Authors:B. S. Kademani, Vijai Kumar, Anil Sagar, and Anil Kumar
This paper attempts to highlight quantitatively the growth and development of world literature on thorium in terms of publication
output as per Science Citation Index (1982-2004). During 1982-2004 a total of 3987 papers were published by the scientists
in the field 'thorium'. The average number of publications published per year were 173. The highest number of papers 249 were
published in 2001. The spurt in the literature output was reported during 1991-2004.There were 94 countries involved in the
research in this field. USA is the top producing country with 1000 authorships (21.11%) followed by India with 498 authorships
(10.51%). Authorship and collaboration trend was towards multi-authored papers. Intensive collaboration was found during 1990-2004.One
paper 'Nuclear Instruments and Methods in Physics Research - A 406 (3) (1998) 411-426' had 64 collaborators. There were 586 international collaborative papers. Bilateral collaboration accounted
for 80.55 percent of total collaborative papers. Bhabha Atomic Research Centre (India) topped the list with 153 authorships
followed by Los Alamos National Laboratory (USA) with 105 authorships.The most preferred journals by the scientists were: Journal of Radioanalytical Nuclear Chemistry with 181 papers, Radiochimica Acta with 139 papers, Journal of Radioanalytical Nuclear Chemistry -Articles with 127 papers, Geochimica Cosmochimica Acta with 96 papers, Health Physics with 91 papers, Applied Radiation and Isotopes with 88 papers, Journal of Alloys and Compounds with 65 papers, Earth and Planetary Science letters with 59 papers and Chemical Geology, Indian Journal of Chemistry -A, Radiation Protection Dosimetry with 55 papers each. English was the most predominant language used by the scientists for communication. The high frequency
keywords were: Thorium (500), Uranium (284), Separation (94), Thorium Isotopes (90), Thorium (IV) (86), Seawater (73), Solvent
Extraction (70), and Rare Earth Elements (68).
Heterobinuclear macrocyclic complexes, i.e. CuCoL 1, CuFeL 2 and CoVL 3, have been synthesized and anchored onto modified carbamate Al2O3 in order to obtain new hybrid supported catalysts. The identities of the supported metal complexes were confirmed by FT–IR, SEM–EDS and AAS. TGA indicated that the catalysts were thermally stable up to 230 °C. These catalysts have been tested for the functionalization of n-hexane with molecular O2. The best result was obtained with CuFeL 2 over Al2O3 (ca. 19% overall conversion; 78% selectivity: hexan-2-one plus hexan-2-ol) and promoted conversion could be obtained with 2-pyrazinecarboxylic acid (as co-catalyst). The effects of various factors (temperature, O2 pressure, reaction time and catalyst concentration) were also investigated in detail. The impact of both C- and O- centred radical traps was also assessed to establish a radical mechanism.
Authors:Rakesh Kumar, Anil Kumar, and Ashok Khanna
The solid superacid catalysts were synthesized by loading AlCl3 on silica gel for benzene alkylation. The prepared catalysts were characterized by various techniques such as BET, FT-IR, MAS-NMR and scanning electron microscopy. The Hammett acidity function (Ho) was used to determine the acid strength of the solid catalysts by employing various Hammett indicators. These catalysts were found to be highly active for benzene alkylation with 1-dodecene. The catalyst prepared by the wet impregnation technique showed ~33% selectivity of 2-LAB and AlCl3 vapor treated silica gel catalyst (SG-AlCl3v) showed ~45% selectivity of 2-LAB. The FT-IR spectra of the SG-AlCl3v catalyst showed equal number of Br⊘nsted and Lewis acidic sites. The life of SG-AlCl3v catalyst was evaluated in a packed bed reactor and was found to be ~300 h for benzene alkylation with 1-dodecene. The 27Al MAS-NMR of SG-AlCl3v catalyst showed a band at 96.578 ppm, which is attributed to 4-coordinated Al species (2O, 2Cl). The Ho of SG-AlCl3v catalyst was found in the range of −12.70 > Ho > 13.16, indicates the superacidic nature. A nonlinear optimization algorithm was developed in MATLAB 7.4.0 and used to determine the kinetic parameters of the benzene alkylation with 1 dodecene in presence of SG-AlCl3v catalyst. The concentrations of the products predicted by the model was found in good agreement with experiments.
