scholarly journals Methods to Determine Characteristics of AOD-Converter Decarburization-Slags

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 308
Author(s):  
Patrik Ternstedt ◽  
Gunilla Runnsjö ◽  
Anders Tilliander ◽  
Jesper Janis ◽  
Nils Å. I. Andersson ◽  
...  
Keyword(s):  
Measured Data ◽  
Limited Information ◽  
X Ray ◽  
Solid Phases ◽  
Argon Oxygen Decarburization ◽  
The Difference ◽  
Industrial Samples ◽  
Liquid And Solid Phases ◽  
Aod Slag ◽  
Good Agreement

Argon Oxygen Decarburization (AOD) converter slags are known to consist of both liquid and solid phases, but limited information on the slag characteristics has been published in the open literature. Therefore, a new methodology to study the characteristics of slag samples taken from the AOD converter process during production was developed based on petrography. The results show that the preparations of the slag samples using the borax method are suitable to use when determining the chemical composition of AOD slag samples using the X-ray fluorescence (XRF) method. The results also showed that both the light optical microscopy (LOM) method and a method combining scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) can be used to characterize the slag samples and that the correlation between the methods was found to be good. This means that it is possible to use the faster LOM method instead of the more complicated SEM-EDS method to characterize AOD slag samples. Finally, the results show that the difference between calculated values based on stoichiometry and measured data for Ca and Cr in AOD slags are 11.7 mass% and 11.3 mass%, respectively. This is considered to be a good agreement for industrial samples.

Local atomic structure in tetragonal pure ZrO2nanopowders

2010 ◽  
Vol 43 (2) ◽  
pp. 227-236 ◽  
Author(s):  
Leandro M. Acuña ◽  
Diego G. Lamas ◽  
Rodolfo O. Fuentes ◽  
Ismael O. Fábregas ◽  
Márcia C. A. Fantini ◽  
...  
Keyword(s):  
Tetragonal Phase ◽  
Local Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Atomic Structures ◽  
Crystallite Sizes ◽  
Exafs Study ◽  
The Difference ◽  
X Ray Absorption ◽  
Good Agreement

The local atomic structures around the Zr atom of pure (undoped) ZrO2nanopowders with different average crystallite sizes, ranging from 7 to 40 nm, have been investigated. The nanopowders were synthesized by different wet-chemical routes, but all exhibit the high-temperature tetragonal phase stabilized at room temperature, as established by synchrotron radiation X-ray diffraction. The extended X-ray absorption fine structure (EXAFS) technique was applied to analyze the local structure around the Zr atoms. Several authors have studied this system using the EXAFS technique without obtaining a good agreement between crystallographic and EXAFS data. In this work, it is shown that the local structure of ZrO2nanopowders can be described by a model consisting of two oxygen subshells (4 + 4 atoms) with different Zr—O distances, in agreement with those independently determined by X-ray diffraction. However, the EXAFS study shows that the second oxygen subshell exhibits a Debye–Waller (DW) parameter much higher than that of the first oxygen subshell, a result that cannot be explained by the crystallographic model accepted for the tetragonal phase of zirconia-based materials. However, as proposed by other authors, the difference in the DW parameters between the two oxygen subshells around the Zr atoms can be explained by the existence of oxygen displacements perpendicular to thezdirection; these mainly affect the second oxygen subshell because of the directional character of the EXAFS DW parameter, in contradiction to the crystallographic value. It is also established that this model is similar to another model having three oxygen subshells, with a 4 + 2 + 2 distribution of atoms, with only one DW parameter for all oxygen subshells. Both models are in good agreement with the crystal structure determined by X-ray diffraction experiments.

