Search Results (59)

Expansive soils, widely distributed in nature, often pose challenges to construction stability due to their low unconfined compressive strength (UCS), poor shear strength, and high expansibility. This study investigates the application of phosphoric acid (H₃PO₄) in modifying sodium bentonite, focusing on its effects on the mechanical properties and swelling behavior of bentonite, as well as the underlying mechanisms. H₃PO₄ was added to bentonite at mass ratios of 1% to 8%. Compared to unmodified bentonite, the plastic index of the modified bentonite decreased by 39.9%, and the UCS value increased by 92.24% when the H₃PO₄ dosage was 2%. Notably, at an H₃PO₄ dosage of 8%, the free swelling rate of the modified bentonite decreased by 38.1% relative to the control sample, and the cohesion increased by 165.35%, indicating significant improvements in both the expansibility and bearing capacity of modified bentonite. The results on the physical and chemical properties of modified bentonite revealed an ion exchange involving hydrogen ions from H₃PO₄ and metal cations in sodium bentonite. The zeta potential of bentonite decreased with H₃PO₄ addition, reflecting a reduction in the double electric layer thickness due to hydrogen ion exchange with metal cations. This enhanced the gravitational attraction between soil particles, leading to their closer proximity and a significant increase in the UCS value of the modified soil. Additionally, the XRD results confirmed that the addition of H₃PO₄ facilitated the formation of a new mineral, aluminum phosphate, which is hard and insoluble, filling soil pores, contributing to its densification. This study demonstrates that H₃PO₄ can effectively enhance the swelling resistance and strength of sodium bentonite, offering a promising method to improve its application performance. Full article

Calcium phosphates are often used for biomedical applications. Hydroxyapatite, for example, has a wide range of applications because it mimics the mineral component of natural bone. Widespread interest in the catalytic properties of ceria is due to its use in automotive catalytic converters. Effect of electroless deposited on (non-anodized and anodized) Al 1050 with monolayer Ce₂O₃ + CeO₂, consecutive deposited bilayer Ce₂O₃ + CeO₂/Ca₅(PO₄)₃OH or consecutive deposited bilayer Ce₂O₃ + CeO₂/(AlPO₄ + AlOOH + CePO₄) systems on the indentation modulus (E_IT) and hardness (H_IT), as well as their corrosion-protective ability were investigated. For structural, chemical, electrochemical, and mechanical characterization of the investigated systems, the following methods were used: scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDXS), X-ray photoelectron spectroscopy (XPS), polarization resistance (R_p), corrosion rate (CR) analysis, and nanoindentation. It was found that the H_IT and E_IT of the coatings deposited on an anodized aluminum substrate were much higher than those deposited on a non-anodized aluminum substrate. It established a specific influence of the morphology and chemical composition of formed conversion layers on H_IT and E_IT and improved the corrosion-protective effect of these layers. The obtained results are valuable since there is no data on the mechanical properties of such coatings in the literature to date. Full article

The foamed structure of recycled polyethylene-terephthalate (rPET) is a promising solution for industrial applications; however, the remedy for its inherent melt-dripping property is still a challenging topic. In our research, we were able to improve the flame retardancy of the endothermic–exothermic hybrid rPET foam by adding a different mixture of flame retardants to the formula. Three different kinds of halogen-free flame retardant agents were used: ammonium polyphosphate-based Exolit AP 422 (AP), organic aluminum phosphate in the form of Exolit OP 1240 (OP), and Budit 342 containing melamine polyphosphate (MPP). The hybrid flame retardant mixture, by combining the swelling and charring mechanism, increased the flame retardancy of the samples. The sample made with 15 phr OP and 5 phr MPP displayed outstanding performance, where five samples were capable of self-extinguishing in 5 s, while only slightly decreasing the tensile and flexural strength properties and simultaneously increasing the Young and flexural modulus compared to the reference sample. The addition of MPP reduced the porosity in many cases, while preventing cell coalescence. Our results prove that the hybrid flame retardant agent frameworks efficiently increase the flame retardancy of rPET foams, facilitating their application in industrial sectors such as the aerospace, packaging, renewable energy, and automotive industries to realize sustainability goals. The utilization of halogen-free flame retardants is beneficial for better air quality, reducing toxic gas and smoke emissions. Full article

