[en] The present work deals with sorption of U(VI) and Th(IV) onto synthetic analogue of natrolite belonging to zeolite group. The material possesses high concentration of exchangeable alkali metal ions

[en] In SFR, the inner surface of pipelines and components undergo corrosion by interaction with liquid sodium and forms The sorption behaviour of U(VI), Th(IV) and Eu(III) onto synthetic mordenite was investigated. The experiments included studies on sorption and material synthesis. The influence of temperature, pH of the solution and sorbent amount on the sorption of U(VI), Th(IV) and Eu(III) by the synthetic mordenite was studied at fixed 4 hour equilibration time. Material was synthesized by hydrothermal method and characterized by X-ray diffraction, Infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy. It is observed that these three parameters i.e. temperature, pH and sorbent dose have remarkable effect on sorption of these nuclides. (author)

[en] An analogue of aluminosilicate mica mineral Muscovite has been synthesized hydrothermally at 200 degC and sorption studies performed for UO₂²⁺, Th⁴⁺ and Ru³⁺ at room temperature in acidic medium (0.1M). The X-ray diffractograms and scanning electron micrographs have been used to verify changes in crystallinity and crystal morphology on sorption. The synthesized gel has been characterized by X-ray powder diffraction, energy dispersive spectrometry, thermogravimetric analysis, FT-IR spectroscopy and scanning electron microscopy. The chemical composition of the gel is found to be K_1.4Al_4.2 (Si₆Al₂O₂₀) (OH)₄2H₂O. Energy dispersive spectrometry (EDS) mapping indicates that metal ions are sorbed on the synthesized material by ion-exchange mechanism. Also, the structure of aluminosilicate mineral Muscovite is retained upon UO₂²⁺, Th⁴⁺ and Ru³⁺ sorption implying that surface and end sites are more affected upon sorption while the interlayer positions of the mineral are not engaged in metal ion sorption. (author)

[en] The present work deals with the recovery of Pd(II) valuable PGM from aqueous waste using synthetic inorganic ion-exchanger. Also, the effect of exchanger composition and temperature has been studied

[en] An analogue of aluminosilicate mica mineral Muscovite has been synthesized hydrothermally at 200 deg C and sorption studies performed for UO₂²⁺, Th⁴⁺ and Ru³⁺ at room temperature in acidic medium (0.1 M). The X-ray diffractograms and scanning electron micrographs have been used to verify changes in crystallinity and crystal morphology on sorption. The synthesized gel has been characterized by X-ray powder diffraction, energy dispersive spectrometry, thermogravimetric analysis, FT-IR spectroscopy and scanning electron microscopy. The chemical composition of the gel is found to be K_1.4Al_4.2 (Si₆Al₂O₂₀) (OH)₄2H₂O. Energy dispersive spectrometry (EDS) mapping indicates that metal ions are sorbed on the synthesized material by ion-exchange mechanism. Also, the structure of aluminosilicate mineral Muscovite is retained upon UO₂²⁺, Th⁴⁺ and Ru³⁺ sorption implying that surface and end sites are more affected upon sorption while the interlayer positions of the mineral are not engaged in metal ion sorption. (author)

[en] Modified Korteweg-de Vries (mKdV) equations are derived for the incident, reflected, and transmitted waves in order to examine the soliton reflection and its transmission through an inhomogeneous plasma comprising ions, dust grains with fluctuating charge and two types of electrons, namely nonisothermal electrons and isothermal electrons. All the mKdV equations are coupled at the point of reflection and solved for the reflected soliton. Unlike others, a relation is established between the velocity shifts of the incident, reflected and transmitted solitons, and based on a critical value of the shift of incident soliton the strengths of the soliton reflection and transmission are talked about. Conditions are obtained for the soliton reflection and its transmission, and a comparative study is made for the two cases of fixed and fluctuating charges on the dust grains

[en] Absolute energies of band edges have proven to be very important for various applications like hydrogen generation, solar water splitting and solar cell optimization. Energy differences as small as 50–100 meV have been shown to largely affect device efficiencies. Device operational temperature can vary largely and temperature dependence of band gap is well known in bulk semiconductor literature. However, there are only a few studies on variation of band gap in quantum dots and none of them characterize the relative energy variation of band edges in spite of their importance in various applications. This is mainly due to the absence of an internal standard that can be used to study the variation of band edges. Here, in this paper, we introduce a technique wherein we utilize Cu dopant emission as an internal probe. Using this technique, we report the variation of band gap, conduction band and valence band edges of CdS and CdSe quantum dots as a function of temperature and size. We found that band gap variation is similar to that of bulk but with a higher average phonon energy. The band edge variation is characterized by a dominant conduction band shift for larger sizes with decreasing temperature while the smaller size QDs show the variation in both conduction band and valence band. Further, we have also utilized this method to study the binding energy of the trap states as a function of temperature using Cu photoluminescence quantum yield and average lifetime of Cu photoluminescence. (paper)

[en] Present study reports the structural and dielectric properties of Ce_1_-_xMn_xO_2 (0 ≤ x ≤ 0.15) compounds synthesized by solid state reaction method. X-ray diffraction and Raman measurements confirm the formation of cubic phase corresponding to Fm3m space group for all these compositions investigated. The transition metal Mn ions exhibit multivalency nature in oxides and doping these ions at Ce sites in CeO_2 which is also known to exist in 3+ and 4+ valency state is expected to modify the physical properties. The crystallite size was found to decrease with Mn concentration up to 7%, however, it increases at higher Mn concentration i.e., x = 0.15 which is also confirmed by the images from Scanning Electron Microscope. Raman study reveals red shift in peaks at ∼462.9 cm"−"1 and ∼572.9 cm"−"1 upto x = 0.07, whereas the blue shift was observed from these peaks for x = 0.15. The electrical resistivity measured as a function of temperature (200 K–380 K) indicates an increase in resistivity with Mn doping. Furthermore, the dielectric measurements performed with varying frequency as well as temperature shows an enhancement in dielectric constant and decrease in the dielectric loss with Mn concentration. - Highlights: • Influence of Mn ions on the structural, electrical and dielectric properties of CeO_2 was investigated. • The crystallite size and grain size decreases with Mn doping into CeO_2 matrix. • The dielectric constant and resistivity of samples increases with Mn doping into CeO_2 lattice. • The dielectric loss decreases with Mn doping into CeO_2.