Study of potential oscillations during reaction of an aluminium single crystal with an aqueous KOH solution

1990 ◽  
Vol 55 (2) ◽  
pp. 345-353 ◽  
Author(s):  
Ivan Halaša ◽  
Milica Miadoková
Keyword(s):  
Aqueous Solutions ◽  
Single Crystal ◽  
Single Crystals ◽  
Periodic Potential ◽  
Optimum Conditions ◽  
Potential Oscillations ◽  
Dilute Aqueous Solutions ◽  
Experimental Findings ◽  
Kinetics Of

The authors investigated periodic potential changes measured on oriented sections of Al single crystals during spontaneous dissolution in dilute aqueous solutions of KOH, with the aim to find optimum conditions for the formation of potential oscillations. It was found that this phenomenon is related with the kinetics of the reaction investigated, whose rate also changed periodically. The mechanism of the oscillations is discussed in view of the experimental findings.

Adsorption of U(VI) from dilute aqueous solutions onto peat moss

2007 ◽  
Vol 95 (1) ◽  
Author(s):  
H. A. Omar ◽  
M. Aziz ◽  
K. Shakir
Keyword(s):  
Ionic Strength ◽  
Aqueous Solutions ◽  
Uranium Concentration ◽  
Probable Mechanism ◽  
Peat Moss ◽  
Optimum Conditions ◽  
Low Concentrations ◽  
Equilibrium Data ◽  
Dilute Aqueous Solutions

The adsorption of U(VI) onto peat moss has been studied as a function of uranium concentration, pH, shaking time and ionic strength. The pH and ionic strength of the solution markedly affect the extent of removal. The attainment of equilibrium is fast and the equilibrium data fit well the Freundlich, Langmuir and Dubinin-Radushkevich equations. A probable mechanism of uptake is discussed. Further studies demonstrate that under optimum conditions peat moss can be used for the treatment of waste solutions containing low concentrations of uranium.

Multistage Decomposition Kinetics of Ozone In Dilute Aqueous Solutions

1987 ◽  
Vol 9 (2) ◽  
pp. 165-177 ◽  
Author(s):  
Eddie P. Minchew ◽  
Joseph P. Gould ◽  
F. Michael Saunders
Keyword(s):  
Aqueous Solutions ◽  
Decomposition Kinetics ◽  
Dilute Aqueous Solutions ◽  
Kinetics Of

Syntheses, single-crystal structure determination, and Raman spectra of Rb[C(CN)3] and Cs[C(CN)3]

2015 ◽  
Vol 70 (2) ◽  
pp. 151-154 ◽  
Author(s):  
Olaf Reckeweg ◽  
Armin Schulz ◽  
Francis J. DiSalvo
Keyword(s):  
Crystal Structure ◽  
Aqueous Solutions ◽  
Single Crystal ◽  
Single Crystals ◽  
Raman Spectra ◽  
Structure Determination ◽  
Crystal Structure Determination ◽  
Space Group ◽  
Cell Parameters ◽  
Ethanol Yields

AbstractExtracting residues of an aqueous solutions containing equimolar amounts of K[C(CN)3] and RbF or CsF, respectively, with absolute ethanol, yields triangular, transparent colorless crystals of Rb[C(CN)3] and Cs[C(CN)3] after the ethanol was allowed to evaporate. The compounds are isotypic and crystallize isopointal to calcite in space group R3̅c (no. 167) with the cell parameters a=809.9(1) and c=1461.3(3) pm and a=843.29(9) and c=1459.9(2) pm, respectively. Single crystals were used to record the Raman spectra of the title compounds.

scholarly journals Redetermination of the crystal structure of K2Hg(SCN)4

2017 ◽  
Vol 73 (7) ◽  
pp. 1073-1075
Author(s):  
Jascha Bandemehr ◽  
Matthias Conrad ◽  
Florian Kraus
Keyword(s):  
Crystal Structure ◽  
Aqueous Solutions ◽  
Single Crystal ◽  
Single Crystals ◽  
Rotation Axis ◽  
Potassium Thiocyanate ◽  
Structure Model ◽  
Distorted Tetrahedron ◽  
X Ray Diffraction ◽  
X Ray

Single crystals of K2Hg(SCN)4[dipotassium tetrathiocyanatomercurate(II)] were grown from aqueous solutions of potassium thiocyanate and mercury(II) thiocyanate and studied by single-crystal X-ray diffraction. In comparison with the previously reported structure model [Zvonkova (1952).Zh. Fiz. Khim.26, 1798–1803], all atoms in the crystal structure were located, with lattice parameters and fractional coordinates determined to a much higher precision. In the (crystal) structure, the HgIIatom is located on a twofold rotation axis and is coordinated in the form of a distorted tetrahedron by four S atoms of the thiocyanate anions. The K+cation shows a coordination number of eight.

scholarly journals Seeds of imperfection rule the mesocrystalline disorder in natural anhydrite single crystals

2021 ◽  
Vol 118 (48) ◽  
pp. e2111213118
Author(s):  
Tomasz M. Stawski ◽  
Glen J. Smales ◽  
Ernesto Scoppola ◽  
Diwaker Jha ◽  
Luiz F. G. Morales ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Single Crystal ◽  
Single Crystals ◽  
Calcium Sulfate ◽  
Nucleation Mechanism ◽  
Length Scales ◽  
Growth History ◽  
Self Similar ◽  
Sulfate Crystal ◽  
Shed Light

In recent years, we have come to appreciate the astounding intricacies associated with the formation of minerals from ions in aqueous solutions. In this context, a number of studies have revealed that the nucleation of calcium sulfate systems occurs nonclassically, involving the aggregation and reorganization of nanosized prenucleation species. In recent work, we have shown that this particle-mediated nucleation pathway is actually imprinted in the resultant micrometer-sized CaSO4 crystals. This property of CaSO4 minerals provides us with the unique opportunity to search for evidence of nonclassical nucleation pathways in geological environments. In particular, we focused on large anhydrite crystals extracted from the Naica Mine in Mexico. We were able to shed light on this mineral's growth history by mapping defects at different length scales. Based on this, we argue that the nanoscale misalignment of the structural subunits, observed in the initial calcium sulfate crystal seeds, propagates through different length scales both in morphological, as well as in strictly crystallographic aspects, eventually causing the formation of large mesostructured single crystals of anhydrite. Hence, the nonclassical nucleation mechanism introduces a “seed of imperfection,” which leads to a macroscopic “single” crystal whose fragments do not fit together at different length scales in a self-similar manner. Consequently, anisotropic voids of various sizes are formed with very well-defined walls/edges. However, at the same time, the material retains in part its single crystal nature.

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