scholarly journals Study on the grain size control of metatitanic acid in a mixture acid system based on Arrhenius and Boltzmann fitting

RSC Advances ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 1055-1065
Author(s):  
Ming Tian ◽  
Yahui Liu ◽  
Wei Zhao ◽  
Weijing Wang ◽  
Lina Wang ◽  
...  
Keyword(s):  
Experimental Data ◽  
Particle Size ◽  
Grain Size ◽  
Size Control ◽  
Chloric Acid ◽  
Thermal Hydrolysis ◽  
Acid System ◽  
Metatitanic Acid ◽  
Grain Size Control ◽  
The Relationship

Herein, to control the particle size of metatitanic acid produced via titanium thermal hydrolysis in sulfuric–chloric acid (SCMA) solutions, the relationship between its grain size and hydrolysis parameters are discussed, and the corresponding methematical model is discussed using the experimental data.

Grain size control of sediment composition variability still not resolved

2020 ◽  
Author(s):  
Tomas Matys Grygar ◽  
Karel Hron ◽  
Ondrej Babek ◽  
Kamila Facevicova ◽  
Reneta Talska ◽  
...  
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Compositional Data ◽  
Size Control ◽  
Chemical Extraction ◽  
Sediment Composition ◽  
Geochemical Composition ◽  
Size Fractions ◽  
Grain Size Control ◽  
Log Ratio

<p>The compositional data analysis (CoDA), unbiased interpretation of geochemical composition of sediments and soils, must correctly treat several major challenges, well-known to environmental geochemists but still improperly handled. Among them, dilution by autochthonous components, e.g., biogenic carbonates or organic matter, and grain size effects are the most relevant. These effects cannot be eliminated by sample pre-treatment, e.g. by sieving or chemical extraction of diluting components, but they can be handled by implementation of interelement relationships and particle size distribution functions. The challenges of CoDA are principally twofold: geochemical/mineralogical and mathematical/statistical. Geochemical/mineralogical challenge is that complete deciphering of sediment composition would need knowledge of mineral composition (and stoichiometry of individual minerals and their content of major and trace elements) in each grain size fraction. This information can be achieved by analysis of finely divided grain-size fractions of studied sediments, which is enormously demanding, in particular in the silt and clay size fractions; that approach can, however, be found in scientific papers. Mathematical/statistical challenge consists in need to respect nature of compositional data (relative nature, i.e. scale dependence, data closure – content of each component impacts all other components), polymodal data distributions, including the cases when “outliers” (in terms of Gaussian distribution) are a regular part of compositional datasets. Compositional data are best treated using log-ratio methodology and robust algorithms (not based on the least squares fitting methods), which are not familiar to geoscientists.</p><p>Most traditional geochemical approaches to CoDA are based on empirical knowledge, models, and assumptions which are hardly proven, e.g. a tracer conservativeness or its grain size invariance, which are not easy tested independently. Most novel mathematical/statistical tools are too abstract and computations too complicate for common geochemists. The bottleneck here is to convert geochemical tasks to formal mathematical/statistical terms and develop novel tools, having chance to become routinely used in future.</p><p>We studied composition of 483 sediment samples from floodplain and reservoir impacted by historical pollution from chemical industry in Martktredwitz, Germany. We will demonstrate mathematically/statistically correct routes to (1) distinguishing anthropogenic portion of risk elements in sediments of variable grain size and (2) characterisation of grain size control of sediment composition. Task (1) is best achieved by robust regression with log-ratios of concentrations, which still needs certain a priori geochemical expertise. Task ad (2) is best achieved by the use of a functional analysis of particle size distributions (densities) based on Bayes spaces. To support our recommendations, insufficiency of PCA to solve task (1) will be demonstrated.</p>

Interfacial studies in Nb3Sn superconductors

1991 ◽  
Vol 49 ◽  
pp. 590-591
Author(s):  
Ernest L. Hall ◽  
Lee E. Rumaner ◽  
Mark G. Benz
Keyword(s):  
Grain Size ◽  
Grain Boundaries ◽  
Flux Pinning ◽  
Size Control ◽  
High Magnetic Fields ◽  
Type Ii ◽  
Reaction Interface ◽  
Liquid Diffusion ◽  
Type Ii Superconductor ◽  
Grain Size Control

The intermetallic compound Nb3Sn is a type-II superconductor of interest because it has high values of critical current density Jc in high magnetic fields. One method of forming this compound involves diffusion of Sn into Nb foil containing small amounts of Zr and O. In order to maintain high values of Jc, it is important to keep the grain size in the Nb3Sn as small as possible, since the grain boundaries act as flux-pinning sites. It has been known for many years that Zr and O were essential to grain size control in this process. In previous work, we have shown that (a) the Sn is transported to the Nb3Sn/Nb interface by liquid diffusion along grain boundaries; (b) the Zr and O form small ZrO2 particles in the Nb3Sn grains; and (c) many very small Nb3Sn grains nucleate from a single Nb grain at the reaction interface. In this paper we report the results of detailed studies of the Nb3Sn/Nb3Sn, Nb3Sn/Nb, and Nb3Sn/ZrO2 interfaces.

