Search Results (985)

The increasing reliance on conventional coatings such as WC-Co raises serious environmental and health concerns due to the toxicity of cobalt and the ecological footprint of these materials. To address this challenge, the present study explores the development of eco-friendly multifunctional coatings via the Plasma Spray (PS) process, using titanium (Ti), silicon carbide (SiC), and tungsten carbide-cobalt (WC-Co) mixtures as alternative feedstocks. Steel substrates were coated under different deposition strategies (powder mixing, layer-by-layer) and current settings (800-900 A). The coatings were characterized by scanning electron microscopy (SEM/EDX), 3D profilometry, sliding wear testing, and potentiodynamic corrosion measurements. Results showed that Ti-WC (mix, 900 A) and Ti-SiC (layer, 900 A) coatings achieved the most favorable performance, combining excellent adhesion, uniform coverage, reduced porosity, and improved resistance to wear and corrosion compared to conventional Cr₂O₃ coatings. Notably, Ti-WC coatings provided surface roughness values comparable to Cr₂O₃, while significantly lowering the environmental impact. These findings demonstrate that PS-based Ti-WC and Ti-SiC systems can serve as sustainable and high-performance alternatives for protective applications in harsh environments, particularly in marine industries, supporting the transition toward coatings with reduced ecological footprint. Full article

Zirconium (Zr) thin films were deposited on silicon (Si) substrates via pulsed laser deposition (PLD) using a 248 nm excimer laser. The effects of substrate temperature on film morphology and crystallinity were systematically investigated. X-ray diffraction (XRD) revealed that the Zr(100) plane exhibited the strongest orientation at 400 °C while Zr (002) was maximum at 500 °C. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) analyses demonstrated an increase in surface roughness with temperature, with the smoothest surface observed at lower temperatures and significant island formation at 500 °C due to the transition to 3D growth. At 500 °C, interdiffusion effects led to the formation of zirconium silicide at the Zr/Si interface. To further interpret the experimental findings, computational modeling was employed to analyze the transition from 2D layer-by-layer growth to 3D island formation at elevated temperatures. Using a multi-parameter kinetics-free model based on free energy minimization, the critical film thickness for this transition was determined to be ~1–2 nm, aligning well with experimental observations. A separate kinetic model of island nucleation and growth predicts that this shift is driven by the kinetics of adatom surface diffusion. Additionally, the kinetic simulations revealed that, at 400 °C, adatom diffusivity optimally balances crystallization and surface energy minimization, yielding the highest film quality. At 500 °C, the rapid increase in diffusivity leads to the proliferation of 3D islands, consistent with the roughness trends observed in SEM and AFM data. These findings underscore the critical role of deposition parameters in tailoring Zr thin films for applications in advanced coatings and electronic devices. Full article

Background/Objectives: Spheroid cultures in Matrigel are routinely used to study cell behaviour in complex 3D settings, thereby generating preclinical models of disease. Ideally, researchers would like to modulate gene expression ‘in situ’ for testing novel gene therapies while conserving the spheroid architecture. Here, we aim to provide an efficient method to transfect small RNAs (such as microRNAs and small interfering RNAs, i.e., siRNAs) into human induced pluripotent stem cell (iPSC)-derived 3D lung spheroids, specifically alveolar type II epithelial cells (iAT2) and basal cell (iBC) spheroids. Methods: Transfection of iAT2 spheroids within 3D Matrigel ‘in situ’, whole spheroids released from Matrigel or spheroids dissociated to single cells was explored via flow cytometry using a fluorescently labelled siRNA. Validation of the transfection method was performed in iAT2 and iBC spheroids using siRNA and miRNA mimics and measurement of specific target expression post-transfection. Results: Maximal delivery of siRNA was achieved in serum-free conditions in whole spheroids released from the Matrigel, followed by whole spheroids ‘in situ’. ‘In situ’ transfection of SFTPC-siRNA led to a 50% reduction in the SFTPC mRNA levels in iAT2 spheroids. Transfection of miR-29c mimic and miR-21 pre-miR into iAT2 and iBC spheroids, respectively, led to significant miRNA overexpression, together with a significant decrease in protein levels of the miR-29 target FOXO3a. Conclusions: This study demonstrates successful transfection of iPSC-derived lung spheroids without disruption of their 3D structure using a simple and feasible approach. Further development of these methods will facilitate functional studies in iPSC-derived spheroids utilizing small RNAs. Full article

