18 research outputs found

    International security experience in tourism

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    The article dwells upon the international experience of the provision of safety in tourism. The problem of safe tourist activities is complex and many – sided, as for tourism to develop and function the safety of travelers, holidaymakers and their personal property is extremely important

    Palladium (II) Oxide Nanostructures as Promising Materials for Gas Sensors

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    One of the most important environment monitoring problems is the detection of oxidizing gases in the ambient air. Negative impact of noxious oxidizing gases (ozone and nitrogen oxides) on human health, sensitive vegetation, and ecosystems is very serious. For this reason, palladium (II) oxide nanostructures have been employed for oxidizing gas detection. Thin and ultrathin films of palladium (II) oxide were prepared by thermal oxidation at dry oxygen of previously formed pure palladium layers on polished poly-Al2O3, SiO2/Si (100), optical quality quartz, and amorphous carbon/KCl substrates. At ozone and nitrogen dioxide detection, PdO films prepared by oxidation at T = 870 K have demonstrated good values of sensitivity, signal stability, operation speed, and reproducibility of sensor response. In comparison with other materials, palladium (II) oxide thin and ultrathin films have some advantages at gas sensor fabrication. Firstly, for oxidizing gas detection, PdO films with p-type conductivity are more perspective than the material with n-type conductivity. Secondly, at ambient conditions, palladium (II) oxide is insoluble in water and does not react with it. These facts are favorable for the fabrication of gas detectors because they make possible to minimize the air humidity influence on PdO sensor response values. Thirdly, the synthesis procedure of PdO films is rather simple and is compatible with planar processes of microelectronic industry

    Revised Analysis of Fe vii

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    New spectrograms of multiply ionized iron have been recorded and analyzed, targeting the Fe vii spectrum. As a result, several previously unknown spectral lines and energy levels have been identified in this spectrum. These new data have been analyzed together with all previously published laboratory and astrophysical data on this spectrum. The energy levels have been interpreted using parametric calculations with Cowan codes. Radiative transition rates calculated in this work supplemented other previously published calculations in constructing a complete set of recommended transition probabilities. The ionization energy of Fe vii has been redetermined with a fivefold improvement in accuracy. Its new value is 1,007,928(20) cm−1, corresponding to 124.9671(25) eV

    The Spectrum and Energy Levels of the Low-lying Configurations of Nd III

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    Emission spectra of neodymium (Nd, Z=60) were recorded using Penning and hollow cathode discharge lamps in the region 11500-54000 cm1^{-1} (8695-1852 \r{A}) by Fourier transform spectroscopy at resolving powers up to 106. Wavenumber measurements were accurate to a few 103^{-3} cm1^{-1}. Grating spectroscopy of Nd vacuum sliding sparks and stellar spectra were used to aid line and energy level identification. The classification of 433 transitions of doubly-ionised neodymium (Nd III) from the Penning lamp spectra resulted in the determination of 144 energy levels of the 4f4^4, 4f3^35d, 4f3^36s, and 4f3^36p configurations of Nd III, 105 of which were experimentally established for the first time. Of the 40 previously published Nd III levels, 1 was revised and 39 were confirmed. New Nd III atomic structure calculations were made using the Cowan code parameterised by newly established levels. These results will not only benchmark and improve future semi-empirical atomic structure calculations of Nd III, but also enable more reliable astrophysical applications of Nd III, such as abundance analyses of kilonovae and chemically peculiar stars, and studies of pulsational wave propagation in these stars

    Additions to the Spectrum of Fe ix in the 110–200 Å Region

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    The spectrum of eight-times ionized iron, Fe ix, was studied in the 110–200 Å region. A low inductance vacuum spark and a 3 m grazing incidence spectrograph were used for the excitation and recording of the spectrum. Previous analyses of Fe ix have been greatly extended and partly revised. The number of known lines in the 3p 53d–3p 54f and 3p 53d–3p 43d 2 transition arrays is extended to 25 and 81, respectively. Most of the identifications of the Fe ix lines from the 3p 53d–3p 43d 2 transition array in the solar spectrum have been confirmed and several new identifications are suggested

    Resonance Transitions in the Spectra of the Ag6+–Ag8+ Ions

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    The spectrum of silver, excited in a vacuum spark, was recorded in the region 150–350 Å on a 3-m grazing incidence spectrograph. The resonance 4dk–(4dk−15p + 4dk−14f + 4p54dk+1) was studied in the Ag6+–Ag8+ spectra (Ag VII–Ag IX) with k = 5–3, respectively. Several hundred lines were identified with the aid of the Cowan code and orthogonal operator technique calculations. The energy levels were found and the transition probabilities were calculated

    Resonance Transitions in the Spectra of the Ag6+–Ag8+ Ions

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    The spectrum of silver, excited in a vacuum spark, was recorded in the region 150–350 Å on a 3-m grazing incidence spectrograph. The resonance 4dk–(4dk−15p + 4dk−14f + 4p54dk+1) was studied in the Ag6+–Ag8+ spectra (Ag VII–Ag IX) with k = 5–3, respectively. Several hundred lines were identified with the aid of the Cowan code and orthogonal operator technique calculations. The energy levels were found and the transition probabilities were calculated

    Spectrum of Sn5+ in the Region 500–1300 Å

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    The spectrum of tin, excited in a vacuum spark, was recorded in the region 500–1131 Å on a 6.65-m normal incidence spectrograph. The transitions between 4d85s, 4d86s, 4d85p and 4d85d excited configurations in Sn VI were studied. More than 500 lines of the 4d85p–4d85d and 4d85p–4d86s were identified with the aid of the Cowan code calculations. 67 energy levels (out of 70 possible levels of the 4d85d configuration) and all but two 4d86s levels were found. The wavelength of the 4d85s–4d85p transitions in the region 839–1131 Å were re-measured and supplemented by Sn VI lines in the region 1131–1300 Å measured previously by Srivastava et al. (1977) for optimisation of the energy level values. The SnVI line list in the region 500–1300 Å contains now 741 lines with calculated transition probabilities

    «Dead Men Attack» (Osovets, 1915): Archive Sources Approach

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    The article, basing on archive materials, attempts to examine one of the chapters of World War I history, namely, so-called “dead men attack” during Osovets Tower (westward of Bialystok, within the territory of modern Poland) defense by Russian troops in 1915, reconstructs the battle, specifies attack, rather counterattack conditions, introduces new archive sources for scientific use

    Analysis of the Spectra of Pd-Like Praseodymium and Neodymium (Pr XIV and Nd XV)

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    International audienceThe spectra of palladium-like Pr13+ and Nd14+ ions excited in a laser-produced plasma source have been investigated in the 70 700 Å region. Almost all the energy levels of the 4d95s, 4d95p, 4d94f, 4d95d and 4d95f configurations in Pr XIV and Nd XV as well as the energies of the 4d96s levels in Pr XIV have been determined experimentally. One hundred seven spectral lines belonging to the 5s-5p, 5p-5d, 5d-5f, 4f-5d and 5p-6s transitions in Pr XIV and eighty five lines belonging to the 5s-5p, 5p-5d, 5d-5f and 4f-5d transitions in Nd XV have been classified for the first time. The present analysis is based on an accurate extrapolation of energy parameters in the Pd I isoelectronic sequence. The experimental level energies are described by Generalized Least Squares isoelectronic studies of 4d95l configurations
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