Simulation on Extrusion Comminution Model of Roller Press

2010 ◽  
Vol 156-157 ◽  
pp. 1702-1707
Author(s):  
Xiang Wen Cheng ◽  
Jinchao Liu ◽  
Qi Zhi Ding ◽  
Li Ming Song ◽  
Zhan Lin Wang
Keyword(s):  
Experimental Data ◽  
Particle Size ◽  
Field Experiments ◽  
Size Ratio ◽  
Optimum Operating ◽  
Extrusion Force ◽  
Particle Size Ratio ◽  
Small Constant ◽  
Working Parameters ◽  
The Relationship

How to predict the relationship among particle size and among product size, to establish the relationship between the granularity and working parameters in the process of grinding and to determine the optimum operating parameters. With proposing BS squeeze crush model by L. Bass and the idea of roll surface division as the material uneven extrusion force are adopted. Based on field experiments the experimental data is analyzed, the select function and the breakage functions are fitted with MATLAB software, and obtaining their model. The comminution model is determined by the roller division. We obtain the model parameter through the experimental data. Through model analysis shows: the relationship between particle breakage and energy absorption, namely the smaller size of the same power, the lower broken; the breakage diminishes with the decrease of particle size ratio and it will be tending to a small constant when the smaller particle size ratio. The breakage functions rapidly decrease within ratio of between 0.2-0.7. This shows: the energy consumption will rapidly increase when the particle size of less than 0.2 in broken; the selection diminish with the decrease of particle size. Pressure (8-9MPa) should be the most appropriate value.

Grain size control of perovskite films based on β-alanine self-assembled monolayers surface treatment

2021 ◽  
pp. 138770
Author(s):  
Linlin Guan ◽  
Leiming Yu ◽  
Lijuan Wu ◽  
Shuyu Zhang ◽  
Yuting Lin ◽  
...  
Keyword(s):  
Grain Size ◽  
Surface Treatment ◽  
Size Control ◽  
Self Assembled Monolayers ◽  
Assembled Monolayers ◽  
Grain Size Control ◽  
Self Assembled

scholarly journals Grain size control in polycrystalline colloidal solids

1995 ◽  
Vol 102 (12) ◽  
pp. 5082-5087 ◽  
Author(s):  
Thomas Palberg ◽  
Wolfgang Mönch ◽  
Jürgen Schwarz ◽  
Paul Leiderer
Keyword(s):  
Grain Size ◽  
Size Control ◽  
Grain Size Control

scholarly journals Grain size control of ZIF-8 membranes by seeding-free aqueous synthesis and their performances in propylene/propane separation

2017 ◽  
Vol 544 ◽  
pp. 306-311 ◽  
Author(s):  
Shunsuke Tanaka ◽  
Kenta Okubo ◽  
Koji Kida ◽  
Miki Sugita ◽  
Takahiko Takewaki
Keyword(s):  
Grain Size ◽  
Size Control ◽  
Aqueous Synthesis ◽  
Grain Size Control

scholarly journals Quantitative approach to realization of ultrasonic grain refinement of Al-7Si-2Cu-1Mg alloy

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Soo-Bae Kim ◽  
Young-Hee Cho ◽  
Min-Su Jo ◽  
Jae-Gil Jung ◽  
Young-Kook Lee ◽  
...  
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Grain Refinement ◽  
Particle Diameter ◽  
Nucleation Site ◽  
Melt Temperature ◽  
Transmission Electron ◽  
Refinement Mechanism ◽  
Ultrasonic Melt Treatment ◽  
The Relationship

AbstractUltrasonic melt treatment (UST) was applied to Al-7Si-2Cu-1Mg melt at various temperatures of 620, 650, 700 and 785 °C. MgAl2O4 particles which were often found to be densely populated along oxide films, became effectively dispersed and well-wetted by UST. Transmission electron microscopy work combined with crystallography analysis clearly indicates that MgAl2O4 particles can act as α-Al nucleation site with the aid of UST. However, with UST, grain refinement occurred only at temperature of 620 °C and the grain size increased from 97 to 351 μm with increase of melt temperature to 785 °C for UST. In quantitative analysis of grain size and MgAl2O4 particle diameter, it was found that ultrasonic de-agglomeration decreased mean particle size of the MgAl2O4 particles, significantly reducing size from 1.2 to 0.4 μm when temperature increased from 620 to 785 °C. Such a size reduction with increased number of MgAl2O4 particles does not always guarantee grain refinement. Thus, in this work, detailed condition for achieving grain refinement by UST is discussed based on quantitative measurement. Furthermore, we tried to suggest the most valid grain refinement mechanism among the known mechanisms by investigation of the relationship between grain size and particle size with variation of melt temperature.

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