scholarly journals Understanding the Hydration Process of Salts: The Impact of a Nucleation Barrier

2019 ◽  
Vol 19 (4) ◽  
pp. 2279-2288 ◽  
Author(s):  
Leyla-Cann Sögütoglu ◽  
Michael Steiger ◽  
Jelle Houben ◽  
Daan Biemans ◽  
Hartmut R. Fischer ◽  
...  
Keyword(s):  
Hydration Process ◽  
Nucleation Barrier ◽  
The Impact

scholarly journals MICROSCOPIC AND PHASE ANALYSIS OF CEMENT PASTE CONTAINING WASTE MICRONIZED MARBLE POWDER

2018 ◽  
Vol 15 ◽  
pp. 94-98
Author(s):  
Zdeněk Prošek ◽  
Pavel Tesárek ◽  
Jan Trejbal
Keyword(s):  
Electron Microscopy ◽  
Phase Composition ◽  
Portland Cement ◽  
Phase Analysis ◽  
Cement Paste ◽  
Reference Sample ◽  
Hydration Process ◽  
Cement Composites ◽  
Marble Powder ◽  
The Impact

The article focuses on the impact of waste marble powder on resulting cement composites. We investigate of influence waste marble powder on the hydration process and hence the resulting phase composition. The hydration process was investigated using calorimetry and phase composition of the resulting composite by electron microscopy. The results are compared with a reference sample composed of Portland cement.

scholarly journals Experimental study applied to the lime hydration process, in a thermoelectric coal power plant unit

2020 ◽  
Author(s):  
Rodrigo Saraiva Dantas ◽  
Maria Alejandra Liendo ◽  
Vera Lucia Duarte Ferreira ◽  
Rodrigo Bortoluzzi
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Hydrated Lime ◽  
Hydration Process ◽  
Maximum Temperature ◽  
Main Process ◽  
Coal Power Plants ◽  
Coal Power ◽  
The Impact

Abstract Coal Power Plants need to control SO 2 emissions to the atmosphere from the boiler flue gases, in order to reach standards according to guidelines determined by the Conselho Nacional de Meio Ambiente - CONAMA. For this purpose hydrated lime is used, which is, in fact, produced from lime at the power plant. Hydrated lime is injected into the equipment called desulphuriser that operates capturing the sulfur dioxide from the boiler flue gas. Due to the importance of this process, the present work aimed to evaluate several points that involve: the production of hydrated lime from lime, the analysis of the quality of lime received, the study of the hydration process. Moreover it was evaluated the impact of the temperature of reaction through to the hydration efficiency according to the methodology and routine proposed. In addition, complementary analysis were carried out on the characterization of lime and hydrated lime and the correlation between the main process parameters measured and recorded in lime hydration control system. In relation to the results of hydration efficiency, it was possible to observe its increase when the maximum temperature of the reaction stage was lower, reaching results up to 85%.

scholarly journals EMPLOYMENT OF MAGNETIC WATER TREATMENT IN CONSTRUCTION

2021 ◽  
Vol 25 (4) ◽  
pp. 1-12
Author(s):  
Rawaa A. Al-Safy ◽  
Keyword(s):  
Building Materials ◽  
Water Clusters ◽  
Hydration Process ◽  
Cement Particle ◽  
Construction Sites ◽  
Cement Based Materials ◽  
Time Strength ◽  
The Impact ◽  
Magnetic Water

Magnetic treatment (MT) is one of the interested techniques that have been widely used in various aspects of life due to its positive effectiveness on the properties of water when utilized. Construction sector received great attention by researchers in order to employ magnetic water (MW) in the production of various building materials especially cement-based materials. This is due to the role of water is involved directly in the hydration process of the cement as well as curing process. The effectiveness of using MW came from the influence of magnetic field (MF) on physical properties of water molecular such as surface tension. Break down in the size of water clusters, therefore, is occurred which increases the activity of water molecular to penetrate the cement particle easily to involve in the hydration process. Various parameters may affect the magnetization process such as time, strength of MF and speed of water through the MF. In the current paper, the impact of using MW in the production of various construction and building materials that based on cement is addressed to clarify the actual need in adopting such an attractive technology to magnetize the water to be used in mixing and curing cement-based materials to construct sustainable concrete structures in construction sites.

scholarly journals Effect of MXene (Nano-Ti3C2) on Early-Age Hydration of Cement Paste