For the first time, the kinetics of isothermal curing and thermal degradation of polyethylene glycol maleate (pEGM)–based systems and their composites with mineral fillers were investigated in the presence of a benzoyl peroxide/N,N-Dimethylaniline redox-initiating system. DSC analysis revealed that the curing process at 20 °C can be described by the modified Kamal autocatalytic model; the critical degree of conversion (α_c) decreases with increasing content of the unsaturated polyester pEGM and in the presence of fillers. In particular, for unfilled systems, α_c was 0.77 for pEGM45 and 0.60 for pEGM60. TGA results demonstrated that higher pEGM content and the incorporation of fillers lead to increased thermal stability and residual mass, along with a reduction in the maximum decomposition rate (dTGₘₐₓ). Calculations using the Kissinger–Akahira–Sunose and Friedman methods also confirmed an increase in the activation energy of thermal degradation (E_a): E_KAS was 419 kJ/mol for pEGM45 and 470 kJ/mol for pEGM60, with the highest values observed for pEGM60 systems with fillers (496 kJ/mol for SiO₂ and 514 kJ/mol for CaCO₃). Rheological studies employing three-interval thixotropy tests revealed the onset of thixotropic behavior upon filler addition and an increase in structure recovery after deformation of up to 56%. These findings underscore the potential of pEGM-based systems for low-temperature curing and for the design of composite materials with improved thermal resistance. Full article

This study investigated the effects of individual and combined supplementation of eucalyptus essential oil (EEO) and soy isoflavones (SI) on the growth performance, intestinal health and meat quality of weaned meat rabbits. A total of 120 Ira female rabbits were stratified by body weight (BW) and randomly allocated into four treatment groups. The rabbits were fed for 35 days using (a) basal diet (Control), (b) basal diet + 150 mg/kg EEO, (c) basal diet + 25 mg/kg SI, or (d) basal diet + 150 mg/kg EEO + 25 mg/kg SI. The results showed that supplementing EEO and SI in the diet had a synergistic effect on production performance by increasing BW and average daily gain and reducing the feed intake/gain ratio. The EEO + SI group exhibited the most pronounced improvement in growth performance. Compared with the Control group, individual or combined supplementation significantly increased both semi-clean slaughter and total eviscerated slaughter rates, and showed a synergistic effect when supplemented together. The antioxidant capacity of the rabbits was enhanced, with the EEO + SI group showing the largest improvement. Serum biochemical analysis revealed that the combined treatment improved hepatic and cardiovascular functions. Additionally, we observed that the combined addition of EEO and SI has a synergistic effect on increasing the height of intestinal villi and the villus height/crypt depth ratio. Moreover, EEO and SI synergistically improved meat quality by elevating pH value, water-holding capacity, tenderness, and fat proportion. Notably, supplementation of EEO and SI in the diet regulated the composition of the intestinal microbiota, demonstrating increased relative abundance of beneficial Bacteroides and Lachnospiraceae_NK4A136_group. In conclusion, the combination of EEO and SI outperformed individual supplements in promoting growth and intestinal barrier function, potentially through enhancing antioxidant activity, attenuating oxidative stress, protecting the hepatic/cardiovascular systems, and improving intestinal morphology and microbial composition, thereby collectively enhancing growth performance, slaughter traits, and meat quality. Full article

