Invetigation of the Luminescent Characteristics of Li2SO4 Crystal Grown from Aqueous Solution

Vacuum ultraviolet and thermal activation spectroscopy methods have been used to study the nature of intrinsic radiation and the mechanisms of formation of electron-hole trapping centers in an irradiated Li2SO4 crystal

Mathematical description of the processes occurring during active grain ventilation

The subject of the study is the process of active ventilation of wheat grain with variable heat supply.   The purpose of the work is a mathematical description of the nature of the flows of matter and energy in the process of active ventilation of wheat grain.   Thanks to the selected original design of the exhaust coolant outlet unit, made in the form of a mesh spiral tube, it was possible to optimize the hydrodynamic situation in the layer of dried grain. The developed mathematical model, as a mathematical description, consists of equations of material, thermal balances, equations of hydrodynamics in steady and unsteady states. This mathematical model is the basis for creating a material model of the process and conducting an experiment with subsequent data processing. As a result, it is possible to obtain criteria equations of processes that make it relatively easy to calculate processes under various technological modes

Brillouin spectroscopy and radiography for assessment of viscoelastic and regenerative properties of mammalian bones

Biomechanical properties of mammalian bones, such as strength, toughness, and plasticity, are essential for understanding how microscopic-scale mechanical features can link to macroscale bones’ strength and fracture resistance. We employ Brillouin light scattering (BLS) microspectroscopy for local assessment of elastic properties of bones under compression and the efficacy of the tissue engineering approach based on heparin-conjugated fibrin (HCF) hydrogels, bone morphogenic proteins, and osteogenic stem cells in the regeneration of the bone tissues. BLS is noninvasive and label-free modality for probing viscoelastic properties of tissues that can give information on structure-function properties of normal and pathological tissues. Results showed that MCS and BPMs are critically important for regeneration of elastic and viscous properties, respectively, HCF gels containing combination of all factors had the best effect with complete defect regeneration at week nine after the implantation of bone grafts and that the bones with fully consolidated fractures have higher values of elastic moduli compared with defective bone

Study of the Luminescent Characteristics of K2SO4 Crystals with Impurities Grown from an Aqueous Solution

Paper presents a study of the luminescence characteristics of K2SO4 crystals with impurities grown by the slow evaporation method. The nature of the Tl impurity emission and the formation of electron-hole trapping centers in irradiated K2SO4 – Tl crystals will be studied by spectroscopic methods

Thermal Conversion of Guanylurea Dicyanamide into Graphitic Carbon Nitride via Prototype CNx Precursors

Guanylurea dicyanamide, [(H2N)C(-O)NHC(NH2)2][N(CN)2], has been synthesized by ion exchange reaction in aqueous solution and structurally characterized by single-crystal X-ray diffraction (C2/c, a = 2249.0(5) pm, b = 483.9(1) pm, c = 1382.4(3) pm, β = 99.49(3)°, V = 1483.8(5) × 106 pm3, T = 130 K). The thermal behavior of the molecular salt has been studied by thermal analysis, temperature-programmed X-ray powder diffraction, FTIR spectroscopy, and mass spectrometry between room temperature and 823 K. The results were interpreted on a molecular level in terms of a sequence of thermally induced addition, cyclization, and elimination reactions. As a consequence, melamine (2,4,6-triamino-1,3,5-triazine) is formed with concomitant loss of HNCO. Further condensation of melamine yields the prototypic CNx precursor melem (2,6,10-triamino-s-heptazine, C6N7(NH2)3), which alongside varying amounts of directly formed CNxHy material transforms into layered CNxHy phases without significant integration of oxygen into the core framework owing to the evaporation of HNCO. Thus, further evidence can be added to melamine and its condensation product melem acting as “key intermediates” in the synthetic pathway toward graphitic CNxHy materials, whose exact constitution is still a point at issue. Due to the characteristic formation process and hydrogen content a close relationship with the polymer melon is evident. In particular, the thermal transformation of guanylurea dicyanamide clearly demonstrates that the formation of volatile compounds such as HNCO during thermal decomposition may render a large variety of previously not considered molecular compounds suitable CNx precursors despite the presence of oxygen in the starting material

Russian Muslims: talking about ethnic and confessional identification

Статья поступила в редакцию 23.03.2015 г.Авторы впервые ставят вопрос об этноконфессиональной идентификации россиян, исповедующих ислам. Отмечается, что современная государствообразующая часть россиян — российские мусульмане прошли следующие исторические фазы развития: младоэтническую, националистическую, постэтническую.The authors focus on the issue of ethnic and confessional authentication of Russians, bearers of Islamic values. They point out that modern Russian Muslims as a part of the Russians have gone through the historical ethnic and nationalistic phases of development in theirs history: pre-ethnic, nationalistic, and post-ethnic

Energy Transfer in the <inline-formula><math display="inline"><semantics><mrow><msub><mrow><mi mathvariant="bold-italic">C</mi><mi mathvariant="bold-italic">a</mi><mi mathvariant="bold-italic">S</mi><mi mathvariant="bold-italic">O</mi></mrow><mrow><mn mathvariant="bold">4</mn></mrow></msub><mo mathvariant="bold">−</mo><mrow><mi mathvariant="bold-italic">D</mi><mi mathvariant="bold-italic">y</mi></mrow></mrow></semantics></math></inline-formula> Thermoluminescent Dosimeter from the Excited State of the <inline-formula><math display="inline"><semantics><mrow><msubsup><mrow><mi mathvariant="bold-italic">S</mi><mi mathvariant="bold-italic">O</mi></mrow><mrow><mn mathvariant="bold">4</mn></mrow><mrow><mn mathvariant="bold">2</mn><mo mathvariant="bold">−</mo></mrow></msubsup></mrow></semantics></math></inline-formula> Anionic Complex to the Impurities

The creation of a combined radiative state at 2.95–3.1 eV in the phosphor CaSO4−Dy 3+ has been investigated using vacuum ultraviolet and thermoactivation spectroscopy methods. It is shown that the combined radiative electronic state is formed from the radiative electronic states of the impurity electronic trapping centers Dy 2+− SO4− and the intrinsic electronic radiative states SO43−−SO4− during the excitation of the anion complex SO42−, as a result of charge transfer from the excited anion complex O 2−−Dy 3+ to the impurities and the neighboring anion complex O2−− SO42−. In the CaSO4−Dy phosphor, the combined radiative electronic state and impurity emission of Dy 3+, 2.16 eV and 2.56 eV are excited by photons with energies of 3.95–4.0 eV and 4.5–4.6 eV. Energy transfer from the matrix to the Dy 3+ impurities is revealed upon thermal exposure as a result of the ionization of the electronic capture centers of Dy2+ and SO43−