A solution of the DGLAP equation for gluon at low x

We obtain a solution of the DGLAP equation for the gluon at low x first by expanding the gluon in a Taylor series and then using the method of characteristics. We test its validity by comparing it with that of Glück, Reya and Vogt. The convergence criteria of the approximation used are also discussed. We also calculate εF ₂(x,Q)²/ε In Q ² using its approximate relations with the gluon distribution at low x. The predictions are then compared with the HERA data.     

Radial and angular correlation in heliumlike ions

In the framework of nonrelativistic variational formalism a new type of basis set is proposed, to estimate separately the effect of radial and angular correlations on the ground‐state energy for helium isoelectronic sequence H^? to Ar¹⁶⁺. Effect of radial correlation is incorporated by using multiexponential functions arising from product basis sets suitably formed out of Slater‐type one‐particle orbitals. The angular correlation can be switched on by incorporating an expansion in terms of basis involving interparticle coordinates. With a set of six‐term Slater‐type one‐particle basis and five‐term interparticle expansion, the ground‐state energy of helium is estimated as ?2.9037236 (a.u.) compared with the multiterm variational estimates ?2.9037244 (a.u.) due to Pekeris and Thakkar and Smith and Drake. Matrix elements of different operators in the ground state have been calculated and found to be in good agreement with available accurate results. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2003     

Measurement of storage time, estimation of ion number and study of absorption line profile in a Paul trap

Europium (Eu⁺) ions were confined in a Paul trap and detected by non-destructive method. Storage time of Eu⁺ ions achieved in vacuum was improved by orders of magnitude employing buffer gas cooling. The experimentally detected signal was fitted to the ion response signal and the total number of ions trapped was estimated. It is found that the peak signal amplitude as well as the product of FWHM and the peak signal amplitude is proportional to the total number of trapped ions. The trapped ion secular frequency was swept at different rates and its effect on the absorption line profile was studied both experimentally and theoretically.     

Working group report: Collider Physics

This is summary of the activities of the working group on collider physics in the IXth Workshop on High Energy Physics Phenomenology (WHEPP-9) held at the Institute of Physics, Bhubaneswar, India in January 2006. Some of the work subsequently done on these problems by the subgroups formed during the workshop is included in this report.     

On solving energy-dependent partitioned eigenvalue problem by genetic algorithm: The case of real symmetric Hamiltonian matrices

An energy-dependent partitioning scheme is explored for extracting a small number of eigenvalues of a real symmetric matrix with the help of genetic algorithm. The proposed method is tested with matrices of different sizes (30 × 30 to 1000 × 1000). Comparison is made with Löwdin’s strategy for solving the problem. The relative advantages and disadvantages of the GA-based method are analyzed     

Are the proposed cosmic H particles psionlike in Nature?

Summary The hints to explain the unusual type of cosmic cluster events (called generally the ?exotic? events) in ultrahigh-energy nuclear collisions in terms of proposed H particles have, to date, been neither substantiated nor concretised. We assort here some crucial aspects and assemble a few supportive evidences to favour our idea that the proposed H particles might be viewed as cosmic psionlike particles.     

Spectroscopic investigation of the Dergaon meteorite with reference to 10 μm and 20 μm bands

Analysis of a part of the meteorite which fell at Dergaon (India) on March 2, 16.40 local time (2001) is presented with the help of FTIR, absorption and atomic spectra. The FTIR spectrum exhibits prominent absorption bands in the region 800–1100 cm⁻¹, originating from the valence vibration of SiO⁴, a basic component of the silicate lattice.     

Studies on thermal properties of bismuth vanadate catalysts

Physicochemical properties of bismuth vanadate catalysts with varying compositions, e.g., Bi₄V₆O₂₁-6 1/2H₂O·1 ₂ ¹ NH₃; Bi₆V₂O₁₄·3 H₂O; Bi₆V₄O₁₉·6 H₂O have been studied by chemical analysis, differential thermal analysis, thermogravimetry, infrared, X-ray diffraction, surface area and magnetic susceptibility techniques.The endotherms, in all the cases, prior to exo ones are due to stepwise dehydration and those following exochanges are due to decomposition of adsorbed impurities, sintering and melting, etc. The last endopeak, in all the cases, however is due to melting. The exochanges are attributed to stepwise phase transitions. The V-0 stretching in all the compounds is characteristic of polyvanadates. Two types of vanadium-oxygen bonds e.g., V=O and V-O -V are characterized by IR analysis. The fresh first and third vanadates are amorphous whereas the second one is crystalline. The exochanges (presumably due to disorder-order transitions) are suggested to be related to displacement of oxygen anions. The precipitated vanadates are similar with their corresponding solid state reaction products of Bi₂O₃ and V₂O₅ when they are heated at elevated temperature. The fresh as well as treated vanadates are diamagnetic. These systems display maximum surface area at the temperature corresponding to complete dehydration. The composition of the precipitated vanadates is not ultimately defined by Bi/V ratio and the binary compound consequently formed.

