SNOW CRYSTALS FROM THE CRYSTALLOGRAPHIC STANDPOINT

The physics of snow crystals

We examine the physical mechanisms governing the formation of snow crystals, treating this problem as a case study of the dynamics of crystal growth from the vapour phase. Particular attention is given to the basic theoretical underpinnings of the subject, especially the interplay of particle diffusion, heat diffusion and surface attachment kinetics during crystal growth, as well as growth inst...

Aggregation of needle snow crystals

For the purpose of studying the early process of snowflake growth, characteristics of the Ž . aggregation collision–adhesion process of needle snow crystals were investigated by examining photomicrographs of snowflakes composed of two crystals. The adhesion type of the snowflakes was classified into crossed adhesion and point adhesion types. When the sizes of the two crystals were similar, whic...

From the Standpoint of Dermatology

Because skin color directly reflects every pathological change of skin that causes modification of its optical characteristics, it is vital information in dermatological diagnosis. Photographs have played a substantial role for a long time in recording skin lesions, and recently digital imaging has been introduced for this purpose. But the quality of skin color images reproduced by any currentl...

Crystallographic and optical study of PbHfO3 crystals

The symmetry of the intermediate high-temperature phase of PbHfO3 has been determined unambiguously to be orthorhombic using a combination of high-resolution X-ray diffraction and birefringence imaging microscopy measurements of crystal plates. While lattice parameter measurements as a function of temperature in the intermediate phase are consistent with either orthorhombic or tetragonal symmet...

Morbid Impulses from the Medico-Legal Standpoint