This study investigates the mechanism behind the heat-induced color change (brown to yellowish green) in Mn- and Fe-rich elbaite tourmaline under reducing atmosphere at 500 °C. A combination of analytical techniques including gemological characterization, electron microprobe analysis (EMPA), laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and ultraviolet–visible (UV-Vis) spectroscopy was employed. Chemical analysis confirmed the samples as intermediate members of the elbaite–fluorelbaite series, with an average formula of ^X(Na₀.₆₆ □₀.₂₆ Ca₀.₀₈) _Σ1.₀₀^Y(Li₁.₂₉Al₁.₁₀Mn₀.₃₁ Fe²⁺₀.₁₅Ti₀.₀₁Zn₀.₀₁) _Σ2.₈₇ ^ZAl₆^T[Si₆O₁₈] (BO₃)₃^V(OH)₃.₀₀^W(OH₀.₅₁F₀.₄₉) _Σ1.₀₀, enriched in Mn (17,346–20,669 μg/g) and Fe (8396–10,750 μg/g). Heat treatment enhanced transparency and induced strong pleochroism (yellowish green parallel c-axis, brown perpendicular c-axis). UV-Vis spectroscopy identified the brown color origin in the parallel c-axis direction: absorption bands at 730 nm (Fe²⁺ d–d transition, ⁵T_2g → ⁵E_g), 540 nm (Fe²⁺→Fe³⁺ intervalence charge transfer, IVCT), and 415 nm (Fe²⁺→Ti⁴⁺ IVCT + possible Mn²⁺ contribution). Post-treatment, the 540 nm band vanished, creating a green transmission window and causing the color shift parallel the c-axis. The spectra perpendicular to the c-axis remained largely unchanged. The disappearance of the 540 nm band, attributed to the reduction of Fe³⁺ to Fe²⁺ eliminating the Fe²⁺–Fe³⁺ pair interaction required for IVCT, is the primary color change mechanism. The parallel c-axis section of the samples shows brown and yellow-green dichroism after heat treatment. A decrease in the IR intensity at 4170 cm⁻¹ indicates a reduced Fe³⁺ concentration. The weakening or disappearance of the 4721 cm⁻¹ absorption band of the infrared spectrum and the near-infrared 976 nm absorption band of the ultraviolet–visible spectrum provides diagnostic indicators for identifying heat treatment in similar brown elbaite–fluorelbaite. Full article

This study investigates the influence of plasma electrolytic oxidation (PEO) on corrosion resistance of Ti6Al4V alloys produced by direct metal laser sintering (DMLS) for orthopedic implants. PEO (300 s) and flash-PEO (60 s) coatings containing Si, Ca, P, Mg and Zn were applied on both DMLS and wrought Ti6Al4V alloys. Samples, coated and uncoated, were characterized for microstructure, morphology and composition. Electrochemical behaviour was assessed by potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) in simulated body fluid (SBF) at 37 °C. Ion release was quantified by inductively coupled plasma optical emission spectroscopy (ICP-OES). DMLS alloy was more passive than wrought Ti6Al4V, releasing ~60% less Ti and ~25% less Al, but ~900% more V. For both alloys, correlation of corrosion current and ion release indicated that 98–99% of oxidized Ti remained in the passive layer. Flash-PEO produced uniform porous coatings composed of anatase and rutile with ~50% amorphous phase, while PEO yielded heterogeneous layers due to soft sparking. In both cases, coatings were the main source of ions. For the DMLS alloy, the best protection was afforded by flash-PEO, releasing 0.01 μg cm⁻² d⁻¹ Ti, 26 μg cm⁻² d⁻¹ Al, and 0.25 μg cm⁻² d⁻¹ V over 30 days. Full article

