Liquid-liquid extraction of divalent palladium by solutions of Diesel oil (D.O.) and gas oil II (G.O.II) in benzene and lacquer
petroleum from nitrate media has been studied. Palladium in concentrations of ∼10−3M is very effectively extracted by dilute solutions of extraction reagents and the distribution of palladium is almost independent
of the acidity and nitrate concentration of the aqueous phase. Of other common salts, chlorides, thioeyanates and nitrites
affect the palladium distribution. In many cases high concentrations of salts completely suppress the extraction of palladium.
The rate of palladium extraction by dilute solutions of extractants is relatively small. Some substances such as dimethyl
sulfoxide (DMSO) were found to accelerate the extraction. Palladium extraction from nitric acid media also has been studied
from the points of view of chemical and radiation stability. Diesel oil was found to be a more stable extraction reagent in
acid media than gas oil II.
Solvent extraction of175,181Hf(IV) into solutions of HBPHA** in CHCl3, tetrachloro ethane (C2H2Cl4), CCl4 and benzene from mixtures of water with DMSO or DMFA at 2M HClO4 formal acidity was studied. With diluents containing acidic hydrogen (CHCl3, C2H2Cl4) the presence of DMSO or DMFA in the extraction system leads to an increased extractability of the Hf(IV) chelate. Possible
reasons for this synergism are discussed. Extractions into benzene and CCl4, as well as those into CHCl3 and C2H2Cl4 at high DMSO and DMFA concentrations, are antagonistic. This is caused by the decrease of the partition coefficient of HBPHA,
and changes in the solvation of Hf(IV) ion in the polar phase. The latter effect is very strong at high DMSO concentrations,
and with macroconcentrations of Hf(IV) finally leads to precipitation of crystalline adducts Hf(ClO4)4·xDMSO (x=7–8).
Liquid—liquid extraction of divalent palladium by solutions of the hexachloroderivate of cobalt dicarbolide (HBCl6) in the mixture of solvents (30 v/v % nitrobenzene+20 v/v % n-dodecane +50 v/v/ % toluene) from nitric acid medium has been
studied. Besides HBCl6 the organic phase contained also 2,2′-dipyridyl (dipy). The yield of palladium extraction from 0.5M HNO3 is greater than 99.0%. The species extracted into the organic phase corresponds to the formula [Pd(dipy)2] (BCl6)2.
A new extraction reagent-dibutylester of N-/4-antipyryl/-amidophosphoric acid/DBAAP/—has been developed and used for the extraction of divalent mercury into chloroform from mixture of sodium iodide and perchloric acid. It was found that the composition of the species extracted into the organic phase depends on the acidity of the aqueous phase. The solvate HgI2. DBAAP is extracted at low HClO4 concentrations, an ion-pair, /DBAAPH/+.HgI
, is formed and extracted at high concentrations of perchloric acid.
Authors:E. Firatligil-Durmuş, A. Sýkorová, E. Šárka, Z. Bubník, M. Schejbal, and J. Příhoda
Digital image analysis was used to test the quality parameters of six varieties of
L. and one variety of
L. — projected area, equivalent diameter, MaxFeret and MinFeret (minimum or maximum perpendicular distance between parallel tangents touching opposite sides of the profile of the chosen object), perimeter, thickness and crease depth (both measured using a digital calliper) of a kernel ranging from 16.52–20.22 mm
, 4.58–5.07 mm, 16.70–20.82 mm, 6.21–7.29 mm, 3.32–3.78 mm, 2.69–3.12 mm, 0.23–0.42 mm. The size data were used for calculation of volumes and surface areas of wheat kernels modelled as a general ellipsoid. The calculation of surface area using finite element method (FEM) was based on computer software MAPLE 9.0 and the results were compared with a simplified method. The volumes of kernels from the ellipsoid model were corrected with consideration of measured average crease depth; the difference was then max. 3.6%.We tested the correlation of volume and surface areas obtained from the ellipsoidal model with the measured projected areas; the resulting high correlation coefficient for the varieties of
enables the use of only 2D image analysis measurement, for quick estimation of surface and volume parameters, without time consuming thickness measuring. However, the shape of
kernels was a little different and the designed geometrical model was thus not suitable.We recommend image analysis as a simple and rapid method for obtaining the parameters of wheat grain for engineering purposes.