Corrosion stability of molybdenum and tungsten coatings in lead-bismuth eutectic

The paper presents results of corrosion tests of tungsten- and molybdenum-based protective coatings, deposited on nickel-molybdenum alloys (hastelloy) in heavy metal melts (Pb, Bi, Pb–Bi eutectic). Results of an investigation of hastelloy samples without protective coating are given for comparison. The investigations were carried out under static conditions at 550 °C. The mechanical properties of the samples under investigation have been shown that the corrosion stability of the uncoated alloys studied decreases in the order: lead – lead-bismuth eutectic – bismuth. The use of protective tungsten and molybdenum coatings ensures corrosion stability of hastalloy with retention of its mechanical properties.Наведено результати дослідження корозійної стійкості нікель-молібденових сплавів (хастелой) в розплавах важких металів (Pb, Bi, Pb-Bi). Корозію вивчено в статичних умовах при температурі 550 °С. Встановлено, що в ряді розплавів свинець – свинець-вісмутова евтектика – вісмут корозійна стійкість вивчених сплавів падає. Показано, що використання захисних покрить з вольфраму та молібдену підвищує корозійну стійкість хастелою.Представлены результаты исследования коррозионной стойкости никель-молибденовых сплавов (хастеллой) в расплавах тяжелых металлов (Pb, Bi, Pb-Bi). Коррозия изучена в статических условиях при температуре 550 °С. Установлено, что в ряду расплавов свинец – свинец-висмутовая эвтектика – висмут коррозионная стойкость изученных сплавов падает. Показано, что использование защитных покрытий из вольфрама и молибдена повышает коррозионную стойкость хастеллоя

Mechanism of current flow and temperature dependence of contact resistivity in Au-Pd-Ti-Pd-n⁺ -GaN ohmic contacts

We present the results of structural and morphological investigations of interactions between phases in the layers of Au-Pd-Ti-Pd-n⁺-GaN contact metallization that appear at rapid thermal annealing (RTA). It is shown that formation of ohmic contact occurs in the course of RTA at Т = 900°C due to formation of titanium nitride. We studied experimentally and explained theoretically the temperature dependence of contact resistivity ρс(Т) of ohmic contacts in the 4.2-380 K temperature range. The ρс(Т) curve was shown to flatten out in the 4.2-50 K range. As temperature grew, ρс decreased exponentially. The results obtained enabled us to conclude that current flow has field nature at saturation of ρс(Т) and the thermofield nature in the exponential part of ρс(Т) curve

Nanofiber-Mediated Interaction of Light with Cold Atoms

Light-matter interaction processes are extremely attractive for quantum information problems, where one of the main goals consists in a quantum state of light mapping into a collective atomic state. By analogy with the Purcell effect, which exhibits in the presence of a resonator, enhancement of light-matter interaction can be achieved by using a nanofiber [1-2]. In this work we present a theoretical description of light interaction with a cold atomic ensemble mediated the nanofiber, which lies in a base of the experimental realization of a quantum memory protocol [3]

Organization of a seismological observation point on the Zmiyinyi Island

As a result of expansion of seismic monitoring network in Ukraine, it was decided to install seis-mological observation points on the Snake Island. The article listed one of the possible methods of implementing paragraph for seismic observations using modern software and hardware to receive and transmit digital data

The long-run diversification attributes of commercial property

Bosonic cascades formed by lattices of equidistant energy levels sustaining radiative transitions between nearest layers represent a unique system to study correlated optical phenomena. We show how the light emitted by condensates in the visible range introduces a new regime of emission for cascade systems. Namely, the quantum statistics of bosonic cascades exhibits superbunching plateaus. This demonstrates further potentialities of bosonic cascade lasers for the engineering of correlated properties of light useful for imaging applications