Search Results (1,397)

Background/Objectives: Crystallization is a key process in the manufacturing of active pharmaceutical ingredients (APIs), as it significantly affects the physical and chemical properties of the final product. Nicergoline, a clinically relevant ergot derivative, was chosen as a model compound to investigate how different crystallization strategies affect particle attributes. The objective of this study was to compare controlled and uncontrolled crystallization techniques and evaluate their impact on the physicochemical properties of nicergoline. Methods: Nicergoline was crystallized using controlled methods, including sonication-induced and seeding-induced crystallization, and uncontrolled methods, namely cubic and linear cooling, as well as acetone evaporation. The resulting powders were characterized by using a range of physicochemical techniques to assess particle morphology, size distribution, agglomeration behavior, and surface properties. Results: Uncontrolled crystallization methods produced particles prone to agglomeration, resulting in a broader particle size distribution ranging from 8 to 720 µm and heterogeneous surface characteristics. In contrast, controlled crystallization generated more uniform particles with reduced agglomeration and narrower particle size distributions. Among the evaluated methods, sonocrystallization provided the most effective control over particle size and morphology, demonstrated by a narrow size distribution ranging from 16 to 39 µm which correlated with improved flowability and surface energy. Conclusions: The study demonstrates that the choice of crystallization method significantly influences the structural and physicochemical properties of nicergoline. These findings highlight the importance of method selection for tailoring API properties to enhance downstream processing and product quality. Full article

Wet agglomeration is essential in heap leaching of minerals, as it improves permeability by forming agglomerates through capillary and viscous forces. The Discrete Element Method (DEM) has been used to model this phenomenon, enabling the detailed tracking of interactions between individual particles. This study employs DEM to analyze the effect of particle-size distribution (PSD) on agglomerate formation inside a rotating agglomeration drum. The DEM model was validated using geometry and parameters reported in the literature, which are based on experimental studies of agglomeration in rotating drums. Both wide and bimodal PSD cases were simulated. The results demonstrate that DEM simulations of drums with exclusively fine particles are prone to producing poorly defined macrostructures. In contrast, the presence of coarse particles promotes the formation of stable agglomerates with fine particles attached to them. Additionally, decreasing the maximum particle size increases the number of agglomerates and improves the homogeneity of the final PSD. These findings improve our understanding of wet agglomeration dynamics and provide practical criteria for optimizing feed design in mineral-processing applications. Full article

This study reports on green-synthesized zinc oxide nanoparticles (ZnONPs), focusing on their physicochemical characterization, photocatalytic properties, and agricultural applications. Dynamic light scattering (DLS) analysis revealed a mean hydrodynamic diameter of 337.3 nm and a polydispersity index (PDI) of 0.400, indicating moderate polydispersity and nanoparticle aggregation, typical of biologically synthesized systems. High-resolution transmission electron microscopy (HR-TEM) showed predominantly spherical particles with an average diameter of ~28 nm, exhibiting slight agglomeration. Energy-dispersive X-ray spectroscopy (EDX) confirmed the elemental composition of zinc and oxygen, while X-ray diffraction (XRD) analysis identified a hexagonal wurtzite crystal structure with a dominant (002) plane and an average crystallite size of ~29 nm. Photoluminescence (PL) spectroscopy displayed a distinct near-band-edge emission at ~462 nm and a broad blue–green emission band (430–600 nm) with relatively low intensity. The ultraviolet–visible spectroscopy (UV–Vis) absorption spectrum of the synthesized ZnONPs exhibited a strong absorption peak at 372 nm, and the optical band gap was calculated as 2.67 eV using the Tauc method. Fourier-transform infrared spectroscopy (FTIR) analysis revealed both similarities and distinct differences to the pigeon extract, confirming the successful formation of nanoparticles. A prominent absorption band observed at 455 cm⁻¹ was assigned to Zn–O stretching vibrations. X-ray photoelectron spectroscopy (XPS) analysis showed that raw pigeon droppings contained no Zn signals, while their extract provided organic biomolecules for reduction and stabilization, and it confirmed Zn²⁺ species and Zn–O bonding in the synthesized ZnONPs. Photocatalytic degradation assays demonstrated the efficient removal of pollutants from sewage water, leading to significant reductions in total dissolved solids (TDS), chemical oxygen demand (COD), and total suspended solids (TSS). These results are consistent with reported values for ZnO-based photocatalytic systems, which achieve biochemical oxygen demand (BOD) levels below 2 mg/L and COD values around 11.8 mg/L. Subsequent reuse of treated water for irrigation yielded promising agronomic outcomes. Wheat and barley seeds exhibited 100% germination rates with ZnO NP-treated water, which were markedly higher than those obtained using chlorine-treated effluent (65–68%) and even the control (89–91%). After 21 days, root and shoot lengths under ZnO NP irrigation exceeded those of the control group by 30–50%, indicating enhanced seedling vigor. These findings demonstrate that biosynthesized ZnONPs represent a sustainable and multifunctional solution for wastewater remediation and agricultural enhancement, positioning them as a promising candidate for integration into green technologies that support sustainable urban development. Full article

