• Physical and luminescent properties of glasses in the system WO3-La2O3-B2O3-Nb2O5

    Science. Business. Society., Vol. 4 (2019), Issue 3, pg(s) 91-94

    New multicomponent glasses in the system WO3-La2O3-B2O3-Nb2O5 doped with Eu3+, as a transparent active media for optical application were obtained. Physical parameters as density, molar volume, oxygen molar volume and oxygen packing density were determined. The thermal behavior of the obtained glasses was examined by differential thermal analysis (DTA). It was established that glass crystallization temperature is about 750oC. Microstructural characterization was made by Raman and UV-VIS spectroscopies. Based on the obtained spectral data short-range order and connectivity in glass network were determined. High photoluminescence emissions due to the 4f transitions 5D0→7Fj (j=0-4) of Eu3+ ions were observed. Colorless bulk tungstate glass, containing Nb2O5 with high transparency and high refractive index were prepared.

  • VEHICLE ENGINES. APPLICATION OF FUELS TYPES. EFFICIENCY

    SURFACE PLASMON RESONANCE – A PROMISING METHOD FOR ESTIMATING THE QUALITY OF MOTOR OIL

    Trans Motauto World, Vol. 2 (2017), Issue 1, pg(s) 41-44

    Shown in this paper is the possibility to diagnose quality of motor oil by using the method of surface plasmon resonance (SPR) Investigated in this work were four samples of the motor oil Genuine 5w-30 dexos 2, namely: the fresh one and three ones taken after car mileages 180, 430 and 712 km. When measuring the kinetics of refraction indexes for the studied samples of used oil, the authors observed a characteristic “shoulder” caused by sedimentation of oxidation and wear particles on the surface of SPR device sensitive element, while in the case of fresh oil there took place only the temperature drift of the refraction index. It has been experimentally shown that using the SPR method improves more than one order (from Δfmin = 0.17 vol.% down to Δfmin = 0.0107 vol.%) the detection limit and enhances sensitivity of measuring the wear particles concentration in motor oil as compared with the refractometric method. Thus, it is experimentally proved that the SPR method can be offered to control quality of motor oils as well as the degree of wear inherent to interacting parts of machinery.