Search Results (344)

Anion exchange membrane (AEM) water electrolysis is a potentially inexpensive and efficient source of hydrogen production as it uses effective low-cost catalysts. The catalytic activity and performance of nickel iron oxide (NiFeO_x) catalysts for hydrogen production in AEM water electrolyzers were investigated. The NiFeO_x catalysts were synthesized with various iron content weight percentages, and at the stoichiometric ratio for nickel ferrite (NiFe₂O₄). The catalytic activity of NiFeO_x catalyst was evaluated by linear sweep voltammetry (LSV) and chronoamperometry for the oxygen evolution reaction (OER). NiFe₂O₄ showed the highest activity for the OER in a three-electrode system, with 320 mA cm⁻² at 2 V in 1 M KOH solution. NiFe₂O₄ displayed strong stability over a 600 h period at 50 mA cm⁻² in a three-electrode setup, with a degradation rate of 15 μV/h. In single-cell electrolysis using a X-37 T membrane, at 2.2 V in 1 M KOH, the NiFe₂O₄ catalyst had the highest activity of 1100 mA cm⁻² at 45 °C, which increased with the temperature to 1503 mA cm⁻² at 55 °C. The performance of various membranes was examined, and the highest performance of the tested membranes was determined to be that of the Fumatech FAA-3-50 and FAS-50 membranes, implying that membrane performance is strongly correlated with membrane conductivity. The obtained Nyquist plots and equivalent circuit analysis were used to determine cell resistances. It was found that ohmic resistance decreases with an increase in temperature from 45 °C to 55 °C, implying the positive effect of temperature on AEM electrolysis. The FAA-3-50 and FAS-50 membranes were determined to have lower activation and ohmic resistances, indicative of higher conductivity and faster membrane charge transfer. NiFe₂O₄ in an AEM water electrolyzer displayed strong stability, with a voltage degradation rate of 0.833 mV/h over the 12 h durability test. Full article

This pilot, randomized, double-blind, placebo-controlled trial investigated the effects of branched-chain amino acids (BCAAs)—provided in a 2:1:1 ratio of leucine:isoleucine:valine—combined with exercise on fatigue, physical performance, and quality of life in older adults. Twenty participants (63% female; BMI: 35 ± 2 kg/m²; age: 70.5 ± 1.2 years) were randomized to 8 weeks of either exercise + BCAAs (100 mg/kg body weight/d) or exercise + placebo. The program included moderate aerobic and resistance training three times weekly. Physical function was assessed using handgrip strength, chair stands, gait speed, VO₂ max, and a 400 m walk. Psychological health was evaluated using the CES-D, Fatigue Assessment Scale (FAS), Insomnia Severity Index (ISI), and global pain, fatigue, and quality of life using a visual analog scale (VAS). Significant group x time interactions were found for handgrip strength (p = 0.03), chair stands (p < 0.01), and 400 m walk time (p < 0.01). Compared to exercise + placebo, exercise + BCAAs showed greater improvements in strength, mobility, and endurance, along with reductions in fatigue (−45% vs. +92%) and depressive symptoms (−29% vs. +5%). Time effects were also observed for ISI (−30%), FAS (−21%), and VAS quality of life (16%) following exercise + BCAA supplementation. These preliminary results suggest that BCAAs combined with exercise may be an effective way to improve physical performance and reduce fatigue and depressive symptoms in older adults. Full article

This research evaluates the mechanical properties, environmental impacts, and cost-effectiveness of Hub Coal fly ash (FA)-based geopolymer concrete (FAGPC) as a sustainable alternative to ordinary Portland cement (OPC) concrete. This local FA has not been investigated previously. A total of 24 FAGPC mixes were tested under both ambient and heat curing conditions, varying the molarities of sodium hydroxide (NaOH) solution (10-M, 12-M 14-M and 16-M), sodium silicate to sodium hydroxide (Na₂SiO₃/NaOH) ratios (1.5, 2.0, and 2.5), and alkaline activator solution to fly ash (AAS/FA) ratios (0.5 and 0.6). The test results demonstrated that increasing NaOH molarity enhances the compressive strength (CS.) by 145% under ambient curing, with a peak CS. of 32.8 MPa at 16-M NaOH, and similarly, flexural strength (FS.) increases by 90% with a maximum FS. of 6.5 MPa at 14-M NaOH. Conversely, increasing the Na₂SiO₃/NaOH ratio to 2.5 reduced the CS. and FS. of ambient-cured specimens by 12.5% and 10.5%, respectively. Microstructural analysis revealed that higher NaOH molarity produced a denser, more homogeneous matrix, supported by increased Si–O–Al bond formation observed through energy-dispersive X-ray spectrometry. Environmentally, FAGPC demonstrated a 35–40% reduction in embodied CO₂ emissions compared to OPC, although the production costs of FAGPC were 30–35% higher, largely due to the expense of alkaline activators. These findings highlight the potential of FAGPC as a low-carbon alternative to OPC concrete, balancing enhanced mechanical performance with sustainability. New, green, and cheap activation solutions are sought for a new generation of more sustainable and affordable FAGPC. Full article

