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991.
V. G. Mishra M. K. Das V. V. Raut S. Jeyakumar R. M. Sawant B. S. Tomar K. L. Ramakumar 《Journal of Radioanalytical and Nuclear Chemistry》2014,300(1):125-128
Two methods were developed for determination Li content in Li–Al alloy by employing ion chromatography (IC) and capillary electrophoresis (CE) without any prior separation of Al matrix. In absence of suitable certified reference material the two methods were used to validate each other. Using a high capacity column and a weaker eluent methane sulphonic acid, it was possible to separate Li in IC without eluting strongly retained Al. The method showed good precision and sensitivity and was extended for analysis of routine samples. In the case of CE using imidazole as co-ion, Li was detected in CE by indirect detection. In view of no interference from Al, samples were analyzed without any matrix separation. The CE method was used successfully for sample analysis and results were compared with IC results. 相似文献
992.
Srinivasarao Veedhi Vikas Mishra Sunil Kulkarni Rajasekhar Gorthi 《Journal of Thermal Analysis and Calorimetry》2014,115(1):909-914
Thermal instability is a loss of thermal control which liberates high amount of energy and pressure. An incident took place during drying of an intermediate having amino alcohol functional group in agitated nutsche filter dryer at plant scale. During our investigation using advanced reactive system screening tool (ARSST), thermal decomposition was observed. Onset temperature of decomposition (T o) is at 85 °C, adiabatic temperature rise due to decomposition (ΔT ad) is 215 °C, maximum temperature attained due to decomposition (T max) is 300 °C, maximum self-heat rate (dT/dt)max is 6,215 °C min?1, and maximum rate of pressure rise (dP/dt)max is 1,442 psi min?1 obtained from ARSST experiments. T D24 value is 75 °C which was estimated experimentally. The correlations of these results were utilized to identify the root cause of this incident and necessary control measures were taken accordingly. 相似文献
993.
D. Mishra R. Arora S. Lahiri S. S. Amritphale N. Chandra 《Journal of Structural Chemistry》2014,55(3):525-529
In the present work alkaline iron oxide nanoparticles are synthesized by a novel solvo thermal approach and characterized exhaustively by various complementary techniques. Field emission scanning electron microscopy (FESEM) studies reveal that the size of nanoparticles is in the range of 31.5 nm to 96.9 nm. Energy-dispersive X-ray spectroscopy spectral analysis reveals the presence of oxygen, carbon, iron, and sodium. The X-ray diffraction studies confirm the formation of tetragonal NaFeO2 as the major phase along with orthorhombic NaFeO2·H2O and rhombohedral FeCO3 (siderite) as the minor phases. Fourier transform infrared spectroscopy exhibits peaks due to the stretching and bending vibrations of O-H, C=O, CH3-N, CH3, C-H, C-N, and Fe-O groups. Differential scanning calorimetry (DSC) results display an endothermic peak at 100.85°C and a very small endothermic peak at 791.56°C with 819.73 mJ and 349.28 mJ energies respectively. These DSC peaks can be correlated with thermal gravimetric analysis (TGA) peaks representing 31.04% weight loss and 7.70% weight loss respectively in the sample at around 160°C and 980°C respectively. 相似文献
994.
Ravi Kumar Thakur Akansha Mishra K.K.G. Ramakrishna Rohit Mahar Sanjeev K. Shukla A.K. Srivastava Rama P. Tripathi 《Tetrahedron》2014
A series of novel nucleoside analogues having dual bases (pyrimidine and triazole) and sugars have been synthesized by CuAAC reaction of azido sugars with propynylated pyrimidines. These compounds were evaluated for their in vitro α-glucosidase inhibitory activity. In this series, compounds 4b, 4d, 8a, 8b, 8c, 8e, 8g, 8h, and 8i exhibited very good inhibition of α-glucosidase enzyme. Nucleoside analogues 8a, 4b, 8h, and 8c displayed 47.4%, 41.8%, 39.4%, and 34.6% inhibition, respectively, comparable to the standard drug acarbose (53.4%). 相似文献
995.
