scholarly journals The dependence between the structural-morphological features mixes 0.8SiO2/0.2Al2O3 from the time of mechanicall treatment

2021 ◽  
Vol 22 (3) ◽  
pp. 516-521
Author(s):  
Yu.V. Yavorsky' ◽  
Ya.V. Zaulichny ◽  
M.V. Karpets ◽  
A.I. Dudka ◽  
A.B. Hrubiak ◽  
...  
Keyword(s):  
Mechanical Treatment ◽  
Structural Parameters ◽  
Coherent Scattering ◽  
Lattice Parameter ◽  
Morphological Features ◽  
Sem Images ◽  
X Ray ◽  
Before And After ◽  
Perfect Mixing ◽  
The Relationship

This paper highlights the relationship between changes in structural and morphological features, electronic structure and exanging of time mechanical treatment at microbraker (MBT). Scaning electron microscopy revealed a change in the morphological features of nanoscale powders. From the comparison of SEM images of 0.8SiO2/0.2Al2О3 mixture before and after MBT, it is established that due to MBT, the agglomerates of the initial components are simultaneously crushed with perfect mixing particles of oxides between each other and the formation of new agglomerates with a denser structure. The increase in processing time leads to an increase in the density of the nanocomposite. The effect of time of mechanical treatment  on the structural parameters and phase composition of mixtures of silicon dioxide and titanium were studied using the method of X-ray structural analysis. The established agglomeration is accompanied by a change in the lattice parameter c with a change in the regions of coherent scattering of crystalline Al2О3. Ultra-soft X-ray emission spectroscopy was used to study the distribution of Op-, Sisd- and Alsd- valence electrons in 0.8SiO2/0.2Al2О3 powder mixtures after the different time of mechanicall treatment. An increase in atomic charges has been measured and can be explained by the transfer of electrons from Si and Al to O atoms in split Opπ-binding states.

scholarly journals Changes in the Structural and Morphological Parameters of Fe2O3/SiO2, as a Basis for the Electrode Material of Lithium Power Sources, Due to Shock-Vibrating Treatment

2019 ◽  
Vol 20 (4) ◽  
pp. 360-366
Author(s):  
Yu.V. Yavorskyi ◽  
Ya.V. Zaulychnyy ◽  
М.V. Karpets ◽  
А.B. Hrubiak ◽  
V.V. Moklyak ◽  
...  
Keyword(s):  
Structural Parameters ◽  
Interatomic Interaction ◽  
Coherent Scattering ◽  
Coherent Scattering Region ◽  
Electron Microscopic ◽  
Sem Images ◽  
Power Sources ◽  
Vibration Treatment ◽  
X Ray ◽  
Before And After

Using the method of X-ray diffraction, the effect of shock-vibration treatment on the structural parameters and phase composition of mixtures of silicon dioxide and alpha iron oxide was studied. From these results, has been found that the shock-vibration treatment of oxides mixture leads to an increase in the coherent scattering region of crystalline α-Fe2O3. We obtained SEM images of composites before and after treatment. From the SEM images it is seen that the processing is accompanied by fragmentation of the aggregates, uniform placement of the nanoparticles between each other and the formation of new denser agglomerates. Electron-microscopic study of mixtures using TEM was performed, which showed that the treatment leads to a lay-up of particles each other with the formation of interatomic interaction between them, which is consistent with the results of ultra-soft X-ray emission spectroscopy. The electrochemical properties of LPS, with electrodes based on mixtures before and after treatment, in galvanostatic mode were investigated. It is found that the charge capacity of the LPS with the electrode based on the mixture with the maximum concentration of α-Fe2O3 after treatment is reduced by half. 

SIZE-INDUCED EFFECTS IN NANOSTRUCTURED NiFe2O4

2010 ◽  
Vol 24 (30) ◽  
pp. 5973-5985
Author(s):  
M. GUNES ◽  
H. GENCER ◽  
T. IZGI ◽  
V. S. KOLAT ◽  
S. ATALAY
Keyword(s):  
Electron Microscopy ◽  
Annealing Temperature ◽  
Structural Parameters ◽  
Hydrothermal Process ◽  
Lattice Parameter ◽  
Effect Of Temperature ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

NiFe 2 O 4 nanoparticles were successfully prepared by a hydrothermal process, and the effect of temperature on them was studied. The particles were annealed at various temperatures ranging from 413 to 1473 K. Studies were carried out using powder X-ray diffraction, scanning electron microscopy, infrared spectroscopy, differential thermal analysis, thermogravimetric analysis and a vibrating sample magnetometer. The annealing temperature had a significant effect on the magnetic and structural parameters, such as the crystallite size, lattice parameter, magnetization and coercivity.

