronic absorption spectra of the trivalent iron tris(acetylacetonate) complex, Fe(III)(acac)₃, were computed using hybrid meta-generalized gradient approximation (meta-GGA) density functional theory (DFT). Calculations employed the Jorge double-$\zeta$ valence plus polarization basis sets (standard DZP and relativistic DZP + DKH). Solvent effects were modeled using the SMD continuum solvation framework with acetonitrile as the dielectric medium. This charge-neutral complex exhibits predominantly ionic metal–ligand bonding character, which simplifies the computational treatment. Despite extensive DFT applications to coordination compounds, systematic benchmarks for this bidentate ligand system remain limited. The computed harmonic frequencies ($\nu$) and electronic excitation energies (${\lambda }_{\max }$) demonstrate excellent agreement with available experimental measurements. These results enable comparative analysis of IR and UV-Vis spectral features, both with and without all-electron scalar relativistic effects with the second-order Douglas–Kroll–Hess approach. Full article

Honeybee pollen is widely recognized as a functional apicultural product due to its rich nutritional profile, but its composition is strongly influenced by seasonality and floral availability. Understanding these seasonal dynamics is critical for optimizing the nutritional and bioactive quality of bee-collected pollen. This study investigated the seasonal variation in the physicochemical and mineral composition of honeybee pollen collected monthly from April to September 2024 from an apiary in the Tulkibas district, Turkistan region, Kazakhstan. Pollen samples were analyzed for key quality parameters, including moisture, protein, fat, fiber, carbohydrates, starch, ash, and minerals (Ca, P, K, Mg, Na, Cu, Fe, Zn). Moisture, protein, fat, fiber, starch, and ash were determined using standard AOAC methods, while minerals were quantified by flame atomic absorption spectrophotometry (Ca, Cu, Fe, Mg, Zn; Analytik Jena novAA 350), flame emission spectrophotometry (Na, K), and the molybdenum blue colorimetric method (P). The moisture content decreased significantly from 10.34 ± 1.74% in April to 5.23 ± 0.86% in June (p = 0.0030), while protein increased from 20.28 ± 2.13% to a peak of 23.66 ± 1.70% in June (p = 0.0268). The fat content reached its maximum in July at 8.67 ± 0.11% (p = 0.0446), and carbohydrates peaked at 14.41 ± 0.11% in the same month. Among minerals, Fe and Zn showed substantial increases, with iron rising from 47.51 ± 5.69 mg/kg in April to 143.39 ± 6.58 mg/kg in July (p = 0.0388), and Zn from 38.56 ± 2.36 mg/kg to 57.14 ± 8.54 mg/kg (p = 0.0302). Principal Component Analysis (PCA) and Pearson correlation confirmed strong seasonal clustering and nutrient interrelationships. These findings highlight the superior nutritional value of mid- to late-season pollen and underscore the importance of the harvest timing in optimizing the bioactive profile of bee-collected pollen for apicultural and functional food applications. Full article

The distribution of iron oxide (FeO) across the lunar surface is a key parameter for reconstructing the Moon’s geological evolution and evaluating its in situ resource potential for future exploration. This study applies a spectral-based approach to estimate FeO concentrations using remote sensing reflectance data combined with a Random Forest (RF) regression model. The model was trained on a dataset comprising 89 lunar samples from the Reflectance Experiment Laboratory (RELAB) database, supplemented with compositional data from Apollo samples available via the Lunar Sample Compendium and reflectance spectra from the Clementine mission. Spectral data spanning the visible to shortwave infrared range (415–2780 nm) were analysed, with diagnostic absorption features centred around 950 nm, typically associated with Fe²⁺. Model validation was conducted against FeO estimates from independent nearside locations not included in the training set, as reported by an external remote sensing study. The trained model was also applied to produce a new global FeO abundance map, demonstrating strong spatial consistency with recent high-resolution reference datasets. These results confirm the model’s predictive accuracy and support the use of legacy multispectral data for large-scale lunar geochemical mapping. This work highlights the potential of combining machine learning techniques, such as Random Forest, with remote sensing data to enhance lunar surface composition analysis, supporting the planning of future exploration and resource utilisation missions. Full article

Controlling dissolved nitrogen is critical to meeting increasingly stringent steel quality targets, yet the variable kinetics of gas absorption and removal across production stages complicate real-time decision-making. Leveraging a total of 291 metal samples, the research applied ordinary least squares (OLS) regression, enhanced by cointegration diagnostics, to develop four stage-specific models covering pig iron after desulfurization, crude steel in the basic oxygen furnace (BOF) before tapping, steel at the beginning and end of secondary metallurgy processing. Predictor selection combined thermodynamic reasoning and correlation analysis to produce prediction equations that passed heteroscedasticity, normality, autocorrelation, collinearity, and graphical residual distribution tests. The k-fold cross-validation method was also used to evaluate models’ performance. The models achieved an adequate accuracy of 77.23–83.46% for their respective stages. These findings demonstrate that statistically robust and physically interpretable regressions can capture the complex interplay between kinetics and the various processes that govern nitrogen pick-up and removal. All data are from U. S. Steel Košice, Slovakia; thus, the models capture specific setup, raw materials, and production practices. After adaptation within the knowledge transfer, implementing these models in process control systems could enable proactive parameter optimization and reduce laboratory delays, ultimately minimizing excessive nitrogenation in finished steel. Full article

A new type of vesuvianite jade has recently been discovered in Hanzhong City, Shaanxi Province, China. However, a systematic investigation into its mineralogical characteristics and the origin of its color is currently lacking. In this study, the gemological, mineralogical, and spectroscopic properties of the Hanzhong vesuvianite jade were comprehensively analyzed using a suite of modern analytical techniques, including standard gemological testing, polarizing microscopy, X-ray powder diffraction, Fourier-transform infrared spectroscopy, laser Raman spectroscopy, UV-visible absorption spectroscopy, and X-ray fluorescence spectroscopy. The origin of the jade’s color was also preliminarily investigated. The results indicate that the samples are primarily composed of vesuvianite, with associated minerals including minor amounts of grossular, chlorite, and diopside, and trace amounts of calcite, epidote, chromite, and titanite. The pale green patches consist mainly of chlorite and grossular, the dark green bands are predominantly chlorite, and the dark brown patches are composed of abundant, disseminated microcrystalline chromite intermixed with uvarovite (calcium chromium garnet). The major chemical components of the vesuvianite jade matrix are SiO₂, Al₂O₃, and CaO. Specifically, SiO₂ ranges from 37.01 to 38.54 wt.%, Al₂O₃ from 18.48 to 22.84 wt.%, and CaO from 37.16 to 40.04 wt.%. Minor amounts include MgO (0.76–4.39 wt.%) and FeO_T (total iron expressed as FeO, 0.56–2.09 wt.%). The yellowish-green color of the matrix originates from a combination of ligand-to-metal charge transfer of Fe³⁺, crystal field transitions of Fe³⁺, and intervalence charge transfer between Fe²⁺ and Fe³⁺ in vesuvianite. The emerald-green color of the patches results from the synergistic effect of Fe and Cr; Fe provides a yellowish-green background color, upon which the crystal field transitions of Cr³⁺ (indicated by a doublet at 686/696 nm) impose strong absorption in the red region, resulting in a more vivid green hue. Full article