High-spin structure of yrast-band in 78Kr

Lifetime of levels up to 22⁺, have been measured in ⁷⁸Kr and an oblate shape is assigned to the ground state using the CSM and the configuration dependent shell correction calculations. Calculations further show that ⁷⁸Kr is highly γ-soft nucleus. The experimental Q _t values coupled with theoretical calculations indicate an oblate shape for ⁷⁸Kr at low spins and triaxial shape at higher spins     

Transient and thermally stimulated depolarization currents in pure and iodine doped polyvinyl formal (PVF) films

Transient currents, measured with pure and iodine doped polyvinyl formal (PVF) films as a function of poling field (15–100 kV/cm) and temperature (30–95°C), have been found to follow Curie-von Schweidler law characterized with two slopes in short and long time regions. The isochronals (i.e. current/temperature plots at constant times) have been found to give rise to a peak located at 75°C. The order of current has been found to increase with increase in poling field, temperature and iodine mixing. The comparative studies of the isochronals with the thermally stimulated discharge current (TSDC) indicated the strong resemblance between the two studies. It is suggested that both the dipolar orientation due to molecular mechanism of motions with the side chains and space charge due to trapping of injected charge carriers in energetically distributed traps may be responsible for the observed currents. The dependence of current and activation energy on iodine mixing is explained on the basis of a charge transfer type of interaction.     

Magnetic phase diagram of double-layered La2−2xCa1+2xMn2O7 manganite

Double-layered manganite La_2−2xCa_1+2xMn₂O₇ have been synthesized for compositions ‘x’=0.0, 0.1, 0.2, 0.3, 0.4 and 0.5 by solid state reaction method. From X-ray diffraction study, their crystal structures were found to be tetragonal perovskite with lattice parameters decreasing with increasing ‘x’. The decreasing lattice parameters affect the balance between in-plane, intra-bilayer and inter-bilayer exchange interactions, which is reflected on magnetotransport properties. The metal-to-insulator transition temperature is found to vary with composition and peaked around ‘x’=0.3. From ac-susceptibility study, 2D-ferromagnetic ordering was observed at higher temperatures for all compositions whereas 3D-ferromagnetic ordering was observed at quite low temperatures. In low-temperature region, decreasing susceptibility shows antiferromagnetic state for all compositions. On the basis of electrical and magnetic properties, a magnetic phase diagram is given.     

Temperature dependence of electroresistance for La0.67Ba0.33MnO3 manganite

The influence of dc biasing current on temperature dependence of resistance of La_0.67Ba_0.33MnO₃ bulk sample is reported. A decrease in the resistance (electroresistance) on the application of higher bias current is observed. The electroresistance is maximum at metal-insulator transition temperature (T_MI) and decreases when the temperature is either increased or decreased from T_MI. A two-phase model is proposed to explain the occurrence of electroresistance. The higher bias current leads to an increase in alignment of spins and thus, in turn, leads to an increase in spin stiffness coefficient and decrease in the resistance at T_MI.     

Entrapment of proteins by aggregation within sephadex beads

When a protein is aggregated by chemical crosslinking inside Sephadex beads of appropriate pore size, it gets trapped inside the beads. The above approach was used for immobilization of beta-galactosidase, acid phosphatase, trypsin, and concanavalin A. It was found to be a simple, convenient, and fast method for immobilization of proteins.     

Direct coarse sampling of electronic holograms

We describe a series of experiments in order to test a new sampling criterion for wavefront reconstruction from a carrier-frequency signal as obtained in electronic holography. Both a Fourier-transform configuration and a Fresnel-zone form of a digital holographic microscope are described. Direct coarse sampling of holograms with no phase-shifting elements can be used to obtain wavefront reconstruction, with the number of samples required reduced by the ratio f0/(2Bs), where f0 is the carrier frequency and 2Bs is the signal bandwidth.     

An NMR study of the thiomalic acid complex of cobalt

An NMR study of the thiomalic acid complex of cobalt has been carried out at pH 2.6. The results show that the freshly prepared complex is paramagnetic and it gradually changes to the diamagnetic state, the reaction being complete in about 24 hours. It has been shown that the fresh complex has the hybridization sp³d², whereas the stable complex has the hybridization d₂sp₃. The results have been confirmed by measuring the change in the magnetic susceptibility of the complex with time.     

Elastic scattering of electrons by argon atoms

The partial wave method with a central potential has been applied to investigate the elastic scattering of electrons by the argon atoms in the intermediate energy range (100 eV − 1 keV). The central potential includes the effects of the static field, exchange and polarization. The results are in good accord with recent experimental data. A brief account of this investigation was presented at the X Int. Conf. on the Physics of Electronic and Atomic Collisions held at Paris in July 1977.     

What does the data tell us about the quark-antiquark potential?

In view of the failure of the standard charmonium models to explain $\text{ψ?η}{}_{\mathrm{<mtext>c</mtext>}}\text{and}{}^3\text{P}\text{J}$ splittings, I consider various possible modifications to these models. In particular, I show that for power-law potentials the spin forces are most likely generated through the admixture of scalar-vector-Pauli moment exchanges and that this model can be tested by measuring the ¹p₁ mass. I also show that if instantons really generate a large spin-spin force, then the ¹p₁ mass must be as low as 3250–3270 MeV.