Structural and electrical properties of Cu-doped Ni–Zn nanocrystalline ferrites for MLCI applications

2017 ◽  
Vol 31 (33) ◽  
pp. 1750318 ◽  
Author(s):  
D. Venkatesh ◽  
K. V. Ramesh
Keyword(s):  
Electrical Properties ◽  
Cation Distribution ◽  
Tetrahedral Site ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Structural And Electrical Properties ◽  
Phase Spinel ◽  
Diffraction Patterns

Polycrystalline Cu substituted Ni–Zn ferrites with chemical composition Ni[Formula: see text]Zn[Formula: see text]-Cu[Formula: see text]Fe2O4 (x = 0.00 to 0.25 in steps of 0.05) have been prepared by citrate gel autocombustion method. The samples for electrical properties have been sintered at 900[Formula: see text]C for 4 h. The X-ray diffraction patterns of all samples indicate the formation of single phase spinel cubic structure. The value of lattice parameter is decreases with increasing Cu concentration. The estimated cation distribution can be derived from X-ray diffraction intensity calculations and IR spectra. The tetrahedral and octahedral bond lengths, bond angles, cation–cation and cation–anion distances were calculated by using experimental lattice parameter and oxygen positional parameters. It is observed that Cu ions are distributed in octahedral site and subsequently Ni and Fe ions in tetrahedral site. The grain size of all samples has been calculated by Scanning Electron Microscopy (SEM) images. The variations in DC electrical resistivity and dielectric constant have been explained on the basis of proposed cation distribution.

scholarly journals The Evolutionary Characteristics of Reservoir Microstructure under Long-Term Waterflooding Development and Its Fractal Description

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Fengjiao Wang ◽  
Xu Wang ◽  
Yikun Liu ◽  
Qingjun Deng ◽  
Jianjun Xu ◽  
...  
Keyword(s):  
Pore Structure ◽  
Physical Simulation ◽  
Structural Parameters ◽  
Fractal Theory ◽  
Evolution Model ◽  
Structure Evolution ◽  
Before And After ◽  
Water Cut ◽  
The Relationship

Generally, long-term waterflooding development often leads to the change of reservoir pore and clay mineral composition, which results in the change of permeability and wettability. In order to explore the relationship between core micropore structure and water cut, based on physical simulation experiments and fractal theory, we proposed a fractal evolutionary model to describe the evolution characteristics of microstructure of long-term water driving reservoirs. In this paper, core pore structure by SEM was first conducted to analyze the change of core pore structure before and after waterflooding under the conditions of magnification of 200 times, 800 times, and 2000 times, respectively. Then, conventional and constant rate mercury injection tests were combined to perform the comparative analysis of core structural parameters before and after waterflooding. Finally, a micropore-throat structure evolution model of core was established. Research shows that the connectivity of larger pores becomes better after long-term water driving, the degree of heterogeneity weakens, and the micro heterogeneity of small pores becomes stronger and stronger. The throat characteristics change in a complex manner, the radius tends to increase, and the sorting becomes better, while the connectivity of small throat changes complex. In general, the heterogeneity of throat increases with the time of water injection in reservoirs with low porosity and permeability. On the basis of fractal theory and variation characteristics of rock pore structure in water driving reservoirs, we have established a micropore-throat structure evolution model of core pore-throat characteristics. This fractal evolution model quantitatively characterized the complexity and evolution law of pore structure and clarified the relationship between fractal dimension of core pore structure and water cut under different stages of water driving.