In order to solve the problem of the efficiency reduction and complex manufacturing of traditional grating couplers under environmental temperature fluctuations, a Si₃N₄ high-efficiency grating coupler integrating a distributed Bragg reflector (DBR) and thermo-optical tuning layer is proposed. In this paper, the double-layer DBR is used to make the down-scattered light interfere with other light and reflect it back into the waveguide. The finite difference time domain (FDTD) method is used to simulate and optimize the key parameters such as grating period, duty cycle, incident angle and cladding thickness, achieving a coupling efficiency of −1.59 dB and a 3 dB bandwidth of 106 nm. In order to further enhance the temperature stability, the amorphous silicon (a-Si) thermo-optical material layer and titanium metal serpentine heater are embedded in the DBR. The reduction in coupling efficiency caused by fluctuations in environmental temperature is compensated via local temperature control. The simulation results show that within the wide temperature range from −55 °C to 150 °C, the compensated coupling efficiency fluctuation is less than 0.02 dB, and the center wavelength undergoes a blue shift. This design is compatible with complementary metal-oxide-semiconductor (CMOS) processes, which not only simplifies the fabrication process but also significantly improves device stability over a wide temperature range. This provides a feasible and efficient coupling solution for photonic integrated chips in non-temperature-controlled environments, such as optical communications, data centers, and automotive systems. Full article

In this study, a novel and rapid top-down synthesis method for the successful synthesis of few-layered 2D SiC is reported. Since the theoretical prediction of planar and stable 2D SiC with a direct bandgap, only a few experimental methods have overcome the challenging covalent sp³ hybridization of its bulk structure, unlike Van der Waals layered material bonding, making the synthesis of few-layered or mono-layered SiC more difficult due to the highly time- and energy-consuming methods. Moreover, correctly choosing between the more than 250 SiC polytypes increases the complexity of successful approaches to its 2D synthesis. This work reports, for the first time, multi-layered 2D SiC obtained using the wet ultrasonic probe sonochemical exfoliation method, reducing both the experimental synthesis time and energy consumption. Raman spectra showed the size-dependent correlation of the longitudinal optical (LO) mode, and IR showed the bond modification between bulk and nanostructured SiC. These results demonstrate a scalable and facile route for 2D SiC production; therefore, a wide variety of applications can be explored experimentally rather than theoretically, and methods such as the deposition of ScAlN layers onto SiN can be simplified in further studies. Full article

To reduce the proliferation of greenhouse gases in the construction industry, ternary blended concrete comprising fly ash (FA) powder, waste glass (WG) powder, and ordinary Portland cement (OPC) was developed such that the WG to total binder varied from 0 to 20% at intervals of 5% (C₈₀FA_20-xWG_x:x = WG/(WG + FA + OPC)). The developed concrete was investigated for water absorption, workability, 28-day compressive strength, binder phases, bond characteristics, microstructure, and elemental composition of the concrete. The mixture proportions of C₈₀FA₁₅WG₅ and C₈₀FA₁₀WG₁₀ exhibited better consistency and water absorption than the OPC concrete (C₁₀₀FA₀WG₀). Furthermore, the 28 d strength of C₈₀FA₁₅WG₅ marginally outperformed those of C₈₀FA₁₀WG₁₀ and C₈₀FA₂₀WG₀. The sample with equal proportions of FA and WG (C₈₀FA₁₀G₁₀) was more amorphous owing to the disappearance of the hedenbergite phase (CaFeSi₂O₆) and conversion of tobermorite (CSH) to C-A-S-H. C₈₀FA₁₀WG₁₀ also exhibited better microstructural stability than FA + OPC concrete (C₈₀FA₂₀G₀), owing to the pore-filling of the microcracks within the matrix. Finally, higher Si/Ca, Ca/Al, and Si/Al ratios were recorded in C₈₀FA₁₀WG₁₀ than in the case of FA preponderating WG in ternary blending. Finally, structural concrete can be produced through the ternary blending of glass waste, fly ash, and OPC, thereby promoting the valorization of solid waste and a sustainable environment. Full article

