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Online since: May 2025
Authors: Shuhazlly Mamat, Khamirul Amin Matori, Mohammed Isah Isah Kimpa, Sharifat Olalonpe Ibrahim, Kasim Uthman Isah, Abubakar Sadiq Sanda
The microstructure of the samples comprises cubic grains with smooth surfaces and non-uniform particle distribution in the images.
The melt phase surrounds the irregularly shaped grains, and a few isolated micropores exist in the microstructure, implying partial melting of the NASICON phase.
Thus, the porosity observed in all the samples does not prevent the mobile ion movement between the grains and grain boundaries.
The inset in the EDX spectrum beside each SEM micrograph indicates the atomic and weight percentage of all the various elements present in the samples except Li which cannot be detected by the EDX machine due to the smaller size and lower atomic number.
The microstructure of the samples comprises cubic grains with smooth surfaces and non-uniform particle distribution, indicating crystallization and consistent with the XRD data.
Online since: February 2024
Authors: Oleksandr Kuprin, Igor Kolodiy, Vitaliy Belous, Margarita Bortnitskaya, Orest Ostash, Roman Chepil, Volodymyr Sverdun, Tetiana Prikhna, Viktoriya Podhurska
An analysis of the intensity distribution of the carbide lines revealed the presence of a strong {111} texture, meaning that the grains are predominantly oriented by the {111} crystallographic planes parallel to the sample surface.
The intensity distribution analysis of the carbide lines showed that the {220} texture was present, indicating that the grains are predominantly oriented with {220} crystallographic planes parallel to the sample surface.
In #1 coating homogeneous fine-grained microstructure forms (Fig. 2 c).
This is consistent with our previous grain size calculations, where this coating was characterized by the smallest grain size (9.3 nm).
Both coatings have no columnar structure, and some number of macroparticles on the surface is indicated.
Online since: January 2021
Authors: Li Li, Feng Chen, Yun Xiang Tong, Fu Kuan Liang, Wei Lin Ye
Up to now, a number of high damping alloys such as Mn-Cu and Fe-Cr have been developed and successfully applied in ship and railroad industries [3, 4].
Further increasing Nb content to more than 1%, large amounts of white particles with irregular morphology present and most of them are distributed along the grain boundaries.
(ii) A number of particles with various sizes are randomly distributed inside the ε martensite, at the ε martensitic variants boundaries and γ/ε interfaces.
Shin et al. [30] found that, in Fe-17Mn, the ultra-fine grained sample containing a low volume fraction of ε martensite possesses a damping capacity comparable to that of the coarse-grained sample with a high ε martensite fraction.
De Cooman, The effect of grain size on the damping capacity of Fe-17 wt%Mn, Mater.
Online since: October 2021
Authors: Rostislav Drochytka, Vit Černý, Petr Figala
Great emphasis is placed on the study of protection against sulphate corrosion and there are a big number of studies focused on predicting its course [7], [8], [9], [10].
At the same time, a number of studies are focused on slowing down degradation by partial substitution of suitable additives and secondary raw materials for Portland cement [12], [13].
As for FBC fly ash, fly ash particles do not melt, grains remain porous, their structure is layered and they have a large specific surface area.
Waste foundry sand contains grains of fraction which are smaller than 4 μm and they are used as microfiller.
Recommended replacement rate for fine grain fractions is in the range of 20–30% [25].
Online since: April 2011
Authors: Quang Cherng Hsu, Kun Hong Kuo, Chi Peng Hsu
In this paper, aluminum alloy 7075 is used as the raw material to study the tensile strength of the welding interface and the development of welding seam and grains by using local compression test.
The cut specimen is milled by waterproof abrasive paper of different numbers (#_240, 400, 600, 800, 1200, 1500, 2000, 2400, 4000), and then finished by 0.5μm Al2O3 powder aqueous solution.
On the lower billet, different grains have obvious black lines in different directions, it may because of the new plane direction resulted from the heating pressing process.
The grains in main body specimen, as shown in Fig. 14(a) and (b), are round, whereas long and narrow grain shape is formed on flash part specimen due to material shear flow.
The metallurgical structure observed through OM: (a) upper specimen of main body; (b) lower specimen of main body; (c) flash part has long grains and almost no seam.
Online since: February 2016
Authors: Sana Ali
Analytical surveillance programmes by food controlling agencies are required to control aflatoxin contamination of food grains and human exposure.
This method is recommended for detection and quantification of the less toxic aflatoxin B2, which is presented in grains.