The novel crosslinked composite polymer electrolyte (CPE) was developed and investigated using polytetrahydrofuran (PTHF) and polyethyleneglycol diacrylate (PEGDA), incorporating lithium aluminum titanium phosphate (LATP) particles and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt. Composite polymer electrolytes (CPEs) for solid-state lithium-ion batteries (LIBs) were synthesized by harnessing the synergistic effects of PTHF crosslinking and the addition of LATP ceramics, while systematically varying the film composition and LATP content. CPEs containing 15 wt% LATP (PPL15) demonstrated improved mechanical strength and electrochemical stability, achieving a high conductivity of 1.16 × 10⁻⁵ S·cm⁻¹ at 80 °C, outperforming conventional PEO-based polymer electrolytes. The CPE system effectively addresses safety concerns and mitigates the rapid degradation typically associated with polyether electrolytes. The incorporation of PEGDA not only enhances mechanical stability but also facilitates lithium salt dissociation and ion transport, leading to a uniform microstructure free from agglomerated particles. The temperature-dependent ionic conductivity measurements indicated optimal performance at lower LATP concentrations, highlighting the impact of ceramic particle agglomeration onion transport pathways. These findings contribute to advancing solid-state battery systems toward practical application. Full article

The rapid expansion of flexible and wearable electronics has necessitated a focus on ensuring their safety and operational reliability. Gel polymer electrolytes (GPEs) have become preferred alternatives to traditional liquid electrolytes, offering enhanced safety features and adaptability to the design requirements of flexible lithium-ion batteries. This review provides a comprehensive and critical overview of recent advancements in GPE technology, highlighting significant improvements in its physicochemical properties, which contribute to superior long-term cycling stability and high-rate capacity compared with traditional organic liquid electrolytes. Special attention is given to the development of smart GPEs endowed with advanced functionalities such as self-protection, thermotolerance, and self-healing properties, which further enhance battery safety and reliability. This review also critically examines the application of GPEs in high-energy cathode materials, including lithium nickel cobalt manganese (NCM), lithium nickel cobalt aluminum (NCA), and thermally stable lithium iron phosphate (LiFePO₄). Despite the advancements, several challenges in GPE development remain unresolved, such as improving ionic conductivity at low temperatures and ensuring mechanical integrity and interfacial compatibility. This review concludes by outlining future research directions and the remaining technical hurdles, providing valuable insights to guide ongoing and future efforts in the field of GPEs for lithium-ion batteries, with a particular emphasis on applications in high-energy and thermally stable cathodes. Full article

Concentrating organic matter in sludge and converting it into methane through anaerobic bioconversion can improve resource recovery from domestic wastewater. Enhanced membrane coagulation (EMC) is highly efficient at concentrating organic matter, but residual coagulants (aluminum salts) can obstruct bioconversion by blocking microbial access. Limited research exists on evaluating EMC sludge bioconversion performance and addressing coagulant inhibition. This study proposes alkaline pre-fermentation to break down HO-Al-P backbones in coagulated sludge flocs, thereby improving hydrolysis and organic acid production for anaerobic digestion. Among the tested alkaline conditions (pH 9, pH 10, pH 11), pre-fermentation at pH 11 released the most organic matter (4710.0 mg/L SCOD), 20.4 times higher than without alkaline treatment. At pH 11, phosphate (61 mg/L PO₄³⁻–P) and organic acid production (2728.1 mg COD/L, with nearly 50% acetic acid) peaked, resulting in superior volatile solids removal (65.2%) and methane production (185.8 mL/g VS) during anaerobic digestion. Alkaline pre-fermentation favored alkali-tolerant bacteria such as Firmicutes and Actinobacteria, especially at pH 11, while neutrophilic Proteobacteria were suppressed. Trichococcus and Bifidobacterium, known acid producers, dominated under all conditions, with their abundance increasing at higher pH levels. Anaerobic digestion enriched fermentative bacteria like Chloroflexi and Synergistota (e.g., Thermovirga), especially in high pH reactors. Methanothrix, an acetoclastic methanogen, became the dominant methanogenic archaeon, indicating that methane production from EMC sludge primarily followed the acetoclastic methanogenesis pathway. Our findings demonstrate that alkaline pre-fermentation at pH 11 significantly enhances the hydrolysis efficiency of EMC sludge for methane recovery. Full article

