Search results

With higher biodiesel/diesel blending ratios, particulate number in accumulated mode from passenger car exhaust showed lower value but higher value for nuclei mode, and the center size for peak particulate number emissions moved towards smaller scales.
However, on the urban and suburban high way, using bio-diesel will increase the particle number emission factors, compared with D100, when using BD100, the number of the particle increases 31%.
These reasons lead to the increase of the number of the bio-diesel particle emission, when the speed is high.
On other road types, the variation of the number of the particle is small.
Therein, the grain diameter of 50 nm is the transitional change region of the core state particle and aggregative state particle.

The H content of the negative electrode, expressed as the number o H atoms (n) per formula unit, was determined using the measured storage capacity.
Absorption parameters for the Pr-substituted alloys hydrogenated at RT and number of hydrogen atoms per formula unit determined using the electrochemical measured capacity.
Table 2 gives the hydrogen pressure variation at room temperature for the Mg-substituted alloys and number of hydrogen atoms calculated from electrochemically measured Cmax.
The hydrogenation behavior change on substitution could be partially attributed to the grain structure and phases modifications of these alloys that favor hydrogen absorption.
It has been reported that the substitution of La with Pr in the alloys changed the grain structure from equiaxed to columnar [13,14].

The gauge areas of all the test samples were carefully ground along the loading direction with sand paper up to grit number of 800.
The figure shows that grains growth has occurred in the HAZ of low carbon steel, and the planar mode can be seen.
Fig. 3 (a) shows the combination of low carbon steel and filler metal that the grain growth has occurred in the HAZ of low carbon steel which is planar.
Ferrite is formed in the grain boundaries [4].
As mentioned before (in Fig. 1a and 2a), grain growth happened at the HAZ zone of low carbon steel.

Norman et al. [2], for example, showed a reduction of grain size by two orders of magnitude by modifying an AlCu4.5 alloy with 0.55wt% Sc.
Grain sizes were estimated from Barker etched samples.
The grain size in this case was reduced to 5-10µm.
The work is fostered in the TAKE OFF funding program with the project number 839002.References [1] J.
Robertson, ``Influence of the particle size on recrystallization and grain growth in Al-Mg-X alloys,'' Materials Science and Engineering A, vol. 238, no. 1, pp. 101--107, 1997

Introduction The reinforced concrete is a classical combination of fine-grained concrete with additives of various reinforcing materials – steel, glass or synthetic.
From a large number of polymers available for the fiber production, polypropylene is used primarily because of low cost and good resistance to alkali.
The fiber content in fine-grained concrete is greater than in other concretes.
[10] Klyuyev S.V., Klyuyev A.V., Sopin D.M., Netrebenko A.V., Kazlitin S.A., Heavy loaded floors based on fine-grained fiber concrete, Magazine of Civil Engineering. 3 (2013) 7–14
[19] Lesovik R.V., Klyuyev S.V., Klyuyev A.V., Netrebenko A.V., Yerofeyev V.T., Durachenko A.V., Fine-Grain concrete reinforced by polypropylene fiber, Research Journal of Applied Sciences. 10 (2015) 624–628

These coarse-grained materials cause greater effects on the engineering characteristics and behavior while working on a gravel layer.
For the gravel formations in central Taiwan, the percentage of gravel content is as high as 86% and grain size is as large as 2 m.
The average grain size or D50 of the gravel in central part of Taiwan is about 8–20 cm.
The sizes of the gravels are based on the in situ grain-size distribution.
Small particles are excluded for the analyses since the number of balls will be too large to model.

The deformation mechanisms in beta-titanium alloys can vary widely, depending on the specific alloy composition and beta-grain size[4].The flow stress of many β titanium alloys are extremely sensitive to processing parameters, such as strain, strain rate and deformation temperature in the forming process.
The internal state variable methods, which describe the underlying phenomena in terms of a small number of internal state variables, have been growing in its influence on modeling the constitutive relationship in the past decade[5].
Busso[6] proposed a viscoplastic constitutive theory to describe the microstructure evolution caused by dynamic recrystallization and grain growth, which relies on scalar internal state variables including mean dislocation spacing and average grain size.
Lin et al.[7]developed a set of mechanism-based unified viscoplastic constitutive equations for multi-pass hot rolling of C-Mn steel which model the evolution of dislocation density, recrystallization and grain size during and after hot plastic deformation.
Luo et al.[8] proposed a physically based constitutive model to predict the flow stress and grain size variation of two-phase titanium alloys and it was applied to model the flow behavior of Ti-6Al-4V alloy.

The mechanism of this is hindering the crack propagation and sliding by grain boundary to improve obdurability.
Therefore, in order to ensure material with high plasticity and toughness, the number of carbide substrate cannot overmuch.
The spheroidizing treatment process can be summarized as the breaking →carbide graining→spheroidzing[4].
The carbide can not be broken completely in the first process of "breaking →carbide graining" may cause the carbide is not fully spheroidized in the second stage of the process of process of "carbide graining→spheroidizing ".
Cycling spheroidal annealing is similar with the conventional spheroidizing annealing which is also spheroidized by the grow up of the core of undissolved carbide .But because the austenitizing temperature is low, the carbide could not break completely in the process of "breaking →carbide graining" although after three circulation.

In nanocrystalline materials, the main role of the dispersoids is to limit grain growth at elevated temperatures and to attain a very small grain size, resulting in high strength due to the fine-grain strengthening mechanism [5].
Further, high energy milled powders are characterized by very fine, nano-scaled grain structure, which may be retained even during compaction.
This fine-grained structure contributes to copper matrix strengthening together with Al2O3 particles.
However, also to note further, in the process of milling, the grain of the constituents will be smaller.
Acknowledgements The work described in this paper was supported by the Science and Technology Fund of Thai Nguyen University (TNU) for the Grant number DH2014-TN02-04 project.

The fibrous grain structure.
The SL (hot rolled wire) specimens present a ferrite structure with cementite particles (Fe3CIII) positioned at limit of the grains and nonmetallic inclusions.
The crystalline grains are polyhedral and uniforms with a specific structure for echilibrium state (annealing).
By the degree of deformation is increasing, the grains are elongate more and pronounced in the direction of the drawing line, fragile phases (cementite, inclusions, oxide, silicate exogenous). 3.2.
Therefore, to get the finished product with the appropriate features is very important to predict the changes in properties and their variation, depending on the degree of deformation, quality of raw materials and the number of drawing steps.