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1.
Santosh K. Shrestha Heiko Timmers Aidan P. Byrne Wayne D. Hutchison Don H. Chaplin Rakesh Dogra 《Hyperfine Interactions》2004,158(1-4):407-411
A radioisotope ion implanter has been developed using a cesium-sputtering, negative ion source, which offers versatility and
sustained operation. Employing the molecular 111In16O− ion, μCi activities of the radioisotope probe 111In/Cd have been implanted into different material hosts. The implanted tracer activity has been shown to be sufficient for
LTNO, NMRON and PAC. A new NMRON resonance for 111InAg was observed at 75.08 MHz. In2O3 powder performed well as the radioisotope carrier in the ion source, with the ratio of radioisotope and parasitic ion current
being typically 4 × 10−4. 相似文献
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Biomass conversion has been developed by testing various metal based carbon catalysts. Most of the reported catalysts either use very expensive metals or support that provides lower selectivity. In this context, we fabricated new carbon based nanocomposites and studied their catalytic application for furfural reduction – a promising biomass derived molecule. The mono (Cu, Co and Ni) and bimetallic (CuCo and CuNi) nanoparticle supported on commercial graphite (CG) were prepared and characterized by TEM, EDS, XRD and Raman spectroscopy. The analysis revealed that the nanocomposites are made up of metallic nanoparticles with average particle size of 5–13 nm on the graphite matrix. The obtained results indicated that the Cu+Ni@CG catalyst exhibited high catalytic activity for furfural reduction, thus leaving Cu+Ni as the finest and cost effective catalyst for this study. 相似文献
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R. K. Kuchhal P. V. Dogra K. G. Sharma K. S. Jauhri P. L. Gupta 《Fresenius' Journal of Analytical Chemistry》1977,286(3-4):219-221
Summary A simple gas-liquid chromatographic method has been developed for determining 3-sulfolene in sulfolane. The method involves thermal decomposition of sulfolene and determination of the 1.3-butadiene evolved, by GLC. Influence of the operating parameters on quantitative decomposition of sulfolene has been studied. The accuracy of the method as studied in the concentration range from 0.05 to 4.0 % (w/v) of 3-sulfolene in sulfolane is found to be within ±3.0%. It is rapid and sensitive down to 10 ppm and has potentialities for on-line applications also.
Bestimmung von 3-Sulfolen in Sulfolan durch Reaktions-Gas-Chromatographie
Zusammenfassung Eine einfache gas-chromatographische Methode wurde entwickelt, die auf der thermischen Zersetzung der Probe und der Bestimmung des dabei aus 3-Sulfolen gebildeten 1,3-Butadiens beruht. Der Einfluß der einzelnen Parameter wurde untersucht. Innerhalb eines Konzentrationsbereichs von 0,05–4,0% 3-Sulfolen ergaben sich Fehler von ±3%. Das Verfahren ermöglicht bis herab zu 10 ppm eine schnelle und empfindliche Bestimmung und eignet sich auch zum on-line Betrieb.相似文献
4.
Shiva Kumar Monika Mudgel Anjana Dogra M. Husain V.P.S. Awana Hari Kishan 《Physica C: Superconductivity and its Applications》2010
Synthesis and structural details of MSr2RECu2Oz (M-1212) compounds with M = Ga, Nb, Fe, Al and Co) and RE = Eu, Y are reported. Reitveld refinement of X-ray diffraction (XRD) patterns shows that all compounds are crystallized in single phase. Nb-, Fe- and Al-1212 possess tetragonal P4/mmm space group structure while the Ga-1212 and Co-1212 are crystallized in orthorhombic Ima2 space group. The change of space group from P4/mmm to Ima2 indicating towards the doubling of unit cell. The buckling angle [Cu(2)–O(2)–Cu(2) angle] shows that most of the studied samples are heavily under doped and hence they could not exhibit superconductivity. Thermogravimetric (TGA) analysis shows the M-1212 compounds to be more stable than widely studied 90 K superconductor Cu-1212 (RE-123). 相似文献
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P. Thakur R. Dogra A. K. Bhati S. C. Bedi R. P. Singh S. Muralithar R. K. Bhowmik 《Hyperfine Interactions》2000,131(1-4):103-109
The electric quadrupole moments of the 9/2− and 21/2− isomeric states of 173Ta at 165.8 keV and 1713.2 keV, respectively, were measured as Q(9/2−)=2.92(15) b and Q(21/2−)=6.23(18) b for the first time using the TDPAD technique. A 66 MeV pulsed 12C ion beam from the 15UD pelletron accelerator facility of the Nuclear Science Centre at New Delhi was used in the reaction
165Ho(12C, 4nγ)173Ta. The experimental values of equilibrium deformations β2(9/2−)=0.251(7) and β2(21/2−)=0.391(7) were extracted.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
8.
Sneh K. Dogra 《Journal of Chemical Sciences》1992,104(6):635-647
The present review describes the salient features of inter- and intramolecular proton transfer reactions of 2-(2′-aminophenyl)-,
2-(3′-aminophenyl)-, 2-(4′-aminophenyl)-, 2-(2′-hydroxyphenyl)-, 2-(3′-hydroxyphenyl)- and 2-(4′-hydroxyphenyl)-benzimidazoles,
benzoxazoles and benzothiazoles. Fluorescence quantum yield of the phototautomer produced by the intramolecular hydrogen bonding
decreases on going from benzimidazole to benzoxazole to benzothiazole. This indicates that the rate of internal conversion
increases in the order of compounds as mentioned above. The biprotonic phototautomerism or the presence of intermolecular
proton transfer has led to the formation of (i) nonfluorescent zwitterions in case of hydroxyphenyl derivatives and the ground
state precursor of this species in neutral molecules, (ii) nonfluorescent monoanions from fluorescent monoanions and (iii)
nonfluorescent monocations from monocations in case of aminophenyl derivatives. In the case of 2-(4′-aminophenyl)-substituted
compounds, the first protonation has always led to the formation of two types of monocations; one by protonating the amino
group and the other by protonating the tertiary nitrogen atom. The former is more stable in aqueous media and the latter in
non-polar media. 相似文献
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Systematic DPAC measurements of the electric field gradient at Dy in very low concentration in pure Pr, Nd, Gd, Tb, Dy, Ho
and Er metals in the paramagnetic phase have shown for the first time the host associated aspherical 4f-shell effects. The
results are compared with the presently available first-principles based calculations of the electric field gradient and crystalline
electric field parameters of rare-earth ions in rare-earth metals and alloys. The observed 4f-spin relaxation time of Dy ion
in rare-earth metals is of the order of 2 ps.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献