Thin-Shell Wormholes from Black Holes with Dilaton and Monopole Fields

We provide a new type of thin-shell wormhole from the black holes with dilaton and monopole fields. The dilaton and monopole that built the black holes may supply fuel to construct the wormholes. Several characteristics of this thin-shell wormhole have been discussed. Finally, we discuss the stability of the thin-shell wormholes with a “phantom-like” equation of state for the exotic matter at the throat.     

Reactor decay heat in 239Pu: solving the γ discrepancy in the 4-3000-s cooling period

The β feeding probability of (102,104,105,106,107)Tc, 105Mo, and 101Nb nuclei, which are important contributors to the decay heat in nuclear reactors, has been measured using the total absorption technique. We have coupled for the first time a total absorption spectrometer to a Penning trap in order to obtain sources of very high isobaric purity. Our results solve a significant part of a long-standing discrepancy in the γ component of the decay heat for 239Pu in the 4-3000 s range.     

Determining isotopic distributions of fission products with a Penning trap

A novel method to determine independent yields in particle-induced fission employing the ion guide technique and ion counting after a Penning trap has been developed. The method takes advantage of the fact that a Penning trap can be used as a precision mass filter, which allows an unambiguous identification of the fission fragments. The method was tested with 25MeV and 50MeV proton-induced fission of ²³⁸U . The data is internally reproducible with an accuracy of a few per cent. A satisfactory agreement was obtained with older ion guide yield measurements in 25MeV proton-induced fission. The results for Rb and Cs yields in 50MeV proton-induced fission agree with previous measurements performed at an isotope separator equipped with a chemically selective ion source.     

Evolution of the N=50 shell gap energy towards 78Ni

Atomic masses of the neutron-rich isotopes (76-80)Zn, (78-83)Ga, (80-85)Ge, (81-87)As, and (84-89)Se have been measured with high precision using the Penning trap mass spectrometer JYFLTRAP at the IGISOL facility. The masses of (82,83)Ga, (83-85)Ge, (84-87)As, and 89Se were measured for the first time. These new data represent a major improvement in the knowledge of the masses in this neutron-rich region. Two-neutron separation energies provide evidence for the reduction of the N=50 shell gap energy towards germanium (Z=32) and a subsequent increase at gallium (Z=31). The data are compared with a number of theoretical models. An indication of the persistent rigidity of the shell gap towards nickel (Z=28) is obtained.     

QEC values of the superallowed beta emitters 50Mn and 54Co

Using a new fast cleaning procedure to prepare isomerically pure ion samples, we have measured the beta-decay Q(EC) values of the superallowed beta emitters 5(0)Mn and (54)Co to be 7634.48(7) and 8244.54(10) keV, respectively, results which differ significantly from the previously accepted values. The corrected Ft values derived from our results strongly support new isospin-symmetry-breaking corrections that lead to a higher value of the up-down quark mixing element V(ud) and improved confirmation of the unitarity of the Cabibbo-Kobayashi-Maskawa matrix.     

Fe<Subscript>3</Subscript>O<Subscript>4</Subscript>@SiO<Subscript>2</Subscript> magnetic nanoparticles for bulk scale synthesis of 4′-chloro-2,2′:6′,2″-terpyridine

Terpyridines are unique class of functional compounds that is extensively spotlighted in diverse fields like synthesis of supramolecular chemistry, nanomaterials, medicinal chemistry intermediates, drugs and active pharmaceutical ingredients and so on. The key challenges for the production of terpyridine lie in the bulk scale synthesis of intermediates. The expansively used synthon for terpyridine synthesis is 4′-chloro-2,2′:6′,2″-terpyridine and their bulk scale synthesis under the ambient conditions using a Fe₃O₄@SiO₂ magnetic nanomaterial catalyst is investigated in the present work. In the protocol stabilized, ethyl-2-pinacolate and acetone were reacted in the presence of NaH to obtain 1,5-bis(2-pyridinyl) pentane-1,3,5-trione. The enolate of acetone is difficult to generate even with NaH and we used Fe₃O₄@SiO₂ to increase the rate of H₂ gas evolution. The triketone is cyclized with CH₃COONH₄ to obtain 2,6-bis(2-pyridinyl)-4-pyridine. This reaction proceeds quantitatively and the off-white solid was easy to isolate from the reaction medium. The subsequent aromatization was observed with PCl₅/POCl₃ and acidic silica gel promoted the product yield to reach ~78%. The crux of the present protocol is that it does not involve any column purification and significant yield of 4′-chloro-2,2′:6′,2″-terpyridine can be conveniently attained. The Fe₃O₄@SiO₂ aids in the stabilization of carbonyl on the solid support and abstraction of hydrogen from methyl group of acetone. The 40 nm sized Fe₃O₄@SiO₂ favored the maximum yield attributed to the density of active sites to promote the reactions. Due to high value nature of 4′-chloro-2,2′:6′,2″-terpyridine, the nominal 30% yield improvement achieved at the bulk scale gauges significant at the industrial scale.     

Double-β decay studies with JYFLTRAP

We have applied JYFLTRAP double Penning trap mass spectrometer to study several double-β decay Q values that could be useful for the search of neutrinoless double-β decay and, hence for the determination of neutrino properties.     

A study on copper(II)-Schiff base-azide coordination complexes: Synthesis, X-ray structure and luminescence properties of [Cu(L)(N3)]X (L = Schiff bases; X = ClO4, PF6)

Two Schiff bases N,N′-(bis(pyridin-2-yl)benzylidene)propane-1,3-diamine (pbpd) and N,N′-(bis(pyridin-2-yl)formylidene)butane-1,4-diamine (pfbd) have been prepared and used to synthesize copper(II) complexes. Four complexes of the type [Cu(L)(N₃)]X (1–4) [L = pbpd; X = ClO₄ (1); L = pbpd; X = PF₆ (2); L = pfbd; X = ClO₄ (3); L = pfbd; X = PF₆ (4)] have been synthesized and characterized on the basis of microanalytical, spectroscopic, magnetic, electrochemical, luminescence and other physicochemical properties. Two representative complexes of the series, 2 and 3, have been characterized by single crystal X-ray diffraction measurements which reveal that in each complex the copper(II) ion assumes a distorted trigonal bipyramidal environment through coordination of the metal centre by two pyridine N atoms and two imine N atoms of the Schiff base with the fifth position occupied by a N atom of a terminal . They display intraligand ¹(π–π^*) fluorescence at room temperature and intraligand ³(π–π^*) phosphorescence in glassy solutions (MeOH at 77 K). A band (492 nm) observed for the complexes in their solid-state emission spectra is an excimeric emission arising due to an aromatic π–π interaction. Electrochemical electron transfer study reveals Cu^II–Cu^I reduction in methanolic solutions.