Due to its adsorption with aluminum and iron hydroxides, phosphorus viability is low in acidic soils; thus, the aim of this study was to isolate and identify bacteria from the rhizosphere of four legumes growing in acidic soils of the Cumbaza Sub-basin, San Martín, Peru, as well as to characterize their ability to solubilize aluminum phosphate and iron phosphate. The isolation process was conducted on TSA medium and the isolates were classified based on their origin and morphocolonial characteristics, with the bacillary shape being the most frequent, followed by cocci. To assess the solubilization of aluminum and iron phosphates, the liquid medium GELP was employed. Sixteen strains were selected, among which three stood out for their effectiveness in solubilizing AlPO₄ (Sfcv-098-02, 22.65 mg L⁻¹; Sfc-093-04, 26.50 mg L⁻¹; and Sfcv-041-01-2, 55.98 mg L⁻¹) and one for its ability to solubilize FePO₄ (Sfcr-043-02, 32.61 mg L⁻¹). These four strains were molecularly characterized, being identified as Enterobacter sp., Pseudomonas sp., and Staphylococcus sp. Additionally, a decrease in pH was observed in the reactions, with values ranging from 5.23 to 3.29, which enhanced the phosphate of solubilization. This suggests that the selected bacteria could be used to improve phosphorus availability in agricultural soils. Full article

This paper presents an experimental comparison of two types of Li-ion battery stacks for low-voltage energy storage in small urban Electric or Hybrid Electric Vehicles (EVs/HEVs). These systems are a combination of lithium battery cells, a battery management system (BMS), and a central control circuit—a lithium energy storage and management system (LESMS). Li-Ion cells are assembled with two different active cathode materials, nickel–cobalt–aluminum (NCA) and lithium iron phosphate (LFP), both with an integrated decentralized BMS. Based on experiments conducted on the two assembled LESMSs, this paper suggests that although LFP batteries have inferior characteristics in terms of energy and power density, they have great capacity for improvement. Full article

A synthetic flocculant of aluminum (Al) and iron (Fe) extracted from red mud (RM) has been widely used in sewage treatment, while the remaining RM residue has been ignored. This study aimed to synthesize polymeric aluminum ferric sulfate (PAFS) flocculant from RM by acid leaching and then use the acidified RM residue to produce an acid RM-based ceramsite (ARMC) by mixing bentonite, hydroxypropyl methylcellulose, and starch. Our results showed that sintering, reaction temperature, H₂SO₄ concentration, reaction time, and liquid-to-solid ratio had an obvious effect on the leaching of Al and Fe in RM, which was a necessary prerequisite for the efficient PAFS flocculants. At a PAFS dosage of 60 mg/L, turbidity and phosphate removal rates were 95.21 ± 0.64% and 89.17 ± 0.52%, respectively. When the pH value was 8.0, the turbidity and phosphate removal efficiency were 99.22 ± 0.66% and 95.98 ± 1.63%, respectively. Considering the adsorption capacity and mechanical properties, the best conditions for ARMC production included using 60% ARM and ceramsite calcination at 600 °C, with the BET surface area 56.16 m²/g and a pore volume of 0.167 cm³/g. Thermogravimetric analysis indicated that 400 °C was a reasonable preheating temperature to enhance the ARMC mechanical strength, as this temperature allows the removal of surface-adsorbed and constituent water. Under a scanning electron microscope, the ARMC appeared rough before adsorption, while relatively uniform pores occupied it after adsorption. Our conclusion will help to improve the zero-waste strategy of RM and speed up the industrial production of RM in flocculants as well as utilizing ARMC as a new type of adsorbent for phosphorus adsorption in sewage treatment. Full article

