Search Results (933)

The production of heavy gauge quenched and tempered steel plates requires alloying strategies that ensure adequate hardenability and microstructural uniformity under limited cooling rates. Molybdenum (Mo) and nickel (Ni) are key elements in this context, as they influence both hot-working behavior and phase transformation kinetics. This study investigates the effect of Mo (0.25–0.50 wt%) and Ni (0–1.00 wt%) additions on static recrystallization and transformation behavior using laboratory thermomechanical simulations representative of thick plate rolling conditions. Multipass and double-hit torsion tests were performed to determine the non-recrystallization temperature (Tnr) and quantify softening kinetics, while dilatometry was employed to construct Continuous Cooling Transformation (CCT) diagrams and assess hardenability. Results indicate that Mo significantly increases Tnr and delays recrystallization through a solute drag mechanism, whereas Ni exerts a minor but measurable effect, likely associated with stacking fault energy rather than classical solute drag. Both elements reduce ferrite and bainite transformation temperatures, enhancing hardenability; however, Mo alone cannot suppress ferrite formation at practical cooling rates, requiring combined Mo–Ni additions to achieve fully martensitic microstructures. These findings provide insight into alloy design for thick plate applications and highlight the limitations of existing predictive models for Ni-containing steels. Full article

Salinity has been recognized as one of the major environmental stresses that restrict the growth and quality of celery (Apium graveolens L.). Therefore, this study investigates the impact of different NaCl concentrations on celery growth and photosynthetic characteristics, as well as the potential regulatory role of exogenous trehalose application in mitigating the stress-induced effects. The results indicated that an increase in NaCl concentration from 50 to 200 mM markedly inhibited the growth of celery plants compared to that under control conditions. The application of different concentrations of trehalose mitigated the inhibitory effects of salt stress (100 mM NaCl) on celery growth and photosynthesis. Among the different trehalose treatments, T3 (10 mM trehalose) exhibited the most significant effects, increasing the aboveground biomass, belowground biomass, plant height, chlorophyll a, chlorophyll b, total chlorophyll, and net photosynthetic rate compared to that of salt stress alone, respectively. Furthermore, trehalose treatments enhanced the various fluorescence parameters, including the maximum efficiency of PSII photochemistry (Fv/Fm), coefficient of photochemical quenching (qP), fluorescence intensity, and photosynthetic performance index (PIabs) under salt stress. Meanwhile, trehalose reduced intercellular carbon dioxide concentration, excess excitation energy (1-qP)/NPQ, heat dissipation per unit area (DIo/CSm), and energy dissipated per reaction center (DIo/RC). Additionally, the results of principal component analysis (PCA) and membership function comprehensive evaluation indicate that an appropriate concentration of trehalose positively alleviates the salnitiy-induced effects in celery. Overall, the T3 demonstrated the most promising effects on mitigating the effects of salt stress by decreasing the excess excitation energy of PSII in celery leaves through the heat dissipation pathway. This reduction lowers the excitation pressure on the reaction centers, enhances the activity of PSII reaction centers per unit cross-section, and improves photosynthesis activity, thereby improving the growth of celery plants under salt stress. Full article

In this study, the advanced oxidation system of peroxymonosulfate (PMS) was activated by molybdenite supported on biochar (Molybdenite@BC), and the degradation efficiency, influencing factors and degradation mechanism of sulfamethoxazole (SMX) were explored through experiments. Molybdenite@BC, a composite material used in the study, was prepared by pyrolysis at high temperature. The optimum pyrolysis temperature was 700 °C, and the mass ratio of molybdenite to biochar (BC) was 1:3. By changing dosage of Molybdenite@BC, pH value, initial concentration of PMS, and the types and concentration of inorganic anions, the effects of various factors on SMX degradation were systematically studied. The optimum reaction conditions of the Molybdenite@BC/PMS process were as follows: Molybdenite@BC dosage was 100 mg/L, PMS concentration was 0.2 mM, pH value was 6.9 ± 0.2, and initial SMX concentration was 6 mg/L. Under these conditions, the degradation rate of SMX was 97.87% after 60 min and 99.06% after 120 min. The material characterization analysis showed that Molybdenite@BC had a porous structure and rich active sites, which was beneficial to the degradation of pollutants. After the composite material was used, the peaks of MoO₂ and MoS₂ became weaker, which indicated that there was some loss of molybdenum from the material structure. Electron paramagnetic resonance (EPR) and radical quenching experiments revealed that Molybdenite@BC effectively catalyzed PMS to generate various reactive oxygen radicals and non-free radicals, including singlet oxygen (¹O₂), hydroxyl radical (^•OH), sulfate radical (SO₄^•−) and superoxide radical (^•O₂⁻). ¹O₂ played a leading role in the degradation of SMX, while ^•OH and SO₄^•− had little influence. The intermediate products of the degradation of SMX in Molybdenite@BC/PMS system were analyzed by liquid chromatography–tandem mass spectrometry (LC–MS). The results showed that there were nine main intermediate products in the process of degradation, and the overall toxicity tended to decrease during the degradation of SMX. The degradation path analysis showed that with the gradual ring opening and bond breaking of SMX, small molecular compounds were generated, which were finally mineralized into H₂O, CO₂, CO₃²⁻, H₂SO₄ and other substances. The research results confirmed that the Molybdenite@BC/PMS process provided a feasible new method for the degradation of SMX in water. Full article