X-ray Topography Studies of Relaxation during the Homo-Epitaxy of 4H-SiC

2015 ◽  
Vol 1741 ◽  
Author(s):  
H. Wang ◽  
M. Dudley ◽  
J. Zhang ◽  
B. Thomas ◽  
G. Chung ◽  
...  
Keyword(s):  
Substrate Surface ◽  
Strain Relaxation ◽  
Lattice Parameter ◽  
Relaxation Processes ◽  
Radial Temperature ◽  
X Ray ◽  
Before And After ◽  
Half Loop ◽  
Mismatch Stress ◽  
Epilayer Surface

ABSTRACTA review is presented of Synchrotron X-ray Topography and KOH etching studies carried out on n type 4H-SiC offcut substrates before and after homo-epitaxial growth to study defect replication and strain relaxation processes and identify the nucleation sources of both interfacial dislocations (IDs) and half-loop arrays (HLAs) which are known to have a deleterious effect on device performance. We show that these types of defects can nucleate during epilayer growth from: (1) short segments of edge oriented basal plane dislocations (BPDs) in the substrate which are drawn by glide into the epilayer; and (2) segments of half loops of BPD that are attached to the substrate surface prior to growth which also glide into the epilayer. It is shown that the initial motion of the short edge oriented BPD segments that are drawn from the substrate into the epilayer is caused by thermal stress resulting from radial temperature gradients experienced by the wafer whilst in the epi-chamber. This same stress also causes the initial glide of the surface half-loop into the epilayer and through the advancing epilayer surface. These mobile BPD segments provide screw oriented segments that pierce the advancing epilayer surface that initially replicate as the crystal grows. Once critical thickness is reached, according to the Mathews-Blakeslee model [1], these screw segments glide sideways under the action of the mismatch stress leaving IDs and HLAs in their wake. The origin of the mismatch stress is shown to be associated with lattice parameter differences at the growth temperature, arising from the differences in doping concentration between substrate and epilayer.

The Surface Chemistry Characterization of Pyrite, Sphalerite and Molybdenite after Bioleaching

2017 ◽  
Vol 262 ◽  
pp. 487-491 ◽  
Author(s):  
Sina Ghassa ◽  
Hadi Abdollahi ◽  
Mahdi Gharabaghi ◽  
Saeed Chehreh Chelgani ◽  
Mohammad Jafari
Keyword(s):  
Surface Chemistry ◽  
Dissolution Kinetics ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Chemical Leaching ◽  
Characterization Methods ◽  
X Ray ◽  
Ash Layer ◽  
Before And After

The mineral surface chemistry characterization is essential to describe the dissolution kinetics in leaching and bioleaching. Five different methods, including X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDS), Fourier Transform Infrared Spectroscopy (FTIR) and Raman Spectroscopy, have been applied to study the surface chemistry changes during pyrite, sphalerite and molybdenite bioleaching. The surface characterizations have been done for samples before and after biological and chemical leaching. The SEM images illustrated that the minerals surfaces were smooth before processing, while they covered with an ash layer after biological treatment. Although EDS analysis and Raman spectrum demonstrated the potassium jarosite formation on the pyrite surface during bioleaching, the formation of jarosite layer did not occur on the sphalerite surfaces during bioleaching. On the other hand, a sulfur layer formation on the sphalerite surface was confirmed by mentioned characterization methods. Finally, according to the XRD and EDS spectrum the molybdenite surface had been covered both with sulfur and jarosite.

Structure and Compressive Property of Heterocyclic Aramid Fiber

2017 ◽  
Vol 898 ◽  
pp. 2158-2165 ◽  
Author(s):  
Ying Deng Song ◽  
Bin Tai Li ◽  
Li Ying Xing
Keyword(s):  
Compressive Strength ◽  
Structural Parameters ◽  
Compressive Property ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
Aramid Fibers ◽  
Compressive Properties ◽  
X Ray ◽  
Trade Name ◽  
The Relationship

The F-3 fiber is a trade name of a recently developed type of heterocyclic para-aramid fibers in China. To investigate the relationship between structure and compressive properties for F-3 fiber, the structural parameters and compressive strength have been analyzed in detail compared with the Kevlar-49 fiber. The structural parameters were determined by wide-angle X-ray diffraction (WAXD) analysis and sonic velocity method. The results showed that the orientation of chains of F-3 fiber was higher than that of Kevlar-49 fiber. The results of the tensile recoil method showed that F-3 and Kevlar-49 fibers had approximate compressive strength. The analysis of relation between structure and mechanical properties suggested that the combination of orientation parameter and shear modulus between adjacent chains resulted in the approximate compressive strength of F-3 and Kevlar-49 fibers.

