Density isomerism and the Primakoff effect

We show that the decay width for π⁰→2γ in nuclear matter could be used as a signal for phase transitions in nuclear matter. The decay width of the π⁰ is experimentally measured using pion photoproduction off heavy nuclei by observing the Primakoff peak in the differential cross sections. We present calculations for the differential cross section with corrections to the γ?γ?π⁰ vertex arising from the nuclear medium within the nuclear radius when the medium is in the abnormal matter phase.     

Lattice dynamical analysis of β ↔ γ phase transformation in silicon under high pressure

β-tin and the one-atom primitive hexagonal structure (γ phase), the two high-pressure polymorphs of Si, are related to each other by correlated displacement of atoms. This is interpreted in terms of a zone boundary mode softening $\text{1}\text{2}\text{(101)}{}_{\mathrm{\gamma }}$. It is confirmed by detailed lattice dynamical calculations.     

The synthesis of XTT: A new tetrazolium reagent that is bioreducible to a water-soluble formazan

A new tetrazolium salt, XTT, has been synthesized. XTT is reduced by a considerable variety of cell lines to a water-soluble formazan. XTT appears to merit further investigation as a reagent for broader application to cell culture assay systems.     

Reductive removal of allylic functional groups by nickel boride

Reductive removal of an allylic functional group proceeds most easily and efficiently with nickel boride as the bond being cleaved becomes a better leaving group (e.g. OCH₃<OH <OSiMe₃<OCOCH₃<OCOCF₃)     

Study of effects of dopants on structure of vitreous semiconductors (GeSe3.5)100-xMx (M = Bi,Sb) using high pressure techniques

An investigation of the problem of controlled doping of amorphous chalcogenide semiconductors utilizing a Bridgman anvil high pressure technique, has been undertaken. Bulk amorphous semiconducting materials (GeSe_3.5)_100-x doped with M = Bi (x = 2, 4, 10) and M = Sb (x = 10) respectively are studied up to a pressure of 100 kbar down to liquid nitrogen temperature, with a view to observe the impurity induced modifications. Measurement of the electrical conductivity of the doped samples under quasi-hydrostatic pressure reveals that the pressure induced effects in lightly doped (2 at % Bi) and heavily doped (x = 4, 10) semiconductors are markedly different. The pressure effects in Sb-doped semiconductors are quite different from those in Bi-doped material.     

Mixed Ligand Complexes of Chromium (III) Ethylenediamine Tartrate: A Polarographic Study

Polarographic techniques have been used to investigate the complexing behaviour of chromium (III)-ethylenediamine-tartrate in aqueous solution. These complexes are reduced irreversibly at the dropping mercury electrode. The stability constants have been calculated by the method of Sundaresan and Sundaram. The values of the kinetic parameters; standard rate constant (K_s), transfer coefficient (α) and activation energy (Q) have also been calculated in each case.     

Kinetics and thermodynamics of ferrous-ferric equilibrium in sodium aluminoborate glasses

The oxidation-reduction equilibrium between ferrous and ferric iron in sodium aluminoborate glass melts having molar composition 15Na₂O·10Al₂O₃·75B₂O₃ has been studied as a function of temperature. The reaction was observed to follow first order kinetics. The energy of activation for the above reaction was calculated. Equations previously suggested to represent the Fe²⁺–Fe³⁺ equilibrium were discussed and a new equation is proposed. The enthalpy of the reaction was ?8.80 kcal mol^?1.     

The short-lived radioisotope production program at manchester

Several short-lived accelerator-produced radionuclides for medical applications have been routinely produced over the last few years in Manchester, namely¹²³I,⁸¹Rb−^81mKr,¹¹¹In,²⁰⁶Bi and¹⁹¹Pt. Nuclear reactions employed, target preparation and the radiochemical separation procedures used are briefly discussed.     

Optical transitions of Eu3+ ions in EuCl3 solutions

The optical absorption spectra of EuCl₃ in aqueous and acidic solutions were measured in the visible anduv regions of the spectrum. The concentration as well as the temperature of the solutions were varied to establish an accurate free-ion energy level scheme of Eu³⁺. The energy levels were assigned on the basis of a correlation between the calculated and the experimentally observed transition energies and associated band intensities.