scholarly journals Fracture, grinding, mechanical activation and synthesis processes in solids under mechanical action

2005 ◽  
Vol 37 (2) ◽  
pp. 93-105 ◽  
Author(s):  
M.V. Chaikina ◽  
Sergej Aman
Keyword(s):  
Mechanical Activation ◽  
Mechanochemical Synthesis ◽  
Mechanochemical Activation ◽  
Mechanical Action ◽  
Multicomponent Systems ◽  
Chemical Changes

The parameters of mechanical action on solids were determined for apatite and quartz as examples, providing separation between fracture, grinding and mechanical activation processes in solids. The texture, structural and chemical changes accompanying these processes in the samples under investigation are shown. The data on mechanochemical synthesis of isomorphous apatite modifications in multicomponent systems are reported. A reversible character of mechanochemical activation and mechanochemical synthesis is discovered.

scholarly journals Mechanochemistry of fluoride solids: from mechanical activation to mechanically stimulated synthesis

ChemTexts ◽  
2021 ◽  
Vol 7 (2) ◽  
Author(s):  
Gudrun Scholz
Keyword(s):  
Mechanical Activation ◽  
Mechanochemical Synthesis ◽  
Alkaline Earth ◽  
Earth Metal ◽  
Alkaline Earth Metal ◽  
Technical Equipment ◽  
Metal Compounds ◽  
Potential Applications ◽  
The Given ◽  
Mechanochemical Reactions

Abstract This lecture text is focused on the comparatively young field of mechanochemistry of fluoride solids, considering both their mechanical activation and their mechanochemical synthesis. Beside a literature survey, the mechanochemical synthesis of binary fluorides MF2, MF3, of complex fluorides MMgF4, of solid solutions MaxMb1−xF2 or M1−xLnxF2+x (Ln: Y, Eu) and of fluorine-containing coordination polymers is presented. Owing to their interesting potential applications in the field of fluoride ion conductivity or luminescence properties when doped, most of the given examples are alkaline earth metal compounds. A short historical survey, remarks on peculiarities and consequences of mechanical activation as well as the necessary technical equipment for mechanochemical reactions precede the section. Graphic abstract

scholarly journals Multistage Mechanical Activation of Multilayer Carbon Nanotubes in Creation of Electric Heaters with Self-Regulating Temperature

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4654
Author(s):  
Alexandr Viktorovich Shchegolkov ◽  
Sung-Hwan Jang ◽  
Aleksei Viktorovich Shchegolkov ◽  
Yuri Viktorovich Rodionov ◽  
Olga Anatolievna Glivenkova
Keyword(s):  
Carbon Nanotubes ◽  
Temperature Field ◽  
Mechanical Activation ◽  
Thermal Effect ◽  
Supply Voltage ◽  
Mechanical Energy ◽  
Mechanical Action ◽  
Multilayer Carbon Nanotubes ◽  
Starting Current ◽  
Paddle Mixer

The article deals with research related to the issues of nanomodification of elastomers as a basis of electric heaters with self-regulating temperature. The effect of multistage mechanical activation of multilayer carbon nanotubes (MCNTs) with graphite on the uniformity of the temperature field distribution on the surface of nanomodified organosilicon elastomer has been studied. The influence of the stages of mechanical action on the parameters of MCNTs is revealed. It has been ascertained that for the MCNTs/graphite bulk material, which has passed the stage of mechanical activation in the vortex layer apparatus, a more uniform distribution of the temperature field and an increase in temperature to 57.1 °C at the supply voltage of 100 V are typical. The distribution of the temperature field in the centrifugal paddle mixer “WF-20B” for mixing MCNTs with graphite has been investigated. It has been found that there is also a thermal effect in addition to the mechanical action on the MCNTs in the paddle mixer “WF-20B”. The thermal effect is associated with the transfer of the mechanical energy of friction of the binary mixture MCNTs/graphite on the paddle and the walls of the vessel. The multiplicity of the starting current Ip to the nominal In (Ip/In) is 5 for the first sample, 7.5 for the second sample, and 10 for the third sample at the supply voltage of 100 V. The effect of reducing the starting current and stabilizing the temperature indicates the presence of self-regulation, which is expressed in maintaining a certain level of temperature.