Research on the Influence of Diffluent Salt Microstructural Variation in the Course of Recrystallization on the Strength of Salty Soil

2012 ◽  
Vol 170-173 ◽  
pp. 1226-1229
Author(s):  
Chun Lei Wang ◽  
Chong Xi Jiang ◽  
Feng Ju Guan
Keyword(s):  
Mechanical Property ◽  
Spatial Arrangement ◽  
Soil Strength ◽  
X Ray ◽  
Soil Microstructure ◽  
Additional Equipment ◽  
Before And After ◽  
The Relationship ◽  
Engineering Characteristic ◽  
Salty Soil

Salty soil distributed widely and the engineering characteristic was complicated. The mechanical property had the relationship with spatial arrangement of soil grains, mineral component and occurrence condition of diffluent salt. The soil microstructure was an important factor to engineering characteristics. The influence of diffluent salt recrystallization on soil strength was learned according to the microstructure analysis by using environment scanning electron microscope and additional equipment X-ray energy spectrum (EDX). The influence of microstructure variation on salt soil strength was obtained by direct shear test on the salty soil before and after dehydrating. The results showed that diffluent salt recrystallization affected soil internal structure. The salty soil microstructure character was different before and after dehydrating, which changed the soil- mechanical property of salty soil.

scholarly journals The Comparative PDT Experiment of the Inactivation of HL60 on Modified TiO2Nanoparticles

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Kaiqi Lu ◽  
Qiyun He ◽  
Li Chen ◽  
Baoquan Ai ◽  
Jianwen Xiong
Keyword(s):  
Electron Microscope ◽  
Leukemia Cells ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Ultrasonic Methods ◽  
Photocatalytic Inactivation ◽  
Before And After ◽  
Inactivation Effect ◽  
Scanning Electron

Four samples of modified titanium dioxide (TiO2), Fe/TiO2(2 wt%), Fe/TiO2(5 wt%), and 5-ALA/TiO2, were experimented in photodynamic therapy (PDT) on leukemia cells HL60, performing promising photocatalytic inactivation effect. Fe/TiO2and 5-ALA/TiO2were synthesized in methods of precipitation and ultrasonic methods, respectively. X-ray diffraction spectra and UV-Vis spectra were studied for the samples’ crystalline phase and redshift of absorption peak. Further, FTIR spectra and Raman spectra were obtained to examine the combination of 5-aminolevulinic (5-ALA) and TiO2nanoparticles. The toxicity of these four kinds of nanoparticles was studied through darkroom experiments. And based on the concentration which caused the same toxic effect (90%) on HL60, PDT experiments of TiO2, Fe/TiO2(2%), Fe/TiO2(5%), and ALA/TiO2were done, resulting in the fact that the photokilling efficiency was 69.7%, 71.6%, 72%, and 80.6%, respectively. Scanning electron microscope (SEM) images of the samples were also taken to study the morphology of HL60 cells before and after PDT, resulting in the fact the activation of the modified TiO2from PDT was the main cause of cell apoptosis.

scholarly journals Structural Features of Sm-=SUB=-1-x-=/SUB=-Eu-=SUB=-x-=/SUB=-S Thin Polycrystalline Films

2017 ◽  
Vol 51 (6) ◽  
pp. 860
Author(s):  
V.V. Kaminskii ◽  
S.M. Solov'ev ◽  
G.D. Khavrov ◽  
N.V. Sharenkova ◽  
Shinji Hirai
Keyword(s):  
Coherent Scattering ◽  
Structural Features ◽  
Lattice Parameter ◽  
Film Deposition ◽  
Polycrystalline Films ◽  
Variable Valence ◽  
X Ray ◽  
Thin Polycrystalline

Thin polycrystalline Sm1-xEuxS films (x=0.1, 0.167, 0.2, 0.25, 0.33, 0.5) were prepared by evaporation of SmS and EuS powders. Structural features of the films were investigated. The influence of Eu concentration and temperature of film deposition on the value of lattice parameter and sizes of x-ray coherent scattering regions was studied. It is shown that formation of Sm1-xEuxS films comes about according to the theory that was previously suggested for SmS films and that the deviation of lattice parameter is explained by the variable valence of samarium ions. DOI: 10.21883/FTP.2017.06.44569.8409

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