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Venkatapuram Padmavathi Mudigonda Rajagopala Sarma Adivireddy Padmaja Dandu Bhaskar Reddy 《Journal of heterocyclic chemistry》2003,40(5):933-937
Novel 2‐pyrazolines were obtained by the cycloaddition of diazomethane to bis(arylsulfonylethenyl)‐sulfones ( 3 ) and 1‐arylsulfonyl‐2‐styrylsulfonylethenes (7). Dehydrogenation of 2‐pyrazolines with chloranil gave pyrazoles. 相似文献
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Gurumurthy Dummi Mahadevan Feng Zhao 《Journal of Radioanalytical and Nuclear Chemistry》2017,314(3):1477-1485
Currently, the existing microbial radionuclides transformations processes are not completely understood. Bacteria, however, solubilize radionuclides by direct enzymatic reduction, or indirectly by its metabolites and by facilitating electrochemical redox systems. Microbes exchange electrons from proteins, organelles, metabolites to metals and electrodes have strengthened the novel bioremediation methods. In contrast, MRCs based on this redox behavior has offered considerable value over traditional treatment because of growing renewable and conception of energy incentives methods. Moreover, MRCs provides a flexible platform that enables us to access integrated treatment process of generating power and for recovering valuable resources from the contaminated sites. 相似文献
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The kinetics of oxidation of ethyl S-phenylmercapto acetate and several para-, meta-, and ortho-substituted ethyl S-phenylmercaptoacetates by chloramine-B have been studied in 50% (V/V) aqueous ethanol medium containing phosphate buffer. This oxidation is of first order with respect to substrate and zero order with respect to oxidant. A catalytic effect of mercury is observed and the order with respect to mercury is fractional (0.74). The increase in pH decreases the rate of oxidation and the order with respect to H+ is 0.05. In general electron-releasing substituents accelerate the rate while electron-attracting groups retard the rate. A good correlation is found to exist between log k 1 and Hammett constants. Susceptibility of the reaction to the steric effect of ortho-substituents has been analyzed in the light of application of Taft's steric energy parameters. © John Wiley & Sons, Inc. 相似文献
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Water-soluble self-assembled nanostructures were synthesised by simple counter ion exchange of thiacyanine dyes which helps in the formation of nematic (N) and hexagonal (M) chromonic liquid-crystalline (CLCs) phases. Conjugated double bonds as central spacers connected between two benzothiazole segments affect water solubility and liquid crystal formation. Aggregation-dependent properties characterised by ultraviolet–visible, fluorescence and 1H nuclear magnetic resonance spectroscopy. Sol–gel reaction of dye aggregates with silica species furnishes entangled nanotubular fibres with constant diameter and their length in excess of micrometres, having templates of pore sizes below the mesoporous range. The π–π stacked chromonic aggregate dyes are also of importance in shape selective catalysis, adsorption, desorption micro-patterned materials, and provide a significant step towards biosensor medical applications because of their water-soluble nature. 相似文献
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Gurumurthy Hegde Govindaswamy Shanker S. M. Gan A. R. Yuvaraj Syed Mahmood Uttam Kumar Mandal 《Liquid crystals》2016,43(11):1578-1588
Azobenzene derivatives containing phenyl/4-halogen-phenyl 4-{(E)-[4-(pent-4-en-1-yloxy)phenyl]diazenyl}benzoate group with different electronegative substituent (H, F, Cl, Br and I) at other end was synthesised. These azo-based benzoate derivatives have been characterised by FTIR, 1H-NMR, 13C-NMR, elemental analyser, POM and UV-Vis spectroscopy. Photosaturation at 358 nm obtained after 82 s of UV irradiation and the longest thermal back relaxation time of 45 h recorded by UV-Vis. The azo derivative could be possible photolock under UV light, as observed by the improved thermal back relaxation time. The resulting photolockable chain of azobenzene might prove valuable in the development of optical device application. These azobenzene moieties also exhibit liquid crystalline behaviour with respect to the halogen substitution as an electron withdrawing group shows that strong structure property relationship exists among them. 相似文献
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V. Padmavathi D. R. C. Venkata Subbaiah M. Rajagopala Sarma A. Balaiah 《Heteroatom Chemistry》2004,15(7):477-481
4‐Substituted pyrazolidinediones, isoxazolidinediones, and 5‐substituted pyrimidinetriones, thioxopyrimidinediones were obtained by exploiting gem‐diester functionality in mono‐ and di‐substituted dimethyl malonates. © 2004 Wiley Periodicals, Inc. Heteroatom Chem 15:477–481, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20053 相似文献
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Avula Sreenath Gurumurthy Ramachandran James H. Vincent 《Particle & Particle Systems Characterization》1999,16(6):257-265
This paper describes the different ways of analyzing the output of a real-time device for measuring and counting airborne particles, the aerodynamic particle sizer (APS). This instrument is very widely used in aerosol research throughout the world. It is a time-of-flight instrument in which a particle's measured transit time in the changing flow in a jet passing between two laser beams is converted to its aerodynamic diameter. As the particle passes between the two laser beams, two signal processors, the small particle processor (SPP) and the large particle processor (LPP), independently provide measures of the particle's transit time from the light pulses that are produced. This information is related to the aerodynamic particle diameter of the particle (dae) by means of calibration against ‘unit’ density (1000 kg/m3) spheres. If more than one particle is involved in the analysis of particle transit time, then it gives rise to coincidence effects, resulting in ‘phantom’ particle generation. The SPP is known to generate phantom counts, while the LPP is known to reduce phantom counts. A new method is described in this paper that gives guidance on how to deal with such coincidence problems. The principle is that it relies on additional information to obtain ‘correction factors’. In this case, well-established theory for the aspiration efficiencies of thin-walled aerosol sampling probes has been used along with corresponding experimental data obtained in a wind tunnel using the APS. Results using this method are compared with various other methods that have been tried in the past. The paper provides insights on to how the user can operate the APS to avoid counting errors like those described, and the advantages and limitations of different correction methods are discussed. 相似文献