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A simple all glass manometer, which can be used for measuring the pressures from 0.1 mm. to 0.001 mm. has been described. The manometer consists of a thermometer enclosed in a tube. The pressure measurement is done by measuring the time required to cool the thermometer from a given temperature to the other under a given condition. Using a thermometer of long mercury bulb and limiting the operating temperature range so narrow that the Newton’s law of cooling holds, we get the following relation: (Remark: Graphics omitted.) This relation was well confirmed by experiments using the air and the hydrogen.

The freezing behavior of supercooled liquid sulfur droplets were studied by means of a microscopic method. The number fraction of the solidified droplets in the experiments of continuous cooling on well-purified sulfur was only about 15% over the temperature range from 120°C to −70°C at the cooling rate of 0.20°C/min, and no abruptly discontinuous nucleation was found in these supercooling temperatures. The number fractions of the solidified droplets were found to be related to their volumes below −20°C. The nucleations in the well-purified liquid surfur droplets were confirmed to be a homogeneous process under these conditions. The specific nucleation rates per unit of volume were estimated to be 0.450, 1.13, and 1.16 cm−3sec−1 at the specified temperatures of −20, −40, and −50°C respectively. The dependences of (lnI+ΔFA⁄kT) on 1⁄(ΔT)2T obeyed the theory of Turnbull and Fisher. The interfacial free energy of sulfur at the liquid-crystal surface was estimated to be 12.1 erg/cm2; this value was considered ...

The viscoelastic behavior of selenium and of partially-chlorinated selenium was studied by the dilatometric method. The glass transition temperature, Tg, of selenium was determined to be 32.0°C at a cooling rate of 0.2°C/min. The glass transition temperature decreased linearly with the reciprocal of the average chain length of selenium. The chain length was calculated using the degree of chlorination. An abrupt increase in Tg was observed at a chlorine content of about 0.013%. The volume-time curves obtained by the determination of the volume of selenium in the neighborhood of Tg were superposed on each other by sliding them along the abscissa. The values of the shift factor and of Tg fit well in Williams, Landel and Ferry’s equation. The parameters in the WLF equation, C1g and C2g, of selenium were calculated to be 6.86 and 28.6 respectively. Both the parameters increased with an increase in the chlorine content up to 0.0125%, and reached the values of usual polymers above 0.0125%. The WLF fg value of se...

The viscosities and densities of liquid oligotrifluorochloroethylene were measured over a molecular-weight range from 820 to 1090 at temperatures from 40°C to 100°C. The temperature dependences of the viscosities did not show an Arrhenius-type variation, but were extremely adaptable in the WLF equation; i. e., a viscoelastic behavior was shown under the present experimental conditions. The apparent activation energies, ΔHa, for the viscous flow of the liquid samples were comparatively large and increased with an increase in the number-average molecular weight. The logarithm of the viscosity, logη, varied linearly with the logarithm of the number-average molecular weight, logη=AlogMn+B. The slopes, A, of the linear relationships were estimated to be 11.0, 10.4, 9.3, and 8.4 at 50, 60, 70, and 80°C respectively. The values of the slopes, A, were very much larger than unity in the case of usual organic polymers below the critical values of the molecular weight, and they decreased with an increase in the temp...

The viscosities of liquid selenium and partially-chlorinated liquid selenium were measured in the temperature range from 235°C to 305°C using an Ubbelohde-type tilting viscometer. The “intrinsic” viscosities, η0, were estimated by extrapolating the values of the viscosities, ηθ, of various rates of shear to a zero rate of shear. The “intrinsic” viscosities of the liquid selenium were estimated to be 20.18, 13.46, 9.11, 6.32, 3.67 and 2.30 poise at 235, 245, 255, 265, 285, and 305°C respectively. The viscosities of the chlorinated liquid selenium decreased with an increase in the chlorine content, but they varied discontinuously at a chlorine content of 0.0125% and then decreased linearly. The apparent activation energy for the viscous flow of the liquid selenium was estimated to be 17.9 kcal/mol. The apparent activation energies for the viscous flow of the chlorinated selenium varied discontinuously at a chlorine content of about 0.0125%, as in the case of the viscosity. The average-chain length of the se...

The growth rates of spherulites of selenium were estimated by the photomicrographic method in the temperature range from 80°C to 120°C. The selenium was used in the pure and the chlorinated states. At a constant temperature, the spherulite radius increased at a constant rate. The growth rate for pure selenium, logG, varied linearly with 1/T, and the apparent activation energy for growth, EA was estimated to be 24.9 kcal/mol. The apparent activation energy for growth is much larger than that for the transport of the chain molecule, which was estimated from the activation energy for the viscous flow. The linear variation in the growth rate, logG, with 1/T appeared at temperatures well below the melting point of crystalline selenium, and the apparent activation energy for growth was nearly equal to the enthalpy change for the thermal equilibrium of the opening reaction of the Se8 ring molecule. These facts indicate that the selenium spherulite growth is not a diffusion-controlled process, but a breaking proc...

A sharp exothermic peak at 980°C, which is found characteristic of allophane in its differential thermal analysis, shifted to the lower-temperature side and broadened as the iron content in the iron-coprecipitated samples increased. In the case of the iron-mixed samples, however, this exothermic peak did not shift, and a new broad exothermic peak, which was ascribed to hydrated ferric oxide, appeared. The crystallization processes in the heat-treated samples were found to depend on the coexistence state and the quantity of the iron. The dimensions of a unit cell of the mullite, crystallized at 1200°C from the iron-coprecipitated samples, varied with the iron content. The iron-mixed samples, however, showed little change in their cell dimensions. It is concluded that there are two states of the coexistence of iron in the allophanes. In one of them, iron ions form solid solutions of the allophane, i.e., as an iron-allophane. In the other, iron is in the mixture as the hydrated ferric oxide. The maximum amou...

The decomposition of solid NH/sub 4/NO/sub 3/ by gamma rays was performed. The effect of salt addition on the rate of decomposition was studied. The decomposition was found to accelerate upon the addition of metal ions. (C.J.G.)