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11.
The one-electron oxidation of toluidine blue by specific oxidising radicals such as Cl
2
−
, Tl(II), N3, Br
2
−
etc. has been studied by employing the pulse radiolysis technique. The Br
2
−
radical was found to be less efficient in oxidising toluidine blue as compared to Cl
2
−
., Tl+2 and N3. The semioxidised species exhibited only onepK
a indicating the presence of two conjugate acid-base forms whose spectral and kinetic features were evaluated. Reaction of
OH radicals with the dye gave rise to a transient species which exhibited spectral and kinetic features different from that
of the semioxidised species indicating that the mode of reaction of OH is different. 相似文献
12.
Leslie W. Deady Andrew B. Hughes Indumathy B. Mahadevan Nurul H. Quazi Leann M. Tilley 《合成通讯》2013,43(5):803-820
The synthesis of fluorescent 2,10-derivatives of the title chromophore are described. The substituents contain amino-reactive N-hydroxysuccinimde ester and thiol-reactive iodoacetamide groups for attachment to biomolecules. A phosphate derivative was also prepared as an enzyme substrate. 相似文献
13.
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
14.
Gundibasappa K. Nagaraja Vijayavittala P. Vaidya Koodamara Sheshappa Rai Kittappa M. Mahadevan 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):2797-2806
A novel and efficient method for the synthesis of substituted thiazepines and diazepines has been developed. A simple one-pot reaction of chalcones 1a–f with 1-amino-2-mercapto-5-phenyl-1,3,4-triazole and o-phenylenediamine in the presence of a catalytic amount of sodium acetate under microwave irradiation gave 2-(3,8-diphenyl-7,8-dihydro[1,2,4]triazolo[3,4-b][1,3,4]thiadiazepin-6-yl)phenoles 2a–f and 2-(2-phenyl-2,3-dihydro-1H-1,5-benzodiazepin-4-yl)phenoles 3a–f, respectively. The structure of all the synthesized compounds was elucidated on the basis of elemental analysis, IR, 1H and 13C NMR, and mass spectral data. 相似文献
15.
B. P. Nandeshwarappa D. B. Aruna Kumar M. N. Kumaraswamy Y. S. Ravi Kumar H. S. Bhojya Naik K. M. Mahadevan 《Phosphorus, sulfur, and silicon and the related elements》2013,188(7):1545-1556
A series of novel substituted thiopyrano[2,3-b]quinolines 4a–e , 5a–e , and 6a–e were prepared from substituted 3-formyl-2-mercapto quinolines 2a–e , on reaction with ethyl acetoacetate, diethyl malonate, and ethyl cyanoacetate 3a–c by microwave irradiation in the presence of piperidine. Synthesized compounds were evaluated for antimicrobial activities. Among the compounds tested, 7-chloro-2-oxo-2H-thiopyrano[2,3-b]quinoline-3-carbonitrile 6d and 7-nitro-2-oxo-2H-thiopyrano[2,3-b]quinoline-3-carbonitrile 6e were highly active against S. aureus and M. roseus. 相似文献
16.
Abstract Palladium(II) acetate has been anchored onto a copolymer support containing pyridyl and carboxyl groups. XPS studies showed the Pd 3d binding energies for the recovered catalyst to be less by 1 eV after being used in hydrogenation studies. However, x-ray studies and a chemical test based on KCN treatment failed to reveal any palladium oxide or palladium metal formation in the recovered catalyst. It is presumed that an acetate ligand is lost during hydrogenation, which could be the reason for the lowering of the palladium 3d binding energies in the recovered catalyst. Results of investigations of the hydrogenation of olefins and selectivity of the catalyst toward the hydrogenation of dienes and alkynes are presented. The loss of palladium due to leaching under the reaction conditions employed was found to be very low (<1%/cycle). 相似文献
17.
S. Vijay Kumar T. E. Musturappa S. Prasannakumar K. M. Mahadevan 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(11):1161-1169
Free radical copolymerization of N‐vinyl‐2‐pyrrolidone with 2‐ethoxyethyl methacrylates was carried out with 2,2′‐azobisisobutyronotrile as an initiator in 1,4‐dioxane. The resulting copolymer was characterized by FTIR, H1‐NMR and C13‐NMR spectroscopic techniques thermal properties of copolymer were determined by DSC and TGA. The reactivity ratios of the monomers were computed by the Fineman‐Rose (F‐R), Kelen‐Tudos (K‐T) and extended Kelen‐Tudos (EK‐T) method at lower conversion, using the data obtained from both FTIR and elemental analysis studies; the results are in good agreement with each other. The average reactivity ratio, Alfrey‐Price Q and e values were found to be r 1=0.769, r 2=0.266 and Q 1=0.0859, e 1=0.4508, respectively for NVP/EOEMA copolymer. The distribution of monomer sequence along the copolymer chain was calculated using a statistical method based on obtained reactivity ratio. The number average molecular weight and polydispersity were determined by GPC. 相似文献
18.
Vethathiri Pakkirisamy Sridhar Mahadevan Surianarayanan Suthangathan Paramashivan Sivapirakasam Asit Baran Mandal 《Journal of Thermal Analysis and Calorimetry》2013,112(3):1335-1341
The objective of this article is to generate thermal decomposition data on fireworks tip mixture, a mixture used to coat the tip of fireworks, for easy ignition. This mixture has reportedly involved in triggering many accidents in fireworks industry. Different quantities of water were added to the mixture and its thermal characteristics were studied. Differential scanning calorimeter was used for screening tests and accelerating rate calorimeter was used for detailed studies in adiabatic and isothermal modes. The self-heat rate data obtained showed onset temperature for different quantity of water, at a range of 80–170 °C. The mixture with 40 % water wt/wt had onset at 80 °C in adiabatic mode. The same mixture on isoaging at 40 °C exhibited exothermic characteristics with a substantial rise in system pressure (57 bar). The heats of exothermic decomposition and Arrhenius kinetics were also computed. 相似文献
19.
Karthikeyan Rajendran Surianarayanan Mahadevan Rajendhran Jeyaprakash Gunasekaran Paramasamy Asit Baran Mandal 《Applied biochemistry and biotechnology》2013,171(6):1328-1338
Bacillus badius isolated from soil has been identified as potential producer of penicillin G acylase (PGA). In the present study, batch experiments performed at optimized inoculum size, temperature, pH, and agitation yielded a maximum PGA of 9.5 U/ml in shake flask. The experiments conducted in bioreactor with different oxygen flow rates revealed that 0.66 vvm oxygen flow rate could be sufficient for the maximum PGA activity of 12.7 U/ml. From a detailed investigation on the strategies of the addition of phenyl acetic acid (PAA) for increasing the production of PGA, it was found that the controlled addition of 10 ml of 0.1 % (w/v) PAA once in every 2 h from 6th hour of growth showed the maximum PGA activity of 32 U/ml. Thus, our studies for the first time showed that at concentration above 0.1 % (w/v) PAA, the PGA production decreased. This selective condition paves the way for less costly bioprocess for the production of PGA. 相似文献
20.
Kim C Liu Y Kühnle A Hess S Viereck S Danner T Mahadevan L Weitz DA 《Physical review letters》2007,99(2):028303
Colloidal suspensions are susceptible to gravitationally induced phase separation. This can be mitigated by the formation of a particle network caused by depletion attraction. The effectiveness of this network in supporting the buoyant weight of the suspension can be characterized by its compressional modulus. We measure the compressional modulus for emulsion networks induced by depletion attraction and present a model that quantitatively predicts their gravitational stability. We also determine the relationship between the strength of the depletion attraction and the magnitude of the compressional modulus. 相似文献