Gel polymer electrolytes (GPEs) have high safety and excellent electrochemical performance, so applying GPEs in lithium batteries has received much attention. However, their poor lithium ion transfer number, cycling stability, and low room temperature ionic conductivity seriously affect the utilization of gel polymer electrolytes. This paper successfully synthesized flexible poly (vinylidene fluoride-hexafluoropropylene)–lithium titanium aluminum phosphate (PVDF-HFP-LATP) gel polymer electrolytes using the immersion precipitation method. The resulting GPE has a porous honeycomb structure, which ensures that the GPE has sufficient space to store the liquid electrolyte. The GPE has a high ionic conductivity of 1.03 ×10⁻³ S cm⁻¹ at room temperature (25 °C). The GPE was applied to LiFePO₄/GPE/Li batteries with good rate performance at room temperature. The discharge specific capacity of 1C was as high as 121.5 mAh/g, and the capacity retention rate was 94.0% after 300 cycles. These results indicate that PVDF-HFP-LATP-based GPEs have the advantage of simplifying the production process and can improve the utility of gel polymer lithium metal batteries. Full article

Safeguarding drinking water is a major public health and environmental concern because it is essential to human life but may contain pollutants that can cause illness or harm the environment. Therefore, continuous research is necessary to improve water treatment methods and guarantee its quality. As part of this study, the effectiveness of coagulation–flocculation treatment using aluminum sulfate (Al₂(SO₄)₃) was evaluated on a very polluted site. Samplings were taken almost every day for a month from the polluted site, and the samples were characterized by several physicochemical properties, such as hydrogen potential (pH), electrical conductivity, turbidity, organic matter, ammonium (NH⁺₄), phosphate (PO₄³⁻), nitrate (NO₃⁻), nitrite (NO₂⁻), calcium (Ca²⁺), magnesium (Mg²⁺⁾, total hardness (TH), chloride (Cl⁻⁾, bicarbonate (HCO₃⁻), sulfate (SO₄²⁻), iron (Fe³⁺), manganese (Mn²⁺), aluminum (Al³⁺), potassium (K⁺), sodium (Na⁺), complete alkalimetric titration (TAC), and dry residue (DR). Then, these samples were treated with Al₂(SO₄)₃ using the jar test method, which is a common method to determine the optimal amount of coagulant to add to the water based on its physicochemical characteristics. A mathematical model had been previously created using the support vector machine method to predict the dose of coagulant according to the parameters of temperature, pH, TAC, conductivity, and turbidity. This Al₂(SO₄)₃ treatment step was repeated at the end of each month for a year, and a second characterization of the physicochemical parameters was carried out in order to compare them with those of the raw water. The results showed a very effective elimination of the various pollutions, with a very high rate, thus demonstrating the effectiveness of the Al₂(SO₄)₃. The physicochemical parameters measured after the treatment showed a significant reduction in the majority of the physicochemical parameters. These results demonstrated that the coagulation–flocculation treatment with Al₂(SO₄)₃ was very effective in eliminating the various pollutions present in the raw water. They also stress the importance of continued research in the field of water treatment to improve the quality of drinking water and protect public health and the environment. Full article

Despite the availability of effective vaccines against COVID-19, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to spread worldwide, pressing the need for new vaccines with improved breadth and durability. We developed an adjuvanted subunit vaccine against SARS-CoV-2 using the recombinant receptor–binding domain (RBD) of spikes with synthetic adjuvants targeting TLR7/8 (INI-4001) and TLR4 (INI-2002), co-delivered with aluminum hydroxide (AH) or aluminum phosphate (AP). The formulations were characterized for the quantities of RBD, INI-4001, and INI-2002 adsorbed onto the respective aluminum salts. Results indicated that at pH 6, the uncharged RBD (5.73 ± 4.2 mV) did not efficiently adsorb to the positively charged AH (22.68 ± 7.01 mV), whereas it adsorbed efficiently to the negatively charged AP (−31.87 ± 0.33 mV). Alternatively, pre-adsorption of the TLR ligands to AH converted it to a negatively charged particle, allowing for the efficient adsorption of RBD. RBD could also be directly adsorbed to AH at a pH of 8.1, which changed the charge of the RBD to negative. INI-4001 and INI-2002 efficiently to AH. Following vaccination in C57BL/6 mice, both aluminum salts promoted Th2-mediated immunity when used as the sole adjuvant. Co-delivery with TLR4 and/or TLR7/8 ligands efficiently promoted a switch to Th1-mediated immunity instead. Measurements of viral neutralization by serum antibodies demonstrated that the addition of TLR ligands to alum also greatly improved the neutralizing antibody response. These results indicate that the addition of a TLR7/8 and/or TLR4 agonist to a subunit vaccine containing RBD antigen and alum is a promising strategy for driving a Th1 response and neutralizing antibody titers targeting SARS-CoV-2. Full article

