Stabilization of 6H-Hexagonal SrMnO3 Polymorph by Al2O3 insertion

We demonstrate the structural evolution of polymorphic phases in Al₂O₃-inserted SrMnO₃ ceramics synthesized by solid state reaction. While the 4H-hexagonal phase is predominant in pure SrMnO₃ ceramics, a small amount of 6H-hexagonal polymorph is identified in addition to the primary 4H-hexagonal SrMnO₃ and the secondary hexagonal SrAl₂O₄ phases in the as-sintered ceramics, evidenced by x-ray diffraction and subsequent Rietveld refinement analyses. The existence of the 6H-hexagonal SrMnO₃ phase is corroborated using Raman spectroscopy. The chemical compositions and electronic structures of the Al₂O₃-inserted SrMnO₃ compounds are also examined using energy dispersive spectroscopy and x-ray photoelectron spectroscopy, respectively. The first-principles calculations reveal that there is no clear difference between the total energies of 4H- and 6H-hexagonal polymorphs regardless of the presence/absence of Sr and oxygen vacancies. Possible origins are discussed with the estimation of actual strain based on the refined lattice parameter of 6H SrMnO₃.     

A fog-based security framework for intelligent traffic light control system

Multimedia Tools and Applications - The world is facing many problems including that of traffic congestion. To highlight the issue of traffic congestion worldwide specially in urban areas and to...     

Influence of Different Additives on the Interaction of Quinolone Antibiotic Drug with Surfactant: Conductivity and Cloud Point Measurement Study

Conductometric and cloud point (CP) measurement studies have been performed to investigate the interaction of tetradecyltrimethylammonium bromide (TTAB) and Triton® X-100 (TX-100) with ciprofloxacin hydrochloride (CFH) in different solvents over the temperature range of 295.15–315.15 K. CFH is used for the treatment of various bacterial infections. The observed critical micelle concentration (CMC) values of TTAB were found to be reduced in the presence of electrolytes (Na₂SO₄/Na₃PO₄), and this reduction proceeds with the elevation of salt concentration. The order of the CMC of TTAB follows the trend: > >. The observed CMC values of TTAB were found to increase with increasing temperature and decrease with increasing concentration of CFH in aqueous medium. The values of Gibbs free energy of micellization () for the TTAB/TTAB + CFH mixture were found to be negative, implying spontaneous micellization. The estimated CP of TX-100 decreases with increasing concentration of TX-100 in aqueous medium. The CP values first decrease with increasing concentration of CFH and then increase at higher concentration of CFH almost in all cases investigated. The values of free energy of clouding were found to be positive in all cases studied implying that phase separation of TX-100 was nonspontaneous. The other thermodynamic parameters associated with the micellization of TTAB and the phase separation of TX-100 were estimated and explained.     

Mixed oxide supported hydrodesulfurization catalysts—a review

Support effects form important aspect of hydrodesulfurization (HDS) studies and mixed oxide supports received maximum attention in the last two decades. This review will focus attention on studies on mixed oxide supported Mo and W catalysts. For convenience of discussion, these are divided into Al₂O₃ containing mixed oxide supports, TiO₂ containing mixed oxide supports, ZrO₂ containing mixed oxide supports and other mixed oxide supports containing all the rest. TiO₂ containing mixed oxides received maximum attention, especially TiO₂–Al₂O₃ supported catalysts. A brief discussion about their prospects for application to ultradeep desulfurization is also included. An overview of the available literature with emphasis on research carried out in our laboratory form the contents of this publication.     

Analysis of surface layers on bioactive glasses

FT-Raman spectroscopy proves to be a powerful technique to study surface reactions on bioactive glasses and it eliminates the fluorescence of the organic phase of whole bone, thereby making it possible to compare the reaction layers formed on bioactive glasses with the mineral phase of bone. The spectrum of hydroxycarbonate apatite (HCA) developed on the bioactive glasses is closer to that of bone than synthetic hydroxyapatite (HA) and closely matches that of bone mineral obtained by deproteination of whole human femoral cortical bone.     

Protein-energy malnutrition and oxidative injury in growing rats

1. Weaning rats were fed ad libitum isocaloric diets containing 5% and 20% casein based proteins. 5% protein diet was protein deficient diet. Pair fed rats with the 5% protein group were maintained simultaneously on 20% protein diet but the amount restricted to the amount taken up by PEM group. 2. Glutathione, antioxidative enzymes, lipid peroxidation and histopathological studies in liver and only glutathione and antioxidative enzymes in blood were carried out. 3. Rats fed the 5% protein diet developed a severe protein energy malnutrition (PEM) whereas those on pair-fed diet developed mild to moderate PEM. 4. Glutathione related thiols superoxide dismutase, glutathione peroxidase, catalase and glutathione-Stransferase with (1 Chloro 2,4-dinitro benzene (CDNB) substrate) were decreased in liver with concomitant increase of lipid peroxidation in severe PEM. In blood glutathione, glutathione peroxidase and catalase were decreased while superoxide dismutase was increased in severe PEM group. 5. Mild to moderate PEM (pair-fed group) also resulted in similar changes in liver except glutathione peroxidase, lipid peroxidation in liver and superoxide dismutase in blood. 6. Hepatic injury was detectable only in the severe PEM group. 7. Oxidative-stress and hepatic injury occurred in severe PEM and to a lesser degree in mild to moderate PEM.