| 1. |
- Wang, Dong, et al.
(författare)
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Optimized fire resistance of alkali-activated high-performance concrete by steel fiber
- 2024
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Ingår i: Journal of thermal analysis and calorimetry (Print). - : Springer Nature. - 1388-6150 .- 1588-2926.
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Tidskriftsartikel (refereegranskat)abstract
- The behavior of alkali-activated ultra-high-performance concrete (A-UHPC) at elevated temperatures is unknown. This study addresses this gap by investigating the behavior of A-UHPC under varying temperatures with steel fiber additions (1%, 2%, and 3%), and considering target temperatures (20 °C, 200 °C, 400 °C, 600 °C, and 800 °C) as design variables. As the results, A-UHPC with steel fibers showed improved fire resistance, suffering less compressive strength loss at 800 °C than fiber-free A-UHPC. High temperatures initially optimized A-UHPC’s microstructure at 200 °C but later caused damage through microstructure propagation. Steel fibers enhanced A-UHPC’s ductility, resulting in ductile failure even at 800 °C. A-UHPC exhibited a unique mechanical degradation pattern under elevated temperatures, distinct from ordinary cement-based concrete. Empirical models accurately predicted its behavior, offering valuable insights for engineers dealing with heavy loads and high temperatures.
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| 2. |
- Hedi, Wen, et al.
(författare)
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γ-Cyclodextrin-BSA for nano-encapsulation of hydrophobic substance
- 2021
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Ingår i: Food Bioscience. - : Elsevier. - 2212-4292 .- 2212-4306. ; 41
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Tidskriftsartikel (refereegranskat)abstract
- Self-aggregation and the hemolytic effect limit the application of gamma-cyclodextrin (gamma-CD) in bioactive molecular delivery systems. In this study, gamma-CD was modified by grafting onto bovine serum albumin protein (BSA), with epichlorohydrin (ECH) acting as the cross-linking agent. The effects of BSA concentration, reaction temperature, pH and time on the grafting rate were studied, and the gamma-CD-BSA complex with a grafting rate of 99.5 +/- 0.1% +/- 0.06)% was achieved. The complex was confirmed using H-1 NMR and FT-IR spectra. Compared with gamma-CD, the hemolytic effect and self-aggregation of gamma-CD-BSA were significantly reduced, and the encapsulation efficiency of curcumin was increased by 10.8%. The results of scanning electron microscopy showed that both gamma-CD and gamma-CDBSA nanoparticles were formed and the structure of the gamma-CD-BSA complex was more uniform. The pH stability and salt stability of gamma-CD-BSA were higher than gamma-CD. The release rate of gamma-CD-BSA was 15.2 +/- 0.2% after 2 h at pH 1.2, and 57 +/- 1% after 4 h at pH 7.2. The gamma-CD-BSA nanoparticles could protect curcumin in acidic environments and release it in neutral environments. The results suggested a promising wall material for delivery of hydrophobic substances.
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