STRUCTURES OF IV GROUP ELEMENTS AND SOLID PHASES OF WATER

Keyword(s):  
Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 701 ◽  
Author(s):  
Lei Guo ◽  
Xiaochun Wen ◽  
Qipeng Bao ◽  
Zhancheng Guo

An investigation was made on the super-gravity aided rheorefining process of recycled 7075 aluminum alloy in order to remove tramp elements. The separation temperatures in this study were selected as 609 °C, 617 °C and 625 °C. And the gravity coefficients were set as 400 G, 700 G, 1000 G. The finely distributed impurity inclusions will aggregate to the grain boundaries of Al-enriched phase during heat treatment. In the field of super-gravity, the liquid phase composed of tramp elements Zn, Cu, Mg et al. will flow through the gaps between solid Al-enriched grains and form into filtrate. Both the weight of filtrate and removal ratio of tramp element improved with the increase of gravity coefficient. The total removal ratio of tramp element decreased with the fall of temperature due to the flowability deterioration of liquid phase. The time for effective separation of liquid/solid phases with super-gravity can be restricted within 1 min.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 734
Author(s):  
Aija Trimdale ◽  
Anatoly Mishnev ◽  
Agris Bērziņš

The arrangement of hydroxyl groups in the benzene ring has a significant effect on the propensity of dihydroxybenzoic acids (diOHBAs) to form different solid phases when crystallized from solution. All six diOHBAs were categorized into distinctive groups according to the solid phases obtained when crystallized from selected solvents. A combined study using crystal structure and molecule electrostatic potential surface analysis, as well as an exploration of molecular association in solution using spectroscopic methods and molecular dynamics simulations were used to determine the possible mechanism of how the location of the phenolic hydroxyl groups affect the diversity of solid phases formed by the diOHBAs. The crystal structure analysis showed that classical carboxylic acid homodimers and ring-like hydrogen bond motifs consisting of six diOHBA molecules are prominently present in almost all analyzed crystal structures. Both experimental spectroscopic investigations and molecular dynamics simulations indicated that the extent of intramolecular bonding between carboxyl and hydroxyl groups in solution has the most significant impact on the solid phases formed by the diOHBAs. Additionally, the extent of hydrogen bonding with solvent molecules and the mean lifetime of solute–solvent associates formed by diOHBAs and 2-propanol were also investigated.


Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 570
Author(s):  
Olga Sánchez ◽  
Manuel Hernández-Vélez

ZnOTe compounds were grown by DC magnetron cosputtering from pure Tellurium (Te) and Zinc (Zn) cathodes in O2/Ar atmosphere. The applied power on the Zn target was constant equal to 100 W, while the one applied on the Te target took two values, i.e., 5 W and 10 W. Thus, two sample series were obtained in which the variable parameter was the distance from the Te targets to the substrate. Sample compositions were determined by Rutherford Backscattering Spectroscopy (RBS) experiments. Structural analysis was done using X-Ray diffraction (XRD) spectrometry and the growth of the hexagonal w-ZnO phase was identified in the XRD spectra. RBS results showed high bulk homogeneity of the samples forming ZnOTe alloys, with variable Te molar fraction (MF) ranging from 0.48–0.6% and from 1.9–3.1% for the sample series obtained at 5 W and 10 W, respectively. The results reflect great differences between the two sample series, particularly from the structural and optical point of view. These experiments point to the possibility of Te doping ZnO with the permanence of intrinsic defects, as well as the possibility of the formation of other Te solid phases when its content increases. The results and appreciable variations in the band gap transitions were detected from Photoluminescence (PL) measurements.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Manuel J. Arenas ◽  
Dietmar Hömberg ◽  
Robert Lasarzik ◽  
Pertti Mikkonen ◽  
Thomas Petzold

2015 ◽  
Vol 458 ◽  
pp. 62-67 ◽  
Author(s):  
B. Zgardzińska ◽  
T. Goworek
Keyword(s):  

1977 ◽  
Vol 55 (11) ◽  
pp. 975-983 ◽  
Author(s):  
J. E. Vesel ◽  
B. H. Torrie

The ferroelectric and proposed paraelectric phases of the hydrogen halides have been studied using a lattice of molecules which are represented by a set of electric multipoles. This model shows the dominance of quadrupole–quadrupole interactions and the importance of other multipole interactions which affect the librational motions of these molecular crystals. A dynamic ferroelectric phase model was used to calculate the frequencies of the four librational modes.


1958 ◽  
Vol 36 (11) ◽  
pp. 1511-1517 ◽  
Author(s):  
A. N. Campbell ◽  
E. M. Kartzmark ◽  
E. G. Lovering

In the reciprocal salt pair Li2, K2, Cl2, SO4, and water, at 25 °C there are large areas in which potassium sulphate and potassium lithium sulphate (KLiSO4) are separately in equilibrium with solution. Two incongruent invariant points exist. At one of these the composition of the solution is 0.917 mole fraction chloride, 0.437 mole fraction lithium, and 19.4 moles of water per total mole of salt, the equilibrium solid phases being potassium chloride, potassium sulphate, and the double salt. At the second, the composition of the solution is 0.967 mole fraction chloride, 0.870 mole fraction lithium, and 13.8 moles of water per mole of salt, the solid phases being potassium chloride, double salt, and lithium sulphate monohydrate. One congruent invariant point exists, at which the composition of the solution is 1.00 mole fraction chloride, 0.960 mole fraction lithium, and 9.6 moles of water per mole of salt, the solid phases being lithium sulphate monohydrate, lithium chloride monohydrate, and potassium chloride.In the reciprocal salt pair Li2, Na2, Cl2, SO4, and water, at 25 °C there is an incongruent invariant point at which the composition of the solution is 0.873 mole fraction chloride, 0.668 mole fraction lithium, and 15.1 moles water per total mole of salt, the solid phases being sodium chloride, solid solution of sodium and lithium sulphates, and lithium sulphate monohydrate. A congruent invariant point exists, at which the composition of the solution is practically entirely lithium chloride, the solid phases present being lithium chloride monohydrate, lithium sulphate monohydrate, and sodium chloride.


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