2007
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PublicationArticle Preparation and characterization of CuFe2 - x Crx O4 (0 ≤ x ≤ 1.0) nano spinels for electrocatalysis of oxygen evolution in alkaline solutions(2007) R.N. Singh; J.P. Singh; B. Lal; A. SinghSome new nano-sized ternary ferrites with molecular formula, CuFe2 - x Crx O4 (0 ≤ x ≤ 1) have been prepared by a precipitation method and were investigated as electrocatalysts for the oxygen evolution reaction (OER) in alkaline solutions. The reaction followed first-order kinetics with respect to OH- concentration, regardless of the nature of the electrocatalyst. The Tafel slope for the OER was ∼ 2.3 RT / F with each oxide at low overpotentials. The replacement of Fe by Cr in the CuFe2O4 matrix was found to improve both geometrical as well as electronic properties of the material in favour of electrocatalysis of O2 evolution considerably. © 2006 International Association for Hydrogen Energy.PublicationArticle Variations in soil microbial biomass and crop roots due to differing resource quality inputs in a tropical dryland agroecosystem(2007) Sonu Singh; Nandita Ghoshal; K.P. SinghThe influence of exogenous organic inputs on soil microbial biomass dynamics and crop root biomass was studied through two annual cycles in rice-barley rotation in a tropical dryland agroecosystem. The treatments involved addition of equivalent amount of N (80 kg N ha-1) through chemical fertilizer and three organic inputs at the beginning of each annual cycle: Sesbania shoot (high-quality resource, C:N 16, lignin:N 3.2, polyphenol+lignin:N 4.2), wheat straw (low-quality resource, C:N 82, lignin:N 34.8, polyphenol+lignin:N 36.8) and Sesbania+wheat straw (high-and low-quality resources combined), besides control. The decomposition rates of various inputs and crop roots were determined in field conditions by mass loss method. Sesbania (decay constant, k=0.028) decomposed much faster than wheat straw (k=0.0025); decomposition rate of Sesbania+wheat straw was twice as fast compared to wheat straw. On average, soil microbial biomass levels were: rice period, Sesbania≥Sesbania+wheat straw>wheat straw≥fertilizer; barley period, Sesbania+wheat straw>Sesbania≥wheat straw≥fertilizer; summer fallow, Sesbania+wheat straw>Sesbania>wheat straw≥fertilizer. Soil microbial biomass increased through rice and barley crop periods to summer fallow; however, in Sesbania shoot application a strong peak was obtained during rice crop period. In both crops soil microbial biomass C and N decreased distinctly from seedling to grain-forming stages, and then increased to the maximum at crop maturity. Crop roots, however, showed reverse trend through the cropping period, suggesting strong competition between microbial biomass and crop roots for available nutrients. It is concluded that both resource quality and crop roots had distinct effect on soil microbial biomass and combined application of Sesbania shoot and wheat straw was most effective in sustained build up of microbial biomass through the annual cycle. © 2006 Elsevier Ltd. All rights reserved.PublicationArticle Interactive effect of tillage depth and mulch on soil temperature, productivity and water use pattern of rainfed barley (Hordium vulgare L.)