Implementing successful aggregated charging strategies for electric vehicles to participate in the wholesale market requires an accurate battery model that can operate at scale while capturing critical battery dynamics. Existing models either lack precision or pose computational challenges for fleet-level coordination. To our knowledge, most of the literature widely adopts battery models that neglect critical battery polarization dynamics favoring scalability over accuracy, donated as constant power models (CPMs). Thus, this paper proposes a novel linear battery model (LBM) intended specifically for use in aggregated charging strategies. The LBM considers battery dynamics through a linear representation, addressing the limitations of existing models while maintaining scalability. The model dynamic behavior is evaluated for the four commonly used lithium-ion chemistries in EVs: lithium iron phosphate (LFP), nickel manganese cobalt (NMC), lithium manganese oxide (LMO), and nickel cobalt aluminum (NCA). The results showed that the LBM closely matches the high-fidelity Thevenin equivalent circuit model (Th-ECM) with substantially improved accuracy over the CPM, especially at higher charging rates. Finally, a case study was carried out for bidding in the wholesale energy market, which proves the ability of the model to scale. Full article

Aluminum (Al) toxicity is a major limiting factor for plant growth and crop production in acidic soils. This study aims to investigate the effects of γ-aminobutyric acid (GABA) priming on mitigating acid-Al toxicity to creeping bentgrass (Agrostis stolonifera) associated with changes in plant growth, photosynthetic parameters, antioxidant defense, key metabolites, and genes related to organic acids metabolism. Thirty-seven-old plants were primed with or without 0.5 mM GABA for three days and then subjected to acid-Al stress (5 mmol/L AlCl₃·6H₂O, pH 4.35) for fifteen days. The results showed that acid-Al stress significantly increased the accumulation of Al and also restricted aboveground and underground growths, photosynthesis, photochemical efficiency, and osmotic balance, which could be effectively alleviated by GABA priming. The application of GABA significantly activated antioxidant enzymes, including superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase, to reduce oxidative damage to cells under acid-Al stress. Metabolomics analysis demonstrated that the GABA pretreatment significantly induced the accumulation of many metabolites such as quinic acid, pyruvic acid, shikimic acid, glycine, threonine, erythrose, glucose-6-phosphate, galactose, kestose, threitol, ribitol, glycerol, putrescine, galactinol, and myo-inositol associated with osmotic, antioxidant, and metabolic homeostases under acid-Al stress. In addition, the GABA priming significantly up-regulated genes related to the transportation of malic acid and citric acid in leaves in response to acid-Al stress. Current findings indicated GABA-induced tolerance to acid-Al stress in relation to scavenging of reactive oxygen species, osmotic adjustment, and accumulation and transport of organic metabolites in leaves. Exogenous GABA priming could improve the phytoremediation potential of perennial creeping bentgrass for the restoration of Al-contaminated soils. Full article

Lithium nickel–cobalt–aluminum oxide (NCA) is a promising cathode material for lithium-ion batteries due to its high energy density of more than 274 mAh/g. However, thermal runaway inhibits its practical applications. Lithium ferromanganese phosphate (LFMP), due to its olivine structure, can effectively stabilize the surface stability of NCA and reduce the exothermic reactions that occur during thermal runaway. LFMP can also inhibit cathode expansion and contraction during charging and discharging. To improve the conductivity of an NCM–LFMP composite electrode, three different conductive additives, namely carbon black, carbon nanotubes (CNTs), and graphene, were introduced into the electrode. Finally, battery safety tests were conducted on 1.1 Ah pouch cells fabricated in the present study. The energy density of the NCA–LFMP 1.1 Ah lithium-ion pouch cells with only 0.16% CNT content reached 224.8 Wh/kg. The CNT–NCA–LFMP pouch cell was also the safest among the cells tested. These results provide a strategy for designing high-energy-density and safe pouch cells for energy storage device applications. Full article