HIGH RESOLUTION L X-RAY EMISSION SPECTRA OF Fe AND Cu INDUCED BY O.75 MeV/u ION IMPACT

1995 ◽  
Vol 05 (02n03) ◽  
pp. 203-209 ◽  
Author(s):  
H. KAGEYAMA ◽  
R. TAKAHASHI ◽  
D. HAMAGUCHI ◽  
T. AWATA ◽  
T. NAKAE ◽  
...  
Keyword(s):  
High Resolution ◽  
Lower Energy ◽  
Emission Spectra ◽  
Crystal Spectrometer ◽  
Transition Energies ◽  
X Ray ◽  
The Difference ◽  
Ion Impact ◽  
Electron Vacancy ◽  
Good Agreement

High resolution L x-ray emission spectra of Fe and Cu have been measured by 0.75 MeV/u H and He, and 0.73 MeV/u He, Si and Ar ion impacts with a crystal spectrometer. The x-ray transition energies in the Fe and Cu targets for Lι, Lη, Lα1,2, Lβ1 and Lβ3,4 diagram lines induced by light ion impacts are determined, which are in good agreement with those given in the reference. The difference in L x-ray emission spectra produced by H, He, Si and Ar ions is considered and the emission spectra for the Cu target are compared with the calculated ones based on the multiconfiguration Dirac-Fock method. The origin of the broadening of the Lα1,2 line to the lower energy for Si and Ar ion impacts is attributed to one 2p plus one 3d electron vacancy production.

Pre-Swirled Cooling Air Delivery System Performance

2005 ◽  
Author(s):  
J. W. Chew ◽  
F. Ciampoli ◽  
N. J. Hills ◽  
T. Scanlon
Keyword(s):  
System Performance ◽  
Computational Effort ◽  
Measured Data ◽  
Numerical Results ◽  
Simplified Model ◽  
Swirl Chamber ◽  
Aero Engine ◽  
The Difference ◽  
Cooling Air ◽  
Good Agreement

This paper reports results from numerical simulations of the flow in pre-swirl cooling air delivery systems. Two different systems have been investigated corresponding to experimental rigs for which measured data is available. The rigs are representative of aero-engine conditions. The difference in the performance of the two rigs has been addressed. The flow in the pre-swirl nozzles and in the pre-swirl chambers has been investigated separately. For the pre-swirl chamber a simplified model, in which the nozzle is replaced by a slot, has been used to reduce the computational effort required. Nevertheless numerical results are in good agreement with experimental measurements. It is shown that the difference in the geometry of the pre-swirl chambers is largely responsible for the difference in performance of the rigs. Numerical results have also been compared with predictions from a previously published simplified model. An adjustment of the empirical constants in the simple model has been proposed in order to improve the prediction of the moments in the pre-swirl chamber.

Soil and Plant Water

2000 ◽  
Author(s):  
Peter B. Tinker ◽  
Peter Nye
Keyword(s):  
Gravitational Field ◽  
Kinetic Energy ◽  
Chemical Potential ◽  
Energy State ◽  
Plant Water ◽  
Chemical Potentials ◽  
Solid Phases ◽  
The Difference ◽  
Electrically Charged ◽  
Liquid And Solid Phases

Water is of central importance in the transport of solutes, whether by diffusion or mass flow, and whether in soils or plants (Lösch 1995). It is also extremely important for the biota that live in the soil (Parr et al. 1981). Water is an unusual component of the environment, because its structure suggests it should be a gas at normal temperatures rather than a liquid, and it is the only common compound in the biosphere that occurs to a significant extent in the vapour, liquid and solid phases. We begin this chapter with a very brief statement of the thermodynamic approach to the study of water, which defines the water potential. Without an understanding of chemical potentials, it is difficult to deal with the relationships of ions and water in the soil and the plant. Therefore, in this chapter we give an introduction to this subject with special reference to water, which we then take further in chapters 4 and 5. A clear exposition of this is given in Nobel (1991). The concept of chemical potential is fundamental. It is a measure of the energy state of a particular compound in a particular system, and hence of the ability of a unit amount of the compound to perform work and thereby cause change. In particular, the difference in potential at different points in a system gives a measure of the tendency of the component to move from the region with the high potential to the region with the low potential. A component of a system can have various forms of potential energy in this sense, all of which contribute to the total chemical potential. Here, we exclude chemical reaction energy and kinetic energy. The main forms of energy that contribute to the chemical potential of a specified compound or material are due to its concentration (which may release energy on dilution), to its compression (which may perform work on expansion), to its position in an electrical field (which may release energy if the component is electrically charged and moves within the field), and to its position in the gravitational field (which may release energy as the component moves downwards).

