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Online since: September 2018
Authors: Igor A. Lushkin, Vladimir A. Obrubov, Anatoly D. Bulat, Vladimir M. Filenkov
The number of electrophysical methods of processing, according to the methods of influence, are attractive and fit into the efficiency concept.
Due to re-crushing, the specific surface area of the cement grains exposed to re-crushing is increased approximately 1.5 to 2 times [1].
In this case, the change in the acting force on the cement grains depends on the coefficient of the cement mixture normal density.
From all the above mentioned, it can be concluded that for a certain intensity of the external field the developed force in the cement grains reaches a critical value at which the adsorption layer of the cement grain breaks down, and, consequently, additional contacts of the minerals of the cement grain with free water appear, i.e. the relationship between the surface and the volume of the phase changes.
Assuming a number of assumptions (cement particles having the surface of a ball are uniformly distributed in volume, the same size, and that dispersed systems have maximum stability with the most dense packaging), proceeding from the fact that the destruction of cement grains as a result of electrostatic forces at the interface «cement grains - hydrated shell» occurs along the lines of force of the field, it is possible to assert about the destruction of grain by diameter.
Due to re-crushing, the specific surface area of the cement grains exposed to re-crushing is increased approximately 1.5 to 2 times [1].
In this case, the change in the acting force on the cement grains depends on the coefficient of the cement mixture normal density.
From all the above mentioned, it can be concluded that for a certain intensity of the external field the developed force in the cement grains reaches a critical value at which the adsorption layer of the cement grain breaks down, and, consequently, additional contacts of the minerals of the cement grain with free water appear, i.e. the relationship between the surface and the volume of the phase changes.
Assuming a number of assumptions (cement particles having the surface of a ball are uniformly distributed in volume, the same size, and that dispersed systems have maximum stability with the most dense packaging), proceeding from the fact that the destruction of cement grains as a result of electrostatic forces at the interface «cement grains - hydrated shell» occurs along the lines of force of the field, it is possible to assert about the destruction of grain by diameter.
Online since: May 2011
Authors: Ming Shan, Gui Xiang Chen, Zhao Ran Xiao
· Storage depots are scattered, the number of the depot whose storage is below 10,000 tons is more than 60
One grain logistics park, two grain distribution centers, and 40~60 depots are to be built hierarchically in Mianyang.
Figure 1 shows the layout of the grain logistics node in Mianyang.
Inspection center of the quality of food in Mianyang should get independent legal person qualification, total investment will be 18 million Yuan. ² Informatization construction project The information management system of food and the information network of food will be built in Mianyang, so that the messages of enterprises, the number and the kind in the food warehouse will be managed.
Furthermore, the technology of green storage of grain should also be promoted.
One grain logistics park, two grain distribution centers, and 40~60 depots are to be built hierarchically in Mianyang.
Figure 1 shows the layout of the grain logistics node in Mianyang.
Inspection center of the quality of food in Mianyang should get independent legal person qualification, total investment will be 18 million Yuan. ² Informatization construction project The information management system of food and the information network of food will be built in Mianyang, so that the messages of enterprises, the number and the kind in the food warehouse will be managed.
Furthermore, the technology of green storage of grain should also be promoted.
Online since: August 2015
Authors: Cornel Samoila, Vlad Jinga, A. Bălan, G. Mateescu, A.O. Mateescu, I. Stamatin, Doru Ursuțiu
Roughness and grain size of substrate and samples no. 1 to 9 investigated by AFM
Sample no.
Roughness and grain size of samples no. 10 to 19 investigated by AFM Sample no. 10 11 12 13 14 15 16 17 18 19 Rough-ness [nm] 2.5 µm2 0.59 0.33 0.23 0.47 0.24 0.25 0.67 0.76 0.68 0.34 5 µm2 1.53 0.61 1.14 0.84 0.98 0.47 1.91 1.14 0.87 1.20 Grain size [nm] 4.0 2.25 3.90 2.25 2.75 1.60 3.20 6.85 3.20 2.0 a b c Fig. 2.
All the samples were obtained with very fine nanostructure, as the grain size was less than 10 nm, with 2 exceptions (samples no. 5 and 7).
Acknowledgements This work was supported by a grant of the Romanian National Authority for Scientific Research, Program for research - Space Technology and Advanced Research - STAR, project number 68/2013.
“This paper is supported by the Sectoral Operational Programme Human Resources Development (SOP HRD), financed from the European Social Fund and by the Romanian Government under the project number POSDRU/159/1.5/S/134378”.