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Haibin Yin ◽  
Jianping Zhu ◽  
Xuemao Guan ◽  
Zhengpeng Yang ◽  
Yu Zhu ◽  
...  
Keyword(s):  
Cement Paste ◽  
Cement Hydration ◽  
Hydration Process ◽  
Early Age ◽  
Main Role ◽  
Hydration Products ◽  
Hydration Properties ◽  
Network Connection ◽  
The Impact ◽  
Early Age Hydration

As a new two-dimensional material, MXene (nano-Ti3C2) has been widely applied in many fields, especially for reinforced composite materials. In this paper, mechanical testing, X-ray diffraction (XRD), hydration heat, scanning electron microscope (SEM), and EDS analysis were used to analyze the impact of MXene on cement hydration properties. The obtained results revealed that (a) MXene could greatly improve the early compressive strength of cement paste with 0.04 wt% concentration, (b) the phase type of early-age hydration products has not been changed after the addition of MXene, (c) hydration exothermic rate within 72 h has small difference at different amount of MXene, and (d) morphologies of hydration products were varied with the dosage of MXene, a lot of tufted ettringites appeared in 3 d hydration products when the content of MXene was 0.04 wt%, which will have a positive effect on improving the early mechanical properties of cement paste. MXene has inhibited the Portland cement hydration process; the main role of MXene in the cement hydration process is to promote the messy ettringite becoming regular distribution at a node and form network connection structure in the crystals growth process, making the mechanics performance of cement paste significantly improved.

scholarly journals Impact of admixtures used in underwater concrete on cement hydration process and rheological properties

2020 ◽  
Vol 322 ◽  
pp. 01030
Author(s):  
Aneta Matuszek-Chmurowska ◽  
Alina Kaleta-Jurowska ◽  
Krystian Jurowski ◽  
Stefania Grzeszczyk
Keyword(s):  
Rheological Properties ◽  
Cement Hydration ◽  
Setting Time ◽  
Nano Particles ◽  
Hydration Process ◽  
Rheological Parameters ◽  
Concrete Technology ◽  
Combined Application ◽  
Underwater Concrete ◽  
The Impact

This paper presents test results of the impact of chemical admixtures used in the underwater concrete technology, i.e. a superplasticizer (SP), an anti-wash admixture (AWA) and SiO2 nano- particles (NP) on the cement hydration process, rheological properties and the setting time. The impact of admixtures was tested in combination and separately, with the use of microcalimetry, X-ray diffraction (XRD) and rheology. It was demonstrated that AWA and SP admixtures caused a delay of the hydration process, while the impact of SP was much greater. The above statement was also confirmed by results of rheological tests. Combined application of AWA, SP and NP causes even a larger delay of the hydration process and the increase of paste rheological parameters, with the impact of the superplasticizer particularly visible.

Formation of Lunar Craters and Bright Rays as a Result of Meteorite Impacts

1962 ◽  
Vol 14 ◽  
pp. 415-418
Author(s):  
K. P. Stanyukovich ◽  
V. A. Bronshten
Keyword(s):  
Explosive Charge ◽  
The Moon ◽  
Meteorite Impacts ◽  
The Earth ◽  
Lunar Craters ◽  
The Impact

The phenomena accompanying the impact of large meteorites on the surface of the Moon or of the Earth can be examined on the basis of the theory of explosive phenomena if we assume that, instead of an exploding meteorite moving inside the rock, we have an explosive charge (equivalent in energy), situated at a certain distance under the surface.

The Geosciences Applied to Lunar Exploration

1962 ◽  
Vol 14 ◽  
pp. 169-257 ◽  
Author(s):  
J. Green
Keyword(s):  
Lunar Surface ◽  
Probable Mechanism ◽  
Point Of View ◽  
Lunar Exploration ◽  
Geological Model ◽  
Apply Geophysics ◽  
Surface Features ◽  
The Impact

The term geo-sciences has been used here to include the disciplines geology, geophysics and geochemistry. However, in order to apply geophysics and geochemistry effectively one must begin with a geological model. Therefore, the science of geology should be used as the basis for lunar exploration. From an astronomical point of view, a lunar terrain heavily impacted with meteors appears the more reasonable; although from a geological standpoint, volcanism seems the more probable mechanism. A surface liberally marked with volcanic features has been advocated by such geologists as Bülow, Dana, Suess, von Wolff, Shaler, Spurr, and Kuno. In this paper, both the impact and volcanic hypotheses are considered in the application of the geo-sciences to manned lunar exploration. However, more emphasis is placed on the volcanic, or more correctly the defluidization, hypothesis to account for lunar surface features.