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Zusammenfassung Die physikalisch-chemischen Eigenschaften von Bismuthvanadat-Katalysatoren verschiedener Zusammensetzung, z.B. Bi₄V₆O₂₁·6 ₂ ¹ H₂O·1 ₂ ¹ NH₃; Bi₆V₂O₁₄·3 H₂O; Bi₆V₄O₁₉·6 H₂O wurden durch chemische Analyse, Differentialthermoanalyse, Thermogravimetrie, Infrarot, Röntgendiffraktion, Oberflächenmessung und magnetische Susceptibilitätsmessung untersucht. In jedem Fall werden die den Exo-Änderungen vorangehenden Endo-Änderungen durch stufenweise Dehydratisierung verursacht und diejenigen, welche den Exo-Änderungen folgen, durch Zersetzung adsorbierter Verunreinigungen, Sinterung und Schmelzen. Der letzte Endopeak ist jedoch in jedem Falle dem Schmelzen zuzuschreiben. Die Exo-Änderungen werden stufenweisen Phasenübergängen zugeschrieben. In allen Verbindungen ist die V-O Dehnung für die Polyvanadate charakteristisch. Zwei Typen von Vanadium-Sauerstoff Bindungen, z. B. V=O und V-O-V wurden durch IR-Analyse charakterisiert. Die frisch synthetisierten ersten und dritten Vanadate sind amorph, während das zweite kristallin ist. Die (vermutlich durch Unordnung-Ordnungs Übergänge verursachten) Exo-Änderungen sind wahrscheinlich mit der Bewegung der Sauerstoff-Anionen verbunden. Die gefällten Vanadate sind — wenn sie auf hohe Temperaturen erhitzt werden — ihren entsprechenden Festphasen-Reaktionsprodukten Bi₂O₃ und V₂O₅ ähnlich. Die ursprünglichen wie die behandelten Vanadate sind diamagnetisch. Diese Systeme weisen die maximale Oberfläche bei der ihrer vollständigen Dehydratisierung entsprechenden Temperature auf. Die Zusammensetzung der gefällten Vanadate wird letzten Endes nicht durch. ihr Bi-V-Verhältnis und die in der Folge entstandene Binärverbindung bestimmt.

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Résumé Les propriétés physico-chimiques des catalyseurs au vanadate de bismuth, de diverses compositions, par ex. Bi₄V₆O₂₁ · 6 ₂ ¹ H₂O · 1 ₂ ¹ NH₃,Bi₆V₂Oi₁₄ · 3H₂O, Bi₆V₄O₁₉ · 6H₂O, ont été étudiées par analyse chimique, analyse thermique différentielle, thermogravimétrie, spectroscopie infrarouge, diffraction des rayons X, mesures de surfaces spécifiques et de susceptibilité magnétique.Dans tous les cas, les phénomènes endothermiques qui précèdent ceux de nature exothermique sont dus à la déshydratation par étapes; les phénomènes endothermiques qui suivent ceux de nature exothermique sont dus aux impuretés adsorbées, au frittage, à la fusion, etc ... Cependant, le dernier pic endothermique est toujours dû à la fusion. Les changements exothermiques sont attribués à des transitions de phases par étapes. La déformation V-0 dans tous les composés est caractéristique des polyvanadates. Deux types de liaisons vanadium-oxygène, par ex. V=O et V-O-V ont été caractérisés par analyse infrarouge. Le premier et le troisième vanadate, fraîchement préparés, sont amorphes alors que le second est cristallisé. Les. phénomènes exothermiques (probablement dus à des transitions désordre-ordre) sont sans doute en rapport avec le déplacement des anions oxygène. Les vanadates précipités — si on les. chauffe jusqu'à une température élevée — sont similaires aux produits correspondants, obtenus par réaction à l'état solide entre Bi₂O₃ et V₂O₅. Les vanadates fraîchement préparés ainsi que ceux qui ont subi un traitement thermique, sont diamagnétiques. Ces systèmesmontrent une surface spécifique maximalé à la température correspondant à la déshydratation complète. La composition des vanadates précipités n'est pas finalement définie par le rapport Bi/V et le composé binaire formé par la suite.

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- - , , Bi₄V₆O₂₁ · 6.5 ₂ ·1.5 NH₃; Bi₆V₂O₁₄ · ₂; Bi₆V₄O₁₉· 6H₂O , , , , - , . , , , , , . . . . V- . - : V= V--V. , — . , (-, -) . , Bi₂O₃ V₂O₅ . , . , . Bi/V, a, , .

     

Structural features of some small carbonyls in the 1,3nπ states: An mcscf study

Structural features of a series of tetraatomic carbonyls in the ^1,3nπ* states are studied by using a recently proposed MCSCF algorithm at the INDO/2 level. The computed geometrical parameters and the inversion barrier heights agree quite well with the available experimental or ab initio theoretical data. The calculated transition energies turn out to be somewhat lower than the experimental counterparts. The specific MCSCF algorithm used is found to have excellent convergence properties.