Kolmogorov's Contributions to the Foundations of Probability

Andrei Nikolaevich Kolmogorov was the foremost contributor to the mathematical and philosophical foundations of probability in the twentieth century, and his thinking on the topic is still potent today. In this article we first review the three stages of Kolmogorov's work on the foundations of probability: (1) his formulation of measure-theoretic probability, 1933; (2) his frequentist theory of probability, 1963; and (3) his algorithmic theory of randomness, 1965–1987. We also discuss another approach to the foundations of probability, based on martingales, which Kolmogorov did not consider.     

Uranium(III) in aqueous solutions: Preparation,properties, synthesis of solid compounds

Published data on the preparation procedures, stability, and complexation of U(III) in aqueous solutions are summarized and correlated. Reactions with inorganic and organic free radicals studied by the flash radiolysis method, the spectroscopic properties, the extraction and ion-exchange behavior of U(III), and methods for isolation of solid U(III) compounds from aqueous solutions are discussed.     

Femtochemistry of Guest Molecules Hosted in Colloidal Zeolites

The ultrafast deprotonation of 2‐(2′‐hydroxyphenyl)benzothiazole (HBT) hosted in nanometer‐sized FAU and MFI zeolites is reported. Samples are prepared via in‐situ incorporation of HBT in the precursor colloidal solutions resulting in the formation of nanometer‐sized zeolites under hydrothermal treatment. The diameter of the zeolite particles formed in the crystalline suspensions is determined by dynamic light scattering and high‐resolution transmission microscopy to lie in the range 40–100 nm. It is shown that the HBT loading does not influence the degree of the zeolite crystallinity but does change the size and the morphology of the individual zeolite nanoparticles. Colloidal suspensions containing the crystalline nanoparticles are well suited for optical investigations since they are sufficiently transparent and clear. The photochemical properties of the HBT guest in the zeolite‐host systems are studied with femtosecond transient transmission spectroscopy. Depending on the acid–base properties either the enol or the keto tautomer of HBT is found to be hosted in the internal voids of the zeolites; upon UV excitation, the HBT‐keto tautomer is converted to the enol form in both MFI‐ and FAU‐type hosts. The HBT photoconversion takes place via an ultrafast deprotonation within 1.5 ps as detected by femtosecond transient absorption spectroscopy.     

Catalytic reduction of N2O with CH4 and C3H6 over Ag–Rh/Al2O3 bimetallic catalyst in the presence of oxygen

A study of nitrous oxide (N₂O) reduction with methane (CH₄) and propene (C₃H₆) in the presence of oxygen (5%) over Ag/Al₂O₃, Rh/Al₂O₃ and Ag–Rh/Al₂O₃ catalysts, with Ag and Rh loadings of 5 wt% and 0.05 wt% respectively, has been performed. From the results, it was observed that the Ag–Rh bimetallic catalyst was the most active for both nitrous oxide removal (more than 95%) and hydrocarbon oxidation. This high activity seems to be connected with a synergistic effect between Ag and Rh. The findings from X‐ray diffraction and X‐ray photoelectron spectroscopy studies showed also, that there were no strong interactions (eg alloying) between Ag and Rh. Copyright © 2005 Society of Chemical Industry     

Effect of Nontraditional Additives on the Processes of Silicate and Glass Formation

The results of studying the effect of nontraditional additives, namely, metallic aluminum and zinc powders on the process of silicate and glass formation using polythermal and thermogravimetric analysis, are described. The specifics of the glass-melting process for decorative glasses using the nontraditional additives are considered. __________ Translated from Steklo i Keramika, No. 5, pp. 7 – 10, May, 2005.     

Interferometric method for preventing mode-hopping in tunable external-cavity semiconductor lasers

A problem in frequency-tuning of external-cavity lasers is mode-hopping between neighbouring external-cavity modes. We demonstrate a new interferometric method for monitoring mode-hoping and an automatic control circuit for a 1.3 ?m grating external-cavity laser that maintains single-mode operation when the lasing frequency is tuned.     

Metric-based reasoning about pseudocode design in the partial metrics system

The goal of the PMS project is to produce an environment in which the intelligent online assessment of the design for large-scale ADA programming projects is provided. The focus is on the representation of knowledge about the design process for an individual module. Changes in pseudocode complexity are measured in terms of partial metrics. These metrics can take the designers inferences about the pseudocode program structure into account when assessing module complexity. Next, a model of the stepwise refinement process is given which demonstrates how pseudocode elaboration decisions can be modelled in partial metric terms. Finally, the decisions associated with each refinement step for 17 example refinements taken from the computer science literature are described using partial metrics.