This work presents a comprehensive study on the fabrication, microstructural evolution, and mechanical performance of hybrid aluminum matrix composites based on Al6060 alloy reinforced with ~2 wt.% TiB₂ and ~1 wt.% multi-walled carbon nanotubes (MWCNTs). The composites were produced via ultrasonically assisted stir casting followed by radial-shear rolling (RSR). The combined processing route enabled a uniform distribution of reinforcing phases and significant grain refinement in the aluminum matrix. SEM, EDS, XRD, and EBSD analyses revealed that TiB₂ particles acted as nucleation centers and grain boundary pinning agents, while MWCNTs provided a network structure that suppressed agglomeration of ceramic particles and enhanced interfacial load transfer. As a result, hybrid composites demonstrated a submicron-grained structure with reduced anisotropy. Mechanical testing confirmed that yield strength (YS) and ultimate tensile strength (UTS) increased by 67% and 38%, respectively, in the cast state compared to unreinforced Al6060, while after RSR processing, YS exceeded 115 MPa and UTS reached 164 MPa, with elongation preserved at 14%. Microhardness increased from 50.2 HV0.2 (base alloy) to 82.2 HV0.2 (hybrid composite after RSR). The combination of ultrasonic melt treatment and RSR thus provided a synergistic effect, enabling simultaneous strengthening and ductility retention. These findings highlight the potential of hybrid Al6060/TiB₂–MWCNT composites for structural applications requiring a balance of strength, ductility, and wear resistance. Full article

Despite the immense potential in environmental remediation, the translation of magnetic nanomaterials (MNMs) from laboratory innovations to practical, field-scale applications remains hindered by significant technical and environmental challenges. This is particularly evident in soil environments—which are inherently more complex than aquatic systems and have received comparatively less research attention. Beginning with an outline of the fundamental properties that make iron-based MNMs effective as adsorbents and catalysts for heavy metals and organic pollutants, this review systematically examines their core contaminant removal mechanisms. These include adsorption, catalytic degradation (e.g., via Fenton-like reactions), and magnetic recovery. However, the practical implementation of MNMs is constrained by several key limitations, such as particle agglomeration, oxidative instability, and reduced efficacy in multi-pollutant systems. More critically, major uncertainties persist regarding their long-term environmental fate and biocompatibility. In light of these challenges, we propose that future efforts should prioritize the rational design of stable, selective, and intelligent MNMs through advanced surface engineering and interdisciplinary collaboration. Full article