(2007) S. Sarkar; S.R. SinghSoil porosity and organic matter content influence the hydrology, thermal status and productivity of agricultural soils. Shape, size and continuity of soil pores are determined by tillage practices. Thus appropriate tillage and mulch management can conserve residual soil moisture during the post rainy season. This can play a key role in enhancing productivity under the rainfed ecosystem of subhumid region in eastern India. A field study was carried out on a fine loamy soil from 1993-1994 to 1995-1996. Two tillage treatments were conventional ploughing (150 mm depth) and shallow ploughing (90 mm) depth. Each tillage practice was tested with three mulch management viz., no mulch, soil dust mulch and rice (Oryza sativa L.) straw mulch. Soil organic carbon, bulk density, moisture retentivity, soil temperature with productivity and water use pattern of barley (Hordium vulgare L.) were measured. Reduction in ploughing depth resulted in nominal increase in profile (0.0-1.2 m) moisture status, yield, and soil thermal status at 14:00 and water use efficiency (WUE). However, it decreased the magnitude of soil temperature in the morning (07:00). Straw mulch conserved 19-21 mm of moisture in the profile (1.2 m) over the unmulched condition. Both soil dust and rice straw mulching elevated soil thermal status at 07:00 as compared to unmulched condition, but this trend was reversed at 14:00. Straw mulching significantly increased grain yield and WUE over soil dust mulch and unmulched condition. Impact of straw mulch was more pronounced under shallow ploughing depth. Shallow tillage with rice straw mulching is recommended to the farmers to obtain higher level of yield and water use efficiency. © 2006 Elsevier B.V. All rights reserved.PublicationArticle Stay green trait: Variation, inheritance and its association with spot blotch resistance in spring wheat (Triticum aestivum L.)(2007) A.K. Joshi; M. Kumari; V.P. Singh; C.M. Reddy; S. Kumar; J. Rane; R. ChandOne thousand four hundred and seven spring wheat germplasm lines belonging to Indian and CIMMYT wheat programs were evaluated for stay green (SG) trait and resistance to spot blotch caused by Bipolaris sorokiniana during three consecutive crop seasons, 1999-2000, 2000-2001 and 2001-2002. Disease severity was recorded at six different growth stages beginning from tillering to late milk stage. SG trait was measured by following two approaches: difference for 0-9 scoring of green coloration (chlorophyll) of flag leaf and spike at the late dough stage (GS 87) and a new approach of leaf area under greenness (LAUG). Germplasm lines showed a wide range (7-89) for LAUG and were grouped into four viz., SG, moderately stay green, moderately non-stay green and non-stay green (NSG). However, very few (2.2%) lines showed high expression of SG trait, i.e., LAUG >60. LAUG appeared to be a better measure of SG trait than a 0-9 scale. Mean spot blotch ratings of SG genotypes were significantly lower than those of NSG genotypes at all growth stages. Two spot blotch resistant genotypes (Chirya 3 and Chirya 7) having strong expressions of SG trait were crossed with NSG, spot blotch susceptible cv. Sonalika. Individually threshed F2 plants were used to advance the generations. SG trait and spot blotch severity were recorded in the parents and F1, F3, F4, F 5, F6 and F6-7 generations under disease-protected and inoculated conditions. SG trait in the F1 generation was intermediate and showed absence of dominance. Evaluation of progenies (202-207) in the segregating generations revealed that SG trait was under the control of around four additive genes. Lines homozygous for SG trait in F4, F5, F6 and F6-7 generations showed significantly lower mean area under disease progress curve (AUDPC) for spot blotch than those with NSG expression. A positive correlation (0.73) between SG trait and AUDPC further indicated a positive influence of SG on severity of spot blotch. The study established that variation for SG trait exists in spring wheat; around four additive genes control its inheritance in the crosses