scholarly journals Composite gypsum binder under introducing thermally activated clay as a pozzolanic component and adding ground limestone

2020 ◽  
Vol 890 ◽  
pp. 012093
Author(s):  
Marat Khaliullin ◽  
Alsu Dimieva
Keyword(s):  
Thermally Activated ◽  
Ground Limestone

scholarly journals The effect of ground limestone on the properties of composite gypsum binder using thermally activated clay as a pozzolanic component

2021 ◽  
Vol 274 ◽  
pp. 04006
Author(s):  
Marat Khaliullin ◽  
Alsu Gilmanshina
Keyword(s):  
Energy Consumption ◽  
Construction Industry ◽  
Mechanochemical Activation ◽  
Pozzolanic Activity ◽  
Optimal Amount ◽  
Thermally Activated ◽  
Preliminary Preparation ◽  
Binder Composition ◽  
Clay Ground ◽  
Ground Limestone

The purpose of this research is to study the effect of methods of preliminary preparation of thermally activated clay, which is a pozzolanic component in water-resistant composite gypsum binders, as well as the effect of mechanochemical activation in the joint grinding of thermally activated clay with the addition of a plasticizer on the pozzolanic activity and the change in the required number of pozzolanic component in the composition of composite gypsum binders. It was found that the required amount of thermally activated clay as pozzolanic component in the gypsum-cement-pozzolan composition when ground to specific surfaces of 200-500 m2/kg together with the addition of Melflux 2651 F plasticizer, based on the exclusion of conditions for the formation of an unacceptable amount of ettringite, decreases by 20-25% compared with the use of thermally activated clay ground without the introduction of a plasticizer. The optimal amount of Melflux 2651 F plasticizer introduced by grinding with thermally activated clay has been determined. The significance of the results for the construction industry lies in the fact that the use of the technology of obtaining composite gypsum binders of grinding thermally activated clay to a certain dispersion with the introduction of a plasticizer additive due to the effect of mechanochemical activation makes it possible to reduce the consumption of the pozzolanic component in the binder composition or energy consumption for grinding.

Thermally activated flow of β-titanium and β-titanium-hydrogen alloys

2000 ◽  
Vol 80 (12) ◽  
pp. 2813-2825
Author(s):  
O. N. Senkov, J. J. Jonas, F. H. Froes
Keyword(s):  
Thermally Activated

Solvent Dependence of Structural Dynamics and Spin-flip Processes in 3,4,5-tri(9H-carbazole-9-yl)benzonitrile (ortho-3CzBN)

2020 ◽  
Author(s):  
Masaki Saigo ◽  
Kiyoshi Miyata ◽  
Hajime Nakanotani ◽  
Chihaya Adachi ◽  
Ken Onda
Keyword(s):  
Dft Calculations ◽  
Excited States ◽  
Structural Changes ◽  
Photophysical Properties ◽  
Delayed Fluorescence ◽  
Time Resolved ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Solvent Dependence ◽  
Acetonitrile Solutions

We have investigated the solvent-dependence of structural changes along with intersystem crossing of a thermally activated delayed fluorescence (TADF) molecule, 3,4,5-tri(9H-carbazole-9-yl)benzonitrile (o-3CzBN), in toluene, tetrahydrofuran, and acetonitrile solutions using time-resolved infrared (TR-IR) spectroscopy and DFT calculations. We found that the geometries of the S1 and T1 states are very similar in all solvents though the photophysical properties mostly depend on the solvent. In addition, the time-dependent DFT calculations based on these geometries suggested that the thermally activated delayed fluorescence process of o-3CzBN is governed more by the higher-lying excited states than by the structural changes in the excited states.<br>

Mass spectrometric study of allyl radical, allyl bromide and 1,5-hexadiene interactions with oxides; Cobalt suboxide Co3O4

1979 ◽  
Vol 44 (7) ◽  
pp. 2009-2014 ◽  
Author(s):  
Jana Nováková ◽  
Zdeněk Dolejšek
Keyword(s):  
Room Temperature ◽  
Allyl Bromide ◽  
Catalytic Properties ◽  
Mass Spectrometric Study ◽  
Spectrometric Study ◽  
Flow Conditions ◽  
Allyl Radical ◽  
Knudsen Flow ◽  
Thermally Activated ◽  
Radical Interaction

Products of (a) allyl radical interaction with unheated Co3O4, (b) thermally activated 1,5-hexadiene or thermally activated allyl bromide with unheated Co3O4, (c) moderately heated Co3O4 with unheated 1,5-hexadiene or allyl bromide were studied under Knudsen flow conditions. Cobalt suboxide Co3O4, a typical catalyst of deep oxidations yielded acrolein in reaction with allyl radicals as early as at the room temperature of the catalyst. A similar acrolein formation was also observed in the allyl radical interaction with other oxides exhibiting different catalytic properties. It appears that acrolein is in general the primary product of the allyl radical interaction with the oxides. The results are discussed and compared with previous data obtained with MoO3.

Effect of grain size on the vapour phase hydration of monoclinic and triclinic modifications of tricalcium silicate; role of high temperature activation

1991 ◽  
Vol 56 (10) ◽  
pp. 1993-2008
Author(s):  
S. Hanafi ◽  
G. M. S. El-Shafei ◽  
B. Abd El-Hamid
Keyword(s):  
Particle Size ◽  
Vapour Phase ◽  
Tricalcium Silicate ◽  
Active Centers ◽  
Thermally Activated ◽  
Grain Sizes ◽  
Intermediate Size ◽  
Surface Active ◽  
Temperature Activation

The hydration of tricalcium silicate (C3S) with three grain sizes of monoclinic (M) and triclinic (T) modifications and on their thermally activated samples were investigated by exposure to water vapour at 80°C for 60 days. The products were investigated by XRD, TG and N2 adsorption. The smaller the particle size the greater was the hydration for both dried and activated samples from (M). In the activated samples a hydrate with 2θ values of 38.4°, 44.6° and 48.6° could be identified. Hydration increased with particle size for the unactivated (T) samples but after activation the intermediate size exhibited enhanced hydration. Thermal treatment at 950°C of (T) samples increased the surface active centers on the expense of those in the bulk. Changes produced in surface texture upon activation and/or hydration are discussed.

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