Microfiller Influence on the Modified Cement Granulometric Composition

2021 ◽  
Vol 1043 ◽  
pp. 9-14
Author(s):  
Aleksandr Khalyushev ◽  
Sergey Stel'makh ◽  
Evgeniy Shcherban' ◽  
Alla Smolyanichenko ◽  
Aleksandr Korobkin
Keyword(s):  
Silicon Dioxide ◽  
Water Demand ◽  
Granulometric Composition ◽  
Microscopic Analysis ◽  
Cement Stone ◽  
X Ray ◽  
Average Grain Size ◽  
Mineral Components ◽  
Amorphous Glass ◽  
Mineral Additives

The aim of the work is to study the microfiller effect on the granulometric composition of the modified cement. A scanning electron microscope RМ-106 I was used for microscopic analysis. The survey was carried out in reflected electrons. The chemical analysis of the materials’ structure was investigated by energy dispersive spectroscopy (EDS). The distribution of particles of mineral components was evaluated with a Microsizer 201C laser particle analyzer with a range from 0.2 to 600 μm. Microscopic analysis of the samples of microsilica MK-85 shows that all particles are spherical with an average grain size of about 5 microns and consist of amorphous glass with a different set of particle fractions. The results of X-ray phase analysis of condensed microsilica grade MK-85 show that it consists mainly of silicon dioxide in an amorphous form. The introduction of mineral additives with a high specific surface in the composite Portland cements composition in an amount of more than 5% is not rational without the use of superplasticizers, since the water demand increases sharply, which reduces the cement stone strength. The introduction of a microfiller provides an increase in the compressive strength of a cement stone at the age of 28 days of normal hardening by an average of 37%.

Effect of Temperature on Fe3O4 Magnetic Nanoparticles Prepared by Coprecipitation Method

2014 ◽  
Vol 900 ◽  
pp. 172-176 ◽  
Author(s):  
Ji Mei Niu ◽  
Zhi Gang Zheng
Keyword(s):  
Magnetic Nanoparticles ◽  
Coprecipitation Method ◽  
Effect Of Temperature ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Magnetic Carriers ◽  
Average Grain Size ◽  
Or Gene ◽  
Block Temperature

The Fe3O4 magnetic nanoparticles obtained by the aqueous coprecipitation method are characterized systematically using scanning electron microscope, X-ray diffraction and vibrating sample magnetometer. These magnetic nanoparticles are spheric, dispersive, and have average grain size of 50 nm. The size and magnetic properties of Fe3O4 nanoparticles can be tuned by the reaction temperature. All samples exhibit high saturation magnetization (Ms=53.4 emu·g-1) and superparamagnetic behavior with a block temperature (TB) of 215K. These properties make such Fe3O4 magnetic nanoparticles worthy candidates for the magnetic carriers of targeted-drug or gene therapy in future.

pH Influences on Optical Absorption of Anthocyanin from Black Rice as Sensitizer for Dye Sensitized Solar Cell TiO2 Nanoparticles

2016 ◽  
Vol 864 ◽  
pp. 154-158
Author(s):  
Mariya Al Qibtiya ◽  
Eka Cahya Prima ◽  
Brian Yuliarto ◽  
Suyatman
Keyword(s):  
Solar Cell ◽  
Optical Absorption ◽  
Dye Sensitized Solar Cell ◽  
Black Rice ◽  
X Ray ◽  
Dye Sensitized ◽  
Current Voltage ◽  
Average Grain Size ◽  
Uv Visible

Natural dyes extracted from black rice are used as sensitizer for dye sensitized solar cell. The anthocyanin extracted with various pH in acidic and neutral coditions. Preparation of fotolectrode TiO2 film using doctor blade method and resulting average grain size 33,9 nm using X-Ray Diffractometer. Characterization of morphology and cross-section film TiO2 is confirmed by Scanning Electron microscopy (SEM). Optical absorption using UV-Visible Spectroscopy to obtain spectrum absorbance of anthocyanin in various pH. The current-voltage (J-V) characterization shows the performance DSSC have a match relation to the optical absorption. The best absorption of anthocyanin obtained at pH 6 as well as conversion efficiency reaches 2.26% at this pH condition.

