Emulsion stability and potassium leakage in emulsion liquid membrane systems

Potassium leakage was studied in liquid membrane systems containing various emulsifiers and compared with emulsion, stability in the storage test. The effects of various parameters upon emulsion stability and the leakage of standard traces are discussed. The transfer of cations can be caused by emulsion breaking, by transport with the specific carrier and/or with surfactants used as emulsifiers. The latter case becomes especially important when hydrophilic surfactants, e.g. ones containing polyoxyethylene chains, are present in liquid membranes. In systems containing hydrophobic emulsifiers the transfer of potassium is relatively low. In each case considered the effect of emulsifiers upon the transfer of the standard tracer should be checked prior to using the leakage test to characterize emulsion stability.     

DTA determination of the anhydrite content in rock salts

The DTA method was used to determine the phase diagram of the NaCl-CaSO₄ system over the range 0.55 wt.% of CaSO₄ in air atmosphere. The effects of SiO₂, CaCO₃ and Fe₂O₃ on the melting temperatures of pure NaCl and the eutectic were determined. On the basis of the above temperatures, a method of quantitative determination of the anhydrite content in rock salts has been developed.

---

Zusammenfassung DTA wurde benutzt, um in Luft im Bereich 0 bis 55,0 Gew.% CaSO₄ das Phasendiagramm des Systemes NaCl-CaSO₄ zu bestimmen. Es wurde auch der Einfluß von SiO₂, CaCO₃ und Fe₂O₃ auf die Schmelztemperatur von reinem NaCl bzw. des Eutektikums bestimmt. Auf der Grundlage obiger Temperaturen wurde eine Methode zur quantitativen Bestimmung des Anhydritgehaltes in Steinsalzen entwickelt.

---

- 0–55,0 . , . , ( ) .

     

Differentiable circle maps with a flat interval

We study weakly order preserving circle maps with a flat interval, which are differentiable even on the boundary of the flat interval. We obtain estimates on the Lebesgue measure and the Hausdorff dimension of the non-wandering set. Also, a sharp transition is found from degenerate geometry to bounded geometry, depending on the degree of the singularities at the boundary of the flat interval.Partially supported by KBN grant Iteracje i Fraktale #210909101.     

Gauge group,degeneration, and degrees of freedom in the ECSK theory of gravity. II. The Moncrief decomposition

It is shown that in the ECSK theory (coupled to an arbitrary tensor matter field) the degeneration distribution of the symplectic 2-form is closely connected with the action of the gauge groupG in the space of solutions to the field equations.     

Studies of physico-chemical properties of mixed adsorbent in the zeolite/SiO2 system

The paper presents physico-chemical properties of mixed adsorbents in the clinoptylolite (mordenite)/SiO₂ system containing 30, 50, 80 mass% zeolite. Adsorption capacity towards polar (water, butanol) and non-polar (n-octane) substances as well as total surface heterogeneity (energetic and geometrical) were determined. Desorption energy distribution functions as well as fractal dimensions were also determined and compared with the low-temperature nitrogen adsorption data. Irregular shapes of the curves q=f(E _d) as well as large values of volumetric fractal dimensions (D _f~2.6) revealed heterogeneous properties of the zeolite/SiO2 system surfaces. Addition of zeolite increases total heterogeneity of the material.     

Mutual Solubilities of Water and Alkanes

Summary.  The evaluation of mutual solubility data for systems water with n-alkanes, isoalkanes, and cycloalkanes along the three phase line is reported and a formula for the prediction of solubility of alkanes in water is developed. Then a cubic equation of state with an added term, which accounts for hydrogen bonding is used for correlation of liquid–liquid equilibrium data and for prediction of solubility of water in hydrocarbons using alkane in water solubility data. Comparison of the predicted and experimental solubilities is performed using all accessible experimental data. With this approach it is possible to predict the solubilities of water in alkanes with good accuracy over the temperature range up to about 20 K below critical temperature. Solubility of alkanes in water can also be calculated using experimental data for solubility of water in alkanes but results of these calculations are more sensitive to experimental errors of the data. Corresponding author: E-mail: macz@ichf.edu.pl Received August 5, 2002; accepted (revised) September 13, 2002 Published online March 13, 2003 RID="a" ID="a" Dedicated to Prof. Dr. H. Gamsj?ger on the occasion of his 70^th birthday anniversary     

A Stopped-flow Study on the Kinetics and Mechanism of CO2 Uptake by the cis-[Cr(1,10-phenanthroline)2(OH2)2]3+ Complex Ion

The kinetics of the reaction between gaseous CO₂ and the cis-[Cr(phen)₂(OH₂)₂]³⁺ ion leading to the formation of the carbonato complex ion, have been studied over the pH and temperature ranges: 3 < pH < 6 and 5 < T < 25 °C, respectively, at a constant ionic strength of 1 m (NaClO₄). Investigations were carried out using the stopped-flow spectrophotometry technique in the UV–Vis range: 340–700 nm. The major reactant species in the pH range studied was cis-[Cr(phen)₂(OH)(OH₂)]²⁺ ion, which underwent reaction with CO₂ to form cis-[Cr(phen)₂(OH₂)(HCO₃)]²⁺ ion. Subsequently, slower ring closure of the latter species to form the bidentate carbonato chelate was observed. The possible mechanism has been discussed and the activation parameters ΔH^† and ΔS^† were also determined for the reaction studied.     

Determination of total heterogeneity and fractal dimensions of high-temperature superconductors

Using thermo-analytical and sorptometric methods physicochemical properties and especially surface heterogeneity of HgBa₂Ca₂Cu₃O₈₊, (Hg-1223) was investigated. The desorption energy distribution was derived from mass loss Q-TG and differential mass loss Q-DTG curves of thermodesorption in quasi-isothermal conditions of pre-adsorbed n-octane and water vapour. It is shown that the superconducting Hg-1223 phase is highly sensitive to water vapours. The mechanism of water adsorption depends largely on the activation time. By water vapour saturation in a period of 90 min, physisorption takes place. Prolonged periods result in a chemical decomposition. From nitrogen ad- and desorption isotherms the fractal dimension of superconductors were calculated. A new approach is proposed to calculate fractal dimension from Q-TG curves.This revised version was published online in November 2005 with corrections to the Cover Date.     

Triplet losses in dye lasers

The expression for losses due to triplet states in dye laser considered as a six-level system is given. It is shown that triplet losses depend on pumping parameters and photon number. Depending on molecular and cavity parameters two different behaviours of dye lasers are expected. Physical conditions are discussed in which triplet losses as well as photon number undergo a jump at the threshold.     

Homo- and hetero-nuclear chromium(III) complexes with natural ligands. Part 2. Oxo- and hydroxo-bridged chromium(III)/vanadium(V) species

Six new heteropolynuclear chromium(III)/vanadium(V) complexes with natural ligands: glycine, glutaminic, nicotinic and asparginic acids, have been isolated and physicochemically characterised. The complexes have been analysed using spectroscopic (diffuse reflectance u.v.–vis., i.r.), magnetic methods and by FAB mass spectra. Spectral analyses with the digital filter and band deconvolution methods are presented. Additionally, preliminary toxicity studies have been performed.