Using standard microwave X-band technique and by following Gopalakrishna’s single frequency concentration variational method, dielectric relaxation times (τ) of dilute solutions of N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMA) and several DMF+DMA mixtures in benzene at 15°C have been measured. Such measurements using DMF+DMA mixture containing 50 mol%DMA have also been carried out in benzene at 20, 25 and 30°C. The energy parameters (ΔF_ε, ΔH_ε and ΔS_ε) for the dielectric relaxation process for DMF+DMA mixture containing 50 mol%DMA have been calculated at 15, 20, 25 and 30°C and compared with the corresponding viscosity parameters. A good agreement between the free energy of activation from these two sets of values shows that dielectric relaxation process, like viscous flow, can also be treated as a rate process. From relaxation time behaviour of DMF and DMA binary mixture in benzene solution, solute-solute type of molecular association is proposed.

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Mixtures of cholesterol-dimyristoylphosphatidylcholine (DMPC) and cholesterol-dipalmitoylphosphatidylcholine (DPPC) in bilayers were investigated by 0.75 Hz ac calorimetry. DMPC with 0 to 30 mol% cholesterol and DPPC with 0 to 70 mol% cholesterol were studied over a temperature range 275–340 K. The results by ac calorimetry indicate that the mixtures of phospholipids and cholesterol have a basic structure in which 20 mol% cholesterol is intercalated: in the DMPC-cholesterol mixtures this structure is stabilized and on the other hand, in the DPPC mixtures a loose structure based on that of 20 mol% cholesterol takes place and much cholesterol-rich regions are allowed.

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Reevaluation of the barometer coefficients of neutron monitors at high latitudes has been performed by using the results of the spherical harmonic analysis based on the records from around 20 stations for 12 years from January 1966 to December 1977. The average of data at 8 stations, where continuous records are available for 12 years, shows that the absolute value of barometer coefficient is in positive correlation with the cosmic ray neutron intensity. The variation rate of the barometer coefficient to the cosmic ray neutron intensity is larger in the solar quiet period than in the solar active period.

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The Hinotori gamma-ray spectrometer observed time histories of gamma-ray line and electron bremsstrahlung X-ray emissions from four solar flares. The time histories of impulsive flares require that both nuclei and electrons are rapidly accelerated to energies >10 MeV/nuc and >1 MeV respectively in a time scale of <10 s, and the gamma-ray line peak is coincident with the electron bremsstrahlung peak in <4 s. The gradual flare shows the gamma-ray line peak is apparently delayed by tens of seconds with respect to the electron bremsstrahlung peak. The gamma-ray line peak delay is attributed either to the simultaneous acceleration of nuclei and electrons in one step and a longer life time of the nuclei against the injection, the propagation and the slowing down in the flare region or to the second phase (step) acceleration of nuclei.

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