The vapor-liquid equilibrium of several acetic acid-water-salt systems under atmospheric pressure was determined by employing lithium nitrate, magnesium nitrate, potassium nitrate, and potassium acetate as salts. In the vapor-liquid equilibrium of an acetic acid-water-salt system, lithium nitrate, magnesium nitrate, and potassium nitrate showed a salting-out effect, while potassium acetate showed a salting-in effect. The vapor-liquid equilibria with the nitrate, chloride, bromide, and acetate salts at a salt concentration of 1.0 mol/kg were also determined, and it was shown that by keeping the anion the same and changing the cations of salts with those having a smaller hydration enthalpy showed an increased salting-out effect. Alternatively, when the cation was kept the same, the salts showed the salting-out effect in the following order: chloride > bromide > nitrate > acetate salts; the acetate salt showed a salting-in effect.

View full abstract

In our laboratory, a compact-sized falling needle rheometer (FNR) which is type of a falling body viscometer has been developed in order to analyze the flow property such as blood, ionic liquid and others. In the present study, uncertainty in viscosity measurement using FNR was evaluated. As a result of evaluation of uncertainty in calibration using 8 needles with different densities (ρ_s = 1030-1505 kg/m³), factor of the largest uncertainty is a density difference between needle and sample (ρ_s - ρ_f). It was found that it is required to measure the mass of a needle correctly in order to decrease viscometric uncertainty. It was confirmed that the expanded uncertainty in viscosity measurement of unknown samples using FNR is less than 0.90 % (coverage factor = 2) at 610 kg/m³ of ρ_s - ρ_f.

View full abstract

This paper describes the radiative heat transfer in porous insulation materials at high temperature. The heat transfers in porous insulation materials are heat conduction through solid and gas, convection of gas and thermal radiation.
In this study, a diffuse approximation was applied to several types of porous insulation materials and the radiative heat transfer was considered in proportion to the cube of temperature, T³. From the literature data of the effective thermal conductivity, the Rosseland mean extinction coefficient was estimated and the contributions of heat transfer by solid, gas, and radiation were estimated separately.
The estimation results indicate that the effective thermal conductivities depend on the radiative heat transfer over a wide range of temperature. Additionally for the improvement of insulation performance, the reduction of radiative heat transfer is necessary not only in high temperature condition but also for low and normal temperature conditions.

View full abstract