Effect of Composition on the Morphology and Hardness of Nanostructured Cu Based Composite and Alloy Powders/Granules Produced by High Energy Mechanical Milling

2007 ◽  
Vol 29-30 ◽  
pp. 143-146 ◽  
Author(s):  
Aamir Mukhtar ◽  
De Liang Zhang ◽  
C. Kong ◽  
P. R. Munroe
Keyword(s):  
Grain Size ◽  
Mechanical Milling ◽  
Alloy Powder ◽  
High Energy ◽  
Al2o3 Nanoparticles ◽  
X Ray ◽  
Fine Powders ◽  
Average Grain Size ◽  
Powder Particles

Cu-(2.5 or 5.0vol.%)Al2O3 nanocomposite balls and granules and Cu-(2.5vol.% or 5.0vol.%)Pb alloy powder were prepared by high energy mechanical milling (HEMM) of mixtures of Cu and either Al2O3 or Pb powders. It was observed that with the increase of the content of Al2O3 nanoparticles from 2.5vol.% to 5vol.% in the powder mixture, the product of HEMM changed from hollow balls into granules and the average grain size and microhardness changed from approximately 130nm and 185HV to 100nm and 224HV, respectively. On the other hand, HEMM of Cu–(2.5 or 5.0vol.%) Pb powder mixtures under the same milling conditions failed to consolidate the powder in-situ. Instead, it led to formation of nanostructured fine powders with an average grain size of less than 50nm. Energy dispersive X-ray mapping showed homogenous distribution of Pb in the powder particles in Cu–5vol.%Pb alloy powder produced after 12 hours of milling. With the increase of the Pb content from 2.5 to 5.0 vol.%, the average microhardness of the Cu-Pb alloy powder particles increases from 270 to 285 HV. The mechanisms of the effects are briefly discussed.

Development of arc welding technique to preclude microsegregation in the dissimilar joint of Alloy C-2000 and C-276

2021 ◽  
pp. 095440892110000
Author(s):  
B Arulmurugan ◽  
M Sathishkumar ◽  
D Balaji ◽  
K Muralikrishnan ◽  
S Pranesh ◽  
...  
Keyword(s):  
Charpy Impact ◽  
Hardness Test ◽  
Xrd Analysis ◽  
Grain Structure ◽  
Tensile Fracture ◽  
Structure Property ◽  
X Ray ◽  
Dissimilar Weld ◽  
Dissimilar Alloys ◽  
Average Grain Size

Hastelloy C-2000 and C-276 are widely used in Flue Gas Desulphurization (FGD) system and Chemical Processing Industries (CPI). Current work is focused on weld microstructure, and mechanical properties (structure-property relationship) of the dissimilar combination of alloy C-2000 and C-276. Multi-pass Pulsed Current Gas Tungsten Arc (PCGTA) welding was adopted for joining the dissimilar alloys using the filler ERNiCrMo-17. Microstructural characteristics of the weld joint were assessed by Optical and Scanning Electron Microscope (SEM). Weld interface microstructure examination revealed the presence of grain coarsening near the Heat Affecting Zone (HAZ) of the alloy C-276 side. SEM analysis shows the absence of secondary Topologically Closed Packed (TCP) phases in the Inter-Dendritic (ID) regions of the dissimilar weld. Micro-segregation of alloying elements in the weldment was assessed by Energy-Dispersive X-ray Spectroscopy (EDS). X-Ray Diffraction (XRD) analysis had been carried out to identify the phase constitution and average grain size. Strength, toughness, and hardness of the dissimilar weld were evaluated with the support of the tensile test, Charpy impact test, and Vicker’s hardness test. Tensile study showed that all the tensile fracture occurred at the base metal side of alloy C-276. The average toughness of the dissimilar alloy joint was noted about 84 J. Hardness test results indicated that fusion zone (FZ) hardness value was 6.19% and 2.27% superior to the candidates’ material (C-276 and C-2000) employed in this study. The refined grain structure and absence of microsegregation resulted in the highest hardness in the dissimilar weld FZ. Results revealed the substantiated use of PCGTA welding for the effective joining of dissimilar alloys of C-2000 and C-276 through the evaluation of metallurgical and mechanical characteristics.

