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Online since: August 2012
Authors: Mustafa Bakkal
The WC-Co tool-material has smaller than 1 µm grain size WC in 6% Co binder.
First column in the table shows the experiment numbers.
As shown in the Table 5.3, during the tests number 3, 4, 5, and 7, maximum recorded temperatures exceeded the crystallization temperature of the material.
Besides, the indications of crystallization were only detected in the workpieces used in the experiment numbers 3, 4, and 7 according to X-ray analysis.
Number of tests.
First column in the table shows the experiment numbers.
As shown in the Table 5.3, during the tests number 3, 4, 5, and 7, maximum recorded temperatures exceeded the crystallization temperature of the material.
Besides, the indications of crystallization were only detected in the workpieces used in the experiment numbers 3, 4, and 7 according to X-ray analysis.
Number of tests.
Online since: February 2016
Authors: Klaus Funke
On the one hand, Strock could assign a large number of possible crystallographic sites to them.
Importantly, structural disorder did not require a large number of sites for the mobile cations, but rather a smaller number of more extended regions of space (often called voids), provided by the anion lattice.
(i) The mobile cations are ‘structurally disordered’, if their number is much smaller than the number of voids provided for them by the anion lattice.
The seemingly minor detail that had gone unnoticed in the Göttingen sample preparation was the fact that mechanical machining had created a large number of current-impeding microstructures, such as microcracks and in particular grain boundaries, at and in the vicinity of the sample surface.
At those temperatures, the numbers of accessible reflections with significant intensities were 25, 18, 21 and 19, respectively.
Importantly, structural disorder did not require a large number of sites for the mobile cations, but rather a smaller number of more extended regions of space (often called voids), provided by the anion lattice.
(i) The mobile cations are ‘structurally disordered’, if their number is much smaller than the number of voids provided for them by the anion lattice.
The seemingly minor detail that had gone unnoticed in the Göttingen sample preparation was the fact that mechanical machining had created a large number of current-impeding microstructures, such as microcracks and in particular grain boundaries, at and in the vicinity of the sample surface.
At those temperatures, the numbers of accessible reflections with significant intensities were 25, 18, 21 and 19, respectively.
Online since: July 2019
Authors: Wiktor Matysiak
A similar tendency to change in the diameters of nano-scale fibres and an increase in the number of their structural defects were observed with 16 kV range voltages.
The largest number of defects in the structure of composite PAN/TiO2 nanofibres was observed for samples with the highest concentration of the strengthening phase, produced with a 20 cm distance between the nozzle and the collector.
These fibres are characterised by the greatest number of defects in comparison to other produced composite nanofibres reinforced with powders of TiO2 and Bi2O3.
Using particles of a smaller diameter results in an increased number of defects in the structure of the obtained nanofibres.
Grain size dependent bandgap shift of SnO2 nanofibers.
The largest number of defects in the structure of composite PAN/TiO2 nanofibres was observed for samples with the highest concentration of the strengthening phase, produced with a 20 cm distance between the nozzle and the collector.
These fibres are characterised by the greatest number of defects in comparison to other produced composite nanofibres reinforced with powders of TiO2 and Bi2O3.
Using particles of a smaller diameter results in an increased number of defects in the structure of the obtained nanofibres.
Grain size dependent bandgap shift of SnO2 nanofibers.
Online since: January 2010
Authors: George Gejo, Abderrahim Boudenne, Thomas Sabu, Joseph Kuruvilla
The tensile and flexural properties of those
green composites in comparison with different types of wood specimens showed that although the
tensile and flexural strength and moduli of the former specimens were lower along the grain
direction of testing, they were significantly higher perpendicular to grain direction than the
corresponding wood specimens.
Fiber fragment length or aspect ratio is obtained by dividing the length of domain of investigation by the number of fiber ruptures added by one.
Over the past few years a considerable number of studies [172-180] have been performed on biodegradable composites containing biodegradable plastics with reinforcements of biodegradable natural fibers.
These results confirmed that a stronger adhesion degree was obtained for composites from partially delignified jute strands probably due to the major number of hydrogen bonds between the components [182].
A large number of experimental methods have been developed for determining the thermpohysical properties of materials.
Fiber fragment length or aspect ratio is obtained by dividing the length of domain of investigation by the number of fiber ruptures added by one.
Over the past few years a considerable number of studies [172-180] have been performed on biodegradable composites containing biodegradable plastics with reinforcements of biodegradable natural fibers.
These results confirmed that a stronger adhesion degree was obtained for composites from partially delignified jute strands probably due to the major number of hydrogen bonds between the components [182].
A large number of experimental methods have been developed for determining the thermpohysical properties of materials.
Online since: December 2012
Authors: Ibram Ganesh, P.S.C. Sekhar, G. Padmanabham, G. Sundararajan
In recent years, a considerable number of efforts have been made to create p-type ZnO by doping with group-V elements such as N, P, As and Sb [22-25], but their acceptor levels are theoretically identified to be deep with low solubility limits.
At lower temperatures, the excess Li, which could not be entered into crystal structure of ZnO, is expected to restrict the crystal/particle growth by staying at the grain boundaries, whereas, at higher temperatures, the lithium based compounds melt into a liquid and form big chunks of particles by the faster diffusion of ions [28].
Based on these results, they have suggested that up to a concentration of 3% only, Li enters into ZnO crystal and at above 3% concentration, it congregate on the grain boundaries as a secondary phase, which has been found to be a detrimental factor to p-type conductivity of ZnO.
The ZnO powders doped with ≤ 2% Li did not show any change in the number of bands but a slight shift in the Raman spectrum of ZnO.
