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11.
Chellappan Shobana Basuvannan Rangasamy Subramani Surendran Ramakrishnan Kalai Selvan Mathan Ramesh 《Journal of Cluster Science》2018,29(2):267-279
Biosynthesis of silver nanoparticles has received considerable attention due to their cost-effective, eco-friendly and medicinal values. In this study, silver nanoparticles (Ag NPs) were synthesised using the aqueous leaf extracts of Piper nigrum. TEM images revealed that the particle is spherical with 20–50 nm in size. Furthermore, to evaluate the toxicity of synthesized Ag NPs, fish Labeo rohita were exposed to two different concentrations (2.5 µg/L as the treatment I and 5 µg/L as treatment II) for 35 days, and antioxidant parameters and histology of gill, liver and kidney were examined. A biphasic response in the activity of glutathione S-transferases (GST) was observed in gill and liver of fish. GST activity in the kidney of fish was significantly increased when compared to control group. Glutathione reductase (GR) activity in organs/tissue of fish were found to be increased while peroxidase (POD) activity was significantly decreased. Histopathological changes such as hyperplasia, proliferation of epithelial cells and fusion of lamellae were observed in both the concentrations. In liver, necrosis, nuclear degeneration and dilation of sinusoids were observed. Subsequently, the representative effects of POD activity were assessed based on the Box–Behnken Equation, 3-D contour plot and ANOVA analysis through response surface methodology analysis. 相似文献
12.
Prathibha T. Selvan B. Robert Hemalatha V. Suba M. Amutha Chandra Swaroop Shaji Dinu Vijay Soja K. Sundararajan K. Ramanathan N. 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(5):2383-2391
Journal of Radioanalytical and Nuclear Chemistry - A spectrophotometric method, circumventing interference from F− ions, during estimation of Zr in U-Zr alloy fuel, has been developed.... 相似文献
13.
Pallavi Prasad Dhanashree Selvan Prof. Dr. Saumen Chakraborty 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(55):12494-12509
Hydrogen is a clean and sustainable form of fuel that can minimize our heavy dependence on fossil fuels as the primary energy source. The need of finding greener ways to generate H2 gas has ignited interest in the research community to synthesize catalysts that can produce H2 by the reduction of H+. The natural H2 producing enzymes hydrogenases have served as an inspiration to produce catalytic metal centers akin to these native enzymes. In this article we describe recent advances in the design of a unique class of artificial hydrogen evolving catalysts that combine the features of the active site metal(s) surrounded by a polypeptide component. The examples of these biosynthetic catalysts discussed here include i) assemblies of synthetic cofactors with native proteins; ii) peptide-appended synthetic complexes; iii) substitution of native cofactors with non-native cofactors; iv) metal substitution from rubredoxin; and v) a reengineered Cu storage protein into a Ni binding protein. Aspects of key design considerations in the construction of these artificial biocatalysts and insights gained into their chemical reactivity are discussed. 相似文献
14.
Umesh Balakrishnan Nallamuthu Ananthi Sakthivel Tamil Selvan Ravindra Pal Dr. Katsuhiko Ariga Dr. Sivan Velmathi Dr. Ajayan Vinu Dr. 《化学:亚洲杂志》2010,5(4):897-903
The immobilization of chiral oxazaborolidine complex in the well‐ordered mesochannels of SBA‐15 is demonstrated by a postsynthetic approach using 3‐aminopropyltriethoxysilane as a reactive surface modifier. The immobilized catalysts are characterized by various techniques, such as XRD, nitrogen adsorption, HRSEM, UV/Vis diffuse reflectance spectroscopy, and FTIR spectroscopy. The catalysts are used for the enantioselective reduction of aromatic prochiral ketones. The activity of the chiral oxazaborolidine complex immobilized SBA‐15 catalysts is also compared with that of the pure chiral oxazaborolidine complex, which is a homogeneous catalyst. It is found that the activity of the chiral complex immobilized SBA‐15 heterogeneous catalyst is comparable with that of the homogeneous catalyst. 相似文献
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16.
R. Kalai Selvan C. O. Augustin M. I. Oshtrakh O. B. Milder V. A. Semionkin 《Hyperfine Interactions》2007,179(1-3):33-38
A series of (CuFe2O4)1???x (SnO2) x nanocomposites (x = 0, 1, 5, 10, 20 wt.%) have been prepared by urea–nitrate combustion method. The room temperature Mössbauer spectra of CuFe2O4 and (CuFe2O4)0.99(SnO2)0.01 contained two sextets while remaining samples contained at least four sextets with additional doublet indicating the presence of paramagnetic phase. The variations of isomer shift, quadruple splitting and magnetic hyperfine field values were found with the addition of SnO2. 相似文献
17.