Authors:B. Kademani, Vijai Kumar, Ganesh Surwase, Anil Sagar, Lalit Mohan, Anil Kumar, and C. Gaderao
The paper analyses the citations to 1733 publications published during 1970–1999 by the Chemistry Division at Bhabha Atomic
Research Centre, using Science Citation Index 1982–2003 as the source data. The extent of citations received, in terms of
the number of citations per paper, yearwise break up of citations, domainwise citations, self-citations and citations by others,
diachronous self-citation rate, citing authors, citing institutions, highly cited papers, the categories of citing documents,
citing journals and distribution of citations among them etc. are determined. During 1982–2003 chemistry Division publications
have received a total of 11041 citations. The average number of citations per year was 501.86. The average number of citations
per publication was 6.37. The highest number of citations received were 877 in 2001. The citation rate was peaked during 1990–2003
as maximum 9145 (82.82%) citations were received during the period. Total self-citations were 3716 (33.66%) and citations
by others were 7325 (66.34%). Mean diachronous self-citation rate was 36.16. Citation time lag was zero for 144 (15.52%) papers
and one year for 350 (37.72%) papers. Single authored publications (168) have received 456 (4.13%) citations and 1565 multi-authored
publications have received 10585 (95.87%) citations. The core citing authors were: J. P. Mittal (695) followed by V. K. Jain
(524), H. Mohan (471), T. Mukherjee (307), R. M Iyer (253), H. Pal (251), J. V. Yakhmi (211), A. V. Sapre (174), D. K. Palit
(161), N. M. Gupta (128), and S. K. Kulshrestha (116). Citation life cycles of four highly cited papers was discussed. The
core journals citing Chemistry Division publications were: J. Phys. Chem.-A (436 citations), Chem. Phys. Lett. (372), J. Phys. Chem. (355), J. Chem. Phys. (353), J. Organomet. Chem. (285), J. Phys. Chem.-B (279), J. Photochem. Photobiol.-A (263), Langmuir (245), J. Am. Chem. Soc. (226), Physica-C (225), Radiat. Phys. Chem. (217), Inorg. Chem. (215) and Indian J. Chem.-A (207).
Authors:Alamgir A. Dar, Payare L. Sangwan, Nasseb Singh, and Anil Kumar
Herein, the isolation, characterization, and method validation of 5 bioactive terpenoids, viz., taraxerol (1), 3ß-hydroxyoleanane-12-one (2), betulinic acid (3), ursolic acid (4), and oleanolic acid (5) from Codonopsis ovata has been reported. A novel, accurate, and cost-effective high-performance thin-layer chromatography method was developed for the simultaneous quantification of 5 natural products on silica-gel 60 F254 plate using a ternary solvent system, n-hexane-ethyl acetate-formic acid (8.0:2.0:0.4, V/V). Markers were quantified after post-chromatographic derivatization with ceric ammonium sulfate reagent. The developed method was validated as per the International Conference on Harmonization (ICH) guidelines. All calibration curves showed a good linear relationship (r > 0.995) within the test range. Precision was evaluated by intra- and inter-day tests with relative standard deviations <1.99%, and accuracy validation recovery 85.66–91.87 with relative standard deviations >2.00°%. Oleanolic acid (5) and ursolic acid (4) were found in major quantity which is advantageous because of their anticancer, anti-inflammatory, anti-mutagenic, and anti-obesity activities. Based on our results, the developed method features good quantification parameters and can serve as an effective quality control method for standardization of Codonopsis ovata.
Authors:Neelam Upadhyay, Anil Kumar, Ankit Goyal, and Darshan Lal
Reversed-phase thin-layer chromatography (RP-TLC) is a sensitive, reliable, and reproducible technique, which can analyze a number of components simultaneously. This technique was exploited in the present study to identify the adulteration of vegetable oils (groundnut, soybean, and sunflower oil) in ghee, using the fact that β-sitosterol, an unsaponifiable matter, is present in vegetable oils, while absent in pure ghee. For this, RP-TLC of reference standards, unsaponifiable matter of pure ghee (cow and buffalo), pure vegetable oils, and the ghee adulterated with these vegetable oils (≥1%) was carried out on plates with different stationary phases, viz., RP-18, RP-8, and RP-2 plates using solvent system comprising of petroleum ether, acetonitrile, and methanol. The results revealed that adulteration of vegetable oils in ghee can easily be detected at a level of as low as 1 percent on RP-18 and RP-8 plates, while RP-2 plate did not offer any help in detection of adulteration. Thus, with the help of RP-TLC, a robust technique, the purity of ghee can be screened with respect to the presence of vegetable oils.