Roughness and grain size of samples no. 10 to 19 investigated by AFM Sample no. 10 11 12 13 14 15 16 17 18 19 Rough-ness [nm] 2.5 µm2 0.59 0.33 0.23 0.47 0.24 0.25 0.67 0.76 0.68 0.34 5 µm2 1.53 0.61 1.14 0.84 0.98 0.47 1.91 1.14 0.87 1.20 Grain size [nm] 4.0 2.25 3.90 2.25 2.75 1.60 3.20 6.85 3.20 2.0 a b c Fig. 2.
All the samples were obtained with very fine nanostructure, as the grain size was less than 10 nm, with 2 exceptions (samples no. 5 and 7).
Acknowledgements This work was supported by a grant of the Romanian National Authority for Scientific Research, Program for research - Space Technology and Advanced Research - STAR, project number 68/2013.
“This paper is supported by the Sectoral Operational Programme Human Resources Development (SOP HRD), financed from the European Social Fund and by the Romanian Government under the project number POSDRU/159/1.5/S/134378”.
Online since: January 2010
Authors: Ya Xu, Toshiyuki Hirano, Masahiko Demura
Our previous TEM
observation revealed that a large number of dislocations were accumulated on slip planes in the Ni3Al
elongated pancakes, while they were rearranged into a cell structure in the Ni matrix [6].
In detail, there are a small number of regions having a Goss orientation (dark grey), which Goss component was not detected by the X-ray texture measurement.
They can be assumed to disappear when grain growth proceeds, because their size is smaller than the other grains.
The possibility for this encounter increases as the number of the 40˚<111> rotated Goss grains increases with the progress of the recrystallization.
This may cause the diminishment of the Goss grains during the grain growth.
In detail, there are a small number of regions having a Goss orientation (dark grey), which Goss component was not detected by the X-ray texture measurement.
They can be assumed to disappear when grain growth proceeds, because their size is smaller than the other grains.
The possibility for this encounter increases as the number of the 40˚<111> rotated Goss grains increases with the progress of the recrystallization.
This may cause the diminishment of the Goss grains during the grain growth.
Online since: February 2014
Authors: Huai Wen Wang, Viseslava Rajkovic, Dusan Bozic, Jelena Stasic, Milan T. Jovanovic
The relatively low decrease in microhardness during HTE may be explained by grain growth which is retarded by Al2O3 nano-sized particles precipitated at the grain boundaries.
The grain size was calculated using equation 1.
The grain size, D, of compacts as a function of milling time.
This dislocation network activates the formation of significantly increased number of subgrains which may become the nucleation sites of newly formed recrystallized grains.
Nano-sized Al2O3 particles form a great number of interfaces considered as a possible source of additional electron scatter, which is a significant factor in reducing conductivity [3].
The grain size was calculated using equation 1.
The grain size, D, of compacts as a function of milling time.
This dislocation network activates the formation of significantly increased number of subgrains which may become the nucleation sites of newly formed recrystallized grains.
Nano-sized Al2O3 particles form a great number of interfaces considered as a possible source of additional electron scatter, which is a significant factor in reducing conductivity [3].
Online since: July 2018
Authors: Ivan V. Smirnov, Yuri V. Sudenkov
Most of the publications in the topic of SPD are devoted to the dependence of mechanical properties on a strain degree (number of repetitions) at SPD processing [2].
Commercial pure aluminum AD1 (99.3%) and pure electrolytic copper M1 (99.9%) with a coarse-grained (CG) and ultrafine-grained (UFG) structure are considered.
The aluminum with coarse-grained structure was delivered in the form of an annealed plate with a thickness of 16 mm.
The billets were compressed to the required pressure (6 GPa), then the torsion with a given number of turns (10) was conducted under conditions of hydrostatic pressure.
Maex, Influence of surface and grain-boundary scattering on the resistivity of copper in reduced dimensions, Appl.
Commercial pure aluminum AD1 (99.3%) and pure electrolytic copper M1 (99.9%) with a coarse-grained (CG) and ultrafine-grained (UFG) structure are considered.
The aluminum with coarse-grained structure was delivered in the form of an annealed plate with a thickness of 16 mm.
The billets were compressed to the required pressure (6 GPa), then the torsion with a given number of turns (10) was conducted under conditions of hydrostatic pressure.
Maex, Influence of surface and grain-boundary scattering on the resistivity of copper in reduced dimensions, Appl.