In recent years, biomass utilization has attracted extensive attention. Herein, hexagonal/cubic ZnIn₂S₄ (ZIS) heterojunction catalysts were synthesized via a solvothermal method for the selective oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF). The results demonstrated that the constructed heterojunctions effectively promoted carrier separation. The optimal catalyst achieved an HMF conversion rate of 88.8% and a DFF yield of 86.6% within 1 h in the open air. X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) characterizations confirmed the successful fabrication of the composite phase structure and revealed a porous spherical morphology. Equivalent circuit fitting of electrochemical impedance spectroscopy (EIS) data indicated that the hexagonal/cubic heterojunctions possessed the lowest charge transfer resistance (Rct = 5825 Ω), which effectively reduced interfacial charge transfer resistance and accelerated the transport of photoinduced carriers. Radical quenching experiments and electron paramagnetic resonance (EPR) spectroscopy identified superoxide radicals (·O₂⁻) as the primary reactive species. Meanwhile, density functional theory (DFT) calculations elucidated the formation of the built-in electric field and the charge transfer mechanism. This work’s construction of Type-II ZIS heterojunctions effectively addressed the issue of rapid carrier recombination in pristine ZIS materials, providing a feasible strategy for biomass valorization. Full article

Oats (Avena sativa L.) are a staple grain and forage crop with substantial market demand. In China, they are the second most-imported forage grass, only after alfalfa (Medicago sativa L.). Enhancing the salt tolerance of oats to facilitate their cultivation in saline areas can thereby increase forage yield and promote the utilization of saline land, which constitutes an important reserve land resource in China. This study aimed to identify the bacterial strain Bacillus sp. LrM2 (hereafter referred to as strain LrM2) to determine its precise species-level classification and evaluate its effects on oat photosynthesis and growth under salt stress through indoor pot experiments. The results indicated that strain LrM2, capable of urease production and citrate utilization, was identified as Bacillus mojavensis. The strain LrM2 had a positive effect on shoot and root growth of oats under 100 mM NaCl stress conditions. Strain LrM2 inoculation modulated osmotic stress in oats under 100 mM NaCl stress by significantly increasing soluble sugar and decreasing proline content in leaves. It inhibited Na⁺ uptake and promoted K⁺ absorption in the roots, thereby reducing Na⁺ translocation to the leaves and mitigating ionic toxicity. Inoculation with strain LrM2 significantly increased photosynthetic pigment content (chlorophyll a, carotenoids), improved gas exchange parameters (stomatal conductance, transpiration rate, net rate of photosynthesis), enhanced PSII photochemical efficiency (maximum quantum yield, coefficient of photochemical quenching, actual photosynthetic efficiency of PSII, electron transfer rate), and reduced the quantum yield of non-regulated energy dissipation. These improvements, coupled with increased relative water content and instantaneous water use efficiency, thereby collectively enhanced the overall photosynthetic performance. In conclusion, strain LrM2 represents a promising bio-resource for mitigating salt stress and promoting growth in oats, with direct applications for developing novel biofertilizers and sustainable agricultural strategies. Full article

Polybutadiene has excellent mechanical properties and flexibility. It is widely used in elastomers and industrial fields. However, it has the characteristic of high flammability. The low LOI and rapid heat release upon ignition pose significant fire hazards. This results in a significant fire safety risk during service. Therefore, its application in some key fields has been restricted. In this study, polybutadiene with high-performance flame-retardant properties was developed by adding phosphorus–nitrogen synergistic flame retardants to address this challenge. This flame retardant mainly enhances its flame retardancy through the synergistic gas-phase and condensed-phase mechanisms. Dense and continuous carbon layers could be promoted by flame retardants during combustion. It provides an effective thermal barrier and oxygen barrier. In addition, phosphorus-containing volatiles can function by suppressing flame propagation via radical quenching in the gas phase. The modified polybutadiene reached UL-94 V-1 grade at the optimal load of 1.0 wt%. Meanwhile, its LOI increased to 27%. The cone calorimeter test further confirms a high reduction in peak heat release rate (pHRR). This work provides a feasible strategy for developing advanced polybutadiene materials. It can effectively enhance its fire safety. At the same time, it maintains a balance between flame retardancy and the overall material performance. Full article