With the increasing severity of cadmium (Cd) contamination in soil and its persistent toxicity, developing efficient remediation methods has become a critical necessity. In this study, sodium borohydride (NaBH₄) and tea polyphenols (TP) were employed as reducing agents to synthesize biochar (BC)-supported nanoscale zero-valent iron (nZVI), denoted as BH₄-nZVI/BC and TP-nZVI/BC, respectively. The effects of dosage, pH, and reaction time on Cd immobilization efficiency were systematically investigated. Both composites effectively stabilized Cd, significantly reducing its mobility and toxicity. Toxicity Characteristic Leaching Procedure (TCLP) results showed that Cd leaching concentrations decreased to 8.23 mg/L for BH₄-nZVI/BC and 4.65 mg/L for TP-nZVI/BC, corresponding to performance improvements of 29.9% and 60.5%. The immobilization process was attributed to the reduction of Cd(II) into less toxic species, together with adsorption and complexation with oxygen-containing groups (-OH, -COOH, phenolic) on biochar. TP-nZVI/BC exhibited superior long-term stability, while maintaining slightly lower efficiency than BH₄-nZVI/BC under certain conditions. Microbial community analysis revealed minimal ecological disturbance, and TP-nZVI/BC even promoted microbial diversity recovery. Mechanistic analyses further indicated that tea polyphenols formed a protective layer on nZVI, which inhibited particle agglomeration and oxidation, reduced the formation of iron oxides, preserved Fe⁰ activity, and enhanced microbial compatibility. In addition, the hydroxyl and phenolic groups of tea polyphenols contributed directly to Cd(II) complexation, reinforcing long-term immobilization. Therefore, TP-nZVI/BC is demonstrated to be an efficient, sustainable, and environmentally friendly amendment for Cd-contaminated soil remediation, combining effective immobilization with advantages in stability, ecological compatibility, and long-term effectiveness. Full article

Pneumatic conveying of stiff shotcrete material plays a crucial role in mine support; however, the flow regime evolution mechanism of its complex multi-scale particle system during conveying remains insufficiently studied. This study establishes a customized pneumatic conveying experimental platform, integrating a high-speed camera and pressure sensors to systematically investigate the flow regime evolution and characteristics of stiff shotcrete material under different operating parameters. Experimental results indicate that air velocity and water–cement ratio significantly influence flow regime evolution: at low air velocities, the material primarily exhibits dune flow and stratified flow. As the air velocity increases to 475 m³/h, the flow regime gradually transitions to suspended flow. An increase in the water–cement ratio significantly enhances liquid bridge forces between particles, intensifying particle agglomeration and making the bottom-layer flow characteristics more pronounced. Additionally, pipe diameter plays a crucial role in flow regime distribution, with suspended flow dominating in smaller pipes and bottom-layer flow becoming more prominent in larger pipes. In the downstream section of the elbow, the abrupt decrease in airflow velocity causes the flow regime to degrade from suspended flow to bottom-layer flow, leading to significant particle deposition. This study reveals the flow regime evolution patterns of stiff shotcrete material in pneumatic conveying, providing essential experimental evidence and theoretical support for optimizing long-distance pneumatic conveying systems in mine support applications. Full article

Polymeric nanocomposites have been extensively investigated due to their potential for enhancing the mechanical and tribological properties of polymer composites. In this study, the mechanical performance of carbon fiber-reinforced epoxy composites modified with nano-sized ferrochrome slag particles, an industrial by-product from stainless steel manufacturing, was evaluated. Composite laminates were fabricated using a vacuum-assisted hand lay-up process, with consistent carbon fiber reinforcement and uniformly dispersed nanofillers in the epoxy matrix. Mechanical properties such as tensile, flexural, impact, and Shore D hardness were evaluated as per ASTM and ISO standards. At 2 wt.% nanofiller loading, enhanced tensile strength and hardness by 33.02% and 8.92%, respectively, were achieved, while flexural strength and impact strength increased by 3.70% and 3.62% at 1 wt.% compared to the neat composite. Higher filler contents (>3 wt.%) resulted in reduced performance due to particle agglomeration and microstructural inhomogeneity. A scanning electron microscope was used to determine the uniform dispersion and agglomeration of nanofillers. The results demonstrated the potential of ferrochrome slag as a sustainable and cost-effective nanofiller for advanced composite applications. Full article

In this study, zinc oxide nanoparticles (ZnO NPs) were synthesized via a green chemistry approach using aqueous extract of Camellia sinensis var. assamica (Assam green tea) as a bioreductant and stabilizing agent. Phytochemical analysis of the extract revealed high levels of phenolics (338.57 ± 3.90 mg GAE/mL) and flavonoids (123.92 ± 1.34 µg QE/mL), along with strong antioxidant and reducing activity, supporting its efficacy in nanoparticle formation. ZnO NPs were synthesized at various extract concentrations, with 25% yielding optimal characteristics based on UV–Vis spectrophotometry (λ_Max ≈ 390–410 nm). Structural characterization using XRD confirmed the hexagonal wurtzite phase, and SAXS indicated particle sizes of 58–60 nm. FE-SEM analysis showed semi-spherical agglomerated particles ranging from 74 to 76 nm, while EDX verified the elemental purity of Zn and O. FT-IR spectroscopy confirmed the presence of Zn–O stretching and phytochemical residues on the nanoparticle surface. Stability studies over four weeks revealed red shifts in absorbance and reduced peak intensity at ambient and elevated temperatures, suggesting nanoparticle agglomeration. Antimicrobial assays demonstrated strong antifungal activity of the ZnO NP solution against Candida albicans and, upon concentration, significant antibacterial activity against Streptococcus mutans. The synthesized ZnO NPs exhibit promising potential as eco-friendly antimicrobial agents, particularly for applications in oral healthcare. Full article