Currently, the easy availability of ELISA kits has paved the way for analysis of large number of samples simultaneously.
This technique has been successfully applied for analyzing aflatoxins in grains and peanuts [51].
Pascale, Detection methods for mycotoxins in cereal grains and cereal p roducts, Matica Srpska Proceedings for Natural Sciences 117 (2009) 15-25
Online since: October 2014
Authors: Pavel Iurea, Constantin Carausu
Depending on the size of the volumes in which they manifest (appears an heterogeneity of deformation) are defined the following categories of residual stresses [3, 10, 12]: a) macrostresses: - first order residual stresses (macroscopic) (), which causes deformations and develops in the deformed piece at a larger scale than the grain size of the material or a significant volume element (millimeters), they result from the balance of internal forces and correspond to an average value of all the material; b) microstresses: - second-order residual stresses (microscopic or intergranular) () acting at the grain scale (micrometer), they are almost always at polycrystalline materials because the elastic and thermal properties of neighboring grains are different; their value is a stress variation of every grain around the average value, represented by the () stress; () stresses are referred to as homogeneous microstresses
- third-order residual stresses or ultramicroscopic (), acting on the level of atoms, due to the presence of dislocations or other crystal lattice defects (at a scale on the order of a few tens of nanometers), they are found in materials with multiphasic microstructure, being generated by the phasic transformations; their value fluctuates around the mean value of the stresses of a grain (); stresses can be called heterogeneous microstresses.
Recent specialized literature [14], suggests a concept of residual stress management and a number of engineering tools to analyze the major aspects of residual stresses.
Online since: November 2011
Authors: Guo Qiang Ou, Xian Jun Ji
The accumulation surface④ is level and its friction coefficient is 0.4. ① ② ③ ④ ①sliding surface ②mounding trough ③motion surface④accumulation surface Fig.2 Numerical Experimentation Model 2.2 Generate sample and set parameter Comprehensive calculation efficiency, the grain composition of physical model and similar degree and particle size distribution, the grain size will be enlarged in order to reduce the grain number and computing workload, and improve the calculation efficiency, eventually, 501 particles are generated, which diameter of its size range is 0.1-0.3 m.
Monitoring results of average contact force and average unbalance force between particles and monitoring results of y direction action force the change of the retaining wall of fill the tank (figure 3, 4) showed that average contact force between particles stable, unbalance force tend to zero, accumulation grains get to stable equilibrium state.
[10] LU Xiao-bing, ZHANG Xu-hui ,Numerical simulation of clastic grain flow along a slope[J], Rock and Mechanics,2009,Vol.30 Supp.2:524-527( in Chineses) [11] LIU Jian-bao, WANG Nai-ang, etc, Influencing Factors of Respose Angle of Sand Dunes: an experiment[J], JOURNAL OF DESERT RESEARC, 2010 ,Vol.30 No.4,758-762( in Chineses) [12] Jiang Peng,Yang Shubi, EXPERIMENT STUDY ON RHEOLOGIC BEHAVIOR AND LONG TERM STRENGTH OF GRAVEL IN CHENGDU AREA[J], Journal of Geological Hazards and Environment Preservation, 1998,Vol.9 No.1,38-42( in Chineses)
Online since: June 2014
Authors: Usman Sudjadi
Sample number 1 was the sample before nitrocarburization.
Samples number 2 and 3 were samples after nitrocarburization at a temperature of 400oC for 5 and 6 hours consecutively.
This means that in a change of nitrocarburization time from 5 hours to 6 hours, the number of nitrogen and carbon atoms that have diffused into the local bolt material did not increase much.
Figures 3-7 shows the matrixes of ferrite, pearlite, austenite, and grain boundaries.
Dutka, Journal of Super-hard Materials, 1063-4576, Vol. 30, Number 5, 2008
Online since: September 2011
Authors: Jaroslav Polák, Karel Obrtlík, Tomáš Podrábský, Simona Hutařová, Martin Juliš
The average grain size, found using the linear intercept method, was 3.6 mm.
Hysteresis loops for selected numbers of cycles were recorded in disk memory.
Results and discussion The stress amplitude σa as a function of the number of cycles N obtained for both treated and untreated specimens cycled at 800 °C is shown in Fig. 1.
Fig. 2a shows the stress amplitude σa at half life vs. the number of cycles to fracture Nf in the bilogarithmic representation.
Fatigue life curves in the representation of the plastic strain amplitude εap at half life vs. the number of cycles to fracture Nf are shown in Fig. 2b.
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