Energy transition demands cleaner and more efficient marine engines, accelerating the development of reactivity-controlled compression ignition (RCCI) concepts with multi-fuel capability. However, the coupling between combustion behavior and thermal loading in RCCI engines remains insufficiently understood due to limited experimental capabilities and the absence of integrated modeling tools. This study develops a rapid predictive framework that dynamically couples an in-house chemical-kinetics solver with a GT-Suite engine model and a finite-element wall thermal solver. The framework was calibrated against measurements from a single-cylinder research engine representative of the Wärtsilä 31DF medium-speed NG/LFO RCCI engine. It accurately captured component temperatures and combustion/performance parameters with RMS errors below 5% and cycle times under four minutes. The results show that RCCI operation introduces pronounced component temperature variations across the load range, creating challenges for thermal management and combustion control. Low-load combustion inefficiencies were linked to cylinder head thermal design rather than the conventional flame-quenching explanation. At high load, excessive pressure-rise rates amplified heat transfer demands, with exhaust-valve temperatures exceeding 780 K and posing pre-ignition risks. Increasing coolant temperature by 40 K reduced methane slip by 10% and advanced combustion by nearly 2 CAD, improving efficiency at low load, while coordinated lambda/fuel-blend control lowered peak combustion temperature by ~200 K at high load, mitigating thermal-induced pre-ignition without compromising performance or emissions. Full article

La-doped ZnO nanoclusters confined within mesoporous SBA-15 were synthesized using an impregnation–calcination method and evaluated for their visible-light-driven photocatalytic degradation of Rhodamine B (RhB). Small-angle X-ray diffraction (XRD) and transmission electron microscopy (TEM) confirmed the preservation of the 2D hexagonal mesostructure of SBA-15 post-loading. In contrast, wide-angle XRD and Fourier-transform infrared spectroscopy (FT-IR) analyses revealed that the incorporated ZnO existed predominantly as highly dispersed amorphous or ultrafine clusters within the mesopores. N₂ adsorption–desorption measurements exhibited Type IV isotherms with H1 hysteresis loops. Compared to pristine SBA-15, the specific surface area and pore volume of the composites decreased from 729.35 m² g⁻¹ to 521.32 m² g⁻¹ and from 1.09 cm³ g⁻¹ to 0.85 cm³ g⁻¹, respectively, accompanied by an apparent increase in the average pore diameter from 5.99 nm to 6.55 nm, attributed to non-uniform pore occupation. Under visible-light irradiation, the photocatalytic performance was highly dependent on the La doping level. Notably, the 5% La-ZnO/SBA-15 sample exhibited superior activity, achieving over 99% RhB removal within 40 min and demonstrating the highest apparent rate constant (k = 0.1152 min⁻¹), surpassing both undoped ZnO/SBA-15 (k = 0.0467 min⁻¹) and other doping levels. Reusability tests over four consecutive cycles showed a consistent degradation efficiency exceeding 93%, with only a ~7 percentage-point decline, indicating excellent structural stability and recyclability. Radical scavenging experiments identified h⁺, ·OH, and ·O₂⁻ as the primary reactive species. Furthermore, photoluminescence (PL) quenching observed at the optimal 5% La doping level suggested suppressed radiative recombination and enhanced charge carrier separation. Collectively, these results underscore the synergistic effect of La doping and mesoporous confinement in achieving fast, efficient, and recyclable photocatalytic degradation of organic pollutants. Full article

Background/Objectives: Mood disorders are described by marked disruptions in emotions. Generally speaking, mood disorders are classified into two main categories: unipolar mood disorder, also known as unipolar depression, and bipolar mood disorder, also called manic-depressive illness. It is estimated that 40 million people live with bipolar disorder worldwide. Mathematical modeling of the dynamics of bipolar disorder may help to both better understand and treat the illness. This is especially important for bipolar disorder since, unlike unipolar disorder, there is an oscillation to be quenched between hypomanic and depressive episodes. Methods: By using a nonlinear dynamical model of bipolar disorder, this study offers two different control (treatment) approaches for the disorder. The first one is a nonlinear exact model knowledge controller assuming that all the parameters of the patient model are known. The second one is a nonlinear adaptive controller assuming that all the parameters are unknown. Results: Both controllers aim to drive both emotional mood and the change rate to a stable state. The Backstepping Technique is utilized as a nonlinear controller design tool. For both controllers, Lyapunov-type arguments are used to design the controller and to prove the stability of the designed controllers. Numerical simulation results are also provided to show the performance and feasibility of the proposed controllers. Conclusions: It has been shown that a nonlinear controller is capable of driving the emotional mood to its equilibrium point, zero, by quenching the mood swing. Full article

