The angular dependence of heavy ion range (ADHIR) of energetic Bi in mica and polycarbonate

The variation of the range of 2.72 GeV ²⁰⁹Bi with crystalline anisotropy has been studied using an anisotropic detector - muscovite mica and an isotropic detector - polycarbonate (Bayer). The two detectors were irradiated at five different angles ranging between 15° and 75°. The effect of the crystal structure on the range variance has also been discussed.     

SSNTD and radiochemical studies on the transmutation of nuclei using relativistic ions

Extended targets were irradiated for transmutation studies with relativistic heavy ions. For this, a metal core was surrounded by a paraffin moderator. The metal is either copper or lead and it was irradiated with deuterium, alpha, or carbon beams of 1.5 or 3.7 GeV/u at the SYNCHROPHASOTRON, LHE, JINR, Dubna, Russia. During this irradiation copious amounts of secondary neutrons are produced and studied with SSNTD detectors and radiochemical sensors, for example ¹³⁹La (n, γ) ¹⁴⁰La→β⁻. The yield of reaction products allows an estimation of secondary neutron fluxes. The yields of all kinds of reactions produced with deuterium and alpha beams obey to some extent the law of “limiting fragmentation”, i.e. they show little influence on the energy and the kind of incoming particles. However, one observes with 44 GeV ¹²C ions always enhanced nuclear cross-sections induced by secondary particles. This behavior could not be confirmed with theoretical estimations based on the Dubna Cascade Model in its Cascade Evaporation Model version (DCM-CEM). Finally, some results for transmutation studies on ¹²⁷I and Cu will be presented.     

Photocrystallization in amorphous thin films of Se70Te30−xCdx

Summary The present paper reports a study of photocrystallization in a-Se₇₀Te_30−xCd_x films (0≤x≤4). The photocrystallization is achieved by shining white light at room temperature for different exposure times. The results indicate that the photocrystallization is suppressed on addition of Cd in binary Se₇₀Te₃₀ system. This is explained in terms of the structure of Se-Te-Cd system. Work supported by University Grants Commission. The authors of this paper have agreed to not receive the proofs for correction.     

Effect of antimony on glass transition and thermal stability of Se<Subscript>78−x</Subscript>Te<Subscript>18</Subscript>Sn<Subscript>2</Subscript>Sb<Subscript>x</Subscript> (<Emphasis Type="Italic">x</Emphasis> = 0, 2, 4 and 6 at.%) multicomponent glassy alloys

Multicomponent glassy alloys Se_78?xTe₁₈Sn₂Sb_x (x?=?0, 2, 4 and 6) have been synthesized using melt quench technique. The prepared samples have been characterized by X-ray diffraction technique and differential scanning calorimetry (DSC). Glass transition kinetics of Se_78?xTe₁₈Sn₂Sb_x (x?=?0, 2, 4 and 6 at.%) glassy alloys has been examined using DSC. DSC runs have been recorded at different heating rates (5, 10, 15 and 20 K min^?1) for each sample under investigation. Heating rate dependence of glass transition temperature (T_g) has been studied using Lasocka empirical relation. The activation energy of glass transition has been evaluated using Kissinger and Moynihan’s relation. The effect of antimony concentration on glass transition temperature and activation energy has been investigated in the prepared samples. Glass-forming ability and thermal stability of Se_78?xTe₁₈Sn₂Sb_x (x?=?0, 2, 4 and 6) glassy alloys have been monitored through the evaluation of thermal stability using Dietzal relation, Hurby parameter, and Saad and Poulin parameter. The above-mentioned parameters are found to be compositionally dependent, which indicates that among the studied glass samples the stability is maximum for Sb at 2% content.     

Parametric Excitation of Electron-Acoustic Mode in a Plasma of Two-Temperature Electrons

Using hydrodynamical model of the two-electron-temperatere plasma, the analytical investigation of parametric instability of electron-acoustic wave has been made. It is found that the growth rate decreases with increasing concentration ratio of the hot to the total electrons n_h0/n₀. The growth rate is found to be more for      

Synthesis of l-(N-acelylpiperidino)-4-aryl semicarbazides as possible anticonvulsants

Six 1-(N-acetylpiperidino)-4-aryl semicarbazides were synthesized from ethyl-N-piperidino-aeetatc which on treatment with hydrazine hydrate was converted into N-piperidinoacethydrazide. The resulting hydrazide on treatment with the appropriate arylisoeyanales formed l -(N-acelyl-piperidino)-4-aryl semicarbazides. Amongst these piperidinosemicarbazides, three compound possessed low anticonvulsanl activity and provided 20-40% protection against pentylenetetrazol-induced convulsions in mice. All piperidino semicarbazides (0.1 mM) possessed antihemolytic activity (13-35%) and caused 40-72% inhibition of monoamine oxidase activity of rat brain homogenates at a final concentration of 0.3 mM.     

Statistical mechanical estimation of the entropy of fusion of linear vinyl polymers

The entropy of fusion of linear vinyl polymers [polypropylene, polystyrene, and poly(vinyl chloride)] having asymmetric carbon atoms was calculated on the basis of the rotational isomeric state model. The results are found to be in good agreement with the experimental entropies of fusion per bond for these polymers.     

A Comparative study of p-Em and C12-Em interactions at 4·5 GeV/c per nucleon

In this paper we present a comparative study of inelastic interactions of C¹²-Em and p-Em at 4·5 GeV/c per nucleon. The multiplicity distributions and their correlations have been studied. The results show a strong correlation of n _s onn _h in the case of C¹²-Em but not in the case of p-Em. It is also shown that the n _s increases with the increase of the projectile mass. The angular distribution of the target fragments in C¹²-Em shows a massive forward collimation. Comparison is also made in the pseudorapidity distribution of both C¹²-Em and p-Em, the result shows many interesting features.     

Lewis acid catalyzed regioselective ring opening of azetidines with alcohols and thiols

An efficient synthesis of amino ethers and amino thioethers has been achieved via the ring cleavage of N-tosylazetidines with alcohols or thiols. The reactions were studied in the presence of various Lewis acids and BF₃·OEt₂ was found to be the most efficient. The products were obtained in modest to good yields under very mild conditions in 5-15 min.     

Fabrication of Graphitic Carbon Nitride-Based Film: An Emerged Highly Efficient Catalyst for Direct C-H Arylation under Solar Light

Photoredox C-H bond formation can proceed in aerobic environment under solar light and has therefore become attractive.Nowadays,different types of expensive nov...