This study investigates the valorization of refuse-derived fuel (RDF), waste glass, and mill scale for sustainable ferrosilicon alloy production, contributing to zero-waste practices. RDF was blended with anthracite at ratios of 100, 90, 80, 70, 60 and 50 wt% (designated R1–R6) and applied as a reducing agent in the carbothermic reduction of SiO₂ and Fe₂O₃, thereby decreasing reliance on conventional fossil-based reductants. Ferrosilicon synthesis was conducted at 1550 °C using glass–mill scale blends with reducing agents R1–R6, producing samples named blends A–F. XRD analysis confirmed that the metallic products consisted predominantly of the FeSi intermetallic phase, with characteristic (110) and (310) peaks at 2θ ≈ 45.02° and 78°. The metallic products appeared as numerous small, shiny droplets, with yields ranging from 14.85 to 19.47 wt%; blends D–F exhibited the highest yields. In contrast, blends A–C produced metals with higher Si contents (23.34–27.11 wt%) due to enhanced SiO₂ reduction and efficient Si incorporation into the Fe matrix. Gas analysis and oxygen removal showed that blend B achieved the highest CO generation and reduction extent. Cl removal during RDF heat treatment indicated minimal potential for dioxin and furan formation. Overall, blends A and C were identified as optimal, providing high Si content, satisfactory metallic yield, and reduced CO/CO₂ emissions, demonstrating the effectiveness of RDF-based carbons for environmentally friendly ferrosilicon production. Full article

Power metal-oxide-semiconductor field-effect transistors (MOSFETs) provide numerous advantages and are widely utilized in various power circuits. The junction temperature plays a critical role in determining the reliability, performance, and operational lifetime of power MOSFETs. Therefore, accurate monitoring of the junction temperature of power MOSFETs is essential to ensure the safe operation of power circuit systems. In bridge or motor drive circuits, MOSFETs often operate in a freewheeling state via the body diode, where the freewheeling current is typically variable. The proposed method for junction temperature measurement utilizes the body diode and is designed to accommodate varying forward currents. It also accounts for the temperature-dependent ideality factor to improve measurement accuracy. By integrating the forward voltage and forward current of the body diode, this approach reduces the required sampling frequency. To validate the method’s effectiveness, three representative types of power MOSFETs, a Si MOSFET (IRF520), a SiC MOSFET (C2M0080120D), and an aerospace-grade radiation-hardened MOSFET (RSCS25045T1RH), were used to measure junction temperatures before and after irradiation. Following ideality factor correction, the maximum absolute error compared to reference measurements from thermocouples and a thermal imager remained within 2 K across the temperature range of 300 K to 420 K. Experimental results confirm the feasibility of the proposed method. Full article

Atherosclerosis as a multifactorial disease remains the first cause of death worldwide. Current oral lipid-lowering drugs (especially statins) reduce low-density lipoprotein cholesterol (LDLC) levels in the blood, but their clinical efficacy seems to be partially attributed to pleiotropic effects on different pathophysiologic factors of atherosclerosis extending beyond lipid-lowering properties such as anti-inflammatory, antithrombotic and antioxidative features. Novel drugs that interfere with proprotein convertase subtilisin/kexin type 9 (PCSK9) axis of LDL-C receptors (LDLRs) degradation, from the group of monoclonal antibodies (e.g., alirocumab, evolocumab) or small interfering RNA (siRNA), e.g., inclisiran, are effective in reducing LDLC as well. However, data depicting their antithrombotic and antiplatelet activity are scarce, whereas prothrombotic properties of PCSK9 are widely described. Thus, we performed a study to assess the effects of inclisiran on subclinical prothrombotic [fibrinogen, coagulation factor VIII (FVIII), plasminogen activator inhibitor-1 (PAI-1)] and platelet activation markers (platelet factor-4 (PF-4), soluble p-selectin (sCD62P)). Ten patients at high cardiovascular risk with concomitant heterozygous familial hypercholesterolemia (HeFH)—study group 1, and fourteen patients at very high cardiovascular risk without concomitant HeFH—study group 2, were recruited for the study. Lipid profile, subclinical prothrombotic and platelet activation markers were assessed at the beginning and after 3 months of therapy with inclisiran. During therapy, statistically significant reductions in both study groups were seen in total cholesterol levels (study group 1: from 287.6 ± 94.2 to 215.2 ± 89.1 (mg/dL), p = 0.022; study group 2: from 211.7 ± 52.7 to 147.6 ± 55.4 (mg/dL), p < 0.001) and LDL-c (study group 1: from 180.8 ± 73.3 to 114.7 ± 71.5 (mg/dL), p = 0.031; study group 2: from 129.6 ± 46.8 to 63.4 ± 43.6 (mg/dL), p < 0.001). Lipid profile changes were associated with significant decrease in the concentration of FVIII in both groups (study group 1: from 33.3 ± 22 to 22 ± 14.5 (ng/mL), p = 0.006; study group 2: from 37 ±16.9 to 29.3 ±16.4 (ng/mL), p = 0.002) and fibrinogen, but only in study group 2 (from 51.4 (33.2–72.7) to 42.6 (31.3–57.2) (µg/mL), p = 0.035). Among platelet activation markers, a significant decrease in PF-4 in study group 2 was noted (from 286 (272–295.5) to 272 (268–281.5) (ng/mL), p = 0.047). However, there were no statistically significant changes in PAI-1 and sCD62P throughout the study. In our study, inclisiran appeared to be an effective lipid-lowering drug in patients at high cardiovascular risk. Moreover, it was shown that beyond lipid-lowering properties, the drug may also partially affect thrombogenesis and platelet activation. Full article

