Search Results (153)

Tool steel TD salt-bath vanadizing generally relies on expensive analytical-grade raw materials, yet systematic investigations into low-cost industrial borax-based vanadizing of 9SiCr steel remain insufficient. This work intends to optimize the industrial salt-bath vanadizing process and clarify the growth mechanism of vanadium carbide coatings. TD thermal diffusion vanadizing was performed on 9SiCr steel using a molten borax salt bath containing industrial-grade borax and V₂O₅. Metallurgical microscopy, XRD, SEM-EDS and microhardness testing were adopted to systematically explore the effects of treatment temperature and holding time on coating thickness, microstructure and hardness. Continuous, dense VC coatings with favorable metallurgical bonding were fabricated. Coating thickness increased linearly with temperature and followed a parabolic growth law with respect to holding time. The optimized parameter was identified as 970 °C for 4 h, yielding a 8.3 μm thick coating with an average microhardness of ~2500 HV and an 8 μm thick diffusion transition layer. Comparative chromizing experiments indicated that the chromium carbide coating (16.7 μm) was approximately twice the thickness of the VC coating under identical conditions, demonstrating that VC coating growth is restricted by the diffusion supply of active carbon from the substrate. This research provides experimental data and theoretical guidance for the industrialized optimization of TD salt-bath vanadizing for 9SiCr steel. Full article

This study systematically investigates the effects of Ni and Al addition to a zinc bath on the microstructure, corrosion resistance and Vickers hardness of hot–dip galvanized coatings on Q235 steel. The Zn, Zn–0.04 wt.% Ni and Zn–0.04 wt.% Ni–1 wt.% Al coatings are characterized by scanning electron microscopy (SEM), X–ray diffraction (XRD), neutral salt spray (NSS) testing, electrochemical measurements and Vickers hardness testing. The addition of Ni refines and thins the ζ phase, increases the thickness of the δ phase, reduces the total coating thickness to 56.33 ± 0.89 μm and improves the corrosion resistance. With further Al addition, a continuous and dense inhibition layer forms at the interface, and the coating consists solely of this inhibition layer and the η phase; the total thickness is drastically reduced to 17.66 ± 1.78 μm, accompanied by a substantial improvement in both corrosion resistance and hardness. Electrochemical analysis reveals that the Zn–0.04 wt.% Ni–1 wt.% Al coating exhibits the most negative corrosion potential (0.61 V) and the smallest corrosion current density (2.07 μA·cm⁻²). Characterization of the corrosion products reveals that Al helps to stabilize Zn₅(OH)₈Cl₂·H₂O and Zn₅(OH)₆(CO₃)₂, thereby enhancing the corrosion resistance of the coating. Full article

To promote the sustainable development of the textile industry and address the critical challenges of high water consumption and salt pollution in cotton dyeing, this study developed a short-process cationic dyeing method using 2,3-epoxypropyltrimethylammonium chloride (GTA). Unlike traditional cationic dyeing, this approach eliminates the intermediate drying step by adding reactive dyes directly into the same bath after modification, achieving salt-free dyeing and significant water savings. The effects of key parameters, including GTA concentration, NaOH concentration, modification temperature and time, dyeing bath ratio, holding time, and dyeing temperature, were systematically investigated. The optimal dyeing conditions for C.I. Reactive Red 195, Reactive Black 5, and Reactive Blue 19 were determined as follows: GTA concentration of 40 g/L, NaOH concentration of 1 g/L, modification at 90 °C for 50 min, dyeing at 60 °C with a bath ratio of 1:15, and holding times of 30, 20, and 40 min, respectively. After modification, thermal stability and crystallinity decreased slightly (from 60.51% to 58.18%), while hydrophilicity showed no significant change. This short-process cationic dyeing method saves time, energy, and water while maintaining dyeing performance comparable to conventional methods. It provides a practical and sustainable new approach for salt-free cotton dyeing. Full article

Rushan acid whey is an underutilized by-product of a traditional fermented dairy food and may contain probiotic lactic acid bacteria. This study screened cholesterol-lowering strains from Rushan acid whey and evaluated Limosilactobacillus fermentum A001-A-08 for functional traits, preliminary safety, and lipid-lowering potential in high-fat-diet-induced zebrafish. A001-A-08 showed cholesterol removal, bile salt hydrolase activity, acid/bile/simulated gastrointestinal tolerance, auto-aggregation, gamma-hemolysis, and a mostly susceptible antibiotic profile. A 10⁶ CFU/mL bath concentration maintained larval survival, heart rate, and morphology and enabled intestinal localization during the observation period. In high-fat zebrafish, A001-A-08 reduced Oil Red O-stained lipid accumulation, improved hepatic morphology, lowered TC and TG, and increased HDL-C. Transcriptomic, metabolomic, qRT-PCR, and 16S rRNA sequencing analyses indicated that these phenotypic changes were associated with alterations in lipid transport, lipoprotein assembly, bile acid-related metabolism, selected metabolite features, and gut microbial composition. These findings support A001-A-08 as a promising Rushan acid whey-derived probiotic candidate, while genome-level safety assessment, mammalian oral-administration studies, and food-matrix validation remain necessary before functional-food application. Full article