studied and there is positive association between SG trait and resistance to spot blotch. © 2006 Springer Science+Business Media B.V.PublicationArticle Homologous recombination-mediated double-strand break repair in mouse testicular extracts and comparison with different germ cell stages(2007) Niloo Srivastava; Mercy J. RamanHomologous recombination (HR) is established as a significant contributor to double-strand break (DSB) repair in mammalian somatic cells; however, its role in mammalian germ cells has not been characterized, although being conservative in nature it is anticipated to be the major pathway in germ cells. The germ cell system has inherent limitations by which intact cell approaches are not feasible. The present study, therefore, investigates HR-mediated DSB repair in mouse germ cell extracts by using an in vitro plasmid recombination assay based on functional rescue of a neomycin (neo) gene. A significantly high-fold increase in neo+ (KanR) colonies following incubation of two plasmid substrates (neoΔ1 and neoΔ2) with testicular extracts demonstrated the extracts' ability to catalyze intermolecular recombination. A significant enhancement in recombinants upon linearization of one of the plasmids suggested the existence of an HR-mediated DSB repair activity. Comparison of the activity at sequential developmental stages, spermatogonia, spermatocytes and spermatids revealed its presence at all the stages; spermatocyte being the most proficient stage. Further, restriction analysis of recombinant plasmids indicated the predominance of gene conversion in enriched spermatocytes (mostly pachytenes), in contrast to gonial and spermatid extracts that showed higher reciprocal exchange. In conclusion, this study demonstrates HR repair activity at all stages of male germ cells, suggesting an important role of HR-mediated DSB repair during mammalian spermatogenesis. Further, the observed preference of gene conversion over reciprocal exchange at spermatocyte stage correlates with the close association of gene conversion with the meiotic recombination program. Copyright © 2006 John Wiley & Sons, Ltd.PublicationArticle Failure analysis of a passenger car coil spring(2007) S.K. Das; N.K. Mukhopadhyay; B. Ravi Kumar; D.K. BhattacharyaInvestigation on the premature failure of suspension coil spring of a passenger car, which failed within few months after being put into service, has been carried out. Besides visual examination, other experimental techniques used for the investigation were (a) microstructural analysis and fractography by scanning electron microscopy (SEM), (b) inclusion rating by optical microscopy, (c) hardness testing, (d) residual stress measurement by X-Ray diffraction (XRD) and (e) instrumental chemical analysis. Inherent material defect in association with deficient processing led to the failure of the spring. © 2006.PublicationArticle Influence of simultaneous doping of Sb and Pb on phase formation, superconducting and microstructural characteristics of HgBa2Ca2Cu3O8+δ(2007) Rajiv Giri; R.S. Tiwari; O.N. SrivastavaWe report systematic studies of structural, microstructural and transport properties of (Hg0.80Sb0.2-xPbx)Ba2Ca 2Cu3O8+δ (where x = 0.0, 0.05, 0.1, 0.15, 0.2) compounds. Bulk polycrystalline samples have been prepared by two-step solid-state reaction route at ambient pressure. It has been observed that simultaneous substitution of Sb and Pb at Hg site in oxygen deficient HgOδ layer of HgBa2Ca2Cu3O8+δ cuprate high-Tc superconductor leads to the formation of Hg-1223 as the dominant phase. Microstructural investigations of the as grown samples employing scanning electron microscopy reveal single crystal