Browsing Внеуниверситетские публикации ученых БНТУ by Title

Now showing items 205-224 of 4309

    • Thermo-optic properties of Yb:Lu2O3 single crystals 

      Loiko, P. A.; Yumashev, K. V.; Schödel, R.; Peltz, M.; Liebald, C.; Mateos, X.; Deppe, B. (Springer, 2015)
      A detailed study of thermo-optic properties of 1.5 at.% Yb:Lu2O3 single crystal is performed. Thermo-optic dispersion formulas are derived for dn/dT coefficient and thermal coefficient of the optical path. At the wavelength of 1.03 μm, dn/dT = 5.8 × 10−6 K−1. High-precision temperature-dependent measurements of the thermal expansion coefficient α are performed. At the room ...
      2018-09-17

    • Thermoconvective flow velocity in a high-speed magnetofluid seal after it has stopped 

      Krakov, M. S.; Nikiforov, I. V. (Maik Nauka-Interperiodica Publishing, 2012)
      Convective flow is investigated in the high-speed (linear velocity of the shaft seal is more than 1 m/s) magnetofluid shaft seal after it has been stopped. Magnetic fluid is preliminarily heated due to viscous friction in the moving seal. After the shaft has been stopped, nonuniform heated fluid remains under the action of a high-gradient magnetic field. Numerical analysis has ...
      2016-03-29

    • Thermodynamic properties of multicomponent amorphous alloys in Fe-Si-B-Ni and Fe-Si-B-Ni-Co-Cr-Mo systems 

      Khina, B. B.; Goranskiy, G. G. (2016)
      The chemical potential of iron in a amorphous phase of multicomponent multiphase alloys Fe - 7.3% Si - 14.2% B - 8.26% Ni (alloy 1) and Fe - 0.32% Si - 4.8% B - 6.68% Ni - 2.42% Co - 8.88% Cr - 6.42% Mo (alloy 2), which contain crystalline and amorphous phases, was determined on the basis of experimental results and a theoretical model. The alloys were produced by melt quenching ...
      2021-01-21

    • Thermodynamics of Multicomponent Amorphous Alloys: Theories and Experiment Comparison 

      Khina, B. B.; Goranskiy, G. G. (2017)
      On the basis of the existing thermodynamic theories of the amorphous matter (semi-empirical Miedema model and Shao theory), the integral (enthalpy and Gibbs energy) and partial molar characteristics of a multicomponent iron-based amorphous alloy are determined. It is demonstrated that for quaternary alloy Fe – 7.3 % Si – 14.2 % B – 8.26 % Ni these approaches give substantially ...
      2017-11-27

    • Time resolved photoluminescence anisotropy of CdSe/ZnS nanoparticles in toluene at 300 K 

      Petrov, E. P.; Cichos, F.; Zenkevich, E.; Starukhin, D.; Borczyskowski, C. von (2005)
      For CdSe nanoparticles it has been theoretically and experimentally shown that at low temperatures the photoluminescence is circularly polarized in accordance with a wurtzite structure and the corresponding allowed optical transitions. In the present Letter, we report on related investigations on CdSe/ZnS colloids in toluene solution. From time resolved photoluminescence anisotropy ...
      2017-05-27

    • Tm:KLu(WO4)2 microchip laser Q-switched by a graphene-based saturable absorber 

      Serres, J. M.; Loiko, P.; Mateos, X.; Yumashev, K.; Griebner, K. U.; Petrov, V.; Aguilo, M.; Diaz, F. (2015)
      We report on the first Tm-doped double tungstate microchip laser Q-switched with graphene using a Tm:KLu(WO4)2 crystal cut along the Ng dielectric axis. This laser generates a maximum average output power of 310 mW with a slope efficiency of 13%. At a repetition rate of 190 kHz the shortest pulses with 285 ns duration and 1.6 μJ energy are achieved.
      2017-11-18

    • Two-kink solution for the Hirota–Ramani equation for degenerated parameters 

      Knyazev, M. A. (West Ukrainian Physical Society, 2018)
      The Hirota–Ramani equation is considered. Its two-kink solutions are known and may be constructed, for example, by direct methods if the parameters ki, i = 1, 2 of the solution components are not equal to each other. In this paper, such solution is constructed for k1 = k2.
      2023-12-15

    • Ultrafast laser inscribed Yb:KGd(WO4)2 and Yb:KY(WO4)2 channel waveguide lasers 

      Bain, F. M.; Lagatsky, A. A.; Thomson, R. R.; Psaila, N. D.; Kuleshov, N. V.; Kar, A. K.; Sibbett, W.; Brown, C. T. A. (Optical Society of America, 2009)
      We demonstrate laser action in diode-pumped microchip monolithic cavity channel waveguides of Yb:KGd(WO4)2 and Yb:KY(WO4)2 that were fabricated by ultrafast laser writing. The maximum output power achieved was 18.6 mW with a threshold of approximately 100 mW from an Yb:KGd(WO4)2waveguide laser operating at 1023 nm. The propagation losses for this waveguide structure were measured ...
      2012-01-23

    • Unleashing the power of Twitter 

      Khramtsova, M. V. (АГУ, 2013)
      Khramtsova, M. V. Unleashing the power of Twitter / M. V. Khramtsova // Межкультурная коммуникация и СМИ : материалы IV Международной научно-практической конференции, Барнаул, 15 июня 2013 г. – 2013. – С. 47-50.
      2014-03-31

    • Unusual dynamic relaxation of triplet-excited meso-phenyl-substituted porphyrins and their chemical dimers at room temperatures 

