Preparation of Geopolymers with Nanosilica and Water-in-Air Pickering Emulsion: Mechanisms Underlying Its Rheology, Polymerization, and Strength.

Geopolymers are alkaline-activated aluminosilicate binders recognized as a promising alternative to traditional Portland cement due to their significantly lower greenhouse emissions, energy consumption, and carbon footprint. However, the challenge is meeting or exceeding the strength of Portland cement concrete while being prepared within a desired setting time and possessing workable rheology. A "water-in-air" Pickering emulsion, also called dry water, was prepared by stabilizing water droplets with hydrophobic nano silica and using them to control the geopolymer's strength, setting time, and workability.

Application of a new body surface-assisting puncture device in percutaneous transforaminal endoscopic lumbar discectomy.

Background: Accurate puncture and localization are critical for percutaneous transforaminal endoscopic lumbar discectomy surgery. However, several punctures are often required, followed by X-ray fluoroscopy, which can increase surgical risk and complications. The aim of this study was to demonstrate a new body surface-assisting puncture device that can be used in percutaneous transforaminal endoscopic lumbar discectomy and to assess its clinical effectiveness.

Experimental Characterization and Multi-Factor Modelling to Achieve Desired Flow, Set and Strength of N-A-S-H Geopolymers.

The interaction between compositional ratios, namely, SiO/AlO, NaO/AlO, HO/NaO and the liquid-to-solid ratio, triggers mutual sacrifice between workability, setting time and strength for N-A-S-H geopolymers. The present study characterizes the mechanism underlying the effect of these compositional ratios and, in turn, develops guidelines for mixture design that requires a simultaneous and satisfactory delivery of these engineering properties. The experimental results show that an increase in either the SiO/AlO, NaO/AlO or HO/NaO ratio raises the liquid-to-solid ratio, which in turn improves the workability of fresh mixtures.