In order to make researches in the adsorptive property of water vapor on glass surfaces, two series of experiments of the following (1) and (2) were made using the non-alkali glass fibers of continuous filament type.
(1) After various degrees of outgassing, adsorption isotherms of water vapor on the fiber surfaces at 20°C and 10°C were volumetrically obtained. Even though on the same fiber surfaces, the isotherms were different in shape according to the degrees of respective outgassing. Especially various widths of the hysteresis loop were noted.
(2) To obtain the decreasing rates of the amounts of the water vapor adsorbed on the glass surfaces during evacuation, the following procedures from (a) to (d) were repeated.
(a) The glass fiber surfaces were exposed in the equilibrium pressures of water vapor of either P=1.0 to 1.1 Torr or P=17.0 to 17.2 Torr.
(b) Evacuation took place for a certain length of time, maintaining the temperature of the fibers at 20°C.
(c) The glass fibers were heated for 3 hours at either 150°C or 450°C, while the evolved water vapor was trapped in the U-tube cooled by dry ice-acetone mixture.
(d) The amount of water vapor trapped was volumetrically determined.
The curves of the decreasing rates were shown in the graph, the abscissa being the evacuation time of the process (b) mentioned above, and the ordinate the amount determined by (d).
The curves were descending rapidly for the first few minutes and then became gradually. slow down for the following few hours. They finally reached to the states of the plateau, whose heights varied as a function of the pressure of (a).
Probable factors affecing the shape of the isotherms, the occurrence of the plateaus and the difference in height of the plateaus can be assumed as follows;
A part of the molecules of water vapor adsorbed on the sites of the glass surface ionizes to produce OH^-and H⁺. Most of OH^- ions produced form the hydrogen bond with the sites, while a part of H⁺ ions produced dissolves into the glass, perhaps the latter dissolves into the depth of several atomic layers from the surface, and both ions form an electric double layer. The concentration of OH^- and. H⁺ ions produced, and the depth and the concentration of H⁺ ions dissolved into the glass are the function of the pressures of water vapor at which the.glass surface is exposed.

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Antimony trisulfide was evaporated in Ar gas at low pressure, and the effects of deposition conditions on the physical properties of evaporated films were studied. The deposition parameters such as Ar pressure, evaporation rate, evaporation source temperature, and the distance between a substrate and an evaporation source temperature, exercised a great effect on the properties of evaporated films.
The effects of deposition parameters revealed in this experiment were very different from those observed in the vacuum deposition of antimony trisulfide. This shows the deposition mechanisms in Ar at low pressure are different from the ordinary vacuum deposition mechanisms.
In this paper, those mechanisms are briefly discussed and qualitative explanations are given.

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