Thermodynamics and kinetics of atmospheric aerosol particle formation and growth

In this tutorial review we summarize the standard approaches to describe aerosol formation from atmospheric vapours and subsequent growth - with a particular emphasis on the interplay between equilibrium thermodynamics and non-equilibrium transport. We review the use of thermodynamics in describing phase equilibria and formation of aerosol particles from supersaturated vapour via nucleation. We also discuss the kinetics of cluster formation and transport phenomena, which are used to describe dynamic mass transport between the gaseous and condensed phases in a non-equilibrium system. Finally, we put these theories into the context of atmospheric observations of aerosol formation and growth.     

Local derivations of subrings of matrix rings

We show that on finite incidence algebras every local derivation is a derivation.     

Struktur und magnetische Eigenschaften der Verbindungen PrLiGe,TbLiGe, DyLiGe,YbLiGe und YbLiBi

Structure and Magnetic Properties of PrLiGe, TbLiGe, DyLiGe, YbLiGe, and YbLiBi The compounds PrLiGe, TbLiGe, DyLiGe, YbLiGe, and YbLiBi were prepared and investigated by X-ray methods and magnetic measurements. Powder patterns show that PrLiGe, TbLiGe, DyLiGe, and YbLiGe crystallize isotypically. Single crystal investigations of PrLiGe and YbLiGe gave as a result a modified Fe₂P-type structure. YbLiBi seems to crystallize isotypically to the structure of YLiSn which can be described as a “filled” Wurtzit lattice [1, 2]. Measurements of the magnetic susceptibilities point to electrovalent composition with Pr³⁺ and Yb³⁺ in PrLiGe and YbLiGe and Yb²⁺ in YbLiBi, respectively.     

Determination of the drug content of pharmaceuticals containing phenothiazine compounds by triangle programmed flow titration

Summary A flow-through triangle programmed coulometric titration technique is worked out for the determination of phenothiazine compounds. The oxidation reaction of phenothiazines with hypobromite ion served as titration reaction. A biamperometric detector cell has been used for following the titration process. The titration technique has been used for the determination of the drug content (average and individual) of chlorpromazine, promethazine, diethazine and trifluoperazine in pharmaceutical preparations. The relative standard deviation was in the range of 2.0 to 3.5%.

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Bestimmung des Wirkstoffgehaltes von Phenothiazin-haltigen Pharmazeutica mit Hilfe einer Dreieck-programmierten Durchflu\-Titration

     

Emission Mössbauer study of the interface between a cobalt substrate and a polyimide coating

The emission Mössbauer technique is used to study the chemical structure of the interphase formed between a cobalt substrate and a polyimide coating. The results are interpreted to indicate that the coating is bonded to the cobalt substrate by means of carboxylate bonds with Co²⁺ ions in the oxide film at the interface.     

Preliminary study to prepare a reference material of toluene metabolite – o-cresol and benzene metabolite-phenol – in human urine

The candidate reference material (RM) was prepared by freeze-drying pooled urine samples obtained from healthy persons occupationally exposed to toluene. Homogeneity testing yielded no significant differences of urinary concentrations of o-cresol and phenol in 15 randomly selected units of RM. Stability testing showed no significant changes of concentrations of the above analytes over a period of 6 months. Property (pre-certified) values of phenol and o-cresol concentrations and their uncertainties (9.06±0.47 mg l⁻¹ and 1.03±0.06 mg l⁻¹, respectively) were estimated from results of a small-scale interlaboratory comparison in which two laboratories participated using four different analytical methods.     

New type of bonding formed from an overlap between pi aromatic and pi C=O molecular orbitals stabilizes the coexistence in one molecule of the ionic and neutral meso-ionic forms of imidazopyridine

New bis(imidazo)pyridine dye has been synthesized and tested as a potential photoinitaitor for free-radical polymerization induced with the visible emission of an argon ion laser. The X-ray analysis based on data collected at 170 and 130 K, as well as density functional theory (DFT) calculations, revealed the presence of two different forms of imidazopyridine rings within the same molecule. These two forms of the same moiety had not only different geometries but different electronic structures as well. One of the imidazopyridine rings was in the ionic form, while the other was in the meso-ionic form. DFT calculations provided an explanation for such an observed phenomena. The averaging of ionic and meso-ionic forms of imidazopyridine rings within the same molecule is hindered because of an attractive interaction between them. Analysis of electronic density revealed that, indeed, a new type of bonding is formed as the result of an overlap between pi aromatic and pi C=O molecular orbitals. This bonding, like the hydrogen bond, is primarily of electrostatic character, and its energy was estimated at 3.5 kcal/mol.     

Creatinine determination in urine from the point of view of reference values

In this paper, the creation of a certified reference material for urinary creatinine is described. We used the Jaffe method and HPLC method for establishment of the certified value. Homogeneity tests are also described. We obtained material with sufficient homogeneity, stability, and with certified value (expanded uncertainty, k=2 for CI 95%) (7.77±0.27) mmol·L⁻¹. This material was consequently used for the interlaboratory comparison (EQA Czech Republic for clinical chemistry). Twenty-nine percent of the participants obtained measurement results within the interval of the certified value ± expanded uncertainty, while 85% of the participants obtained values inside the interval of the certified value ± target measurement uncertainty. Direct use of the certified reference materials for method evaluation in EQA programs means a significant advance for monitoring and documentation traceability of results in routine measurements.