To address the challenges of concrete construction in polar regions, this study investigates the feasibility of fabricating cement-based materials under severely low temperatures using electric-induced heating curing methods. Cement mortars incorporating fly ash (FA-CM), ground granulated blast furnace slag (GGBS-CM), and metakaolin (MK-CM) were cured at environmental temperatures of −20 °C, −40 °C, and −60 °C. The optimal carbon fiber (CF) contents were determined using the initial electric resistivity to ensure a consistent electric-induced heating curing process. The thermal profiles during curing were monitored, and mechanical strength development was systematically evaluated. Hydration characteristics were elucidated through thermogravimetric analysis (TG), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR) to identify phase compositions and reaction products. Results demonstrate that electric-induced heating effectively mitigates the adverse effect caused by the ultra-low temperature constraints, with distinct differences in the strength performance and hydration kinetics among supplementary cementitious materials. MK-CM exhibited superior early strength development with strength increasing rates above 10% compared to the Ref. specimen, which was attributed to the accelerated pozzolanic reactions. Microstructural analyses further verified the macroscopic strength test results that showed that electric-induced heating curing can effectively promote the performance development even under severely cold environments with a higher hydration degree and refined micro-pore structure. This work proposes a viable strategy for polar construction applications. Full article

The climate in extremely cold regions is becoming increasingly unstable, resulting in more frequent freeze-thaw cycles. These cycles significantly degrade the mechanical properties of soft soil foundations, reducing their bearing capacity and ultimately compromising the safety and lifespan of construction and infrastructure. To mitigate these effects, soil stabilization technology is commonly employed to reinforce soft soil in cold regions. However, evaluating the durability of stabilized soft soil, particularly its resistance to freezing in extremely cold environments, remains a critical challenge. This study investigates the use of industrial waste raw materials, such as slag and fly ash (FA), in combination with a solid alkali activator (NaOH), to develop one-part alkali-activated cementitious materials (ACMs) for soft soil stabilization. The effects of different raw material ratios, freeze-thaw temperatures, and the number of freeze-thaw cycles on the freezing resistance of one-part alkali-activated slag/FA (OP-ASF) stabilized soft soil were examined. Mass loss, unconfined compressive strength (UCS), and pH value were conducted to assess soil deterioration and structural integrity under freeze-thaw conditions. Additionally, microstructure analysis was conducted using scanning electron microscopy with energy dispersive X-ray spectrometry (SEM-EDS) and X-ray diffraction (XRD) to analyze hydration product formation and internal structure characteristics. Image-pro plus (IPP) was also employed for structure looseness evolution, providing deeper insights into the freezing resistance mechanisms of OP-ASF stabilized soft soil. The results indicated that as the freezing temperature decreases and the number of freeze-thaw cycles increases, both mass loss and UCS loss become more pronounced. When the ratio of slag to fly ash was optimized at 80:20, OP-ASF stabilized soft soil exhibited the highest freezing resistance, characterized by the lowest mass loss and UCS loss, along with the highest UCS and pH value. Furthermore, structure looseness remained at its lowest across all freeze-thaw temperatures and cycles, highlighting the beneficial role of slag and FA in OP-ASF. These findings contribute to the advancement of sustainable and durable construction materials by demonstrating the potential of one-part alkali-activated slag/fly ash for stabilizing soft soils in seasonally frozen regions. Full article