Online since: February 2013
Authors: Jun Pin Lin, Feng Ye, Yong Feng Liang, Kun Yang
Second, grain-refinement treatment can be adopted as a method to average stress loaded on each grain and grain boundaries, performing as obstacles to the dislocation’s expansion and movement.
The grain size in Fig.
According to nucleation model proposed by Rappaz and Oldfield, Gaussian Nucleation isdescribed in equation (1), in which n(△T) is nucleation number, △T is actual cooling degree in K; (1) Nucleation density under certain cooling temperature could be confirmed by equation (2), where nmax is max nucleation number; △T in equation (2) is the cooling degree as max nucleation
The small deviation angles for grain growth indicate a good columnar grain structure along the axis direction.
Shape factor is a measure of grains uniformity.
The grain size in Fig.
According to nucleation model proposed by Rappaz and Oldfield, Gaussian Nucleation isdescribed in equation (1), in which n(△T) is nucleation number, △T is actual cooling degree in K; (1) Nucleation density under certain cooling temperature could be confirmed by equation (2), where nmax is max nucleation number; △T in equation (2) is the cooling degree as max nucleation
The small deviation angles for grain growth indicate a good columnar grain structure along the axis direction.
Shape factor is a measure of grains uniformity.
Online since: January 2010
Authors: C. Schäfer, Günter Gottstein, Olga Sukhopar
CORe is a pure growth model and therefore, separate nucleation
models are required to provide number and orientations of nuclei [3].
The average number of nuclei amounts to ~10 nuclei per deformed Cube band length of 50 µm in rolling direction (Fig.7).
According to this model the number of nuclei is determined by the thickness of the Cube band and can be given by the so-called nucleation parameter �c - the number of recrystallised Cube grains per deformed Cube band.
If several separated bands are introduced instead one big deformed Cube grain, the number of possible nucleation sites on the Cube-S boundaries is increased, which can influence the volume fraction of RX Cube grains.
About 70% of all Cube grain boundaries were boundaries to S grains.
The average number of nuclei amounts to ~10 nuclei per deformed Cube band length of 50 µm in rolling direction (Fig.7).
According to this model the number of nuclei is determined by the thickness of the Cube band and can be given by the so-called nucleation parameter �c - the number of recrystallised Cube grains per deformed Cube band.
If several separated bands are introduced instead one big deformed Cube grain, the number of possible nucleation sites on the Cube-S boundaries is increased, which can influence the volume fraction of RX Cube grains.
About 70% of all Cube grain boundaries were boundaries to S grains.
Online since: July 2012
Authors: Yong Biao Yang, Zhi Min Zhang, Guo Jun Li
These incompatibility stresses, adding to the resolved shear stress due to the applied load, result in a total stress at the grain boundaries considerably higher than that experienced by the matrix of the grain.
Hence, the region near grain boundary flows plastically prior to the matrix.
Therefore, the dislocations concentrated near the grain boundary.
The propagation of dislocations to the matrix is easiest when the maximum shear stress in grain is parallel to longitudinal grain boundaries by applying the external stress in the 45° direction of elongated grain structure.
Acknowledgements It is a project supported by natural science foundation of shanxi province China (project number: 2009011028-1; 2011011021-1).
Hence, the region near grain boundary flows plastically prior to the matrix.
Therefore, the dislocations concentrated near the grain boundary.
The propagation of dislocations to the matrix is easiest when the maximum shear stress in grain is parallel to longitudinal grain boundaries by applying the external stress in the 45° direction of elongated grain structure.
Acknowledgements It is a project supported by natural science foundation of shanxi province China (project number: 2009011028-1; 2011011021-1).
Online since: January 2006
Authors: Miroslav Cieslar, Ivan Procházka, P. Sláma, Margarita Slámová, Petr Homola, Jakub Čížek
The LM micrographs of ARB samples in Fig. 3 show gradual grain flattening with increasing
number of ARB cycles.
Slip lines in individual grains and slip bands going through several grains can be distinguished at low strains.
Subgrain formation due to dynamic dislocation recovery does not occur during the 1st cycle but it becomes more intensive with increasing number of ARB cycles.
High angle boundaries are observed also in ND and their fraction increases with increasing number of cycles.
The grain size is much smaller in ND than in RD and TD.
Slip lines in individual grains and slip bands going through several grains can be distinguished at low strains.
Subgrain formation due to dynamic dislocation recovery does not occur during the 1st cycle but it becomes more intensive with increasing number of ARB cycles.
High angle boundaries are observed also in ND and their fraction increases with increasing number of cycles.
The grain size is much smaller in ND than in RD and TD.