scholarly journals Controlled growth and ordering of poorly-crystalline calcium-silicate-hydrate nanosheets

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Felipe Basquiroto de Souza ◽  
Ezzatollah Shamsaei ◽  
Shujian Chen ◽  
Kwesi Sagoe-Crentsil ◽  
Wenhui Duan
Keyword(s):  
Calcium Silicate ◽  
Calcium Silicate Hydrate ◽  
Layer By Layer ◽  
Portland Cement Concrete ◽  
Sustainable Infrastructure ◽  
Energy Applications ◽  
Simulation Techniques ◽  
Mesoscale Structure ◽  
Strength And Durability ◽  
Computer Simulation Techniques

AbstractOptimising the mesoscale structure of calcium-silicate-hydrate (C-S-H) is critical to achieving durable and sustainable infrastructure using Portland cement concrete. However, control of its intricate formation process, which comprises spatially disordered growth of poorly-crystalline sheets, remains a challenge. Here, through combination of experimental and computer simulation techniques, we report a promising mechanism to control this complex growth process and thereby optimise the C-S-H nanostructure. The pivotal step was utilizing graphene oxide (GO) to restrain the inherent spatial deformations of the C-S-H sheets and guide their concurrent 2D growth and layer-by-layer ordering. Accordingly, we designed a layered GO–C-S-H composite that exhibits 1–2 orders of magnitude improvement in strength and durability compared with C-S-H formed without control. Our findings open a window for nano-engineering of cements and other complex layered materials for ceramic, pharmaceutical and energy applications.

scholarly journals Influence of CNTs, ZnO, Gd2O3 and SiO2 on Calcium Silicate Hydrate: A Raman spectroscopic study

2021 ◽  
Author(s):  
Muhammad Azeem
Keyword(s):  
Metal Oxides ◽  
Calcium Silicate ◽  
Calcium Silicate Hydrate ◽  
Weight Percent ◽  
The Other ◽  
Raman Spectroscopic ◽  
Raman Spectroscopic Study ◽  
The Matrix ◽  
Vibrational Bands ◽  
Strength And Durability

Abstract Raman spectra are collated from the cement paste matrices of CNTs, ZnO, Gd2O3, and SiO2. The spectra show that CNTs do not take part in hydration process and therefore concentration of calcium silicate hydrate (CSH) is unchanged in CNT-OPC matrix. The metal oxides, on the other hand, have shown significant effects on the CSH concentration. The CSH concentration increases with the increase of ZnO weight percent in the matrix whereas spectra collected from Gd2O3 matrix shows the strongest CSH vibrational bands. Moreover, vibrational bands of CaCO3 also become weak in the matrices with Gd2O3. The addition of SiO2 however had opposite effects that is by increasing the weight percent of SiO2 in the matrix, the CSH concentration is decreased. Since CSH acts a glue in a binder, the study shows that its concentration can be controlled by adding foreign elements. Such binders are expected to show improved strength and durability.

Image Analysis of Intramembrane Particles in Freeze-Fractured Biomembranes Using Computer Simulation Techniques

1975 ◽  
Vol 33 ◽  
pp. 214-215
Author(s):  
D.J. Benefiel ◽  
R.S. Weinstein
Keyword(s):  
Membrane Proteins ◽  
Freeze Fracture ◽  
Integral Membrane Proteins ◽  
Systematic Evaluation ◽  
Intramembrane Particles ◽  
Modeling Methods ◽  
Simulation Techniques ◽  
Freeze Fracture Electron Microscopy ◽  
Fracture Electron ◽  
Computer Simulation Techniques

Intramembrane particles (IMP or MAP) are components of most biomembranes. They are visualized by freeze-fracture electron microscopy, and they probably represent replicas of integral membrane proteins. The presence of MAP in biomembranes has been extensively investigated but their detailed ultrastructure has been largely ignored. In this study, we have attempted to lay groundwork for a systematic evaluation of MAP ultrastructure. Using mathematical modeling methods, we have simulated the electron optical appearances of idealized globular proteins as they might be expected to appear in replicas under defined conditions. By comparing these images with the apearances of MAPs in replicas, we have attempted to evaluate dimensional and shape distortions that may be introduced by the freeze-fracture technique and further to deduce the actual shapes of integral membrane proteins from their freezefracture images.

Multiple ions transport and interaction in calcium silicate hydrate gel nanopores: Effects of saturation and tortuosity

2021 ◽  
Vol 283 ◽  
pp. 122638
Author(s):  
Zhiyong Liu ◽  
Yuncheng Wang ◽  
Dong Xu ◽  
Chuyue Zang ◽  
Yunsheng Zhang ◽  
...  
Keyword(s):  
Calcium Silicate ◽  
Calcium Silicate Hydrate ◽  
Ions Transport

Boiler Implosion Control in Fossil Fuel Power Plants

1985 ◽  
Vol 107 (4) ◽  
pp. 267-269 ◽  
Author(s):  
S. Z. Wu ◽  
D. N. Wormley ◽  
D. Rowell ◽  
P. Griffith
Keyword(s):  
Power Plants ◽  
Fossil Fuel ◽  
Companion Paper ◽  
Simulation Techniques ◽  
Power Plant Boiler ◽  
Induced Draft Fan ◽  
Fossil Fuel Power Plants ◽  
Computer Simulation Techniques ◽  
Plant Boiler ◽  
Furnace Pressure

An evaluation of systems for control of fossil fuel power plant boiler and stack implosions has been performed using computer simulation techniques described in a companion paper. The simulations have shown that forced and induced draft fan control systems and induced draft fan bypass systems reduce the furnace pressure excursions significantly following a main fuel trip. The limitations of these systems are associated with actuator range and response time and stack pressure excursions during control actions. Preliminary study suggests that an alternative control solution may be achieved by discharging steam into the furnace after a fuel trip.

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