Investigating the characteristics of the commercial gas tube ‘S10 Starter’ using a time-delay measuring method

The results of the commercial gas discharge tube investigation (starter ‘S10 Philips’), using the time-delay measuring method, are presented in this paper. This gas discharge tube is usually used as a starter, that is, for electrode heating regularization in fluorescent tubes. The measurements of time delay are performed for different voltages (from 210 V to 400 V) and different relaxation times (from 1 ms to 3 s). The obtained memory curves show that the used gas discharge tube has a very small memory effect, which indicates a fast response after a long (out-of-use) time. This characteristic of the used commercial gas discharge tube is a consequence of gas tube geometry. It also shows that the time-delay distributions for small relaxation time values have a Gaussian shape; with the increase in relaxation time the right tail of distributions increases and distributions lose symmetry and become exponential.     

Order-from-disorder effect in the exactly solved mixed spin-(1/2, 1) Ising model on fully frustrated triangles-in-triangles lattices

The mixed spin-(1/2, 1) Ising model on two fully frustrated triangles-in-triangles lattices is exactly solved with the help of the generalized star-triangle transformation, which establishes a rigorous mapping correspondence with the equivalent spin- 1/2 Ising model on a triangular lattice. It is shown that the mutual interplay between the spin frustration and single-ion anisotropy gives rise to various spontaneously ordered and disordered ground states, which differ mainly in an occurrence probability of the non-magnetic spin state of the integer-valued decorating spins. We have convincingly evidenced a possible coexistence of the spontaneous long-range order with a partial disorder within the striking ordered–disordered ground state, which manifests itself through a non-trivial criticality at finite temperatures as well. A rather rich critical behavior including the order-from-disorder effect and reentrant phase transitions with either two or three successive critical points is also found.     

Determination of Chemical Composition of Commercial Rose Bengal Preparations by Chemical and Biological Methods

The method of the fraction separation in commercial rose bengal has been described. Individual fractions were identified on the basis of the absorption maxima obtained on a spectrophotometer. Iodine labelled rose bengal was used for biological investigation in the experimental animals. It was found that rose bengal produced by Durand contains a high percentage of the main component of tetraiodotetrachlor-fluoresceine (absorption maxima at 548 nm) and is therefore most suitable for the labelling process.     

Ruthenium-tin sol-gel catalysts: effect of the preparation and tin precursor influence

The influence of the synthesis route and the chemical nature of tin precursors on the catalytic properties of supported sol-gel Ru-Sn/SiO₂ catalysts were studied. It was demonstrated that introduction of tin afforded better selectivities than a monometallic sol-gel catalyst in the liquid-phase hydrogenation of cinnamaldehyde; however, the chemical nature of the tin precursor did not influence the catalyst performance. Sol-gel catalyst properties depended significantly upon the preparation method used and on the activation temperature. The selectivity to unsaturated alcohol increased with conversion, which is indicative of the in-situ creation of active sites selective in the carbonyl bond hydrogenation.     

The synthetic fragrant compounds based on 2-tert-butylcyclohexanol

The reaction of 2-tert-butylcyclohexanol with dimethyl carbonate resulting in 2-tert-butylcyclohexylmethyl carbonate (1a) and di-(2-tert-butylcyclohexyl) carbonate (1b) was studied. A second part investigates the reactions of 2-tert-butylcyclohexanone (obtained by dehydrogenation of 2-tert-butylcyclohexanol) with diols resulting in the corresponding ketals. The sensoric and fragrant characteristics of the synthesized compounds were also described.     

Base-Modified DNA Labeled by [Ru(bpy)3]2+ and [Os(bpy)3]2+ Complexes: Construction by Polymerase Incorporation of Modified Nucleoside Triphosphates,Electrochemical and Luminescent Properties,and Applications

Modified 2′-deoxynucleoside triphosphates (dNTPs) bearing [Ru(bpy)₃]²⁺ and [Os(bpy)₃]²⁺ complexes attached via an acetylene linker to the 5-position of pyrimidines (C and U) or to the 7-position of 7-deazapurines (7-deaza-A and 7-deaza-G) have been prepared in one step by aqueous cross-couplings of halogenated dNTPs with the corresponding terminal acetylenes. Polymerase incorporation by primer extension using Vent (exo-) or Pwo polymerases gave DNA labeled in specific positions with Ru²⁺ or Os²⁺ complexes. Square-wave voltammetry could be efficiently used to detect these labeled nucleic acids by reversible oxidations of Ru^2+/3+ or Os^2+/3+. The redox potentials of the Ru²⁺ complexes (1.1–1.25 V) are very close to that of G oxidation (1.1 V), while the potentials of Os²⁺ complexes (0.75 V) are sufficiently different to enable their independent detection. On the other hand, Ru²⁺-labeled DNA can be independently analyzed by luminescence. In combination with previously reported dNTPs bearing ferrocene, aminophenyl, and nitrophenyl tags, the Os-labeled dATP has been successfully used for “multicolor” redox labeling of DNA and for DNA minisequencing.     

Experimental simulation of possible radiation-corrosive processes in container with spent nuclear fuel after groundwater ingress

Radiation corrosion in deaerated water/carbon steel systems has been studied. Kinetics of releasing corrosion products into the water and their sorption on the surface of steel tablets is affected by various factors (redox potential, absorbed dose, temperature, irradiation duration). Concentration of corrosion products in the solution was evaluated using various chemical methods. Total concentration of Fe²⁺/Fe³⁺ ions in liquid phase was determined by UV/VIS spectrometry. Solid phase was analysed using X-ray diffraction method. Corrosion processes were studied in deaerated distilled water and synthetic granitic water. Corrosion cells consisted of glass ampoules with inserted steel tablets, completely filled with deoxygenated water. Corrosion cells were carefully enclosed so that air diffusion into system during experiment was kept at minimum. ⁶⁰Co gamma sources with various dose rates were used for irradiation. The obtained results indicated that radiation noticeably contributed to the formation of corrosion products. Kinetics of radiation corrosion was strongly dependent on the parameters under study. The obtained experimental data should be taken into consideration when predicting effects of corrosion on containers with spent nuclear fuel using mathematical models.     

Violation of the 2nd law of thermodynamics in the quantum microworld

For one open quantum system recently reported to work as a perpetuum mobile of the second kind, basic equations providing basis for discussion of physics beyond the system activity are rederived in an appreciably simpler manner. The equations become exact in one specific scaling limit corresponding to the physical regime where internal processes (relaxations) in the system are commensurable or even slower than relaxation processes induced by bath. In the high-temperature (i.e. classical) limit, the system ceases to work, i.e., validity of the second law is reestablished.     

Local Theorems for the Markov Binomial Distribution

Considering the Markov binomial distribution, we study the accuracy of infinitely divisible approximations. A local version of the Kolmogorov first uniform theorem is obtained. Possible approximations in total variation are discussed.