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31.
Sankar J Rath H PrabhuRaja V Chandrashekar TK Vittal JJ 《The Journal of organic chemistry》2004,69(15):5135-5138
Three new methods for syntheses of modified oxa corroles bearing one meso free carbon in reasonably good yields are reported. The formation of the meso carbon bridge and the direct pyrrole-pyrrole linkage occur in a single step by a simple condensation and coupling with TFA as a catalyst with appropriate precursors. The reactions are optimized with different conditions by varying the meso substituents, acid catalyst concentration, and the nature of the solvent to afford corroles in good yields. 相似文献
32.
A. Chaudhury R. Khatirkar N.N. Viswanathan V. Singal A. Ingle S. Joshi I. Samajdar 《Journal of magnetism and magnetic materials》2007
Commercial supply, from several steel manufacturers, of low-silicon non-grain-oriented electrical steel was monitored over a span of several years. A total of 51 samples were selected—selected from many hundreds on the basis of large differences in magnetic properties, but absence of significant variations in chemistry (other than differences in silicon percentage). The selected samples were analyzed for crystallographic texture and for grain size. 相似文献
33.
Daiwon Choi Donghai Wang Vish V. Viswanathan In-Tae Bae Wei Wang Zimin Nie Ji-Guang Zhang Gordon L. Graff Jun Liu Zhenguo Yang Tien Duong 《Electrochemistry communications》2010,12(3):378-381
Li-ion batteries made from LiFePO4 cathode and anatase TiO2/graphene composite anode were investigated for potential application in stationary energy storage. Fine-structured LiFePO4 was synthesized by a novel molten surfactant approach whereas anatase TiO2/graphene nanocomposite was prepared via self-assembly method. The full cell that operated at 1.6 V demonstrated negligible fade even after more than 700 cycles at measured 1 C rate. While with relative lower energy density than traditional Li-ion chemistries interested for vehicle applications, the Li-ion batteries based on LiFePO4/TiO2 combination potentially offers long life and low cost, along with safety, all which are critical to the stationary applications. 相似文献
34.
Ramesh Sundar Amalraj Nagarathinam Selvaraj Ganesh Kumar Veluswamy Rahul Pathirickal Ramanujan Raveendran Muthurajan Malathi Palaniyandi Ganesh Kumar Agrawal Randeep Rakwal Rasappa Viswanathan 《Electrophoresis》2010,31(12):1959-1974
Sugarcane is an important commercial crop cultivated for its stalks and sugar is a prized commodity essential in human nutrition. Proteomics of sugarcane is in its infancy, especially when dealing with the stalk tissues, where there is no study to date. A systematic proteome analysis of stalk tissue yet remains to be investigated in sugarcane, wherein the stalk tissue is well known for its rigidity, fibrous nature, and the presence of oxidative enzymes, phenolic compounds and extreme levels of carbohydrates, thus making the protein extraction complicated. Here, we evaluated five different protein extraction methods in sugarcane stalk tissues. These methods are as follows: direct extraction using lysis buffer (LB), TCA/acetone precipitation followed by solubilization in LB, LB containing thiourea (LBT), and LBT containing tris, and phenol extraction. Both quantitative and qualitative protein analyses were performed for each method. 2‐DE analysis of extracted total proteins revealed distinct differences in protein patterns among the methods, which might be due to their physicochemical limitations. Based on the 2‐D gel protein profiles, TCA/acetone precipitation‐LBT and phenol extraction methods showed good results. The phenol method showed a shift in pI values of proteins on 2‐D gel, which was mostly overcome by the use of 2‐D cleanup kit after protein extraction. Among all the methods tested, 2‐D cleanup‐phenol method was found to be the most suitable for producing high number of good‐quality spots and reproducibility. In total, 30 and 12 protein spots commonly present in LB, LBT and phenol methods, and LBT method were selected and subjected to eLD‐IT‐TOF‐MS/MS and nESI‐LC‐MS/MS analyses, respectively, and a reference map has been established for sugarcane stalk tissue proteome. A total of 36 nonredundant proteins were identified. This is a very first basic study on sugarcane stalk proteome analysis and will promote the unexplored areas of sugarcane proteome research. 相似文献
35.