In this study, the heat treatment of white kidney beans was optimized by a single-factor experiment and an orthogonal experiment. Taking in vitro digestibility as an index, the optimum technological parameters for heating white kidney beans were determined as follows: water addition of 225%, medium pressure heating for 30 min, and a temperature of 110 °C. The results of scanning electron microscopy showed that the layered structure in white kidney beans disappeared, and the original particle morphology was lost. The protein network was broken, forming an irregular agglomerate or flocculent structure, and the porous structure formed by heat-induced crosslinking effectively delayed the contact of amylase. Heat-treated white kidney beans were added to rice, and their nutritional components were determined, and the glycemic index was estimated in vitro to determine the best addition amount. The results of the in vitro digestion rate showed that the rice treated with 40% white kidney beans significantly reduced the glycemic index (eGI = 41.48), and the texture analysis showed that the viscoelasticity of rice could be improved by compounding 40% white kidney beans. It also effectively improves the taste of 100% white rice. This study can provide interdisciplinary solutions for the development of staple food for diabetes and provide a scientific basis for the development of staple food with a low glycemic index and the improvement of traditional diets. Full article

The development of effective catalysts for the oxygen reduction reaction (ORR) is crucial for improving the performance of fuel cells. Efficient carbon-supported Pt-Co nanocatalysts were successfully prepared by a generic two-step method: (i) electroless deposition of a Co-P coating on Vulcan XC72R carbon powder and (ii) subsequent spontaneous partial galvanic replacement of Co by Pt, upon immersion of the Co/C precursor in a chloroplatinate solution. The prepared Pt-Co particles (of a core-shell structure) are dispersed on a Vulcan XC-72 support, forming agglomerates made of nanoparticles smaller than 10 nm. The composition and surface morphology of the samples were characterized by scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDS) as well as transmission electron microscopy (TEM). The crystal structures of the Co-P/C precursor and Pt-Co/C catalyst were investigated by X-ray diffraction (XRD). XPS analysis was performed to study the chemical state of the surface layers of the precursor and catalyst. The electrochemical behavior of the Pt-Co/C composites was evaluated by cyclic voltammetry (CV). Linear sweep voltammetry (LSV) experiments were used to assess the catalytic activity towards the ORR and compared with that of a commercial Pt/C catalyst. The Pt-Co/C catalysts exhibit mass-specific and surface-specific activities (of j_m = 133 mA mg⁻¹ and j_esa = 0.661 mA cm⁻², respectively) at a typical overpotential value of 380 mV (+0.85 V vs. RHE); these are superior to those of similar electrodes made of a commercial Pt/C catalyst (j_m = 50.6 mA mg⁻¹; j_esa = 0.165 mA cm⁻²). The beneficial effect of even small (<1% wt.%) quantities of Co in the catalyst on Pt ORR activity may be attributed to an optimum catalyst composition and particle size resulting from the proposed preparation method. Full article

Environmental contamination with microplastics and trace pharmaceuticals is an increasing ecological and health concern. This study aimed to investigate the effects of low-temperature cold plasma on polyethylene (PE) microplastic particles and to assess the potential for degradation of pharmaceuticals adsorbed onto their surfaces. Two types of PE samples were prepared: suspended in distilled water and in treated wastewater. All samples were exposed to cold plasma. In the second stage, PE particles were saturated with selected pharmaceuticals (diclofenac, sulfamethoxazole, trimethoprim) and then subjected to plasma treatment. Pharmaceutical concentrations were measured using high-performance liquid chromatography (HPLC). Particle morphology was analyzed via light microscopy (after Nile red staining) and scanning electron microscopy (SEM). The results showed that cold plasma treatment leads to agglomeration of PE particles, with the extent increasing with longer plasma exposure time. Pharmaceuticals adsorbed to the PE surface in the range of 20–70% of the applied dose. Cold plasma demonstrated the ability to remove pharmaceutical contaminants, particularly diclofenac (>98%), sulfamethoxazole (99.99%) and trimethoprim (>98%). These findings indicate that cold plasma has promising potential as a supportive technology for removing both microplastics and pharmaceutical residues from wastewater and aquatic environments. Full article

