Mosaic Structure of Photographic Emulsion Crystals
CRYSTAL imperfections play an important part in present studies of the formation of the photographic latent image. In large silver bromide crystals it has been shown1 that silver prints out along individual dislocation lines. Little direct evidence has yet been given on defects within the small grains of photographic emulsions, since neither light microscopy nor electron microscopy has yet proved effective in this field.
Pressure effect of cavitation on photographic emulsion.
The nature of the dislocations in photographic emulsion grains is discussed with regard to the tilt boundaries which were generated by the pressure gradient produced by the contraction of cavitation in ultrasonic field. On the mechanism of the latent fog formation by the pressure effect, some remarks are given on the standpoint of the Mitchell theory of development.
Experimental energy barriers to anions transporting through nanofiltration membranes.
Environmentally relevant contaminants fluoride, chloride, nitrate, and nitrite face Arrhenius energy barriers during transport through nanofiltration (NF) membranes. The energy barriers were quantified using crossflow filtration experiments and were in the range of 7-17 kcal·mol(-1), according to ion type and membrane type (Filmtec NF90 and NF270). Fluoride faced a comparatively high energy barrier for both membranes. This can be explained by the strong hydration energy of fluoride rather than other ion properties such as bare ion radius, fully hydrated radius, Stokes radius, diffusion coefficient, or ion charge. The energy barrier for fluoride decreased with pressure, indicating an impact of directional force on energy barriers. The influence of temperature-induced pore radius variability and viscosity on energy barriers was considered. The novel link between energy barriers and ion properties emphasizes the importance of ion hydration and/or partial dehydration mechanisms in determining transport in NF.