scholarly journals X-Ray Diffraction and Density Distribution Measurements on the Al2O3 Crystals Grown by Czochralski Method with Different Pull Rate

2015 ◽  
Vol 1 (1) ◽  
pp. 1 ◽  
Author(s):  
Hamdan Hadi Kusuma
Keyword(s):  
Density Measurement ◽  
Czochralski Method ◽  
X Ray Diffraction ◽  
Powder Diffraction File ◽  
Hexagonal System ◽  
X Ray ◽  
Lattice Constants ◽  
The Difference ◽  
Measurement Base ◽  
Good Agreement

The Al<sub>2</sub>O<sub>3</sub> crystal has been done by Czochralki Method with different pull rate. The effect of pull rate on the Al<sub>2</sub>O<sub>3</sub> single crystal was characterized using X-ray diffraction and density measurement. Base on the XRD result of Al<sub>2</sub>O<sub>3</sub> crystal, which belongs to the hexagonal system, except for the difference in the relative intensity, present diffraction data which are found to be in good agreement with those of the powder diffraction file (PDF) 43-1484 provided by the JCPDS. It was observed the structure with symmetry group <em>D</em><sup>6</sup><sub>3d</sub>–<em>R</em>3<em>C </em>and has lattice constants being <em>a </em>= 4.759 Å, <em>c</em> = 12.99 Å. The density of the crystals increased with the pull rate. This phenomenon is caused by the speed of the pull rate crystal that causes changes in the heat flow in the furnace and then changed homogeneities of species distribution of atoms along the crystal. © 2015 JNSMR UIN Walisongo. All rights reserved.

scholarly journals PHASE EQUILIBRIA IN THE NaCl–CaCl2–CaO SYSTEM

2021 ◽  
Vol 87 (2) ◽  
pp. 77-86
Author(s):  
Anatoliy Omelchuk ◽  
Igor Skryptun ◽  
Nikolay Zakharchenko ◽  
Olha Bosenko ◽  
Ruslan Savchuk ◽  
...  
Keyword(s):  
Ternary System ◽  
Phase Equilibria ◽  
Metal Oxides ◽  
Calcium Oxide ◽  
Refractory Metal ◽  
Polythermal Section ◽  
X Ray ◽  
Polythermal Sections ◽  
Solid Phases ◽  
Liquid And Solid Phases

The phase equilibria of the ternary system CaCl2 – NaCl – CaO in the area which enriched of calcium and sodium chloride were investigated by the methods of differential-thermal analysis and powder X-ray phase analysis. In the systems were determined the equilibrium concentration of calcium oxide and the composition of the phases, which at the same time exist in an equilibrium state at different temperatures. The surfaces of liquidus and solidus were established, the compositions of the sections of the ternary system CaCl2–NaCl–CaO were defined, which recommended for electrochemical reduction of refractory metal oxides (titanium, zirconium and other), which allow electrolysis in the temperature range from 550 to 1000 °С. Five polythermal sections of the NaCl – CaCl2 – CaO ternary system were studied. For each polythermal section the regions of existence of the liquid and solid phases were established. For each polythermal section state diagrams were constructed. Used X-Ray phase analyses it was established the compositions of liquid and solid phases for each polythermal sections. The phases of which the system consists were determined. At a constant ratio of components [NaCl]:[CaCl2] = 1.06 (mol.) in the melts of the ternary system CaCl2 – NaCl – CaO, the equilibrium content of calcium oxide reaches 12.0 mol.%, while their crystallization temperature does not exceed 550 °C. This allows us to recommend mixtures of this composition for electrochemical reduction of refractory metal oxides in a wide range of temperatures (from 550 to 1000 °C) with a high content of both calcium and sodium chlorides (not less than 40 mol.%) and oxide. calcium (up to 12.0 mol.%). The eutectic of this ternary system has a melting point of 480 ° C and corresponds to he composition (mol.%): CaCl2 (45.8) – NaCl (47.0) – CaO (7.2).