The use of nanofluids in components of absorption cooling systems enhances heat and mass transfer processes. Limited information exists on the thermophysical properties of the nanofluid prepared with water–lithium bromide (H₂O–LiBr) as the base fluid and CuO nanoparticles. Due to the limited data available, viscosity is experimentally assessed in this study, providing novel results. The nanofluid was formed using the two-step method, using first a magnetic stirrer and second a sonication bath. A high-accuracy sensor was utilized for viscosity measurements. The nanoparticle mass fraction in the nanofluid was 0.1 wt%, while the salt mass fraction in the base fluid ranged from 56.62 to 60.69 wt% and the temperature from 24 to 60 °C. A strong temperature and salt concentration dependence of viscosity was observed for the nanofluid, exhibiting a 3–9% lower viscosity than the base fluid. As an additional scientific novelty, the viscosity of both the H₂O–LiBr mixture and the CuO/H₂O–LiBr nanofluid was examined for variable shear rates, showing a slight dilatant behavior. To develop a method for predicting viscosity, machine learning techniques were used. The best performing model was the multi-layer perceptron, which closely reproduces the experimental data and was selected for creating a graphical user interface for viscosity prediction. Full article

In this study, multilayer modified structures were fabricated on the surface of nuclear-grade 2.25Cr–1Mo steel via salt bath nitriding at different temperatures. Fretting corrosion tests were subsequently conducted in liquid sodium at 723 K. The results indicate that the multilayer structures formed by salt bath nitriding effectively enhance the cross-sectional hardness and improve the wear resistance of the substrate. However, after prolonged exposure to liquid sodium at 723 K, these multilayer structures undergo failure, primarily manifesting as cracking, spalling, and corrosion micropores. Material degradation of the nitrided steel is governed by the synergistic effects of tribological removal, chemical corrosion, and thermal acceleration. Notably, the QPQ 550 treatment, featuring a thinner compound layer, exhibited superior tribological performance during extended testing. This is attributed to the fact that while a higher salt bath nitriding temperature (QPQ 590) yields a thicker multilayer structure, it simultaneously induces premature failure—characterized by microcracking and the formation of corrosive channels—which ultimately compromises the wear performance. Full article

In response to the technical bottleneck of the Venlo greenhouse’s inability to achieve year-round production due to the high temperature and humidity in the summer in South China, this study took an existing Venlo-type greenhouse in Guangzhou as the research object and constructed a three-dimensional computational fluid dynamics (CFD) model of the greenhouse by comprehensively considering key factors such as solar radiation, thermal radiation, and crop canopy resistance. After on-site experiments, it was verified that, except for the top area of the greenhouse, the temperature deviation between the model simulation values and the measured values was less than 2 °C, and the error rate was less than 5%, confirming the model’s accurate representation of the temperature field distribution within the greenhouse. Based on the characteristics of the temperature and humidity fields revealed by the CFD simulation (canopy temperature gradient K = 0.144 °C/m, maximum temperature difference between upper and lower layers 20 °C), an optimized scheme of “wet curtain fan + salt bath dehumidification equipment” for local cooling and dehumidification of the crop canopy was proposed, and a non-uniform air duct layout was designed according to the temperature gradient characteristics. Field experiments showed that after optimization, the daytime temperature of the crop canopy was mostly controlled within 30 °C, the relative humidity was stably maintained below 80%, and the maximum temperature difference along the length of the greenhouse was reduced from 7 °C to 2 °C, effectively solving the problem of poor cooling and dehumidification effects of the traditional system. This scheme enabled the stable operation and year-round production of Venlo-type greenhouses in South China during the summer, providing technical support and engineering reference for greenhouse environmental control in high-humidity areas. Full article

Corrosion resistance of steel wires can be achieved through several approaches, one of the most established being hot-dip galvanizing. The effectiveness of anticorrosive protection of a galvanized wire is considered to depend not only on the galvanizing process itself, namely bath composition, temperature, and immersion duration—but also on the post-galvanizing wiping method, which ultimately determines the final thickness and uniformity of the zinc coating. This study describes and quantifies the resulting parameters of the Zn layer, systematically comparing two technical variants. Four parameters were analyzed to characterize the coating: the effective thickness of the constituent layers, their morphology (examined by SEM), their compositional profile (EDX mapping), and their microhardness. To comprehensively assess the influence of the wiping method on the anticorrosion performance of the galvanized wire, the final corrosion tests, fifth in the sequence, will be conducted in a salt fog environment using an Erichsen chamber, in accordance with standardized procedures. Full article