This paper comprehensively reports experimental proof of parity violation in the ground and photoexcited states of three mirror-symmetric Si–Si bond polymers in homogeneous solutions of achiral molecules under non-stirring conditions by analyzing 370 chiroptical datasets relating to multiple second-order helix–helix transitions in the circular dichroism (CD) of poly(di-i-butylsilane) (iBS), poly(di-i-pentylsilane) (iPS), and poly(di-i-hexylsilane) (iHS) in achiral alkanols and p-dioxane-h₈/-d₈. Particularly large (–)-CD of g_abs = −3.1 × 10⁻² at 290 nm was found for iBS in i-pentanol at 25 °C. Notably, iPS in n-propanol at −5 °C generated (–)-CD with g_abs = −0.48 × 10⁻² at 300 nm, but (+)-circularly polarized luminescence (CPL) with g_lum = +0.84 × 10⁻² at 326 nm. In contrast, iHS in n-octanol at 0 °C showed only very weak (–)-CD of g_abs ~−0.03 × 10⁻² at 310 nm. The H/D isotopes of p-dioxane-h₈/-d₈ weakly affected the helix–helix transition characteristics of iBS. (–)-Sign vibrational CD signals assigned to the handed symmetric and asymmetric bending modes of the CH₃ and CH₂ groups of the solvents and other achiral molecules were observed. We assumed (i) three ¹H nuclear-spin-1/2 induced handed motions of CH₃ rotors at i-alkyl side chains and achiral alkanols, and (ii) helical main-chain Si atoms (δ⁺) coordinated by handed lone pairs at oxygen (δ⁻) in gauche-containing n- and i-alkanols induced by the CH₃ rotors. A possible origin of biomolecular handedness is proposed based on the first observation of far-UV CD and UV spectra of zwitterionic glycine bearing H₃N⁺ rotor in neutral H₂O. Full article

Enhancing user access capacity in satellite beam-hopping systems remains challenging due to dynamic traffic and limited beam dwell times. Conventional Multi-Frequency Time-Division Multiple Access (MF-TDMA) proves highly inefficient under such constraints. To overcome this, we propose a novel scheme that integrates power-domain Non-Orthogonal Multiple Access (NOMA) with MF-TDMA, employing Successive Interference Cancelation (SIC) for multi-user signal separation. A bi-directional adaptive carrier synchronization method and optimized burst structure are introduced, which collectively reduce synchronization overhead by over 40% compared to MF-TDMA. Simulations demonstrate a dramatically improved frame error rate of 0.0005% at 4 dB SNR—30 times lower than the 0.016% achieved by MF-TDMA—and a transmission efficiency of 92–97%, significantly outperforming conventional MF-TDMA. These results validate the proposed method’s substantial gains in capacity and efficiency for next-generation satellite systems. Full article