like large grains embodying spiral like features. Superconducting properties particularly transport current density (Jct) have been found to be sensitive to these microstructural features. As for example (Hg0.80Sb0.05Pb0.15)Ba2Ca 2Cu3O8+δ compound which exhibits single crystal like large grains (∼50 μm) and appears to result through spiral growth mechanism, shows highest Jct (∼1.85 × 103 A/cm2) at 77 K. A possible mechanism for the generation of spiral like features and correlation between microstructural features and superconducting properties have been put forward. © 2006.PublicationArticle Shape evolution in76,78Kr nuclei at high spins in tilted axis cranking Hartree-Fock-Bogoliubov approach(2007) A. Ansari; P. Sharma; U.R. Jakhar; H.L. YadavA two-dimensional tilted axis cranking Hartree-Fock-Bogoliubov (CHFB) calculation is performed for 76Kr and 78Kr nuclei up to high spins J = 30 employing a pairing-plus-quadrupole (PPQ) model interaction Hamiltonian. Intricate details of the evolution of single particle structures and shapes as a function of spin have been investigated. The results show the existence of energy levels with high K quantum numbers lying close to the yrast line in both the nuclei. Such high K states should exhibit isomeric characteristics due to the K-selection rules for the γ-decays. Moreover, in 78Kr a new band with J = 20-30 lying below the observed ground band is predicted. © Indian Academy of Sciences.PublicationArticle Measurement of direct photon production in p+p collisions at s=200GeV(American Physical Society, 2007) S.S. Adler; S. Afanasiev; C. Aidala; N.N. Ajitanand; Y. Akiba; A. Al-Jamel; J. Alexander; K. Aoki; L. Aphecetche; R. Armendariz; S.H. Aronson; R. Averbeck; T.C. Awes; V. Babintsev; A. Baldisseri; K.N. Barish; P.D. Barnes; B. Bassalleck; S. Bathe; S. Batsouli; V. Baublis; F. Bauer; A. Bazilevsky; S. Belikov; M.T. Bjorndal; J.G. Boissevain; H. Borel; M.L. Brooks; D.S. Brown; N. Bruner; D. Bucher; H. Buesching; V. Bumazhnov; G. Bunce; J.M. Burward-Hoy; S. Butsyk; X. Camard; P. Chand; W.C. Chang; S. Chernichenko; C.Y. Chi; J. Chiba; M. Chiu; I.J. Choi; R.K. Choudhury; T. Chujo; V. Cianciolo; Y. Cobigo; B.A. Cole; M.P. Comets; P. Constantin; M. Csanád; T. Csörgo; J.P. Cussonneau; D. D'Enterria; K. Das; G. David; F. Deák; H. Delagrange; A. Denisov; A. Deshpande; E.J. Desmond; A. Devismes; O. Dietzsch; J.L. Drachenberg; O. Drapier; A. Drees; A. Durum; D. Dutta; V. Dzhordzhadze; Y.V. Efremenko; H. En'Yo; B. Espagnon; S. Esumi; D.E. Fields; C. Finck; F. Fleuret; S.L. Fokin; B.D. Fox; Z. Fraenkel; J.E. Frantz; A. Franz; A.D. Frawley; Y. Fukao; S.-Y. Fung; S. Gadrat; M. Germain; A. Glenn; M. Gonin; J. Gosset; Y. Goto; R. Granier De Cassagnac; N. Grau; S.V. Greene; M. Grosse Perdekamp; H.-Å. Gustafsson; T. Hachiya; J.S. Haggerty; H. Hamagaki; A.G. Hansen; E.P. Hartouni; M. Harvey; K. Hasuko; R. Hayano; X. He; M. Heffner; T.K. Hemmick; J.M. Heuser; P. Hidas; H. Hiejima; J.C. Hill; R. Hobbs; W. Holzmann; K. Homma; B. Hong; A. Hoover; T. Horaguchi; T. Ichihara; V.V. Ikonnikov; K. Imai; M. Inaba; M. Inuzuka; D. Isenhower; L. Isenhower; M. Ishihara; M. Issah; A. Isupov; B.V. Jacak; J. Jia; O. Jinnouchi; B.M. Johnson; S.C. Johnson; K.S. Joo; D. Jouan; F. Kajihara; S. Kametani; N. Kamihara; M. Kaneta; J.H. Kang; K. Katou; T. Kawabata; A.V. Kazantsev; S. Kelly; B. Khachaturov; A. Khanzadeev; J. Kikuchi; D.J. Kim; E. Kim; G.