The ground impedance (insulation resistance R_isol) of photovoltaic (PV) modules is usually measured only in the dry state, even though arrays frequently operate under dew-wet or rain-wet conditions, when leakage paths can change. We measured dry insulation resistance R_dry and IEC 61215 MQT 15 wet leakage resistance R_wet for N = 37 field-aged crystalline-silicon modules from utility-scale plants and related the results to the IEC 40 MΩ·m² criterion (R_wet × A ≥ 40). The measurements used 1000 V DC and a 2 min dwell; R_wet was obtained in a salted bath with a solution resistivity < 3500 Ω·cm. The median R_dry was 42.4 GΩ, whereas the median R_wet was 462.5 MΩ, resulting in a median R_dry/R_wet ratio of ~110×. Three modules (8.1%) failed the 40 MΩ·m² limit already in the dry state, whereas eight modules (21.6%) failed under IEC-wet conditions; five were dry-pass/wet-fail cases that would have passed dry screening. For a representative area A = 1.8 m², a practical conservative dry triage threshold of approximately 55.5 GΩ identifies modules needing IEC-wet verification rather than serving as a stand-alone limit. Overall, combining dry and IEC-wet measurements improves safety and supports sustainability through resource-efficient repowering/revamping and end-of-life decisions in large PV fleets, particularly in hot climates. Full article

OsHKT1;1, a member of the high-affinity K⁺ transporter (HKT) family, plays a key role in Na⁺ homeostasis and salinity tolerance in rice. In our previous study, multiple potential OsHKT1;1 splicing variants were identified, as well as the full-length (FL) OsHKT1;1 transcript from the salt-tolerant rice Pokkali. However, most previous studies focused solely on the full-length protein, leaving the transport functions of splice variants largely unexamined. In this study, we focused on the splice variant OsHKT1;1-V2 and compared its function and gene expression with those of OsHKT1;1-FL. Two-electrode voltage clamp experiments using Xenopus laevis oocytes revealed that the 1st start codon of OsHKT1;1-V2 is functional to exhibit bidirectional currents in bath solutions containing NaCl. Unlike the Na⁺-selective feature of OsHKT1;1-FL, OsHKT1;1-V2 primarily mediated Cl⁻ transport with weak Na⁺ selectivity, which was supported by the higher Cl⁻ accumulation in OsHKT1;1-V2–expressing oocytes. Subcellular localization analyses using oocytes and Arabidopsis mesophyll cells indicated plasma membrane localization of OsHKT1;1-V2, similar to OsHKT1;1-FL. Functional assays using a yeast mutant further indicated that OsHKT1;1-FL, but not OsHKT1;1-V2, mediates Na⁺ uptake. The same OsHKT1;1 variants were identified in the japonica cultivar Nipponbare, and OsHKT1;1-V2 of the cultivar showed Cl⁻ transport properties similar to the one from Pokkali. Quantitative PCR analyses revealed higher abundance of OsHKT1;1-FL transcripts in Nipponbare than in Pokkali with markedly lower OsHKT1;1-V2 levels in Pokkali under salt stress. This study provides a new insight into HKT-mediated ion homeostasis under salinity stress. Full article

Reverse electrodialysis (RED) is a relatively recent technology for renewable energy harvesting from the interaction of river and seawater. This paper revisits the thermodynamic equilibrium governing the ionic transport processes through ion-exchange membranes (IEMs) under RED conditions and theoretically derives approximate analytical expressions for the ionic concentrations at the inner boundaries of a permeable membrane with well-stirred baths. The equation for the Donnan ion partitioning at the membrane–solution interface, which is based on the equality of the electrochemical potential in the two phases, is analysed for binary salts with symmetric (1:1) and asymmetric (2:1) electrolytes, by considering bathing solutions with the equivalent concentrations 0.02 M in the dilute bath, and 0.5, 1, and 1.5 M in the concentrate one. Simple approximate analytical expressions exhibiting the evolution with the membrane fixed-charge concentration of the counter-ionic concentrations at the inner boundaries of the membrane, the concentration gradients inside the membrane, the total Donnan electric potential, and the ionic partitioning coefficients have been derived. The approximate generalised expressions for a general z₁:z₂ binary electrolyte are also presented for the first time. Full article