      Knyukshto, V.; Zenkevich, E.; Sagun, E.; Shulga, A.; Bachilo, S. (1998)
      It has been found that for mono- and di-meso-phenyl-substituted octaethylporphyrin (OEPs), etioporphyrins, corresponding Zn complexes and OEP chemical dimers (with a meso-phenyl spacer) a drastic shortening of triplet lifetimes from a ms to μs timescale in deaerated toluene solutions at 295K takes place without any changes of the spectral-kinetic parameters of the S₀ and S₁ states. ...
      2017-05-25

    • Up- and down-conversion emissions from Er3+ doped K2YF5 and K2YbF5 crystals 

      Loiko, P. A.; Khaidukov, N. M.; Mendez-Ramos, J.; Vilejshikova, E. V.; Skoptsov, N. A.; Yumashev, K. V. (Elsevier, 2016)
      Up- and down-conversion emissions from Er3+ doped K2YF5 and K2YbF5 crystals / P. A. Loiko [et al.] // Journal of Luminescence. – 2016. – Vol. 170. – P. 1-7.
      2016-03-29

    • UP-конверсионная люминесценция оксифторидной стеклокерамики с нанокристаллами PbF2:(Yb3+, Eu3+, RE3+) (RE = Tm, Ho или Er) 

      Вилейшикова, Е. В.; Лойко, П. А.; Рачковская, Г. Е.; Захаревич, Г. Б.; Юмашев, К. В. (Институт физики им. Б.И. Степанова НАН Беларуси, 2016)
      Cинтезирована прозрачная оксифторидная стеклокерамика с нанокристаллами PbF2:(Yb3+, Eu3+, RE3+ ) (где RE = Tm, Ho, Er) путем вторичной термической обработки легкоплавких стекол системы SiO2-PbO-PbF2-CdF2. Исследовано оптическое поглощение и люминесценция редкоземельных ионов. При возбуждении на длине волны 960 нм излучением лазерного InGaAs-диода получена мультицветовая (оранжевая, ...
      2019-03-01

    • Validation of mathematical model of differential protection 

      Romanyuk, F. A.; Novash, I. V.; Loman, M.; Wegierek, P.; Szrot, M. (2014)
      Comparison of results of mathematical modeling and field tests of a transformer differential protection is presented in this paper. An inrush current mode, external two-phase and three-phase faults are considered. Proposed mathematical model can be used to test differential protection in different modes of transformer operation.
      2022-08-09

    • Virtual reality as a factor of development of addictive behavior in conditions of modern environment 

      Drozdov, I.; Shershniova, T. (2017)
      Consumer society is a social and cultural phenomenon that was formed in developed countries in the second half of the twentieth century. Formed by this time, the middle class became the basis of consumer culture, which was heavily influenced by advertising, the media and cinematography.
      2018-06-13

    • Virtual reality as an innovativ setting for simulations in engineering education 

      Makarych, M. V. (БГУИР, 2016)
      The article is devoted to simulation techniques in engineering education. The distinctive features that are useful for educational purposes are stressed. The author gives an example of using Building information models (BIMs) for postgraduate engineering students at practical English classes. The course design focuses on learning about virtual reality by simulating interdisciplinary ...
      2022-10-24

    • Warm ups for net generation of students aimed at developing their listening proficiency 

      Khramtsova, M. V. (БГУИР, 2016)
      This article reviews some strategies and approaches to Net Generation of students with intermediate and pre-intermediate level of listening proficiency. It provides concrete guidelines for integrating internet resources, selecting and applying appropriate video and audio materials as systematic warm ups for business English classes.
      2022-10-25

    • The ways of soil salinization reduction and soil restoration in the areas of jsc «Belaruskali» industrial activity 

      Basalay, I. A.; Belskaya, G. V.; Suruntovich, N. V. (Кубанский государственный аграрный университет, 2015)
      The article is a review of the prominent technical solutions regarding potash salt deposits mining. The article shows the efficiency of application of biological restoration of saline soil by using salt marsh plants.
      2018-04-10

    • Wye-connected current transformers simplified model validation in Matlab-simulink 

      Romanyuk, F. A.; Novash, I. V.; Rumiantsev, Y.; Wegierek, P. (Wydawnictwo SIGMA, 2015)
      This paper presents the wye-connected current transformers (CTs) simplified mathematical model with the initial data based on nominal parameters (nameplate data) of the simulated CT. Designed user-friendly graphical interface allows to specify the CT data (nominal parameters, remanence and burdens) in convenient form. Results of the carried out experiments confirmed the CT model ...
      2022-07-25

    • Yb3+-doped YVO4 crystal for efficient Kerr-lens mode locking in solid-state lasers 

      Lagatsky, A. A.; Sarmani, A. R.; Brown, C. T. A.; Sibbett, W.; Kisel, V. E.; Selivanov, A. G.; Denisov, I. A.; Troshin, A. E.; Yumashev, K. V.; Kuleshov, N. V.; Matrosov, V. N.; Matrosova, T. A.; Kupchenko, M. I. (Optical Society of America, 2005)
      We report the first demonstration, to our knowledge, of soft-aperture Kerr-lens mode locking in a diode-pumped femtosecond Yb3+:YVO4 laser. Near-transform-limited pulses as short as 61 fs are generated around a center wavelength of 1050 nm with an output power of 54 mW and a pulse repetition frequency of 104.5 MHz. This is, to our knowledge, the shortest pulse generated directly ...
      2012-01-23

    • "... А кто ваш клиент?" 

      Карпей, Х. Н.; Воронцова, Н. Е. (Промкомплекс, 2013)
      Чаще всего креативные технологии применяются для генерации идей новой продукции, услуг или их рекламных образов. Мы же попытались заставить группу отечественных маркетологов применить их к таким процедурам, как составление «портрета потребителя» и позиционирование. Эти процедуры, к сожалению, проводятся редко в наших отделах маркетинга, руководители которых потом удивляются ...
      2015-01-31