36.
S. Viswanathan 《Journal of Geometry》1994,51(1-2):178-186
In this paper we give tight lower and upper bounds for the number of edge guards required for covering spiral polygons. We have proved that [(n + 2)/5]edge guards are necessary and sufficient to cover a spiral polygon. It has been shown by Aggarwal [2] that [(n + 2)/5]diagonal guards are necessary and sufficient to cover a spiral polygon. Edge guards are more restrictive than diagonal guards. Hence the previous theorem can be got as a corollary using our theorem. The necessary condition of the edge guard problem for spiral polygons has not been investigated although the diagonal guard problem for the same has been solved [2]. The necessary proof of the edge guard problem follows from the necessary condition of the diagonal guard problem but we have given an alternate proof of necessity. 相似文献
37.
38.
Udayakumar VELU Alexander STANISLAUS Gayathri VIRUPAIAH Shivakumaraiah Viswanathan BALASUBRAMANIAN 《催化学报》2011,32(2):280-285
A polymer-supported palladium-imidazole catalyst was used to catalyze the hydrogenation of various olefins under mild conditions. The rate of hydrogenation was studied. The effects of factors such as substrate concentration,catalyst concentration,partial pressure of hydrogen and temperature on initial rate of reaction of selected olefins were investigated. A mechanism for the reaction was proposed from the rate equation. The effects of the solvent and structure of the olefin on the rate of hydrogenation were investigated. The catalyst showed good reusability without any leaching of metal from the support. The homologous analog of the polymer-supported catalyst could not be used as catalyst for the hydrogenation of olefins in methanol because there was precipitation of the metal during reaction. 相似文献
39.
The whole plant of Phyllanthus wightianus (PW) was investigated for the antioxidant effects of three successive extracts: hexane (PWHE), chloroform (PWCE) and methanol (PWME), using standard in vitro models. The PWME exhibited a strong scavenging effect on 2,2-diphenyl-2-picryl hydrazyl (DPPH) free radicals and nitric oxide radical inhibition activity, due to possessing the highest content of tannins. The free radical scavenging effect of PWME was comparable with that of reference antioxidants. The extracts were subjected to isolation of their compounds: isomeric sterol mixture (1) [stigmasterol (1a), compesterol (1b) and β-sitosterol (1c)], fredilin (2), lupeol (3), gallic acid (4), bergenin (5), geraniin (6), corilagin (7) and ellagic acid (8) were established through the use of column chromatographic methods and spectral data. The percentage of tannins was also determined and estimated using the HPLC method. The data suggest that tannins are the active antioxidant compounds of P. wightianus. This study provides proof for the ethnomedical claims and reported biological activities of this plant. The plant therefore has very good therapeutic potential. 相似文献
40.
S. Gopal C. Viswanathan M. Thamilselvan K. Premnazeer Sa. K. Narayandass D. Mangalaraj 《Ionics》2004,10(3-4):300-303
Indium Selenide thin films were electrodeposited on Indium Tin Oxide (ITO) coated glass substrates from a mixture of Indium
trichloride (InCl3) and selenium dioxide (SeO2) in aqueous solution by the potentiostatic electrodeposition technique. The InSe films showed that Mott’s variable-range
hopping conductivity (VRH) is dominant under low field (∼2×105 Vcm−1) condition. At high field the Current-Voltage studies (in the temperature range 300 – 380 K) revealed that the conductivity
of Indium selenide thin films is of Poole-Frenkel type. The plot drawn between Ln (I/V) and tV showed a straight line and
also the experimental data and the theoretical data closely matches. Hence Poole-Frenkel mechanism is confirmed and discussed
in detail.
Paper presented at the 2nd International Conference on Ionic Devices, Anna University, Chennai, India, Nov. 28–30, 2003. 相似文献