-B. Kim; H.J. Kim; E. Kinney; A. Kiss; E. Kistenev; A. Kiyomichi; C. Klein-Boesing; H. Kobayashi; L. Kochenda; V. Kochetkov; R. Kohara; B. Komkov; M. Konno; D. Kotchetkov; A. Kozlov; P.J. Kroon; C.H. Kuberg; G.J. Kunde; K. Kurita; M.J. Kweon; Y. Kwon; G.S. Kyle; R. Lacey; J.G. Lajoie; Y. Le Bornec; A. Lebedev; S. Leckey; D.M. Lee; M.J. Leitch; M.A.L. Leite; X.H. Li; H. Lim; A. Litvinenko; M.X. Liu; C.F. Maguire; Y.I. Makdisi; A. Malakhov; V.I. Manko; Y. Mao; G. Martinez; H. Masui; F. Matathias; T. Matsumoto; M.C. McCain; P.L. McGaughey; Y. Miake; T.E. Miller; A. Milov; S. Mioduszewski; G.C. Mishra; J.T. Mitchell; A.K. Mohanty; D.P. Morrison; J.M. Moss; D. Mukhopadhyay; M. Muniruzzaman; S. Nagamiya; J.L. Nagle; T. Nakamura; J. Newby; A.S. Nyanin; J. Nystrand; E. O'Brien; C.A. Ogilvie; H. Ohnishi; I.D. Ojha; H. Okada; K. Okada; A. Oskarsson; I. Otterlund; K. Oyama; K. Ozawa; D. Pal; A.P.T. Palounek; V. Pantuev; V. Papavassiliou; J. Park; W.J. Park; S.F. Pate; H. Pei; V. Penev; J.-C. Peng; H. Pereira; V. Peresedov; A. Pierson; C. Pinkenburg; R.P. Pisani; M.L. Purschke; A.K. Purwar; J.M. Qualls; J. Rak; I. Ravinovich; K.F. Read; M. Reuter; K. Reygers; V. Riabov; Y. Riabov; G. Roche; A. Romana; M. Rosati; S.S.E. Rosendahl; P. Rosnet; V.L. Rykov; S.S. Ryu; N. Saito; T. Sakaguchi; S. Sakai; V. Samsonov; L. Sanfratello; R. Santo; H.D. Sato; S. Sato; S. Sawada; Y. Schutz; V. Semenov; R. Seto; T.K. Shea; I. Shein; T.-A. Shibata; K. Shigaki; M. Shimomura; A. Sickles; C.L. Silva; D. Silvermyr; K.S. Sim; A. Soldatov; R.A. Soltz; W.E. Sondheim; S.P. Sorensen; I.V. Sourikova; F. Staley; P.W. Stankus; E. Stenlund; M. Stepanov; A. Ster; S.P. Stoll; T. Sugitate; J.P. Sullivan; S. Takagi; E.M. Takagui; A. Taketani; K.H. Tanaka; Y. Tanaka; K. Tanida; M.J. Tannenbaum; A. Taranenko; P. Tarján; T.L. Thomas; M. Togawa; J. Tojo; H. Torii; R.S. Towell; V.-N. Tram; I. Tserruya; Y. Tsuchimoto; H. Tydesjö; N. Tyurin; T.J. Uam; J. Velkovska; M. Velkovsky; V. Veszprémi; A.A. Vinogradov; M.A. Volkov; E. Vznuzdaev; X.R. Wang; Y. Watanabe; S.N. White; N. Willis; F.K. Wohn; C.L. Woody; W. Xie; A. Yanovich; S. Yokkaichi; G.R. Young; I.E. Yushmanov; W.A. Zajc; O. Zaudtke; C. Zhang; S. Zhou; J. Zimányi; L. Zolin; X. Zong; H.W. VanheckeCross sections for midrapidity production of direct photons in p+p collisions at the Relativistic Heavy Ion Collider (RHIC) are reported for transverse momenta of 35GeV/c, where the uncertainties of the measurement and theory are comparable. We also report on the effect of requiring the photons to be isolated from parton jet energy. The observed fraction of isolated photons is well described by pQCD for pT>7GeV/c. © 2007 The American Physical Society.PublicationArticle Changes in oxidative stress defense system in wheat (Triticum aestivum L.) and mung bean (Vigna radiata L.) cultivars grown with and without mineral nutrients and irradiated by supplemental ultraviolet-B(2007) S.B. Agrawal; Dheeraj RathoreField study was conducted to evaluate the inter- and intra-specific variations in sensitivity of two cultivars each of wheat (Triticum aestivum L. cv. HD 2329 and HUW 234) and mung bean (Vigna radiata L. cv. Malviya Jyoti and Malviya Janpriya) to supplemental levels of UV-B irradiation (sUV-B, 280-315 nm) with and without recommended levels of mineral nutrients. Results showed decrease in photosynthetic pigments and biomass of all the four cultivars due to sUV-B radiation. Antioxidative defense system was activated in all the cultivars after irradiation with sUV-B. SOD, peroxidase and total thiol contents increased, while catalase activity and ascorbic acid contents decreased under sUV-B irradiation. On the basis of biomass, UV-B sensitivity can be arranged in decreasing order as: Malviya Janpriya < Malviya Jyoti < HD 2329 < HUW 234. Application of mineral nutrients (N, P and K) showed significant positive response in all cultivars by ameliorating the negative impact of sUV-B. © 2005 Elsevier B.V. All rights reserved.