51 research outputs found

    OES diagnostics as a universal technique to control the Si etching structures profile in ICP

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    In this work, we demonstrate the high efficiency of optical emission spectroscopy to estimate the etching profile of silicon structures in SF6_{6}/C4_{4}F8_{8}/O2_{2} plasma. The etching profile is evaluated as a ratio of the emission intensity of the oxygen line (778.1 nm) to the fluorine lines (685.8 nm and 703.9 nm). It was found that for the creation of directional structures with line sizes from 13 to 100 μm and aspect ratio from ≈ 0.15 to ≈ 5 the optimal intensities ratio is in the range of 2–6, and for structures from 400 to 4000 μm with aspect ratio from ≈ 0.03 to ≈ 0.37 it is in the range 1.5–2. Moreover, the influence of the process parameters on the etching rate of silicon, the etching rate of aluminum, the inclination angle of the profile wall of the etched window, the selectivity of silicon etching with respect to aluminum, and the influence on the overetching (Bowing effect) of the structure was investigated

    Identification of absolute geometries of cis and trans molecular isomers by Coulomb Explosion Imaging

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    Citation: Ablikim, U., Bomme, C., Xiong, H., Savelyev, E., Obaid, R., Kaderiya, B., . . . Rolles, D. (2016). Identification of absolute geometries of cis and trans molecular isomers by Coulomb Explosion Imaging. Scientific Reports, 6, 8. doi:10.1038/srep38202An experimental route to identify and separate geometric isomers by means of coincident Coulomb explosion imaging is presented, allowing isomer-resolved photoionization studies on isomerically mixed samples. We demonstrate the technique on cis/trans 1,2-dibromoethene (C2H2Br2). The momentum correlation between the bromine ions in a three-body fragmentation process induced by bromine 3d inner-shell photoionization is used to identify the cis and trans structures of the isomers. The experimentally determined momentum correlations and the isomer-resolved fragment-ion kinetic energies are matched closely by a classical Coulomb explosion model

    Оцінка факторів силового впливу та визначення умов рівноваги дисперсної фази в малогабаритних в апаратах для створення гранул з особливими властивостями

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    Запропоновано метод визначення умов рівноваги краплі у вихровому газовому потоці. Розроблено комплексну методику визначення гідродинамічних і термодинамічних параметрів створення гранул пористої структури. Результати досліджень дозволяють визначити оптимальні умови проведення процесу і спроектувати малогабаритні конструкції вихрових апаратів. При цитуванні документа, використовуйте посилання http://essuir.sumdu.edu.ua/handle/123456789/24959Предложен метод определения условий равновесия капли в вихревом газовом потоке. Разработана комплексная методика определения гидродинамических и термодинамических параметров создания гранул пористой структуры. Результаты исследований позволяют определить оптимальные условия проведения процесса и спроектировать малогабаритные конструкции вихревых аппаратов. При цитировании документа, используйте ссылку http://essuir.sumdu.edu.ua/handle/123456789/24959The method of terms drop equilibrium determination in a vortical gas stream is offered. The complex method of hydrodynamic and thermodynamics parameters determination of porous structure granules creation of is developed. The results of researches allow defining the optimum terms of process conducting and project small constructions of vortical vehicles. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2495

    Ultrafast x-ray-induced nuclear dynamics in diatomic molecules using femtosecond x-ray-pump-x-ray-probe spectroscopy

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    Citation: Lehmann, C. S., Picon, A., Bostedt, C., Rudenko, A., Marinelli, A., Moonshiram, D., . . . Southworth, S. H. (2016). Ultrafast x-ray-induced nuclear dynamics in diatomic molecules using femtosecond x-ray-pump-x-ray-probe spectroscopy. Physical Review A, 94(1), 7. doi:10.1103/PhysRevA.94.013426The capability of generating two intense, femtosecond x-ray pulses with a controlled time delay opens the possibility of performing time-resolved experiments for x-ray-induced phenomena. We have applied this capability to study the photoinduced dynamics in diatomic molecules. In molecules composed of low-Z elements, K-shell ionization creates a core-hole state in which the main decay mode is an Auger process involving two electrons in the valence shell. After Auger decay, the nuclear wave packets of the transient two-valence-hole states continue evolving on the femtosecond time scale, leading either to separated atomic ions or long-lived quasibound states. By using an x-ray pump and an x-ray probe pulse tuned above the K-shell ionization threshold of the nitrogen molecule, we are able to observe ion dissociation in progress by measuring the time-dependent kinetic energy releases of different breakup channels. We simulated the measurements on N-2 with a molecular dynamics model that accounts for K-shell ionization, Auger decay, and the time evolution of the nuclear wave packets. In addition to explaining the time-dependent feature in the measured kinetic energy release distributions from the dissociative states, the simulation also reveals the contributions of quasibound states

    Hetero-site-specific X-ray pump-probe spectroscopy for femtosecond intramolecular dynamics

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    Citation: Picon, A., Lehmann, C. S., Bostedt, C., Rudenko, A., Marinelli, A., Osipov, T., . . . Southworth, S. H. (2016). Hetero-site-specific X-ray pump-probe spectroscopy for femtosecond intramolecular dynamics. Nature Communications, 7, 6. doi:10.1038/ncomms11652New capabilities at X-ray free-electron laser facilities allow the generation of two-colour femtosecond X-ray pulses, opening the possibility of performing ultrafast studies of X-ray-induced phenomena. Particularly, the experimental realization of hetero-site-specific X-ray-pump/X-ray-probe spectroscopy is of special interest, in which an X-ray pump pulse is absorbed at one site within a molecule and an X-ray probe pulse follows the X-ray-induced dynamics at another site within the same molecule. Here we show experimental evidence of a hetero-site pump-probe signal. By using two-colour 10-fs X-ray pulses, we are able to observe the femtosecond time dependence for the formation of F ions during the fragmentation of XeF2 molecules following X-ray absorption at the Xe site

    Vive la radiorésistance!: converging research in radiobiology and biogerontology to enhance human radioresistance for deep space exploration and colonization.

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    While many efforts have been made to pave the way toward human space colonization, little consideration has been given to the methods of protecting spacefarers against harsh cosmic and local radioactive environments and the high costs associated with protection from the deleterious physiological effects of exposure to high-Linear energy transfer (high-LET) radiation. Herein, we lay the foundations of a roadmap toward enhancing human radioresistance for the purposes of deep space colonization and exploration. We outline future research directions toward the goal of enhancing human radioresistance, including upregulation of endogenous repair and radioprotective mechanisms, possible leeways into gene therapy in order to enhance radioresistance via the translation of exogenous and engineered DNA repair and radioprotective mechanisms, the substitution of organic molecules with fortified isoforms, and methods of slowing metabolic activity while preserving cognitive function. We conclude by presenting the known associations between radioresistance and longevity, and articulating the position that enhancing human radioresistance is likely to extend the healthspan of human spacefarers as well

    Amaerobic metabolism of drugs and nutraceuticals - models of the digestive tract

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    Katedra biochemieDepartment of BiochemistryFaculty of SciencePřírodovědecká fakult

    Amaerobic metabolism of drugs and nutraceuticals - models of the digestive tract

    No full text
    Katedra biochemieDepartment of BiochemistryFaculty of SciencePřírodovědecká fakult
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