In this study, CuO nanoparticles were synthesised by chemical precipitation assisted by ultrasonic irradiation (UI), a rapid and environmentally friendly procedure without high temperature that enhances the sustainability of the synthesis process. They were also employed as a catalyst to activate peroxydisulfate (PDS) in the removal of ciprofloxacin (CIP) from a polluted solution. The effects of various factors, such as CIP concentration, catalyst dosage, PDS concentration, and initial pH, on the efficiency of this contaminant treatment were investigated. Under optimal conditions, CIP and TOC removal reached 100% and 49%, respectively, after only 30 min of reaction time and using high initial concentrations of CIP (20 mg/L), PDS (0.5 mM), and CuO (0.5 g/L) in pH (10). For the best set of processing conditions, pseudo-first-order reaction rate kinetics can be assumed and characterised. The possible degradation pathway of CIP is also suggested. Furthermore, by quenching experiment, the presence of O₂⁻*, *OH, and SO₄⁻* were identified, with O₂⁻* being a radical species with great impact on CIP removal. This study demonstrates that, in alkaline environments, ultrasonically synthesised CuO can effectively activate PDS for the degradation of CIP, achieving total removal within 30 min. The results indicate that UI-synthesised CuO is a very promising catalyst for the removal of emerging organic pollutants. Full article

We report a fully biogenic route to ZnO, Fe₃O₄, and their hydrothermally coupled ZnO/Fe₃O₄ heterostructure and establish a synthesis–structure–function link. Phase-pure, quasi-spherical wurtzite ZnO and finer inverse-spinel Fe₃O₄ nanoparticles assemble into a biphasic interface without forming a solid solution; optical analysis yields E_g = 2.36 eV (ZnO), 1.46 eV (Fe₃O₄), and 1.45 eV (ZnO/Fe₃O₄), while PL shows near-band-edge quenching and green–yellow defect reweighting at 490–560 nm, consistent with interfacial band bending. Magnetically, ZnO/Fe₃O₄ is soft-ferrimagnetic with M_S/M_R/H_C = 226 emu g⁻¹/17 emu g⁻¹/0.010 T (at 300 K), enabling rapid magnetic recovery. Under natural sunlight (572.6 ± 32 W m⁻²), adsorption-corrected methylene blue removal (10 mg L⁻¹; 10 mg in 50 mL) gives real degradation rates RDR = 90% (ZnO), 65% (ZnO/Fe₃O₄), and 30% (Fe₃O₄) at 180 min, with pseudo–first-order constants k = 1.9 × 10⁻², 0.7 × 10⁻², and 0.4 × 10⁻² min⁻¹, respectively; dark adsorption baselines are 10%, 14%, and 49%. Reusability over four cycles preserves pseudo-first-order kinetics (ZnO/Fe₃O₄: 65% → 50%). Scavenger tests implicate ${}^{•}\mathrm{O}\mathrm{H}$ as the dominant oxidant in ZnO and ZnO/Fe₃O₄, and ${}^{•}\mathrm{O}_2^{-}$ in Fe₃O₄. Taken together, the band alignment, photoluminescence quenching, radical-scavenger profiles, and kinetic synergy are consistent with a defect-rich S/Z-scheme-like ZnO/Fe₃O₄ heterojunction, delivering a green, sunlight-operable, and recyclable platform for affordable wastewater remediation. Full article

Food security and human health are directly related to the condition of agricultural soils. Soil contamination by heavy metals is a global environmental problem. Lead (Pb) is a toxic and non-biodegradable element posing a significant risk to ecosystems and human health. 24-Epibrassinolide (EBR) has multiple benefits in plant metabolism, including maximizing gas exchange. In plants, exogenous application of dopamine (DOP) confers tolerance to abiotic stresses, minimizing interferences on growth. This study aimed to investigate whether the exogenous application of EBR and DOP, administered independently or jointly, can contribute to mitigating the oxidative stress and impacts on photosystem II in Pb-stressed tomato, evaluating parameters related to nutritional status, photosystem II activity, gas exchange, antioxidant enzymes, and biomass. Better results were observed with the isolated EBR application, improving the photosynthetic efficiency, as evidenced by the increases in chlorophyll contents, effective quantum yield of PSII photochemistry, photochemical quenching coefficient, and electron transport rate, resulting in a higher net photosynthesis rate. Parallelly, treatment using both plant growth regulators (DOP and EBR) promoted significant increases of 14%, 18%, 13%, and 35% in the activities of superoxide dismutase, catalase, ascorbate peroxidase, and peroxidase, contributing to the reduction in oxidative stress in photosystem II of Pb-stressed plants. Therefore, this research proves that the exogenous application of DOP and EBR, alone or in combination, attenuates the toxic effects generated by Pb in tomato plants. Full article