Solid waste-based cementitious materials (SWBC) are composed of steel slag (SS), granulated blast furnace slag (GBFS), fly ash (FA), desulfurization gypsum (DG), and Portland cement (PC). Currently, SWBC holds great potential as a sustainable building material; however, its low early compressive strength and volume expansion limit its range of application. Therefore, the main objective of this study is to enhance the mechanical properties and dimensional stability of SWBC by adding nano-SiO₂, while also improving its resistance to chloride ions, thereby promoting its use in the field of sustainable building materials. A comprehensive experimental approach integrating mechanical performance testing, shrinkage analysis, and chloride diffusion coefficient evaluation was established, with the testing methods of thermogravimetric analysis-differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The study found that adding nano-SiO₂ enhanced the nucleation of calcium silicate hydrates (C-S-H) gel in hydrated SWBC, leading to improved compressive strength and reduced chloride permeability when SiO₂ addition was 0.5%. When the hydration period extends to 28 days, the modified SWBC achieves a compressive strength of 56 MPa. However, excessive nano-SiO₂ (≥1%) inhibited the long-term hydration of SWBC but had no significant effect on the final compressive strength. Full article

Traditional landfill cover materials have low strength and poor dry–wet durability. Municipal solid waste incineration fly ash (MSWI FA) can be used to partially replace cement solidification dredging sediment (DS). This article investigates the possibility of using MSWI FA and ordinary Portland cement (OPC) composite cured DS as a covering material. The mechanical properties, permeability, and wet–dry durability of the cured system were investigated under the conditions of MSWI FA content ranging from 0% to 60% and OPC content ranging from 10% to 15%. The microscopic mechanism was analyzed by scanning electron microscopy and X-ray diffraction. The results showed that when the OPC and MSWI FA contents were 15% and 20%, respectively, the comprehensive performance of the cured specimens was best after 28 days of natural curing. The unconfined compressive strength reached 1993.9 kPa, and the permeability coefficient decreased to below 1 × 10⁻⁷ cm/s, fully meeting the requirements for landfill coverage. C-S-H gel is the main strength source of the solidified body, while Friedel salt and ettringite enhance the compactness of the matrix. An excessive moisture environment promotes the water absorption of soluble salts produced by MSWI FA hydration, leading to sample expansion and reduced strength. MSWI FA and OPC cured DS exhibit good compression performance in the intermediate cover system of landfills, and can maintain good engineering performance under periodic dry–wet cycles. This dual strategic synergy solves the hazardous disposal problem of MSWI FA and the resource utilization demand of DS, demonstrating enormous application potential. Full article

A ternary geopolymer mortar (TGM) was synthesized using steel slag (SS), granulated blast furnace slag (GGBS), and fly ash (FA) as raw materials. The effect of the SS content (0–60%) and the GGBS/FA mass ratio (5:1 to 1:5) on the TGM’s setting time was studied. To address the issue of rapid setting, the impact of different mixing methods ((A) dry mixing, (B) pre-dissolution, and (C) pre-coating) and dosages of BaCl₂ on the setting and hardening properties of TGM was further explored. The hydration product evolution and microstructural characteristics were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectrometry (EDS), with an in-depth analysis of the retarding mechanism of BaCl₂. The results indicate that, as the steel slag content increases, the setting time of TGM significantly shortens. The setting time decreases slightly with an increase in the GGBS/FA mass ratio. The mixing method influences the retarding effect of BaCl₂, with the C method showing significant advantages over both the A and B methods. Under the C mixing method, BaCl₂ consumes the alkaline components (SiO₃²⁻) in the alkaline activator and forms a BaSiO₃ coating layer on the precursor surface, which further delays the hydration process of the precursor particles. This study provides a promising approach for the high-value utilization of multi-source solid waste and suggests that future research should focus on large-scale application strategies and long-term performance evaluation to support its practical use in sustainable construction. Full article

In this study, complexes of pregelatinized Chinese yam starch with ferulic acid (PCYS+FA) were prepared using a boiling water bath, with varying levels of Chinese yam starch (CYS) and ferulic acid (FA). The investigation focused on the effects of FA addition (3%, 9%, and 15%) on the physicochemical properties and structure of PCYS+FA complexes. The solubility, swelling, and water-holding capacity of PCYS+FA were compared with those of CYS, with the solubility and swelling showing a gradual enhancement with increasing FA content. The incorporation of FA reduced the thermal stability of CYS, decreasing the initial degradation temperature from 245.94 °C (CYS) to 228.17 °C (PCYS+15%FA). Infrared spectroscopy revealed that CYS and FA were bound through non-covalent intramolecular hydrogen bonding. Furthermore, X-ray diffractograms showed that FA and CYS formed a V-type complex, in which the crystallinity of PCYS reached a minimum of 3.72%, and the degree of molecular ordering was reduced. Scanning electron microscopy analysis demonstrated that FA adhered to the surface of starch granules, resulting in the formation of pores that facilitated the entry of FA molecules into the internal crystal region of starch, allowing them to interact with starch molecules. Full article