Regioregular poly(3-hexylthiophene), rr-P3HT, has been commonly synthesized using Grignard metathesis (GRIM) polymerization and is used as an active material for large area printing of various optoelectronic devices. Batch to batch reproducibility which is very crucial for the development of a large area printing technology for any material still remains one of the major challenges for bulk synthesis. This is due to the insolubility of the GRIM catalyst (1,3-bis(diphenylphosphino)propane nickel(II) chloride) in polymerization solvents. In this article, we have successfully developed a continuous-flow process for the ultrafast syntheses of rr-P3HT with high throughput and low polydispersity index (PDI). The key to success was the use of 3,4-ethylenedioxythiophene, EDOT, as an inert solvent for dissolving the GRIM catalyst. We could successfully carry out the flow syntheses of rr-P3HT at high concentration (500 mM monomer solution) with low PDI (~1.2) along with good batch to batch reproducibility and high throughput of 32.8 g per channel per hour for rr-P3HT. The combination of higher monomer concentration with ultrafast polymerization resulted in an efficient process for the large-scale syntheses of rr-P3HT with reduced chemical waste. Furthermore, the optical studies along with electrical characterization indicated better packing and higher charge carrier mobility as compared to the commercial samples with high polydispersity index.
Authors:Abhishek Niranjan, Nem Kumar Ngpoore, Naushi Anis, Anil Kumar, Alok Lehri, Pramod Arvind Shirke, and Shri Krishna Tewari
Fresh pods of Moringa oleifera with nutraceutical importance are widely consumed in food commodities as vegetables. It is nutritious and it also has several biological activities. In the present study, a simple, rapid, cost-effective, and sensitive high-performance thin-layer chromatography (HPTLC) method was applied for the simultaneous determination of six phenolic compounds, viz., gallic (phenolic acid), p-coumaric, caffeic acid (hydroxycinnamic acid), chlorogenic acid (cinnamic acid derivative), quercetin and kaempferol (flavonols) in flowers, pods, leaves, twigs, and seeds of M. oleifera. Simultaneous separation and quantification of compounds were achieved on HPTLC pre-coated silica gel 60 F254 aluminum plates using the mobile phase toluene–ethyl acetate–formic acid (14:10:1). Densitometric determination was carried out at λmax 282 nm. The calibration curves were linear, ranged between 0.984 and 0.998; the limit of detection and quantification ranged between 110.8 ng mL−1 and 142.3 ng mL−1, and 301.6 ng μL−1 and 410.8 ng μL−1; and recovery ranged between 96.2% and 97.9%. The validated method was successively used to analyze the above compounds in the plant parts of M. oleifera. The amount of the total phenolic content and specific phenolic compounds ranged from 4.86 mg g−1 (gallic acid equivalent [GAE]) to 14.79 mg g−1 (GAE) and 0.007% quercetin (flower and flower with pods) to 0.099% gallic acid (pods of 15 days). This study reveals that the presence of specific phenolic compounds in M. oleifera shall be a good source for the isolation of the above-mentioned compounds for industrial use.
Authors:S. Ravi, S. Ravi, A. K. Deepa, A. K. Deepa, S. Susheela, S. Susheela, P. V. Achuthan, P. V. Achuthan, S. Anil Kumar, and U. Jambunathan
A method has been developed for the estimation of 90Sr in reprocessed uranium oxide samples obtained from the Purex processing of natural uranium spent fuel discharged from the
research reactor. The method employs a combination of precipitation and solvent extraction procedure to eliminate other beta-impurities
prior to resorting to the estimation of 90Sr by beta-counting. 106Ru was eliminated by volatalizing with perchloric acid, uranium was removed by carrier precipitation with strontium as sulphate.
The sulphate precipitate was converted to carbonate and dissolved in nitric acid. 234Th and 234Pa were eliminated by synergistic solvent extraction using tri-n-butyl phosphate and thenoyl trifluoroacetone extractant mixture
in xylene. An iron scavenging step was included to remove any residual impurities. Finally, strontium is precipitated as SrC2O4. H2O. The separated 90Sr activity was followed to check the equilibrium growth of 90Y.