scholarly journals Influence of PPA on the Short-Term Antiaging Performance of Asphalt

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Lining Gao ◽  
Nana Cai ◽  
Xiaohong Fu ◽  
Rui He ◽  
Honggang Zhang ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
High Temperature ◽  
High Performance ◽  
Main Function ◽  
Short Term ◽  
Temperature Resistance ◽  
Modified Asphalt ◽  
High Temperature Resistance ◽  
Before And After

It has been confirmed that polyphosphoric acid (PPA) can significantly improve the high-temperature resistance, storage stability, and aging resistance of asphalt. The low price of PPA is conducive to the development of modified asphalt with high performance and excellent economy, suggesting its great application prospects. At present, there is little research on the role of PPA in delaying the aging process of PPA-modified asphalt, and a consensus has not yet been reached. Therefore, PPA-modified asphalt with different blending amounts (0 wt%, 0.4 wt%, 0.8 wt%, and 1.2 wt%) was prepared in this study. On the basis of variable performance, the role of PPA in the short-term antiaging process of asphalt is analyzed through Fourier transform infrared spectroscopy (FTIR) analysis of PPA-modified asphalt before and after aging, combined with the analysis of the change in components. The results showed that after PPA addition, the high-temperature resistance and the thermal stability of asphalt were improved and the temperature sensitivity was weakened. Both curves of ductility and G ∗ indicate the potential saturation effect of PPA addition; together with infrared spectroscopy, we proved that there are both chemical reactions and physical mixing in the PPA-modified asphalt. The component fractions show that PPA will cause the asphalt to transform from sol to gel and the main function of PPA in retarding asphalt aging is the dispersion of the agglomerates of asphaltene micelles by PPA.

Research and Development of Self-Lubricating Bearing Materials

2013 ◽  
Vol 651 ◽  
pp. 198-203
Author(s):  
Xiu Ling Wang ◽  
Li Ying Yang ◽  
Shou Ren Wang
Keyword(s):  
High Temperature ◽  
Research And Development ◽  
Metal Matrix ◽  
Future Trend ◽  
Al Alloy ◽  
Temperature Resistance ◽  
The Future ◽  
High Temperature Resistance ◽  
Bearing Materials ◽  
New Type

It is significant and necessary to carry out the research and development of self-lubricating bearing. The current study of metal matrix self-lubricating bearing materials is summarized. A new type of high temperature self-lubricating Ti-Al alloy bearing materials is proposed. It is light, anti-friction, anti-corrosion and high temperature resistance (600 °C). The future trend is introduced in the end of this paper.

Mineral-impregnated carbon fibre reinforcement for high temperature resistance of thin-walled concrete structures

2019 ◽  
Vol 97 ◽  
pp. 68-77 ◽  
Author(s):  
Kai Schneider ◽  
Albert Michel ◽  
Marco Liebscher ◽  
Lucas Terreri ◽  
Simone Hempel ◽  
...  
Keyword(s):  
High Temperature ◽  
Carbon Fibre ◽  
Concrete Structures ◽  
Fibre Reinforcement ◽  
Temperature Resistance ◽  
High Temperature Resistance ◽  
Thin Walled

scholarly journals Duodenal Dysbiosis and Relation to the Efficacy of Proton Pump Inhibitors in Functional Dyspepsia

2021 ◽  
Vol 22 (24) ◽  
pp. 13609
Author(s):  
Lucas Wauters ◽  
Raúl Y. Tito ◽  
Matthias Ceulemans ◽  
Maarten Lambaerts ◽  
Alison Accarie ◽  
...  
Keyword(s):  
Functional Dyspepsia ◽  
Proton Pump Inhibitors ◽  
Proton Pump ◽  
Potential Role ◽  
Short Term ◽  
Beneficial Effects ◽  
Rrna Sequencing ◽  
Before And After

Proton pump inhibitors (PPI) may improve symptoms in functional dyspepsia (FD) through duodenal eosinophil-reducing effects. However, the contribution of the microbiome to FD symptoms and its interaction with PPI remains elusive. Aseptic duodenal brushings and biopsies were performed before and after PPI intake (4 weeks Pantoprazole 40 mg daily, FD-starters and controls) or withdrawal (2 months, FD-stoppers) for 16S-rRNA sequencing. Between- and within-group changes in genera or diversity and associations with symptoms or duodenal factors were analyzed. In total, 30 controls, 28 FD-starters and 19 FD-stoppers were followed. Mucus-associated Porphyromonas was lower in FD-starters vs. controls and correlated with symptoms in FD and duodenal eosinophils in both groups, while Streptococcus correlated with eosinophils in controls. Although clinical and eosinophil-reducing effects of PPI therapy were unrelated to microbiota changes in FD-starters, increased Streptococcus was associated with duodenal PPI effects in controls and remained higher despite withdrawal of long-term PPI therapy in FD-stoppers. Thus, duodenal microbiome analysis demonstrated differential mucus-associated genera, with a potential role of Porphyromonas in FD pathophysiology. While beneficial effects of short-term PPI therapy were not associated with microbial changes in FD-starters, increased Streptococcus and its association with PPIeffects in controls suggest a role for duodenal dysbiosis after long-term PPI therapy.

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