Stages of Embryonic Development of the Amazonian turtle Kinosternon Scorpioides (Testudines, Kinosternidae)

Background: The developmental biology of K. scorpioides is described, based on the phenotype. This species is important for the flora because they are excellent seed disseminators. In addition, basic embryological information is not yet fully clarified, and this research provides unprecedented information on the chelonian embryology of the Amazonian fauna. Methods: Females were monitored throughout the reproductive cycle, by video monitoring, to identify nests and the presence of newly laid eggs. At regular weekly intervals, embryo samples were collected fixed in a 4% paraformol solution and preserved in 70% alcohol. For the embryonic characterization we used a stereomicroscope and the scanning electron microscopy method. Results: We describe 15 embryonic stages for a 15-week (105-day) incubation cycle. Only at 42 days (6th week) was the morphological characterization of a chelonian observed and at the 12th week (Stage XII) the phenotypic characterization of the species kinosternon scorpioides. Conclusions: In view of the evidence, we found that these phases are similar to the other turtles, with structural variations in the appearance and disappearance of structures due to the specific characteristics for the species.

Electrodeposition of catalytically active polyporphyrin films of metal complexes of amino-substituted tetraphenylporphyrins

The process of electrodeposition of polyporphyrin films based on amino-substituted tetraphenylporphyrins and their metal complexes (CuT([Formula: see text]-NH[Formula: see text]Ph)P, FeClT([Formula: see text]-NH[Formula: see text]Ph)P, MnClT([Formula: see text]-NH[Formula: see text]Ph)P) has been studied by the quartz crystal microbalance method. The surfaces of the films have been characterized by the scanning electron microscopy method and the number of electrons taking part in porphyrin electropolymerization has been determined. It has been established that the most intensive film growth is observed for the metal-free porphyrin ligand. The obtained polyporphyrin films have been analyzed for the catalytic ability in oxygen electroreduction reactions.

EFFECT OF ULTRASOUND ON SCALE FORMATION AND CORROSION PROTECTION OF THE HEAT EXCHANGE SURFACE

The processes of scale formation and corrosion on the surface of heat exchange using ultrasound with a frequency of 26.5 kHz of low power in the provisional and transient modes and without it were studied. The functional dependences of the build-up of the specific mass of the scale and the corrosion rate are established, depending on the ultrasonic irradiation regimes. The morphology and structure of the scaled layers formed by the scanning electron microscopy method are studied. It has been established that ultrasonic treatment of low intensity promotes the formation and maintenance of a phase microlayer with anticorrosion properties, which practically does not reduce the heat exhange between the metal surface and the coolant. Bibl. 8, Fig. 8.

Features of Wear of Abrasive Grains Depending on Microcuttings Speed of Steels

In this article by the example of two abrasive materials from oxide of aluminum and nitride of boron, the processes developing in a thin surface layer between a grain of abrasive and the material, processed by microcutting with speeds of 40 and 160 m/s, the preforms from armko-iron, steels R18, 45, H18N10T and alloy titanium VT6 are investigated, using the scanning electron microscopy method.