scholarly journals Morphology and Energy Distribution of the Valence Electrons After Mechanochemical Activation SiO2/Al2O3

2015 ◽  
Vol 16 (3) ◽  
pp. 501-505
Author(s):  
Ya.V. Zaulychnyy ◽  
V. Ya. Ilkiv ◽  
Y. V. Yavorskyi ◽  
O. I. Dudka ◽  
V.I. Zarko ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Energy Distribution ◽  
Mechanical Activation ◽  
Mechanochemical Activation ◽  
Morphological Characteristics ◽  
Aluminum Oxides ◽  
Nanoscale Structures ◽  
Valence Electrons ◽  
Before And After

The analysis of morphological characteristics of nanoscale structures x-Al2O3 + y-SiO2 (x = 0,2; 0,3; 0,75; y = 0,8; 0,7; 0,25) before and after mechanical activation is hold. During the investigation of spot chemical composition is was revealed that as the consequence of mechanical activation in the structure of composites agglomerates are formed where nanoparticles of silicon and aluminum oxides are present simultaneously. The changes of the structure of morphology are confirmed by the redistribution of valence Ор-, Sisd- та Alsd electrons mixtures as a result of mechanical activation.

Solid State of Polymolybdenum(VI) Phenylsiloxanes - Synthesis and Structure

2019 ◽  
Vol 806 ◽  
pp. 57-63 ◽  
Author(s):  
Nikolai P. Shapkin ◽  
Alevtina Kapustina ◽  
Natalya Dombai ◽  
Vitalii Libanov ◽  
Irina G. Khal'chenko ◽  
...  
Keyword(s):  
Solid State ◽  
Diffraction Analysis ◽  
Mechanical Activation ◽  
Cross Section ◽  
Mechanochemical Activation ◽  
Analysis Data ◽  
X Ray Diffraction ◽  
X Ray ◽  
Soluble Polymers ◽  
Activation Conditions

Interaction of molybdenyl(VI) bis(acetylacetonate) with polyphenylsiloxane in xylene and under mechanochemical activation conditions has been investigated. The interaction of the above reagents under mechanical activation conditions proceeds with formation of soluble polymers similar to those obtained in a solution with the silicon/molybdenum ratio equal to 2.6. The crystal chemistry parameters of the fraction obtained in solution with the ratio Si/Mo = 1:2 have been calculated on the basis of the X-ray diffraction analysis data using the Debye–Shearer equation. It has been demonstrated that the chain cross-section found using the Miller–Boyer method coincides with that calculated geometrically on the basis of literature data on bond lengths and angles.

scholarly journals CHEMICAL CHANGES IN THE ADDUCTOR MUSCLE OF THE CHELIPED OF THE CRAYFISH IN RELATION TO THE DOUBLE MOTOR INNERVATION

1938 ◽  
Vol 22 (2) ◽  
pp. 193-206 ◽  
Author(s):  
W. R. Bergren ◽  
C. A. G. Wiersma
Keyword(s):  
Lactic Acid ◽  
Adductor Muscle ◽  
Mechanical Action ◽  
Phosphate Content ◽  
Motor Innervation ◽  
Chemical Changes ◽  
Maximum Extent ◽  
Mechanical Effects ◽  
Slow Contraction ◽  
Stimulation Of

An investigation has been made of the phosphate and lactic acid changes in the adductor muscle of the cheliped of the crayfish Cambarus clarkii upon stimulation of the isolated axons for the fast and slow contractions at determined frequencies. The data obtained point to the following conclusions: 1. When the mechanical effects of the two types of contraction are the same, the chemical changes are of the same order. If the mechanical effects are different, the chemical changes likewise are not equivalent. This is especially to be seen in the case of stimulation at 50 shocks per second: a slowly rising, long continued, strong slow contraction takes place with no apparent change in the phosphate content; a quickly rising fast contraction occurs with a large increase in the phosphate. 2. Since equivalent chemical changes accompany equivalent mechanical action, the two types of contraction do not differ in the essential mechanism of the chemical changes involved, and only one type of contractile substance is present. 3. Even when a contraction has taken place to the maximum extent obtainable, only enough phosphate is found to correspond to one-fifth to one-third of the available phosphagen.

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