Статті та доповіді НДІ Фізики

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https://dspace.onu.edu.ua/handle/123456789/25660

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Перегляд Статті та доповіді НДІ Фізики за Автор "Drahan, Hryhorii S."

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  • Ескіз
    Документ
    Adsorption Hysteresis in Open Slit-like Micropores
    (2021) Drahan, Hryhorii S.; Kutarov, Volodymyr V.; Schieferstein, Eva; Iorgov, Alexander; Драган, Григорій Сильвестрович; Драган, Григорий Сильвестрович; Кутаров, Володимир Володимирович; Кутаров, Владимир Владимирович
    Adsorption hysteresis in the low-pressure range is only rarely described in the literature. To optimise, for example, heat storage technologies, a deeper understanding of the low-pressure hysteresis (LPH) process is necessary. Here, two thermodynamically based approaches are further developed for analysing the LPH within the framework of thermodynamically irreversible processes and fractal geometry. With both methods developed, it is possible to obtain the description of the adsorption and desorption branches with high accuracy. Within the framework of the two thermodynamic models of the hysteresis loop, generalised equations are obtained with the control parameter in the form of the degree of irreversibility. This is done by taking the adsorption of water on alumina as an example. It is shown that the fractal dimension of the adsorption process is larger than the fractal dimension of the desorption branch, meaning that the phase state of the adsorbate is more symmetric during the adsorption step than in the desorption process.
  • Ескіз
    Документ
    Structured Light Control and Diagnostics Using Optical Crystals
    (2021) Angelsky, Oleg V.; Bekshaiev, Oleksandr Yа.; Drahan, Hryhorii S.; Maksimyak, P. P.; Zenkova, C. Yu.; Zheng, Jun; Бекшаєв, Олександр Янович; Бекшаев, Александр Янович; Драган, Григорій Сильвестрович; Драган, Григорий Сильвестрович
    We describe experimental results exposing the possibilities of optical crystals, especially anisotropic and birefringent, for creation, control, and diagnostics of structured light fields with singular and extraordinary properties. The efficiency of birefringent media is demonstrated for purposeful generation of optical beams with phase singularities (optical vortices) and desirable patterns of internal energy flows, in both the mono- and polychromatic light. On the other hand, anisotropic micro-objects can be used as probing bodies forinvestigationofthepeculiarfeaturesof internalenergy flowsandcorresponding momentumandangularmomentumdistributionsinstructuredlight fields.Inparticular,the specific mechanical action of light fields, formed under the total-reflection conditions, has been detected that confirms the existence of “extraordinary” dynamical characteristics of evanescent light waves predicted theoretically: the “transverse” momentum and “vertical” spinandtheirdependenceontheincidentbeampolarization.Theresultscanbeusefulfor the optical trapping and micromanipulation techniques, including the biomedical and pharmaceutical applications.