THE PROGRESSIVE PHENOTYPE OF PNEUMOCONIOSIS

2021 ◽  
Author(s):  
Y.Y. Gorblyansky ◽  
◽  
M.A. Panova ◽  
O.P. Ponamareva
Keyword(s):  
Computed Tomography ◽  
Silicon Dioxide ◽  
Retrospective Analysis ◽  
Russian Federation ◽  
Medical Examination ◽  
X Ray ◽  
Radiological Parameters ◽  
Rostov Region ◽  
The Russian Federation

Abstract: The prevalence of progressive forms of pneumoconiosis in the Russian Federation has been little studied. At the same time, the number of workers exposed to silicon dioxide, both in our country and abroad, is not decreasing. The purpose of our research to determine the criteria for the progression of pneumoconiosis in miners. A retrospective analysis of the results of a comprehensive medical examination of 150 miners of the Rostov region, observed in the center of occupational pathology, was carried out. All patients underwent radiography, computed tomography of the chest organs, and spirometry. X-ray description of the changes was carried out in accordance with the recommendations of the ILO. As a result, 24.5% had statistically significant signs of negative dynamics of functional and radiological indicators, which we referred to the criteria of progression. Thus, the progression of pneumoconiosis is determined by the negative dynamics of clinical and radiological parameters.

A Study on Nanocrystalline Nickel Parts Prepared by Jet Electrodeposition

2010 ◽  
Vol 37-38 ◽  
pp. 64-67
Author(s):  
Jin Song Chen ◽  
Yin Hui Huang ◽  
Bin Qiao ◽  
Jian Ming Yang ◽  
Yi Qiang He
Keyword(s):  
Dimensional Accuracy ◽  
Processing Parameters ◽  
X Ray Diffraction ◽  
Scanning Microscope ◽  
Nanocrystalline Nickel ◽  
X Ray ◽  
Fine Grained ◽  
Average Grain Size ◽  
Jet Electrodeposition ◽  
Fine Grained Structure

The principles of jet electrodeposition orientated by rapid prototyping were introduced. The nanocrystalline nickel parts with simple shape were fabricated using jet electrodeposition. The microstructure and phase transformation of nanocrystalline nickel were observed under the scanning microscope and X-ray diffraction instrument. The results show that the jet electrodeposition can greatly enhance the limited current density, fine crystalline particles and improve deposition quality. The nickel parts prepared by jet electrodeposition own a fine-grained structure (average grain size 25.6nm) with a smooth surface and high dimensional accuracy under the optimum processing parameters.

Hydrothermal Synthesis of Lead Titanate Epitaxial Film for Non-Volatile Memory Device Application

2013 ◽  
Vol 652-654 ◽  
pp. 1846-1850
Author(s):  
Thin Thin Thwe ◽  
Than Than Win ◽  
Yin Maung Maung ◽  
Ko Ko Kyaw Soe
Keyword(s):  
Electron Microscopy ◽  
Silicon Dioxide ◽  
Lead Titanate ◽  
Conduction Mechanism ◽  
Epitaxial Film ◽  
Memory Device ◽  
X Ray Diffraction ◽  
X Ray ◽  
Non Volatile Memory ◽  
Scanning Electron

Hydrothermal synthesized lead titanate (PbTiO3¬) powder was prepared in a Teflon-lined stainless steel bomb at different bath temperatures. X-ray diffraction was performed to examine the phase assignment and crystallographic properties of hydrothermal synthesized lead titanate powder. Silicon dioxide (SiO2) was thermally deposited and adapted as intermediate layer on p-Si (100) substrates for MFIS (Metal/Ferroelectric/ Insulator/Semi-conductor) design. The microstructures of PbTiO3 film for both MFS and MFIS designs were observed by scanning electron microscopy (SEM). Charge conduction mechanism was also interpreted by C-2-V relationship. Polarization and electric field characteristics were measured by Sawyer-Tower circuit and good hysteresis nature was formed for both structures of the films. The loop of MFIS was wider than that of MFS cell. Also, the higher value of polarization (Ps=3.21E-03µC/cm2) for MFIS could be explained on the basis of higher dipole moment in this SiO2 buffer layer.

