[en] In this work, the redmud reinforced polypropylene composites were fabricated by compression molding setup. The effects of the redmud content on the mechanical, melting and crystalline behavior of the composites was investigated. The melting and crystalline behavior of the composites were investigated using Digital Scanning Calorimeter. The test results show that hardness of the composites increases with increasing redmud content while incorporation of redmud content decreases tensile and impact strength of the composites. It is determined that the addition of redmud on the polypropylene does not affect the crystalline behavior of the composites. (paper)

[en] A self-activated Ca₂KZn₂V₃O₁₂ (CKZVO) phosphor was synthesized by the solid state reaction method under different calcination temperatures. A high crystalline single-phased CKZVO material occurred at 600 °C belongs to the cubic structure with Ia $\stackrel{¯<!--\; ??\; -->}{3}$ d space group. The vibrational modes were characterized by IR and Raman spectra. All the samples consist of intense absorption spectra in UV region owing to charge transfer of (VO₄)³⁻ tetrahedral group and the band gap energy of the single-phased CKZVO phosphor was found to be 3.2 eV. Photoluminescence broad emission spectrum ranging from 400 to 700 nm, ascribing to the charge transfer in (VO₄)³⁻ tetrahedral group. The colorific properties of the single-phased CKZVO phosphor was investigated and reported. Ultimately, the device performance showed that the self-activated Ca₂KZn₂V₃O₁₂ phosphor served as a potentially applicable candidate in UV chip excited white LED applications. (paper)

[en] In the present work, a significant rotational lines of the $B^4{\mathrm{\Sigma <!--\; ??\; -->}}^{-<!--\; ???\; -->}\text{--}{X}^4{\mathrm{\Sigma <!--\; ??\; -->}}^{-<!--\; ???\; -->}$ ($0,0$) band system of the AlC molecule were identified in high resolution FTS sunspot umbral spectra in the region from 22,450 to 22,600 cm⁻¹. Among the well-resolved identified lines, the rotational temperatures have been estimated to be 4018 K for photosphere and 3722 K for a hot umbra. Hence, the estimated effective rotational temperatures provide evidence for the possible presence of the AlC molecule in a sunspot umbra. The radiative transition parameters for $A^4{\mathrm{\Pi <!--\; ??\; -->}}^{-<!--\; ???\; -->}\text{--}{X}^4{\mathrm{\Sigma <!--\; ??\; -->}}^{-<!--\; ???\; -->}$ and $B^4{\mathrm{\Sigma <!--\; ??\; -->}}^{-<!--\; ???\; -->}\text{--}{X}^4{\mathrm{\Sigma <!--\; ??\; -->}}^{-<!--\; ???\; -->}$ systems of the AlC molecule have been estimated for experimentally known vibrational levels using the Rydberg–Klein–Rees (RKR) potential. The Franck-Condon (FC) factor of $B^4{\mathrm{\Sigma <!--\; ??\; -->}}^{-<!--\; ???\; -->}\text{--}{X}^4{\mathrm{\Sigma <!--\; ??\; -->}}^{-<!--\; ???\; -->}$ ($0,0$) band system is most intense ($q_{v^{\prime }{v}^{″}}=0.741$). For the $B^4{\mathrm{\Sigma <!--\; ??\; -->}}^{-<!--\; ???\; -->}$ state, the radiative lifetime of $v^{\prime }=0$ level is found as 103.93 ns. The effective vibrational temperature of the $A^4{\mathrm{\Pi <!--\; ??\; -->}}^{-<!--\; ???\; -->}\text{--}{X}^4{\mathrm{\Sigma <!--\; ??\; -->}}^{-<!--\; ???\; -->}$ and $B^4{\mathrm{\Sigma <!--\; ??\; -->}}^{-<!--\; ???\; -->}\text{--}{X}^4{\mathrm{\Sigma <!--\; ??\; -->}}^{-<!--\; ???\; -->}$ band systems of the AlC molecule is 3981 K and 2706 K, respectively. Therefore, the effective vibrational temperature and radiative transition parameters help us to ascertain the possible presence of the AlC molecule in the solar atmosphere.