High-temperature superconductor (HTS) magnet systems, especially those designed for fusion reactors, require effective and reliable monitoring to avoid damaging anomalies. In tokamaks, some of the magnetic coils are time-dependent, which causes strain and large inductive voltages within the magnet, rendering detection of incipient quench challenging. Ionizing radiation can also create material defects and lead to non-uniform degradation of conductors. The resulting decrease in critical current uniformity across the magnet, along with manufacturing defects, such as failure of structural materials or cooling systems, can all potentially initiate a quench. HTS magnets have a lower normal zone propagation velocity than low-temperature superconductors, and this causes normal zones to be localized, increasing the risk of permanent damage. Fiber optic sensors have several qualities that are essential in fusion systems. Unlike traditional voltage-based sensors, fiber optic cables are immune to the large electromagnetic fields present. This study presents and validates a fiber optic interrogation technique for monitoring magnetic confinement fusion and other high-temperature superconducting magnet systems. Coherent-phase optical time domain reflectometry (OTDR) allows for the high sampling rates (tens of kHz) necessary to quickly detect and mitigate quench events over the long distances required to monitor fusion magnet systems. This technique was demonstrated to successfully detect localized thermal transients at cryogenic temperatures as low as 6 K. These outcomes were also demonstrated using fibers embedded in HTS magnet coils at 77 K, verifying the potential for this interrogation technique’s use for failure detection in HTS coils. Full article

Most reported fluorescent Al³⁺ probes rely on fluorescence signal enhancement or quenching. Since the change in fluorescence intensity is the sole detection signal, various factors such as instrumental efficiency, environmental conditions, and probe concentration can interfere with the signal output. In contrast, ratiometric probes, which utilize two emission bands for self-calibration, provide significant advantages by minimizing or eliminating these uncertainties. In this study, a naphthalimide-rhodamine based the transition between the cyclic and open-ring forms of rhodamine as an Al³⁺-selective ratiometric probe, in which chitosan was identified as an ideal bridge and biocompatibility. The design concept was that when the target metal ion was present, the fluorescence intensity of naphthalimide remained largely unchanged, serving as an internal standard. In contrast, rhodamine B was employed to label the target molecules, with its fluorescence intensity varying in accordance with the target concentration. A series of experiments were carried out to investigate the fluorometric properties of the grafted polymer P. The results demonstrated that P exhibited selective interaction with Al³⁺ among the various metals tested. Using the fluorescence intensity ratio (I_{603 nm}/I_{538 nm}) of P, a good linear relationship was achieved for Al³⁺ concentrations ranging from 1.0 to 35.0 μM with a detection limit of 0.33 μM was obtained. Meanwhile, we employed the standard addition method for the quantitative analysis and detection of Al³⁺ in commercially available bottled water and tap water, achieving an ideal recovery rate. Full article

The studied Ce_0.5Y_0.5−XTb_XF₃ (X = 0, 0.001, 0.002, 0.005, 0.01, and 0.05) nanoparticles were synthesized via the water-based co-precipitation method. All the samples demonstrated diameters in the 17–20 nm range and a hexagonal phase corresponding to the phase of CeF₃. Under 266 nm excitation (4f–5d absorption band of Ce³⁺), the luminescence spectrum shape was notably dependent on temperature. The integrated luminescence intensity ratio (LIR) of Ce³⁺ and Tb³⁺ (⁵D₄–⁷F₃) peaks was chosen as a temperature-dependent parameter. It was shown that the LIR functions linearly decay. The rate of decay decreases with the increase in Tb³⁺ concentration. This was explained by the fact that in the case of low Tb³⁺ concentrations, the spectral temperature dependence is mostly based on effective thermal quenching of Ce³⁺ luminescence. At higher Tb³⁺ concentrations, there is a higher probability of Ce³⁺ to Tb³⁺ energy transfer. Here, the efficiency of the temperature dependence of this process is lower, and the rate of LIR decay is lower as well. Full article