On the Chemical Composition of Thermally Treated Coal-Tar Pitches

2001 ◽  
Vol 15 (1) ◽  
pp. 214-223 ◽  
Author(s):  
R. Menéndez ◽  
C. Blanco ◽  
R. Santamaría ◽  
J. Bermejo ◽  
I. Suelves ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Coal Tar ◽  
Thermally Treated

CHARACTERIZATION OF COAL TAR PITCHES: RELATIONSHIP WITH CHEMICAL COMPOSITION OF PARENT TARS

1991 ◽  
pp. 516-519
Author(s):  
A.I. Gónzalez ◽  
R. Alvarez ◽  
M. Granda ◽  
R. Menéndez ◽  
M.A. Díez ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Coal Tar

scholarly journals Electroless Ni-P Coatings: Preparation and Evaluation of Fracture Toughness and Scratch Hardness

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Wagner Sade ◽  
Reinaldo Trindade Proença ◽  
Thiago Daniel de Oliveira Moura ◽  
José Roberto Tavares Branco
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Chemical Composition ◽  
Scratch Hardness ◽  
Hard Particles ◽  
Steel Aisi ◽  
Electroless Ni ◽  
Preparation And Evaluation ◽  
Phase Relationships ◽  
Thermally Treated

Ni-P chemical coatings have been used to prevent wear, corrosion and as an alternative for hard chromium, since the latter's deposition processing is very harmful to the human health and the environment. In the present paper, Ni-P coatings with 8 and 10% P were deposited in steel AISI 1020 and thermally treated. Ni-1wt%P coatings with incorporation of hard particles of Al2O3 were also investigated. The microstructure and phase relationships were analyzed and correlated with the fracture toughness and scratch hardness of the coatings.The results show that the fracture toughness of the coating was smaller when thermally treated at 400°C for 1 hour and the scratch hardness reached a peak in this temperature. The relation of chemical composition and microstructure with mechanical properties of Ni-P coatings is presented. The phosphorus contents, the crystallization, and the incorporation of hard particles in the coatings change the values of toughness fracture and scratch hardness.

Separation and characterization of the isotropic phase and co-existing mesophase in thermally treated coal-tar pitches

Carbon ◽  
2000 ◽  
Vol 38 (8) ◽  
pp. 1169-1176 ◽  
Author(s):  
C. Blanco ◽  
R. Santamarı́a ◽  
J. Bermejo ◽  
R. Menéndez
Keyword(s):  
Coal Tar ◽  
Isotropic Phase ◽  
Thermally Treated

A comparative study of air-blown and thermally treated coal-tar pitches

Carbon ◽  
2000 ◽  
Vol 38 (4) ◽  
pp. 517-523 ◽  
Author(s):  
C. Blanco ◽  
R. Santamarı́a ◽  
J. Bermejo ◽  
R. Menéndez
Keyword(s):  
Comparative Study ◽  
Coal Tar ◽  
Thermally Treated

scholarly journals Theory of systems with chaos of chemical composition in nature and technology

2020 ◽  
Vol 61 (2) ◽  
pp. 1-11
Author(s):  
Mikhail Yu. Dolomatov ◽  
Keyword(s):  
Chemical Composition ◽  
Interstellar Dust ◽  
Coal Tar ◽  
Point Of View ◽  
Oil Refining ◽  
Multicomponent Systems ◽  
Informational Entropy ◽  
Natural Systems ◽  
Statistical Ensembles ◽  
Diversity Of Components

According to the theory developed by the author, a substance is built from statistical ensembles more general than atoms, molecules, and supramolecular structures, namely, from multicomponent systems with chaos of chemical composition (MSCC). Any imperfect substance exists in the form of multicomponent systems with chaos of composition and consists of an infinite number of components. It is shown that all natural and man-made substances are MHS, with varying degrees of chemical chaos. According to the theory, MSCC with small composition chaos are distinguished, which are identified as individual substances and systems with significant chaos – multicomponent mixtures. Natural MSCC with significant Gaussian compositional chaos include hydrocarbon systems, for example, natural gases, fuel fractions, gas condensates, space systems, for example, interstellar dust and gas clouds, geochemical, and biogeochemical objects. Technogenic MSCC are obtained by processing natural systems, such as coal tar, and oil refining. Biogenic MSCC include humic acids, blood plasma, etc. Individual substances (colorblind) are Poisson systems with chaos of chemical composition, or systems with small chaos of composition. MSCC are objects that manifest themselves as a whole in physicochemical processes. These systems are qualitatively different from conventional mixtures by a certain statistical law of the distribution of the composition according to physicochemical properties and have thermodynamic and kinetic features. For example, the Ministry of Agriculture does not comply with the law of consistency. To characterize such systems, it is proposed to use the informational entropy of the composition and the entropy of the diversity of components. The point of view on matter as a system with chaos of composition is justified, one of the laws of evolution of which is the increase in the entropy of the diversity of states, which is the source of evolution of the MSCC.

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