B.K. Nayak B. Eaton J.A.A. Selvan J. McLeskey M.C. Gupta R. Romero G. Ganguly 《Applied Physics A: Materials Science & Processing》2005,80(5):1077-1080
Semiconductor laser (=805 nm) crystallization of hydrogenated amorphous silicon (a-Si:H) deposited on a low-cost fluoride-doped tin-oxide-coated glass substrate is demonstrated. X-ray diffraction confirms that the structure of the polycrystalline silicon thus formed shows (111), (220), and (311) peaks. A sharp Raman peak at 520 cm-1 further confirms the crystallization. Atomic force microscope images of a Secco-etched laser-treated sample reveal the granular structure of the poly-Si. Grains as big as 10 times the film thickness are readily obtained and sample as thick as 5000 Å is easily crystallized. The method can be extended to films with a thickness of several microns. PACS 42.55.Px; 42.62.Cf; 81.05.Gc 相似文献
18.
B. Selvan K. Ramachandran B. C. Pillai D. Subhakar 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2011,61(3):663-675
Temperature of the substrate during plasma heating and spraying plays an
important role on quality of the substrate and coating. In this study a
three dimensional numerical model is developed to simulate the Ar-N2
plasma jet and conjugate heat transfer between plasma and substrate. The
influencing of operating parameters on thermal flux from the plasma to the
substrate and substrate temperature are discussed. Transient simulations are
carried out to predict the substrate temperature with heating time. The arc
current, gas flow rate, stand-off distance, substrate material and
environment around the substrate significantly affect the thermal flux to
the substrate. Heat flux to the substrate cannot be neglected in the coating
built-up models. Present model is validated by comparing the results of
present model with previous predictions and measurements. 相似文献
19.
R. Kalai Selvan A. Gedanken P. Anilkumar G. Manikandan C. Karunakaran 《Journal of Cluster Science》2009,20(2):291-305
We report herein on an efficient sonochemical method for the synthesis of rare earth orthovanadate nanorods/nanoparticles/nanospindles,
(general formula RVO4; R = La, Ce, Nd, Sm, Eu and Gd). TGA, XRD, FTIR, Raman, UV–Vis, and TEM studies are employed for their characterization and
for understanding their morphologies. In order to vary the textural properties of the rare earth vanadates, two surfactants,
polyethylene glycol (PEG) and amphiphilic triblock copolymer Pluronic P123, are chosen in the preparation. While the sonochemical
synthesis in the presence of PEG results in the formation of nearly spherical nanoparticles of LaVO4, CeVO4, SmVO4 and EuVO4, the same technique yields nanorods and nanospindles of NdVO4 and GdVO4, respectively. When P123 is used as the surfactant, the morphologies of RVO4 are strikingly different, and in most cases nanorods and nanospindles are formed. The photocatalytic activities of the rare
earth orthovanadate have been evaluated by studying the degradation of methylene blue, and CeVO4 seems to be the best catalyst in the heterogeneous photolysis. The electrocatalytic activity of the vanadates has been examined
by studying the hydrogen evolution reaction using a linear sweep voltammogram technique in 1 M of a H2SO4 solution. GdVO4 seems to be the best electrocatalyst.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
20.
K. Dasthaiah B. Robert Selvan A. S. Suneesh K. A. Venkatesan M. P. Antony R. L. Gardas 《Journal of Radioanalytical and Nuclear Chemistry》2017,313(3):515-521
The imidazolium bis(2-ethylhexyl) phosphate moiety was chemically attached on silica gel by chemical modification. The resulting product ([SG-Im]+ [DEHP]?) was characterized by FT-IR spectroscopy, thermogravimetry and elemental analysis. The sorption behavior of Am(III) and Eu(III) on [SG-Im]+ [DEHP]? was studied from dilute nitric acid medium for the separation of Am(III) and Eu(III) from aqueous waste. The effect of time, concentrations of nitric acid and europium in aqueous phase on the distribution coefficient (K d) was studied. The study indicated the possibility of using modified silica for the separation of Eu(III) from Am(III) with high separation factors (>50 at 0.1 M HNO3). 相似文献