Alumina (Al₂O₃) is a key material in inorganic and hybrid electronics due to its excellent dielectric, chemical, and thermal stability properties. In this work, we present the first results of alumina films deposited by ultrasonic spray pyrolysis (USP) at low temperatures (40–100 °C) using water as the sole solvent, followed by an annealing step at 100 °C. The films were characterized by SEM, XRD, EDS, and UV-Vis spectroscopy to evaluate their morphology, structure, composition, and optical properties. Preliminary results show an average thickness of approximately 8 µm, with surface features consisting of agglomerates (average particle size ≈ 7.252 µm) distributed over the film. XRD patterns revealed the presence of tetragonal and orthorhombic phases, while EDS confirmed the presence of aluminum and oxygen with slight compositional variations depending on deposition and annealing conditions. UV-Vis absorption spectra exhibited characteristic bands between 259 nm and 263 nm. These results provide a comprehensive understanding of the optical, structural, and morphological behavior of Al₂O₃ films processed at low temperatures. The motivation for studying these films is to enable more eco-friendly gate oxides for organic MIS structures, as well as functional layers in photonic devices. This approach represents a sustainable and straightforward route for obtaining Al₂O₃ coatings compatible with temperature-sensitive substrates, paving the way for future applications in hybrid and organic electronics. Full article

Nano-silica (NS) is used to enhance the mechanical and durability properties of cementitious materials; however, its frequent tendency to agglomerate limits its effectiveness and uniform distribution within the cement matrix. The main goal of this study was to improve NS dispersion and therefore to improve the properties of the concrete by coating NS onto standard sand particles (sand@NS) using the Stöber method, creating a composite material that acts as a filler, nucleation site, and highly reactive pozzolanic agent. The resulting sand@NS was incorporated into cement mixtures, and its compressive strength was measured after 3, 7, and 28 days of curing. In addition, water absorption and microstructural density were also evaluated. Comparative results showed that sand@NS significantly enhanced early-age hydration and initial strength, with a 145% increase in compressive strength at 28 days compared to the reference, whereas free NS resulted in a 120% increase. The early-age strength improvement was mainly due to the increased number of nucleation centers, while later strength gains were attributed to pozzolanic activity of the immobilized NS. Additionally, sand@NS reduced water absorption and increased microstructural density, even with reduced cement content, supporting more sustainable and eco-efficient concrete production. This work shows a promising, scalable, and cost-effective strategy to maximize the performance of NS in cementitious systems and supports its broader adoption in advanced construction materials. Full article

Cold gas dynamic spraying (CGDS) enables the production of protective coatings without melting or oxidation. In this study, Al–Zn–TiO₂ composite powders were prepared by wet agglomeration with binders and by dry mechanical mixing, and deposited onto mild steel substrates. COMSOL simulations of gas dynamics and particle acceleration identified optimal parameters (0.6 MPa, 600 °C, 15 mm, 90°), which were then validated experimentally. Coatings formed under these conditions exhibited dense microstructures, minimal porosity (~0.5%), and continuous, defect-free interfaces with the substrate. SEM and XRD confirmed solid-state bonding without new phase formation. Corrosion tests in 3.5% NaCl revealed a tenfold reduction in corrosion current density compared to bare steel, resulting from synergistic sacrificial (Zn), barrier (Al), and reinforcing/passivating (TiO₂) effects. Tribological tests demonstrated reduced friction (CoF ≈ 0.4–0.5) and wear volume. Compared with reported Al- or Zn-based cold- and thermal-sprayed coatings, the optimized Al–Zn–TiO₂ system shows superior performance, highlighting its potential for industrial anti-corrosion and wear-resistant applications. Full article