Using industrial byproducts to replace cement is an important way to reduce carbon emissions from the cement industry. In this study, the effects of two industrial byproducts, fly ash (FA) and quartz powder (QZ), as supplementary cementitious materials (SCMs) on the macroscopic properties and microstructure of cement-based materials were experimentally investigated. The results of the compressive strength and ultrasonic pulse velocity experiments showed that QZ significantly mitigated the decrease in strength and ultrasonic pulse velocity caused by the reduction in cement dosage in the early stage. Moreover, the 28-day compressive strength of the FA group was comparable to that of the control group, and regression analysis indicated a negligible effect of FA addition on 28-day compressive strength. X-ray diffraction and Fourier transform infrared spectroscopy experiments showed that QZ can promote the hydration reaction in the early stage. Scanning electron microscopy images revealed that a layer of hydration products can form on the surface of FA after 28 days of hydration. Hydration heat experiments indicated that FA significantly reduces the release of hydration heat, while QZ promotes the formation of ettringite through nucleation effects in the early stage of hydration, thereby accelerating the release of hydration heat. Thermogravimetric analysis after 28 days showed that the amount of hydration products and calcium hydroxide produced decreased with the addition of cementitious materials. Finally, the use of FA and QZ was analyzed for carbon emissions and energy consumption. The results showed that using these two cementitious materials significantly reduces carbon dioxide emissions and energy consumption. Full article

The incorporation of mineral admixtures plays a crucial role in enhancing the performance and sustainability of geopolymer systems. This study evaluates the influence of fly ash (FA), silica fume (SF), and metakaolin (MK) as typical mineral admixtures on slag–Yellow River sediment geopolymer eco-cementitious materials. The impact of varying replacement ratios of these admixtures for slag on setting time, workability, reaction kinetics, and strength development were thoroughly investigated. To understand the underlying mechanisms, microstructural analysis was conducted using thermogravimetric–differential thermal analysis (TG-DTA), X-ray diffraction (XRD), scanning electron microscopy–energy dispersive spectroscopy (SEM-EDS), and mercury intrusion porosimetry (MIP). The results indicate that the incorporation of FA, SF, and metakaolin delayed the initial reaction, prolonged the induction period, and reduced the acceleration rate. These effects hindered early strength development. At 30% FA content, the matrix exhibited excellent flowability and sustained heat release. The 28-day splitting tensile strength increased by 42.40%, while compressive strength decreased by 2.85%. In contrast, 20% SF significantly improved compressive strength, increasing the 28-day compressive and splitting tensile strengths by 11.19% and 6.16%, respectively. At 15% metakaolin, the strength improvement was intermediate, with 28-day compressive and splitting tensile strengths increasing by 3.55% and 10.59%, respectively. However, dosages exceeding 20% for SF and metakaolin significantly reduced workability. The incorporation of FA, SF, and metakaolin did not interfere with the slag’s alkali-activation reaction. The newly formed N-A-S-H and C-S-H gels integrated with the original C-A-S-H gels, optimizing the pore structure and reducing pores larger than 1 µm, enhancing the matrix compactness and microstructural reinforcement. This study provides practical guidance for optimizing the use of sustainable mineral admixtures in geopolymer systems. Full article

To address the issues of the low pozzolanic activity and high pollution potential of red mud (RM), this study utilizes different industrial solid wastes to synergistically enhance the physicochemical properties of red mud-based filling materials. The compressive strengths of red mud-based filling materials activated by three types of solid wastes—desulfurized gypsum (DG), carbide slag (CS), and steel slag (SS)—were compared, revealing the differences in their effects on the physicochemical properties of the materials. The results showed that DG significantly enhanced the compressive strength of the backfill material. The composite system composed of 65.8% RM, 18.8% FA, 9.4% cement, and 6% DG achieved a compressive strength of 7.36 MPa after 28 days of curing, demonstrating a 97.8% increase compared to the control group. Techniques such as X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and Brunauer–Emmett–Teller (BET) analysis were employed to characterize the microstructural evolution of the red mud-based filling materials activated by different solid wastes. This study investigated the differences in the pore structure, microscopic morphology, and chemical composition of the materials containing different solid wastes. The results indicated that DG effectively promotes the formation of ettringite and C(-A)-S-H gel, optimizes the pore structure of the filling materials, and forms a dense matrix, thereby enhancing the stiffness and strength of the materials. Additionally, the red mud-based filling materials developed in this study exhibit excellent environmental performance. This not only provides theoretical support for the development of red mud-based filling materials but also offers new insights for mine backfilling and the co-disposal of solid wastes. Full article