Asteroid and Comet Impact Speeds upon Mars: Significance for Panspermia and the Supply of Organics

1997 ◽  
Vol 161 ◽  
pp. 197-201 ◽  
Author(s):  
Duncan Steel
Keyword(s):  
Probability Distributions ◽  
Regions Of Interest ◽  
Significant Fraction ◽  
Organic Chemicals ◽  
Impact Speed ◽  
The Mean ◽  
The Impact

AbstractWhilst lithopanspermia depends upon massive impacts occurring at a speed above some limit, the intact delivery of organic chemicals or other volatiles to a planet requires the impact speed to be below some other limit such that a significant fraction of that material escapes destruction. Thus the two opposite ends of the impact speed distributions are the regions of interest in the bioastronomical context, whereas much modelling work on impacts delivers, or makes use of, only the mean speed. Here the probability distributions of impact speeds upon Mars are calculated for (i) the orbital distribution of known asteroids; and (ii) the expected distribution of near-parabolic cometary orbits. It is found that cometary impacts are far more likely to eject rocks from Mars (over 99 percent of the cometary impacts are at speeds above 20 km/sec, but at most 5 percent of the asteroidal impacts); paradoxically, the objects impacting at speeds low enough to make organic/volatile survival possible (the asteroids) are those which are depleted in such species.

Organic Syntheses During the Impact of a Comet with a Gaseous Planet

1997 ◽  
Vol 161 ◽  
pp. 189-195
Author(s):  
Cesare Guaita ◽  
Roberto Crippa ◽  
Federico Manzini
Keyword(s):  
Polymeric Material ◽  
Molecular Form ◽  
Parent Compound ◽  
Blue Filter ◽  
Organic Syntheses ◽  
The Impact

AbstractA large amount of CO has been detected above many SL9/Jupiter impacts. This gas was never detected before the collision. So, in our opinion, CO was released from a parent compound during the collision. We identify this compound as POM (polyoxymethylene), a formaldehyde (HCHO) polymer that, when suddenly heated, reformes monomeric HCHO. At temperatures higher than 1200°K HCHO cannot exist in molecular form and the most probable result of its decomposition is the formation of CO. At lower temperatures, HCHO can react with NH3 and/or HCN to form high UV-absorbing polymeric material. In our opinion, this kind of material has also to be taken in to account to explain the complex evolution of some SL9 impacts that we observed in CCD images taken with a blue filter.

Hydrogen Cyanide Polymers from the Impact of Comet P/Shoemaker-Levy 9 on Jupiter

1997 ◽  
Vol 161 ◽  
pp. 179-187
Author(s):  
Clifford N. Matthews ◽  
Rose A. Pesce-Rodriguez ◽  
Shirley A. Liebman
Keyword(s):  
Amino Acids ◽  
Solar System ◽  
Hydrogen Cyanide ◽  
Nitrogen Heterocycles ◽  
Laboratory Studies ◽  
Heterogeneous Solids ◽  
The Many ◽  
Comet Halley ◽  
The Impact ◽  
By Products

AbstractHydrogen cyanide polymers – heterogeneous solids ranging in color from yellow to orange to brown to black – may be among the organic macromolecules most readily formed within the Solar System. The non-volatile black crust of comet Halley, for example, as well as the extensive orangebrown streaks in the atmosphere of Jupiter, might consist largely of such polymers synthesized from HCN formed by photolysis of methane and ammonia, the color observed depending on the concentration of HCN involved. Laboratory studies of these ubiquitous compounds point to the presence of polyamidine structures synthesized directly from hydrogen cyanide. These would be converted by water to polypeptides which can be further hydrolyzed to α-amino acids. Black polymers and multimers with conjugated ladder structures derived from HCN could also be formed and might well be the source of the many nitrogen heterocycles, adenine included, observed after pyrolysis. The dark brown color arising from the impacts of comet P/Shoemaker-Levy 9 on Jupiter might therefore be mainly caused by the presence of HCN polymers, whether originally present, deposited by the impactor or synthesized directly from HCN. Spectroscopic detection of these predicted macromolecules and their hydrolytic and pyrolytic by-products would strengthen significantly the hypothesis that cyanide polymerization is a preferred pathway for prebiotic and extraterrestrial chemistry.

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