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Online since: October 2014
Authors: Xin Wang, Chao Yong Deng, Rui Rui Cui
The subscripts m is the number of the oxygen octahedron, and the m-1 is the number of the pseudo-perovskite units [10].
These results further prove that the dysprosium ions in the CaBi4Ti4O15 do not form the second phases or segregate from the interior grain but dissolve into the CaBi4Ti4O15 host lattice [16].
In oxide phosphors, Rc can be obtained as follow equation [20]: (1) Here V is the volume of the unit cell, Xc is the critical concentration, n is the number of lattice sites in the unit cell that can be occupied by activator ions.
Presume that the activator Dy is introduced totally on Ca ion sites, so the number N of Ca site in the unit cell is 1×4=4.
Online since: April 2014
Authors: Qing Wei Jiang, Zheng Li, Feng Yi, Xiao Lan Cai, Lei Zhou, Ming Jun Yu
Grain growth and recrystallization of nanocrystalline Al3Ti prepared by mechanical alloying[J].
The strain can produced a large number of defects; these defects are very easy to induce micro cracks, powder become more brittle.
After milling 3h, The peaks of Ti and Al all disappeared and peaks of Ti were obviously widen, disordered fcc Ti (Al) solid solution were prepared, only (200) and (111) diffraction peak of Al existed, TiAl, Ti3Al, Al3Ti were found .With prolong the milling time to 5h, Ti and Al single peak was completely disappeared, and a large number of TiAl, Ti3Al, Al3Ti intermetallic compound were emerged.
With prolong the milling time to 5h, Ti and Al single peak was completely disappeared, a large number of TiAl, Ti3Al, Al3Ti intermetallic compound were emerged .After milling 9 hours, Ti - 48 at % Al amorphous were produced.
This work was supported by the national natural science foundation of china [grant number 51201077].
Online since: December 2014
Authors: Pei Xin Li, Yan Mu, Hong Xiao Ma, Xiao Lin Ren, Jian Bo Chen
Its chemical composition and grain degrees have shown in Table 1 and Table 2 respectively.
Table 1 Main chemical compositions of fly ash composition LoI CaO MgO SiO2 Fe2O3 Al2O3 SO3 total mass fraction (%) 5.78 3.55 2.25 54.52 1.80 30.55 1.25 99.7 Table 2 Size distribution of fly ash size distribution >100 mesh number 100~180 mesh number 180~320 mesh number <320 mesh number content(%) 24 13.5 17.5 35 Fig. 1 Mineral compositions of fly ash Experimental Methods The project development combines of the laboratory small experiments and industrial production.
Online since: June 2017
Authors: O.V. Tarakanov, M.A. Gavrilov
Introduction Buildings and structures are often susceptible to a number of aggressive environmental and industrial factors, such as chemical corrosion.
The numbers 1, 2, 3 and 4 represent mixtures with different degrees of filling, “polymer-to-filler” (designated further as P/F) ratio: for mixture 1 P/F is 1/1, for mixture 2 P/F is 1/5, for mixture 3 P/F is 1/10, for mixture 4 P/F is 1/15.
With further increase of P/F ratio an increasing number of active centers of polymerization appears, thus resulting in a more gradual nature of plastograms and increasing the viscosity of the mixtures.
Such methods during the process of material manufacturing allow to fill the voids between the grains of the filler and the outer surface of the filling material with chemically resistant binder.
An increase in the number of contact points due to a close encounter of the molecules of the binder and filler is also notable.
Online since: May 2021
Authors: Sanjeev Reddy K. Hudgikar, C. Thirupathaiah
Sample number 1: 100% of Al 6063 Sample number 2: 97% of Al 6063+1% of B4C+1% of SiC+1% of Fly-ash Sample number 3: 95% of Al 6063+2% of B4C +2% of SiC+1% of Fly-ash Sample number 4: 94% of Al 6063+2% of B4C +2% of SiC+2% of Fly-ash Fig. 1.
Table and graph shows the improvement of mechanical property by adding the reinforcement of composite material Al6063, In microstructure structure silicon carbide, boron carbibe and fly ash particles are shows the fine distribution of grains which is shown in Fig.2.
Online since: June 2005
Authors: L.D. Laude, H.F. Hildebrand, N. Blanchemain, G. Mayer, M. Traisnel, C. Dupas-Bruzek, D. Derozier
Scanning / 2 mm.s-1 Irradiation mode / Speed Ambient air Atmosphere 10 pulses / 10 Hz Number of pulses / Repetition rate 12 à 120 mJ/cm² ± 1,8 mJ/cm² Irradiation intensity 22 kV Voltage Lambda Physik, Compex 205, 248 nm Model of excimer LASER (KrF) 0 100 200 300 400 500 600 700 800 900 1000 0 20 40 60 80 100 120 Laser energy (mJ/cm²) Ablated depth (nm) Profilometer 36 mJ/cm² 44 46 48 50 0 12 24 36 48 60 72 84 96 108 120 Laser energy (mJ/cm²) Surface tension (mJ/m²) Surface tension Table 1: Irradiation parameters of PET samples.