scholarly journals The XXL Survey

2018 ◽  
Vol 620 ◽  
pp. A2 ◽  
Author(s):  
A. B. Mantz ◽  
Z. Abdulla ◽  
S. W. Allen ◽  
J. E. Carlstrom ◽  
C. H. A. Logan ◽  
...  
Keyword(s):  
Galaxy Cluster ◽  
Limited Information ◽  
X Ray ◽  
Average Temperature ◽  
Mass Estimate ◽  
Self Similar ◽  
Single Cluster ◽  
Lower Redshift ◽  
Massive Cluster ◽  
Good Agreement

We present results from a 100 ks XMM-Newton observation of galaxy cluster XLSSC 122, the first massive cluster discovered through its X-ray emission at z ≈ 2. The data provide the first precise constraints on the bulk thermodynamic properties of such a distant cluster, as well as an X-ray spectroscopic confirmation of its redshift. We measure an average temperature of kT = 5.0 ± 0.7 keV; a metallicity with respect to solar of Z/Z⊙ = 0.33−0.17+0.19, consistent with lower-redshift clusters; and a redshift of z = 1.99+0.07-0.06 , consistent with the earlier photo-z estimate. The measured gas density profile leads to a mass estimate at r500 of M500 = (6.3 ± 1.5) × 1013 M⊙. From CARMA 30 GHz data, we measure the spherically integrated Compton parameter within r500 to be Y 500 = (3.6 ± 0.4) × 10−12. We compare the measured properties of XLSSC 122 to lower-redshift cluster samples, and find good agreement when assuming the simplest (self-similar) form for the evolution of cluster scaling relations. While a single cluster provides limited information, this result suggests that the evolution of the intracluster medium in the most massive, well-developed clusters is remarkably simple, even out to the highest redshifts where they have been found. At the same time, our data reaffirm the previously reported spatial offset between the centres of the X-ray and SZ signals for XLSSC 122, suggesting a disturbed configuration. Higher spatial resolution data could thus provide greater insights into the internal dynamics of this system.

scholarly journals Solution of the direct alloy solidification problem including the phenomenon of material shrinkage

2017 ◽  
Vol 21 (1 Part A) ◽  
pp. 105-115 ◽  
Author(s):  
Edyta Hetmaniok ◽  
Damian Słota ◽  
Adam Zielonka
Keyword(s):  
Solid Phase ◽  
Heat Of Fusion ◽  
Solution Technique ◽  
Mass Balance Equation ◽  
Direct Alloy ◽  
Solidification Problem ◽  
Solid Phases ◽  
The Difference ◽  
Account Due ◽  
Liquid And Solid Phases

In the paper we describe the solution technique for solving the direct problem of the alloy solidifying within the casting mould with the phenomenon of material shrinkage taken into account. Due to the difference between densities of the liquid and solid phases, the shrinkage of metal often appears during the solidification. The investigated process is modeled by means of the solidification in the temperature interval basing on the heat conduction equation with the source element enclosed which includes the latent heat of fusion and the volume contribution of solid phase. Whereas the shrinkage of metal is modeled by the proper application of the mass balance equation.

Calculation of the phase diagram for the system water-dimethyl sulphoxide

1983 ◽  
Vol 48 (7) ◽  
pp. 1936-1943 ◽  
Author(s):  
Ivan Horsák ◽  
Ivo Sláma
Keyword(s):  
Experimental Data ◽  
Phase Diagram ◽  
Dimethyl Sulphoxide ◽  
Published Data ◽  
Solid Phases ◽  
The Difference ◽  
Equilibrium Chemical Reaction ◽  
Equilibrium Chemical ◽  
Liquid And Solid Phases ◽  
System Water

Liquidus curves of the phase diagram for the system water-dimethyl sulphoxide (DMSO) have been calculated in such a way as to give a good fit to experimental data for the phase diagram. The calculation is based on the assumption of an equilibrium chemical reaction yielding DMSO.3 H2O, and on the relation for the excess Gibbs energy in a ternary system composed of the two starting components and their compound. The data for the temperature dependence of the difference in the heat capacities of the liquid and solid phases of the pure components in the supercooling region have been obtained by extrapolation of experimental data in the case of DMSO, and for water by adopting published data measured down to -40 °C and by estimating their further trend.

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