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Effect of superplasticizers on fly ash pastes was evaluated by consistency tests (for lower water content pastes) and mini-slump tests (for higher water content pastes). Results indicate that only the polycarboxylate superplasticizers (PCEs) largely improved the flowability of fly ash pastes. Zeta potential measurements were conducted to explain the influence of electrostatic repulsion on flow behaviours of pastes with different superplasticizers. In fly ash pastes, Lignosulfonates (LS) and Polynaphthalene superplasticisers (PNS) depressed the zeta potential to more negative values, while the PCEs increased the zeta potential to less negative values. The more negative zeta potential represents higher electrostatic repulsion between particles. However, the workability results revealed that PCEs had better dispersing ability than PNS and LS. It was deduced that the steric hindrance may be the dominating mechanism for the better dispersing noticed with fly ash pastes, while the electrostatic repulsion may have no impact on dispersing of these pastes.

In the interest of solving the resource and environmental problems of the construction industry, low-carbon geopolymer coating ensures great durability and extends the service life of existing infrastructure. This paper presents a multidisciplinary assessment of the protective performance and environmental impacts of geopolymer coating. Various parameters, such as main substance, water-solid (W/S) ratio, activator type and curing time, were investigated for their effects on interface characterization in terms of contact angle, surface energy, mechanical properties and microstructure. These parameters had negligible effects on the amounts and types of hydrophilic functional groups of geopolymer surfaces. A combination of organic surface modifiers and geopolymer coatings was shown to ensure hydrophobic surface conditions and great durability. Silicon-based modifiers exhibited better wetting performance than capillary crystalline surfactants by eliminating hydroxyl groups and maintaining structural backbone Si-O-T (Si, Al) on geopolymers’ surfaces. Finally, life-cycle analysis was conducted to investigate the environmental performance. Geopolymer coating yielded substantially lower environmental impacts (50–80% lower in most impact categories) than ordinary Portland cement (OPC) coating. Silicon-based modifiers had negligible influence due to their minimal usage. Increasing the W/S ratio diluted the geopolymer coating and decreased the environmental impacts, and slag-based geopolymer coating achieved lower environmental impacts than FA-based and MK-based varietie.

Background: Hysterectomy places a huge physical and mental burden on young female patients with congenital cervical and complete vaginal atresia. Thus, it is necessary to develop a method to detach the obstruction and simultaneously preserve the vagina and uterus in these patients. This study sought to evaluate the efficacy and safety of laparoscopic vaginoplasty using the peritoneal flap and cervicoplasty in patients with congenital cervical and complete vaginal atresia.Methods: Between April 2013 and June 2022, 9 patients with congenital cervical and complete vaginal atresia at Henan Provincial People's Hospital were enrolled in this prospective study. All the patients were treated with laparoscopic vaginoplasty using the peritoneal flap and cervicoplasty. Baseline clinical features (such as age, uterus size, etc.) were collected. The surgical success rate and adverse events were assessed. Results:The 9 enrolled patients had a median [interquartile range (IQR)] age of 15.0 (14.0-18.0) years, and 5/9 patients presented with pelvic adhesions. The surgeries were successful in all (9/9) patients, who preserved their vagina and uterus with a normal menstrual cycle. After a median follow-up duration of 48 months, the neovagina had a median length of 7.5 cm. Post-surgical complications occurred in 3/9 patients, which were cured by an appropriate treatment. The 5/9 married patients reported being satisfied with their sexual life.Conclusions: Even though the current study preliminary exhibits the efficiency of laparoscopic vaginoplasty using the peritoneal flap and cervicoplasty in patients with congenital cervical and complete vaginal atresia, due to the small sample size, lack of a control group, and relatively high incidence of the adverse events, further studies are still needed to verify the current findings. The current study put forward a further direction for preserving the vagina and uterus simultaneously for those patients with congenital cervical and complete vaginal atresia.