The colony forming method showed that PET (powder reduced Melinex® with a grain size <10µm) is not toxic for L132 cells even at a high concentration of this polymer (400µg/ml).
Cell proliferation showed a dose-dependant increase in the cell number reciprocal to the irradiation energy (from 88 to 138% with respect to control).
This is probably due to the higher cell number of proliferation rather than to real cell activation.
In further investigations, other parameters, i.e. number of pulses, repetition rate, atmosphere, etc. will be varied in the aim to assess the optimal experimental conditions for maximal surface improvement.
Online since: December 2014
Authors: Galina G. Kashevarova, Yuri E. Kurbatov, Roman V. Sevastyanov
So, the problem of determining the fatigue durability of concrete can be reduced to the determination of the number of cycles which are applied until the moment of complete destruction the cement components of concrete.
The grains of aggregate, having the form of a cylinder, and the cement stone were simulated in accordance with [7] by layer extrusion of flat shapes (fig. 2).
The total number of finite elements after dividing was 52682, of which 42188 were components of the cement stone.
The values of fatigue life for the calculation model Load The number of cycles before destruction N Normalized dimensionless values Natural values [Pa] 0,1 4 903 350 29 622 300 0,5 24 516 750 7 041 450 0,9 44 130 150 114 800 Figure 5.
The kinetic of damage accumulation for one of the “cube” outer planes The number of cycles 0 3 520 725 7 041 450 CONCLUSION Based on the techniques developed in this work and confirmed by a series of computational experiments, we can formulate the algorithm a fatigue study of building structures using mathematical and physical modeling. 1.
Online since: June 2018
Authors: Grigory Ivanovich Yakovlev, Anastasiya Fedorovna Gordina, Valery Grakhov, Irina Sergeevna Polyanskikh, Zarina Saidova, Tatyana Plekhanova, Аleksandr F. Buryanov
The packing density of the whole composition is in direct relation with their number and ratio [4].
The growing number of scientific papers dealing with carbon nano-additives is being published nowadays all around the world, confirming its positive effect on the operational properties of construction materials.
The growing number of structural particles with high surface energy makes the whole system thermodynamically unstable.
Based on the data mentioned above, the number of carbon nanotubes in a cubic meter of cement composite is NMWCNT=7x1018, according to the Eq.6: NMWCNT=mCNTm1
Formation of the boundary layer in mineral binder-based materials modified with multilayered carbon nanotubes Graphistrenght TM: (a) - fine-grained concrete, (b) - natural anhydrite The characteristics of these hydration products are as follows: Average length lhsc=7,5×10-6 m; Calcium hydrosilicates diameter dhsc =5×10-6 m; Density of hydration products ρhsc=2400 kgm3.
Online since: November 2013
Authors: Eva Tillová, Lenka Hurtalová, Mária Chalupová
Fatigue lifetime is measured by a number of cycles that the material can withstand before fatigue damage occurs [3].
The nominal stresses are lower than the yield strength by fatigue process and the development of the fatigue cracks demands a number of cycles to be initiated [4].
The experimental material was not modified or grain refined.
Therefore the number of cycles 107 was taken as the infinite fatigue lifetime.
The relationship between the maximum stress level, S, and the life in the form of the number of fatigue cycles Nf, (S-Nf curves) is given in Fig. 2.
Online since: October 2020
Authors: Alla G. Sokolova, Yulia A. Sokolova, Marina A. Akulova, Tatjana E. Slizneva
Impaction of composite material takes place due to formation of a thin water-repellent film [7], closely tied with a cement matrix and splitting it into the number of smaller clusters [3].
At higher concentrations, the greater number of specific sites is formed leading to entangled polymeric network formation and noticeable feeding of liquid medium. 2′ 2 1 2′ b) 1 2 а) 1 c) 1 1 2′ 2’ 2 2 d) 2’ 2 f) 2’”” 1 2 e) Fig. 1.
Distribution of the parameters of relative scatter intensity according to the particles size (a, b), relative volume of particles (c, d) and relative number of particles (e, f) in the initial state (1), mechanoactivated state (2) and the state matured after activation during 24 hours (2′) of the solutions Na-CMC with the concentration: a), c), e) – 53.57 g/l; 8.37 mmol/l; b), d), f) – 0.357 g/l; (0.056 mmol/l) Impact of MMA on the phase composition of cement stone.
Judging from the number and intensity of ettringite’s peaks (2.625; 2.19; 2.135; 2.06; 1.67) on the X-ray diffraction pattern of the activated specimen (3.25; 2.625; 2.19; 2.135; 1.95; 1.67) and on the X-ray diffraction pattern of the non-activated specimen, one could make a conclusion that in the non-activated specimen the larger amount of hydrated calcium sulfoaluminate was formed if compared to non-activated one.
Sokolova, Fine Grain Concrete on Mixing Water Activated in Cavitation Permanent Magnet-Type Apparatus, J.
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