A thermodynamic interpretation of the behavior of higher fatty alcohols and acids upon the chromatographic paper

An idea was presented of treating the chromatographed substance as a “solute,” and the chromatographic system, composed of the stationary and the mobile phase as a “solvent.” Moreover the concept of “local equilibrium” was introduced, allowing to regard a given chromatographic spot as a “binary solution.” Thus a possibility arose to apply the classical thermodynamic approach, normally used for binary solutions, and namely: μ_i = μ_i + RT ln x_iƒ_i, where μ_i—chemical potential of the “i”-th compound in the solution, μ_i—chemical potential of the pure “i”-th compound, x_i-molar fraction of the “i”-th compound, ƒ_i—its activity coefficient, in a modified form, suitable for the chromatographic purpose.     

Molecular dynamics study of early events during photooxidation of eye lens protein γB-crystallin

Molecular dynamics modeling on 200 ps time scale was used to study bovine eye lens protein γB-crystallin (GCS) and two possible products of its photooxidation. The mutations were done at positions of tryptophan (Trp) residues which were changed into N-formylkynurenine (NFK) in position 42 (1NFK) or in positions 42, 68, 131 and 157 (4NFK). Quantum chemical calculations using the DFT, HF and AM1 methods were performed for both Trp and NFK. The stronger hydrophilic character of NFK results in structural rearrangements in the regions related to disulfide bridges formation. The protein mutations studied may have impact on the cataract formation.     

<Superscript>103</Superscript>Ru/<Superscript>103m</Superscript>Rh generator

^103mRh is a very promising radionuclide for Auger electron therapy due to its very low photon/electron ratio. The goal of the present work was the elaboration a method for production of large quantities of ^103mRh for generator system. It was found that the combination of solvent extraction with evaporation of ¹⁰³RuO₄ followed by decomposition of H₅IO₆ makes it possible to produce ^103mRh of high radionuclidic and chemical purity.     

Laser Spectroscopy and \beta-NMR Measurements of Short-Lived Mg Isotopes

The feasibility of studying the neutron-rich ²⁹Mg, ³¹Mg, and ³³Mg isotopes has been demonstrated with the laser and β-NMR spectroscopy setup at ISOLDE/CERN. The values of the magnetic moment and the nuclear spin of ³¹Mg are reported and reveal an intruder ground state. This proves the weakening of N = 20 shell gap and places this nucleus inside the so-called ‘island of inversion.’ The experimental setup and technique, as well as the results, are presented.     

Ferrocene Derivative in 1,3 Dipolar Cycloaddition Reaction to Fullerene C60

Journal of Thermal Analysis and Calorimetry - Properties of FeC60 solid samples were investigated by X-ray diffraction, 57Fe Mössbauer spectroscopy and magnetic measurements in order to...     

An ion cooler-buncher for high-sensitivity collinear laser spectroscopy at ISOLDE

A gas-filled segmented linear Paul trap has been installed at the focal plane of the high-resolution separator (HRS) at CERN-ISOLDE. As well as providing beams with a reduced transverse emittance, this device is also able to accumulate the ions and release the sample in bunches with a well-defined time structure. This has recently permitted collinear laser spectroscopy with stable and radioactive bunched beams to be demonstrated at ISOLDE. Surface-ionized ^{39, 44, 46}K and ⁸⁵Rb beams were accelerated to 30keV, mass separated and injected into the trap for subsequent extraction and delivery to the laser setup. The ions were neutralized in a charge exchange cell and excited with a co-propagating laser. The small ion beam emittance allowed focussing in the ion-laser overlap region, which is essential to achieve the best experimental sensitivity. Fluorescent photons were detected by a photomultiplier tube as a frequency scan was taken. A gate (typically 7-12μs wide) was set on the photomultiplier signal to accept the fluorescent photons within the time window defined by the bunch. Thus, using accumulation times of 100ms, the dominant contribution to background due to continuous laser scattering could be reduced by a factor of up to 4×10⁴ .     

Characteristics of the oxidation process in the oleyl alcohol-oleic acid,oleyl alcohol-methyl oleate,and oleic acid-methyl oleate systems by means of dielectric constant measurements

The investigation of the autoxidation process in the three model systems: oleyl alcohol-oleic acid, oleyl alcohol-methyl oleate, and oleic acid-methyl oleate by means of peroxide number and dielectric constant measurements were presented. The experiments were conducted at 60 °C, in the conditions of relatively lower amount of different kinds of hydrogen-bond polyassociates. One can state that in the case of the systems including oleyl alcohol it is possible to forecast the course of their autoxidation owing to the dielectric measurements.     

Thermal modification of ferrocene derivative adducts to c60for SMT observations

Molecules that may adopt various stable conformations might be applied to store information. The conformational changes could be induced by suitable polarized tip of STM. For the STM experiments two types of fullerene:ferrocene cycloadducts (C₆₀:Fn) were selected where ferrocene fragment is bound to C₆₀ at the 6-6 bond by different heterocyclic pentagon rings. According to semiempirical quantum chemistry calculation one of them may be used to STM observation without any modification, while the second cycloadduct must be exposed to thermal treatment in order to obtain bistable molecule. This revised version was published online in July 2006 with corrections to the Cover Date.     

Mechanism of the hydroperoxide destruction in the oxidized methyl oleate,oleyl alcohol,and oleic acid

The differentiated mechanism of destruction of hydroperoxides derived from methyl oleate, oleyl alcohol and oleic acid was explained with the influence of the hydrogen-bond interactions. The evidence for the proposed models was given through the quantitative yields of the five classes of the secondary products of autoxidation: monohydroxy-, dihydroxy-, keto-, ketohydroxyderivatives and monofunctional products of degradation of the oxidized molecules.