At lower temperatures, the excess Li, which could not be entered into crystal structure of ZnO, is expected to restrict the crystal/particle growth by staying at the grain boundaries, whereas, at higher temperatures, the lithium based compounds melt into a liquid and form big chunks of particles by the faster diffusion of ions [28].
Based on these results, they have suggested that up to a concentration of 3% only, Li enters into ZnO crystal and at above 3% concentration, it congregate on the grain boundaries as a secondary phase, which has been found to be a detrimental factor to p-type conductivity of ZnO.
The ZnO powders doped with ≤ 2% Li did not show any change in the number of bands but a slight shift in the Raman spectrum of ZnO.
Online since: May 2016
Authors: Vimal Chandra Srivastava, Shang Lien Lo, Seema Singh
A large number of industrial effluents are discharged without proper treatment into clean sources of water thus polluting them and creating the water pollution.
At higher temperature, agglomeration increases with simultaneous growth of crystal grain.
The presence of oxidizing agents such as H2O2, persulfate (S2O82−), periodate (IO4−), bromate (BrO3−), oxone (HSO5−) and ozone (O3) traps the CB electrons to favor the charge separation and also generates more number of free radicals (Figure 1), as well resulting in the complete decomposition of intermediate products [61, 68-70].
However, Pt nonmaterial grain size had very little effect on the catalytic performance [111].
At higher temperature, agglomeration increases with simultaneous growth of crystal grain.
The presence of oxidizing agents such as H2O2, persulfate (S2O82−), periodate (IO4−), bromate (BrO3−), oxone (HSO5−) and ozone (O3) traps the CB electrons to favor the charge separation and also generates more number of free radicals (Figure 1), as well resulting in the complete decomposition of intermediate products [61, 68-70].
However, Pt nonmaterial grain size had very little effect on the catalytic performance [111].
Online since: February 2016
Authors: Helmut Mehrer
There is quite a number of natural glasses found on earth.
They owe many of their favourable properties to their amorphous structure, which does not contain lattice defects such as grain-boundaries and dislocations.
The number density of mobile ions is obtained from the mass density ϱ, the molecular weight M of the mobile ion, and the Avogadro number NA from Nion=ρNA/M.
MNa2O and MB2O3 denote the molecular weights of Na2O and B2O3 respectively and NA is the Avogadro number.
Frenkel disorder implies equal numbers of, e.g.
They owe many of their favourable properties to their amorphous structure, which does not contain lattice defects such as grain-boundaries and dislocations.
The number density of mobile ions is obtained from the mass density ϱ, the molecular weight M of the mobile ion, and the Avogadro number NA from Nion=ρNA/M.
MNa2O and MB2O3 denote the molecular weights of Na2O and B2O3 respectively and NA is the Avogadro number.
Frenkel disorder implies equal numbers of, e.g.
Online since: March 2023
Authors: Lazhar Hadjeris, Tarek Diab Ounis, Hicham Bahtoun, Sabrina Iaiche
It has been reported by Baruah et al. that ZnO has emerged as a more efficient photocatalyst than TiO2 due to its high surface reactivity owing to its large number of active surface defect states [11].
The photocatalytic efficiency of ZnO can be improved through a number of ways; doping with metal and nonmetal elements, coupling with narrow bandgap materials, creating surface defects and specific morphologies, higher ratio of exposed ZnO polar facets or promotion the separation and transportation of the photo-excited charge carriers. [8, 9, 13-15].
It is observed that the commercial ZnO powder is also porous but there is a non-ordered porosity and the grains distribution is not homogenous, so the photo-response was limited, comparatively to the ZnO catalysts generated from Zn(NO3)2 and Zn(CH3 CO2)2 precursors.
ISSN Number: 2149-2123
The photocatalytic efficiency of ZnO can be improved through a number of ways; doping with metal and nonmetal elements, coupling with narrow bandgap materials, creating surface defects and specific morphologies, higher ratio of exposed ZnO polar facets or promotion the separation and transportation of the photo-excited charge carriers. [8, 9, 13-15].
It is observed that the commercial ZnO powder is also porous but there is a non-ordered porosity and the grains distribution is not homogenous, so the photo-response was limited, comparatively to the ZnO catalysts generated from Zn(NO3)2 and Zn(CH3 CO2)2 precursors.
ISSN Number: 2149-2123
Online since: October 2022
Authors: Gurpreet Singh, Vivek Aggarwal, Sehijpal Singh, Rajiv Kumar Garg, Balkar Singh
· Consideration of infinite strain
· Higher shear strain
· Absurd behaviour of work material
· Limited numbers of variable for metal cutting
· Improper tool work contact during cutting
· Invalid for machining brittle materials
As mentioned earlier, the calculated strain in machining process is much higher as compared to strain obtained during mechanical testing work material.
However, later model is much suitable than former due to consideration of larger number of metal cutting variables as mentioned in equation (1-19).
(a) (b) Figure 3 Schematic diagrams of MQL setup (a) and different types of inserts (b) The full factorial approach has been used in present study with total 54 (3*3*3*2) numbers of experiments.
Jahazi, Finite element simulation-based predictive regression modeling and optimum solution for grain size in machining of Ti6Al4V alloy: Influence of tool geometry and cutting conditions, Simul.
However, later model is much suitable than former due to consideration of larger number of metal cutting variables as mentioned in equation (1-19).
(a) (b) Figure 3 Schematic diagrams of MQL setup (a) and different types of inserts (b) The full factorial approach has been used in present study with total 54 (3*3*3*2) numbers of experiments.
Jahazi, Finite element simulation-based predictive regression modeling and optimum solution for grain size in machining of Ti6Al4V alloy: Influence of tool geometry and cutting conditions, Simul.