An X-ray fluorescence microscopic analysis of the tissue surrounding the multi-channel cochlear implant electrode array

2016 ◽  
Vol 17 (3) ◽  
pp. 129-131 ◽  
Author(s):  
Kathryn Spiers ◽  
Tina Cardamone ◽  
John B. Furness ◽  
Jonathan C. M. Clark ◽  
James F. Patrick ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Electrode Array ◽  
Microscopic Analysis ◽  
X Ray ◽  
Fluorescence Microscopic Analysis

scholarly journals MODIFIED SAWDUST CONCRETE/MODIFIKUOTAS PJUVENŲ BETONAS

2000 ◽  
Vol 6 (2) ◽  
pp. 113-119
Author(s):  
Aras Kantautas ◽  
Giedrius Vaickelionis
Keyword(s):  
Compressive Strength ◽  
Liquid Phase ◽  
Shrinkage Strain ◽  
Developed Countries ◽  
Mass Relation ◽  
Concrete Compressive Strength ◽  
Wood Extracts ◽  
Cement Additive ◽  
Mineral Components ◽  
Mineral Additives

Wood-cement materials are widely produced and applied in many developed countries. In this case special prepared wood aggregates are employed. Wood sawdust practically is not employed. Extracts, present in wood, slow down the cement hydration. The influence of mineral additives on this process was determined. The efficiency of mineral additives depends on their hydraulic activity. It has been found that the mineral components (additives) of sawdust concrete have a positive effect on cement setting and hardening due to two reasons: 1) hydraulic and other mineral additives absorb wood extracts from liquid phase which inhibit and retard setting of cement and reduce their concentration in solution; 2) reduce pH of liquid phase so the hemicellulose which is in sawdust or other wood aggregates, less disintegrate lightly soluable sugars. When sawdust amounts are different, the optimum cement and rottenstone relation is not constant: y = 1,29x −0,66 where y is cement and rottenstone mass relation, x is sawdust and binding material (cement+rottenstone) volume relation. The influence of sawdust concrete humidity on its strength was found: where y is concrete compressive strength (MPa), when its humidity X (%), R is concrete compressive strength (MPa), when its humidity W(%). The possibility of accelerating the hardening process of concrete mixes of cement-rottenstone (gaize)-sawdust system by means of steaming at 80 °C was studied, too. It is impossible when producing ordinary wood-cement materials. The physical and technical properties of sawdust concrete such as shrinkage strain, expansion deformations and elastic modulus were determined. Sawdust concrete contraction deformation depending on concrete density may vary by 8…14 mm/m and expansion (in humid conditions) by 1,1…2,5 mm/m. Deformation decreases when quartz sand additive is used. When the concrete gets dry repeatedly, deformations are smaller. The sawdust concrete elasticity modulus is similar to that of light concrete with inorganic additives having the same density. Its frost resistance depends on the concrete structure and cement quantity. When the concrete with a small amount of sawdust is used (cement+additive: sawdust=5:1), the samples endure 75 freezing cycles. The heat conductivity of sawdust concrete is low. The experimental data have shown that structural thermoinsulated small blocks can be produced from these concrete mixes.

scholarly journals Effect of Re and Tm-site on morphology structure and optical band gap of ReTmO3 (Re: La, Ce, Nd, Gd, Dy, Y and Tm: Fe, Cr) prepared by sol-gel method

2018 ◽  
Vol 64 (4) ◽  
pp. 381
Author(s):  
Muhammad Tufiq Jamil ◽  
Javed Ahmad ◽  
Syed Hamad Bukhari ◽  
Murtaza Saleem
Keyword(s):  
Band Gap ◽  
Sol Gel ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
X Ray Diffraction ◽  
Orthorhombic Crystal ◽  
X Ray ◽  
Average Grain Size ◽  
Auto Combustion ◽  
Uv Visible

Rare earth nano sized pollycrystalline orthoferrites and orthocromites ReT mO3 (Re = La, Nd, Gd, Dy, Y and T m = Fe, Cr) have been synthesized by sol-gel auto combustion citrate method. The samples have been characterized by means of X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), and UV-visible spectroscopy. The samples are single phase as confirmed by XRD analysis and correspond to the orthorhombic crystal symmetry with space group pbnm. Debye Scherer formula and Williamson Hall analysis have been used to calculate the average grain size which is consistent with that of determined from SEM analysis and varied between 25-75 nm. The elemental compositions of all samples have been checked by EDX analysis. Different crystallographic parameters are calculated with strong structural correlation among Re and Tm sites. The optical energy band gap has been calculated by using Tauc relation estimated to be in the range of 1.77 - 1.87 eV and 2.77 - 3.14 eV, for ReFeO3 and ReCrO3, respectively.

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