Kalamse V.,iversity |
Wadnerkar N.,iversity |
Chaudhari A.,The Institute of Science
Energy | Year: 2013
A density functional study of hydrogen uptake capacity of multi-functionalized naphthalene with Ti and Li metal atom has been carried out. It is observed that, the naphthalene functionalized with two Ti atoms can interact with total eight hydrogen molecules in which each Ti metal atom interacts with four hydrogen molecules. Naphthalene decorated with two Li atoms can interact with total three H2 molecules only. First (19Li) and second (20Li) Li atom can interact with only one and two hydrogen molecule respectively. It is observed that, hydrogen molecules bind strongly to the C10H8Ti2 complex than C10H8Li2 complex. The gravimetric hydrogen uptake capacity of C10H8Ti2 and C10H8Li2 complex is found to be 6.72 and 3.73 wt% respectively. Moreover, after functionalizing naphthalene with four Li atoms, the uptake capacity is increased to 7.20 wt %. However, the thermochemistry result favors to Ti functionalized naphthalene complex (C10H8Ti2) for hydrogen storage over Li functionalized naphthalene (both C10H8Li2 and C10H8Li4) complexes. Atom-centered density matrix propagation (ADMP) molecular dynamics simulations have been performed which showed that C10H8Li2 and C10H8Li4 complex cannot bind single hydrogen molecule at room temperature whereas C10H8Ti2 can bind five hydrogen molecules. © 2012 Elsevier Ltd.
Naganathappa M.,Dr. Babasaheb Ambedkar Marathwada University |
Chaudhari A.,The Institute of Science
Monthly Notices of the Royal Astronomical Society | Year: 2012
Polycyclic aromatic hydrocarbons (PAHs) or PAH-related molecules are considered to be responsible for the unidentified infrared (UIR) emission features at 3.3, 6.2, 7.7, 8.6 and 11.2 μm. However, the exact identification of PAH or PAH-related molecules is difficult. There have been several investigations on the spectroscopic characterization of PAH molecules. But none of them compared the spectra of isomers of PAHs, which might have help in the identification of the UIR emission features. This work presents the infrared and electronic absorption spectra of isomers of C 16H 10. The aim of the present work is to compare infrared and electronic absorption spectra of four isomers of C 16H 10 PAH viz. pyrene, aceanthrylene, acephenanthrylene and fluoranthene, their ions and doubly ions. We also compare the spectra of pyrene in the gas-phase and in H 2O ice. We have used the density functional theory with B3LYP exchange and correlation functional and 6-311++g** basis set to study the infrared spectra. The time-dependent density functional theory (TDDFT) has been used to obtain the electronic absorption spectra. Significant difference in the CC stretching, CH in-plane bending and CH out-of-plane bending vibration modes is observed for the isomers of C 16H 10 whereas there is no large difference in the CH stretching vibration band. A significant change in the vibrational band is observed for pyrene in H 2O ice compared to gas-phase pyrene. Though isomers of C 16H 10 PAH have the same number of carbon and hydrogen atoms, their spectroscopic characteristics are different. This study should help in identifying the isomers of C 16H 10, their ions and doubly cation in the interstellar medium. © 2012 The Authors Monthly Notices of the Royal Astronomical Society © 2012 RAS.
Kothekar D.K.,The Institute of Science |
Dasgupta D.,Padmashree Dr. D.Y. Patil University
International Journal of Pharma and Bio Sciences | Year: 2013
The aim of this study was to evaluate the growth conditions affecting production of hosphatidylinositol-specific phospholipase-C (PIPLC) by Staphylococcus aureus ATCC 9144. A simple colorimetric method for direct estimation of phospholipids was adapted for rapid assaying of PIPLC. First phase of the study involved preliminary screening of nutritional and physical parameters. In the second phase, Plackett-Burman statistical design was employed to identify the most critical factors. Of the eleven variables studied, peptone, sodium carbonate (buffer), and rotational speed exhibited significant positive influence while glucose showed a negative influence on PIPLC activity. Thus, low C/N ratio, aeration, and buffering agent were identified as important factors controlling production of PIPLC. These results contribute to the existing knowledge on PIPLC regulation in Staph. aureus and would help optimize production of this enzyme for its successful application in biochemical research and industry.
Alphonso P.,The Institute of Science |
Saraf A.,The Institute of Science
Asian Pacific Journal of Tropical Biomedicine | Year: 2012
Objective: To establish the chemical fingerprint of various secondary metabolites of Zanthoxylum rhetsa (Roxb.) DC, a medicinally important plant. Methods: Preliminary phytochemical screening for various secondary metabolites was carried out. HPTLC profiles of various individual secondary metabolites were done and profiles were developed for authentication. Result: The ethanolic extract of the fruit showed the presence of 8 Glycosides, 10 Flavonoids, 6 Essential Oils, 5 Anthraquinones, 9 bitter principles, 7 Coumarins and 8 Terpenoids. Conclusions: The development of such fingerprint for the fruits of Zanthoxylum rhetsa (Roxb.) DC is useful in differentiating the species from the adulterant and also act as biomarker for this plant in the Pharmaceutical industry. © 2012 Asian Pacific Tropical Biomedical Magazine.
Lavand A.B.,The Institute of Science |
Malghe Y.S.,The Institute of Science
Advanced Materials Letters | Year: 2015
Nanosized bare and carbon (C)-doped TiO2 were prepared using reverse micro-emulsion method. Synthesized powders were characterized with the help of X-ray diffractometer (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive X-ray spectroscope (EDX) and UV-visible spectrophotometer. EDX study reveals that as calcination temperature increases amount of C on TiO2 decreases. SEM and TEM images show that TiO2 particles are spherical in shape and after increasing the calcination temperature size of particle increases. Particle size of TiO2 obtained from TEM data varies between 10 to 17nm. Visible light photocatalytic degradation of 2,4,6-trichlorophenol (TCP) aqueous solution was carried out using nanosized bare as well as C-doped TiO2. UV-visible spectrophotometer and high pressure liquid chromatography (HPLC) techniques were used to analyze the concentration of TCP during the degradation process. In presence of visible light C-doped TiO2 obtained after calcination of precursor at 300°C shows better photocatalytic activity. Parameters affecting the photocatalytic process such as calcination temperature, amount of catalyst and TCP concentration are investigated. TCP photocatalytic degradation process was optimized. It is observed that to get better photocatalytic activity optimum amount of photocatalyst and concentration of TCP solution required are 1.0 gL-1 and 20 mg L-1 respectively. Reusability study indicates that C doped TiO2 prepared in the present work is highly stable and reusable photo catalyst. © 2015 VBRI Press.