Critical Point of the 152Sm, 154Gd,and 156Dy Isotones

Physics of Atomic Nuclei - The even—even rare-earth nuclei in U(5)—SU(3) region at neutron number (N) = 90, have been systematically studied using the Bohr—Mottelson Model (BM),...     

Nonplanar Electrostatic Solitary Waves in a Relativistic Degenerate Dense Plasma

By employing the reductive perturbation technique, the propagation of cylindrical and spherical ion acoustic solitary waves is studied in an unmagnetized dense relativistic plasma, consisting of relativistically degenerate electrons and cold fluid ions. A modified Korteweg-de-Vries equation is derived and its numerical solutions have been analyzed to identify the basic features of electrostatic solitary structures that may form in such a degenerate Fermi plasma. Different degrees of relativistic electron degeneracy are discussed and compared. It is found that increasing number density leads to decrease the amplitude the width of the ion acoustic solitary wave in both the cylindrical and spherical geometries. The relevance of the work to the compact astrophysical objects, particularly white dwarfs is pointed out.     

One-pot conversion of carbamates of unsaturated β-aminoesters into unsaturated β-lactams by use of trimethylsilyl iodide

Trimethylsilyl iodide (TMSI) is introduced as an efficient reagent for the one-pot and direct transformation of carbamates of unsaturated β-aminoesters into the corresponding α-methylene-β-lactams and α-arylidene-β-lactams. The mild reaction conditions, excellent yields and easy work-up procedures make it a useful alternative to previously applied procedures for the rapid synthesis of β-lactams from easily available Baylis-Hillman adducts.     

Crystal structure and magnetic properties of Sr4Mn2NiO9

The crystal structure of Sr₄Mn₂NiO₉ has been refined on single crystal. This phase belongs to the series A_1+x(A^′_xB_1–x)O₃ (x=1/3) related to the 2H-hexagonal perovskite. The structure contains transition metals in chains of oxide polyhedra (trigonal prisms and octahedra); neighboring chains are separated from each other by the Sr atoms. The sequence of the face sharing polyhedra along the chains is two octahedra + one trigonal prism. Mn occupies the octahedra and Ni is disordered in the trigonal prism with ≈80% in the pseudo square faces of the prism and ≈20% at the centre. This result has been confirmed by XANES experiments at Mn K and Ni K edges, respectively. Sr₄Mn₂NiO₉ is antiferromagnetic with a Néel temperature at T=3 K. The Curie constant measured at high temperature is in good agreement with ≈80% of the Ni²⁺ ions in the spin state configuration S=0.     

Local modal participation analysis of nonlinear systems using Poincaré linearization

Nonlinear Dynamics - This study proposes a modified recurrence quantification analysis, called global recurrence quantification analysis (GRQA). It is well known that the recurrence threshold is an...     

Magnetoacoustic waves with effect of arbitrary degree of temperature and spin degeneracy in electron-positron-ion plasmas

The linear properties of magnetosonic waves are studied in nearly degenerate and nearly non-degenerate quantum plasmas composed of electrons, positrons and ions in the presence of spin- effect. Using the fluid equations, a generalized dispersion relation for perpendicular and oblique propagation is derived. It is found that degree of temperature and spin degeneracy modify the dispersive properties of the given modes. The results of analysis are beneficial for understanding the collective phenomena in dense quantum astrophysical plasmas.     

188Rhenium-EDTMP: A potential therapeutic bone agent

Bone seeking radiopharmaceuticals such as ethylenediaminetetramethylene phosphonate (EDTMP) complexes of ¹⁵³Sm and ¹⁶⁶Ho are receiving considerable attention for therapeutic treatment of bone metastases. Rhenium-188 has both beta-particle emissions for a therapeutic effect and gamma-emissions for imaging and it is available from an in-house generator system similar to the current ^99mTc generator, which makes it convenient for clinical use. The preparation of ¹⁸⁸Re-EDTMP is described using ¹⁸⁸Re, which was obtained from the alumina-based ¹⁸⁸W/¹⁸⁸Re generator. Dependence of the radiolabeling yield of ¹⁸⁸Re-EDTMP on reducing agent concentration, EDTMP concentration, incubation time, pH and addition of carrier was examined. In the case of optimum conditions, the radiolabeling yields of ¹⁸⁸Re-EDTMP were ~98% for carrier-free as well as carrier-added ¹⁸⁸Re. The addition of ascorbic acid plays an important role in the stability of carrier-free as well as carrier-added ¹⁸⁸Re-EDTMP preparations. The biodistribution of carrier-free and carrier-added ¹⁸⁸Re-EDTMP compounds in rats was also studied. The results show that ¹⁸⁸Re (carrier-added)-EDTMP is a potential bone pain palliation radiopharmaceutical due to its high skeletal uptake, rapid blood clearance and relatively low soft tissue absorption.     

[Bu3NH][HSO4] catalyzed: an eco-efficient synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-diones and 2H-indazolo[2,1-b]phthalazine-triones under solvent-free conditions

Research on Chemical Intermediates - A Brønsted acidic ionic liquid [Bu3NH][HSO4] as an eco-efficient catalyst for the one-pot multicomponent synthesis of...     

Observation of a large magnetic anisotropy in the new 2H-perovskite related oxide Ba8CoRh6O21: magnetic measurements on aligned single crystals

Single crystals of Ba8CoRh6O21, grown out of a potassium carbonate flux, were characterized by single-crystal X-ray diffraction and magnetic measurements. X-ray data were collected in a superspace group approach and solved using the JANA2000 software package. Ba8CoRh6O21 represents the first example of a structurally characterized m = 5, n = 3 member of the A3n+3mA'nB3m+nO9m+6n family of 2H hexagonal perovskite related oxides and contains chains consisting of six consecutive RhO6 octahedra followed by one distorted CoO6 trigonal prism. Magnetic measurements were carried out on large aligned single crystals, and a very large magnetic anisotropy in the magnetic susceptibility, persisting up to room temperature, was observed.     

Desorption of99Mo from spent99Mo/99mTc generator

A simple method for desorption and purification of⁹⁹Mo from spent⁹⁹Mo/^99mTc generators is described. The alumina column was washed successively with 0.9% saline water, 35% H₂O₂, and then the⁹⁹Mo was eluted with 2M NH₄OH. Ammonia and residual H₂O₂ were removed by heating the eluate. Finally,⁹⁹Mo solution was passed through a 0.2 m membrane filter to remove precipitated aluminium hydroxide.