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Ground granulated blast-furnace slag (GGBS) is a common substitute for ordinary Portland cement (OPC). However, GGBS–OPC lacks early strength when OPC content is low (<50%). A new cementitious material called GGBS–OPC–EMR (GOE) was developed by adding electrolytic manganese residue (EMR) to address this issue. Tests were conducted using XRD, SEM, and TG to analyze the micro-structural mechanisms of strength development in GOE. Environmental and economic evaluations were conducted, including CO2-eq (carbon dioxide equivalent) analysis, leaching tests, and economic analysis. Results showed that mixture of GGBS, OPC, and EMR in a 4:2:1 ratio increased the unconfined compressive strength by 25% after 28 days compared to OPC while reducing cement consumption by 70%. Major hydration products in GOE were C–S–H and ettringite (AFt), with approximately 14% EMR promoting AFt production. GOE reduced CO2-eq emissions by 35.9% and saved $46.6/ton compared to OPC. Leaching tests demonstrated GOE's ability to stabilize heavy metals, sulfate, and ammonia nitrogen. [ABSTRACT FROM AUTHOR]

AbstractThe traditional foundation design does not consider the bearing capacity under multi-directional coupling load. However, the foundation is usually subjected to vertical (V), horizontal (H) and moment (M) loading simultaneously on the seabed. The present study examines the undrained multi-directional bearing capacity of hybrid subsea foundation in saturated soft clay using finite element analysis. The contribution of the mudmat and the suction bucket to the bearing capacity of the hybrid subsea foundation was evaluated. The results show that the suction bucket can effectively make up for the lack of horizontal anti-slip and anti-overturning ability of the mudmat. It has a significant contribution to the horizontal and moment bearing capacity. In addition, the failure envelope of bearing capacity in horizontal-moment (H-M), vertical-horizontal (V-H), and vertical-moment (V-M) load space is obtained by using prescribed displacement ratio loading method. Based on the simulation results, the expression of approximate envelope of foundation bearing capacity under combined load of horizontal and moment is proposed. The study also found that a certain value of vertical load can increase the horizontal and moment bearing capacity of the hybrid subsea foundation, while excessive vertical load will lead to a decrease in bearing capacity. [ABSTRACT FROM AUTHOR]

Chemical solidification based on cement is one of the most widely used methods to treat marine dredged silt (DS) with very poor engineering properties. This study investigated the strength and microstructure of cement-solidified salt-rich dredged silt (CSDS) modified by nanoparticles. The unconfined compressive strength (UCS) test showed that the UCS of CSDS containing 9% NaCl was obviously lower than that without NaCl. Furthermore, the detrimental effect of chloride salt on the UCS increased with its content significantly. The nano-SiO2 (NS) used as cement additives can significantly improve the UCS of CSDS and adding 8% NS can reduce cement usage by at least 40%. Compared with NS, the nano-MgO (NM) mainly improved the early UCS of CSDS within 7 days. The needle-like Friedel's salt (the reaction product of chloridion with cement) and lamellar brucite (expansive mineral) were clearly detected by the X-ray diffraction test. The calcium silicate hydrate and magnesium silicate hydrate mainly contributed to construct the skeleton, which was confirmed by the scanning electron microscopy images. The NS and NM with high reactivity can be used as effective cement additives to overcome the negative effect of chloride salt, so as to increase the strength of CSDS. [ABSTRACT FROM AUTHOR]

This study investigates the mechanical behavior of cement-stabilized dredged sediment (CDS) improved by nano-MgO (NM) and polypropylene fiber (PF). The effects of NM content, PF content and PF length on the mechanical behavior of NM-modified and PF-reinforced CDS (CNPDS) were evaluated by conducting unconfined compressive strength (UCS, qu) and splitting tensile strength (STS, qt) tests. Furthermore, optical microscope scans were conducted to detect the interface friction evolution. The results indicated that adding NM can significantly improve UCS and STS of CDS, and the optimum NM content was 1.2%. The optimum PF content tended to increase with increasing curing age, and the 3 mm-length PF was the most effective in improving UCS and STS. Increasing NM content mainly increased the strength, but had little influence on ductility. The inclusion of PF can effectively improve the ductility of CNPDS, and contributed to its tensile strain-hardening characteristic. The relation of q t = 0.23 q u was obtained regardless of other influence factors. The combination of NM-modification and PF induced "bridging" effect provided a coupling effect inside CNPDS, and a concept model representing this process was established. The key findings in this study can be used as an effective method for dredged sediment stabilization in practical engineering. [ABSTRACT FROM AUTHOR]

The strength, durability and swelling behavior of cement-solidified dredged sludge (CDS) has been attracted more and more attention in recent years. This study performed a series of laboratory tests including unconfined compressive strength (UCS), water absorption, swelling tests and pH to investigate the effectiveness of using fly ash (FA) and nano-SiO2 (NS) blended with Portland cement (PC) for DS solidification. Microstructural properties were also analyzed by conducting scanning electron microscopy (SEM) and X-ray diffraction (XRD) tests. The results showed that the addition of FA and NS can significantly improve the UCS of CDS. Using FA and NS together as PC admixture can effectively improve the water resistance. Compared with FA, NS was more effective to reduce the water absorption and swelling of CDS. Adding 0.9% NS to CDS notably reduced the 7-day water absorption and swelling value by up to 40% and 67.5%, respectively. Furthermore, the addition of NS is beneficial to control the pH level of CDS. The SEM and XRD results showed that CSH and CAH gels were the major cementitious products inside solidified DS. The addition of NS contributed to the formation of additional CSH gels in CDS. [ABSTRACT FROM AUTHOR]