Hydroxamic acid extractants, such as LIX984, demonstrate high efficiency in extracting nickel from electron-free nickel waste solutions; however, they suffer from a slow extraction rate. This study investigated the effect of adding 2–5 vol.% of three organophosphate extractants (P507, P204, and Cyanex272) to LIX984. The results show that incorporating 2–5 vol.% of P507 or Cyanex272 significantly improves both extraction efficiency and kinetics. The addition of organophosphate extractants increased the extraction rate by 1.5–10 times, indicating a direct correlation between the extractant content and the acceleration of the extraction process, with higher concentrations yielding faster extraction. Compared to the use of LIX984 alone, where nickel extraction efficiency was only 46%, the addition of 5 vol.% P507 increased efficiency to over 99%, with a substantial improvement in extraction rate. Similarly, 2 vol.% P204 achieved a nickel removal efficiency of 99.8%. In non-electroplating waste solutions (pH 4–6), selective removal of iron and zinc impurities was achieved by first adding 2–5 vol.% P204 or P507, followed by adjusting the pH to 6–7 and using a mixture of organophosphate extractants. The spent electroless nickel plating baths were then treated with LIX984 combined with organophosphoric acid extractants, yielding nickel salt solutions of higher purity. Thus, P507, P204, and Cyanex272 serve as effective promoters for the hydroxamic acid extractant LIX984, resulting in both enhanced nickel extraction efficiency and faster extraction kinetics. Full article

Synthetic cathinones (SCs), commonly referred to as “bath salts”, are a class of novel psychoactive substances (NPSs) that elicit amphetamine-like effects and severe cardiovascular outcomes, including myocardial infarction and sudden cardiac death. Despite these risks, the mechanisms underlying SC-induced cardiotoxicity remain poorly studied. This study investigated the in vitro cardiotoxicity of two prevalent SCs—methylone and 3,4-dimethylmethcathinone (3,4-DMMC)—in H9c2 rat cardiomyoblasts, focusing on oxidative stress and the potential protective role of antioxidants. Cells were exposed to methylone (0.01–4.0 mM) or 3,4-DMMC (0.0005–0.8 mM) for 24 and 48 h, and cytotoxicity was assessed by an MTT assay. Intracellular reactive oxygen/nitrogen species (ROS/RNS) were quantified by fluorescence, and antioxidant effects were evaluated using ascorbic acid, N-acetylcysteine, and Trolox. Both SCs caused concentration-dependent cytotoxicity, with 3,4-DMMC showing higher potency than methylone (IC₅₀: 0.28 vs. 0.98 mM, p = 0.0013). ROS/RNS levels increased in a concentration- and time-dependent manner for both compounds, reflecting early and sustained redox imbalance. Of the antioxidants, only ascorbic acid significantly improved cell viability. Taken together, these findings demonstrate for the first time that methylone and 3,4-DMMC exert cardiotoxic effects in vitro, with oxidative stress as a key contributor. The protective effect of ascorbic acid highlights its potential as a therapeutic candidate against SC-induced cardiac injury. Full article

Through employing WO₃ as a precursor, we successfully deposited a complete and continuous WC coating onto the surface of diamond particles by means of the salt bath method. Initially, a tungsten (W) layer forms on the diamond surface, which gradually transitions to a tungsten carbide (WC) coating as either the temperature is elevated or the duration of the process is prolonged. A thorough thermodynamic analysis was conducted to investigate this phase transition mechanism. At a lower synthesis temperature of 1000 °C, significant differences were observed in both the thickness and phase composition of the coatings formed on the (100) and (111) crystal planes of diamond. Specifically, the coating on the (100) plane exhibited earlier growth compared to that on the (111) plane, with WC phases appearing sooner within the coating’s composition. However, as the synthesis temperature increases, these differences in both thickness and phase composition between coatings on different diamond crystal faces tend to diminish, leading towards convergence. Furthermore, a detailed kinetic analysis of the coating growth process was conducted. It was found that the reduction reaction of carbon on WO₃ led to the formation of the W coating, and the diffusion of carbon in the W coating resulted in the formation of the WC coating. The diffusion of carbon in the coating ensured its continuous growth, providing deeper insights into the mechanisms governing the deposition and transformation processes. Full article

This work is based on studying the effect of different kinds of support on the prepared reverse osmosis membranes. Different kinds of woven and non-woven supports were tested and characterized to select the best one for RO membrane preparation. The prepared membrane on polyester woven support (M1ws) provides 39.9 LMH permeate flux using a piperazine coagulation bath during membrane preparation, while polyester non-woven support (M2ns) exhibits the highest salt rejection percentage, which was 92.2% using a Melamine coagulation bath. The mechanical properties for preparing membranes using supports were arranged in descending order as follows: M1ws > M2ns > M3np. The membrane on polypropylene support (M3np) provides the lowest mechanical properties. Full article