Hepatocellular carcinoma (HCC) causes the third highest mortality worldwide. Liver ablation, surgery, and embolization are conventional methods for treatment. However, these methods have limitations. To overcome these issues, nanomedicines have potential due to their high stability, high drug load capacity, and controlled release. Thus, we prepared quercetin-loaded polylactic-co-glycolic acid (PLGA) nanoparticles coated with folic acid-chitosan (QPCF-NPs) to improve drug delivery and targetability applications of quercetin for the treatment of HCC. We prepared QPCF-NPs by solvent evaporation and coated them with chitosan-folic acid (CS-FA). QPCF-NPs were examined using Fourier-Transform infrared (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). In addition, the drug release rate and cytotoxicity were studied. Moreover, in vivo HCC studies such as histopathology and biochemical parameters were conducted. Subsequently, QPCF-NPs with a spherical shape and an average size of 200–290 nm have been demonstrated to have formed by FTIR, XRD, SEM, and TEM. Further, we observed sustained drug release from QPCF-NPs compared to quercetin. Cellular cytotoxicity showed significant inhibition in the HEPG2-cell line with QPCF-NPs treatment. Biochemical estimate and oxidative stress regulation were considerably more regulated in the treatment groups than the HCC group in a dose-dependent way after subcutaneous administration of QPCF-NPs. ELISA of interleukin and caspase-3 demonstrated the anticipated results in comparison to the carcinogen control group. Compared to earlier preparations, the QPCF-NPs generated demonstrated better drug targetability and potency for treating HCC. Full article

This study evaluates the impact of PM2.5 exposure from wood combustion on reproductive health and fetal development using an experimental model in Sprague Dawley rats. The study was conducted in Temuco, Chile, where high levels of air pollution are primarily attributed to residential wood burning. A multigenerational exposure model was implemented using controlled exposure chambers with filtered (FA) and unfiltered (NFA) air. Second-generation (G2) female rats (n = 48) were exposed pregestationally (60 days) and gestationally (23 days) under four conditions: FA/FA, FA/NFA, NFA/FA, and NFA/NFA. PM2.5 concentration and composition were monitored using beta-ray attenuation and X-ray fluorescence spectrometry. Reproductive parameters, ovarian follicle counts, and hormonal levels were assessed via vaginal cytology, histological analysis, and chemiluminescence immunoassays. PM2.5 exposure disrupted estrous cyclicity (p = 0.0001), reduced antral and growing follicles (p = 0.0020; p = 0.0317), and increased post-implantation losses (p = 0.0149). Serum progesterone and estradiol levels were significantly altered (p < 0.05). Despite ovarian disruptions, fertility rates remained unchanged. These findings suggest that chronic exposure to wood smoke-derived PM2.5 adversely affects ovarian function and fetal growth without significantly impairing overall reproductive capacity. This study highlights the need for public health policies to mitigate wood smoke pollution. Full article

Overdose intake of acetaminophen (APAP) causes liver injury involving hepatic drug metabolism and activation of oxidative stress pathways, and forsythiaside A (FA) has hepatoprotective pharmacological activity, but knowledge of the mechanism of FA treatment for APAP liver injury is still lacking the literature. In this study, we investigated the effects of FA on the pregnane X receptor (PXR) by molecular docking and reporter gene assays. In addition, we explored the effects of FA on oxidative stress, endoplasmic reticulum stress (ERS), apoptosis, and hepatic pathology by interfering with PXR in ex vivo and in vivo models. The results showed that FA decreased the PXR protein expression level and effectively reduced the oxidative stress level in the APAP model. In addition, FA reduced the expression of ERS pathway ProteinkinaseR-likeERkinase (PERK)-translation initiation factor 2 (eIF-2α)-activating transcription factor 4 (ATF4) by inhibiting PXR, and at the same time, decreased the expression of apoptotic proteins C/EBP homologous protein (CHOP), Bax, Caspase 3, and Caspase 7, and elevated the expression of apoptosis-suppressing protein Bcl-2, which ultimately treated the hepatic pathology injury of APAP in mice. The present study confirmed that FA improved APAP metabolism by inhibiting PXR-mediated CYP1A2 and CYP3A11 and alleviated APAP-induced hepatic impairment by inhibiting hepatic oxidative stress, ERS, and apoptosis. Full article