The strength, durability and swelling behavior of cement-solidified dredged sludge (CDS) has been attracted more and more attention in recent years. This study performed a series of laboratory tests including unconfined compressive strength (UCS), water absorption, swelling tests and pH to investigate the effectiveness of using fly ash (FA) and nano-SiO2 (NS) blended with Portland cement (PC) for DS solidification. Microstructural properties were also analyzed by conducting scanning electron microscopy (SEM) and X-ray diffraction (XRD) tests. The results showed that the addition of FA and NS can significantly improve the UCS of CDS. Using FA and NS together as PC admixture can effectively improve the water resistance. Compared with FA, NS was more effective to reduce the water absorption and swelling of CDS. Adding 0.9% NS to CDS notably reduced the 7-day water absorption and swelling value by up to 40% and 67.5%, respectively. Furthermore, the addition of NS is beneficial to control the pH level of CDS. The SEM and XRD results showed that CSH and CAH gels were the major cementitious products inside solidified DS. The addition of NS contributed to the formation of additional CSH gels in CDS. [ABSTRACT FROM AUTHOR]

Background: Microtubule dynamics plays a crucial role in the spatial arrangement of cell organelles and activation of the NLRP3 inflammasome. Purpose: This study aimed to explore whether microtubule affinity regulating kinase 4 (MARK4) can be a therapeutic target of periodontitis by affecting microtubule dynamics and NLRP3 inflammasome-mediated pyroptosis in macrophages. Materials and Methods: The NLRP3 inflammasome-related genes and MARK4 were measured in the healthy and inflamedhuman gingival tissues. Bone marrow-derived macrophages (BMDMs) were infected with Porphyromonas gingivalis, while the MARK4 inhibitors (OTSSP167 and Compound 50) and small interference RNAwere utilized to restrain MARK4. Apoptosisassociated speck-like protein (ASC)speck was detected by confocal, and levels of interleukin-1ß (IL-1ß), as wellas IL-18, were assessed by ELISA. Results: Increased staining and transcription of MARK4, NLRP3, ASC, and Caspase-1 were observed in the inflamed gingiva. P. gingivalis infection promoted MARK4 expression and the NLRP3 inflammasome in BMDMs. Inhibition of MARK4 decreased LDH release, IL-1ß and IL-18 production, ASC speck formation, and the pyroptosis-related genes transcription. Furthermore, MARK4 inhibition reduced microtubule polymerization and acetylation in P. gingivalis-infected BMDMs. Conclusions: MARK4 promoted NLRP3 inflammasome activation and pyroptosis in P. gingivalis-infected BMDMs by affecting microtubule dynamics. MARK4 inhibition might be a potential target in regulating the NLRP3 inflammasome during periodontitis progress. [ABSTRACT FROM AUTHOR]

This study investigated the feasibility of using lime (L) and carbide slag (CS) to activate ground granulated blast-furnace slag (GGBS), as a potential substitute to Portland cement (PC) for stabilizing dredged sludge (DS). A series of unconfined compressive strength (UCS), scanning electron microscopy (SEM) and X-ray diffraction (XRD) tests were performed to evaluate the strength development and micro-mechanisms of stabilized DS. The results showed that the optimum lime content was 20-25% for L-GGBS stabilized DS, which can achieve the highest UCS. The 28-, 60- and 90-day optimum UCS of stabilized DS with 20% L-GGBS were 1.38, 1.14 and 1.06 times that of 15% PC stabilized DS. Similarly, the optimum CS content of 25-30% was recommended for achieving the highest UCS of CS-GGBS stabilized DS. The 28-, 60- and 90-day optimum UCS of 20% CS-GGBS stabilized DS were 1.45, 1.12 and 1.02 times that of 15% PC stabilized DS. It was suggested using 20% L-GGBS or CS-GGBS instead of 15% PC for stabilizing DS. The SEM and XRD results revealed that the CSH and CAH gels were the main hydration products for stabilized DS, and the ettringite was also obviously detected in CS-GGBS stabilized DS. [ABSTRACT FROM AUTHOR]

Acetone is widely used as an organic solvent or as an intermediate in material preparation. However, acetone is fairly volatile and highly toxic. Long-term exposure to acetone may damage the kidney, liver, and nerve. Therefore, the detection of acetone is of great significance to ensure the safety of laboratory personnel and facilities. We systematically explored the adsorption of acetone, methane and formaldehyde on pristine tellurene based on first-principles calculations. The electron localisation function (ELF) and density of states (DOS) for three organic gases adsorption on tellurene indicate that they are all physically adsorbed on the substrate. The results of adsorption energy, charge transfer, work function and charge density difference (CDD) show that the gas sensor made of tellurene can exhibit high sensitivity to acetone. In addition, we demonstrated that doping Cu atom to pristine tellurene can enhance the adsorption strength between tellurene and acetone. In summary, our investigation will provide some guidance for experimentalists to exploit the novel acetone sensors. [ABSTRACT FROM AUTHOR]