Direct Synthesis of Hexagonal NaGdF4 Nanocrystals from a Single‐Source Precursor: Upconverting NaGdF4:Yb3+,Tm3+ and Its Composites with TiO2 for Near‐IR‐Driven Photocatalysis 下载免费PDF全文
Ying Chen Dr. Shashank Mishra Dr. Gilles Ledoux Dr. Erwann Jeanneau Marlene Daniel Prof. Jinlong Zhang Prof. Stéphane Daniele 《化学:亚洲杂志》2014,9(9):2415-2421
A novel single‐source precursor NaGd(TFA)4(diglyme) (TFA=trifluoroacetate) was synthesized, characterized thoroughly, and used to obtain the hexagonal phase of NaGdF4 nanoparticles as an efficient matrix for lanthanide‐doped upconverting nanocrystals (NCs) that convert near‐infrared radiation into shorter‐wavelength UV/visible light. These NCs were then used to prepare well‐characterized TiO2@NaGdF4:Yb3+,Tm3+ nanocomposites to extend the absorption range of the TiO2 photocatalyst from the UV to the IR region. While the visible/near IR part of the photoluminescent spectra remains almost unaffected by the presence of TiO2, the UV part is strongly quenched due to the absorption of TiO2 above its gap at approximately 380 nm by energy transfer or FRET. Preliminary results on the photocatalytic activity of the above obtained nanocomposites are presented. 相似文献
996.
Abstract A large number of castor oil based polyurethanes were prepared using various diisocyanates such as isophorone diisocyanate varying the NCO/OH ratio. All the polyurethanes were reacted with acrylamide and methacrylamide using ethylene glycol dimethacrylate as crosslinker and benzoyl peroxide as initiator. Thermogravimetric analysis of the polymers were followed using computer analysis method for assigning the kinetic mechanism. The degradation steps have been discussed in the light of kinetic parameters. The SEM of some of the IPNs has been studied and the morphology has been examined. The samples were subjected to wide angle X-ray diffraction analysis. Ruland and Vonk method was used to calculate the degree of crystallinity (Xcr). 相似文献
997.
Ephraim Vunain A. K. Mishra R. W. Krause 《Journal of Thermal Analysis and Calorimetry》2013,114(2):791-797
In this study, we investigate the effect of nano sized Fe3O4 nanoparticles on the mechanical and thermal properties of EVA/PCL–Fe3O4 composites. Composites were prepared using the melt mixing technique on a Rheomex mixer coupled to a single screw extruder. The fine dispersion of nano-Fe3O4 aggregates in the polymer matrices led to a significant improvement in the crystallinity, thermal and mechanical properties of EVA/PCL–Fe3O4 nanocomposites compared to that of native polymers due to improved interface bonding between the filler and the polymer matrix. Techniques such as scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and Instron for mechanical properties were used to characterize nanocomposites samples. The results obtained from this investigation demonstrated that composite materials could be promising raw materials in industry. 相似文献
998.
999.
Suryakant Mishra Amit Kumar Mondal Eilam Z. B. Smolinsky Ron Naaman Katsuhiro Maeda Tatsuya Nishimura Tsuyoshi Taniguchi Takumu Yoshida Kokoro Takayama Eiji Yashima 《Angewandte Chemie (International ed. in English)》2020,59(34):14671-14676
Spin‐dependent conduction and polarization in chiral polymers were studied for polymers organized as self‐assembled monolayers with conduction along the polymer backbone, namely, along its longer axis. Large spin polarization and magnetoresistance effects were observed, showing a clear dependence on the secondary structure of the polymer. The results indicate that the spin polarization process does not include spin flipping and hence it results from backscattering probabilities for the two spin states. 相似文献
1000.
A. Yadav A. Kaushik Y.K. Mishra V. Agrawal A. Ahmadivand K. Maliutina Y. Liu Z. Ouyang W. Dong G.J. Cheng 《Materials Today Chemistry》2020
This review article describes the state-of-art methodologies, mainly self-assembly routes, which are in practice to fabricate photonic crystals (PCs) for advanced applications. The self-assembly of colloidal building blocks is an effective, affordable, and tunable approach to fabricate varieties of photonic materials of desired shapes and surface areas. Because of easy fabrication and controlled performance factors, PCs emerged as a potential platform for designing and developing optical devices with desired features such as photonic bandgap, high reflectance/transmittance, low loss, and lasing in the visible range of wavelengths. To develop next-generation optoelectronics and optical system, significant efforts are being made to explore novel and cost-effective fabrication methods to design and develop 3D-PCs platform, which is covered in this mini-review. The challenges, potential alternatives, and prospects of self-assembled 3D PCs are also discussed in this review. 相似文献