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The process of polycondensation of urea with formaldehyde has been studied and a technology for producing an environmentally safe biodegradable nitrogen fertiliser based on urea acting by a prolonged mechanism has been developed. The influence of various factors on the course of the reaction has been studied: the duration of the process, temperature, molar ratio of the initial components, structure and composition of the amide component, concentration. The main parameters of kinetics were determined: reaction order, activation energy, probability coefficient. The main kinetic parameters of the process were determined during the reaction in the temperature range of 50--70oC, before the deep conversion of formaldehyde. In order to develop a technology for the production of perennial forage grasses, stationary field tests were conducted. Using the fertilisers obtained, in the field, on the basis of forage herbs, high-quality animal feed was obtained both in raw form and in the form of silage, haylage and hay flour. [ABSTRACT FROM AUTHOR]

The effect of hardeners on the properties of cured epoxy polymers for the synthesis of polymers with enhanced thermal properties has been studied. The glycide ethers of polycyclic bisphenols synthesised by us were used as a diol component. Since the thermal and heat resistance of polymers, in addition to the chemical structure of bisphenols, also depend on the structure of the hardener used, amine hardeners of different chemical structure are used to improve the thermal performance of polymers, both thermal resistance and heat resistance. The influence of the chemical structure of these hardeners on the properties of epoxy polymers has been investigated. Cured epoxy polymers are characterised by high heat resistance. High heat resistance results are obtained by 4,4'-diaminodiphenylsulphone, benzidine, 4,4'-diaminodiphenyloxide and other aromatic diamines. Polymers obtained by curing with these hardeners are deformed in the temperature range 220-245°C. The use of the above hardeners gives high results in terms of heat resistance. In all cases, polymers obtained on the basis of these hardeners decrease in mass by 10% in the temperature range of 340-400°C. [ABSTRACT FROM AUTHOR]

Novolac on the base of adamantine type bisphenol was obtained. Some kinetic regularities of reaction of interaction of adamantane type bisphenol and formaldehyde were studied. It was proved that the reaction proceeded according to the second order. Activation energy and reaction rate constants were calculated. IR-spectroscopy was used to study the process of thermal hardening of novolac at isothermal terms on the air. [ABSTRACT FROM AUTHOR]

Composites capable to absorb thermal neutrons have been developed on the basis of novolac - oligomers, in which thermally modified natural sorbents -diatomite and boron carbide were used as fillers. Technological schemes and parameters have been offered for matrix and modified diatomite. Composites of various compositions have been considered. Composites which contained 40 mass% novolac oligomers revealed optimal mechanical and thermalphysical characteristics. Results of testing of thermal neutrons flux of various composition samples have been offered. [ABSTRACT FROM AUTHOR]

The organ of mollusc equilibrium - statocyst appears to be the analogue of acoustic-vestibular system in vertebrate animals. In terrestrial pulmonary snail the epithelial lining of statocyst cavity is created by two types of the cells - a small amount of large cells, provided with kinocilia of sensitive cells and considerably a large number of small supporting or inserted cells, covered with the microvilli. By means of transmission and scanning electron microscopy the ultrastructure and intercellular connections of these cells were studied. The sensitive cells have in a certain way structured cytoplasm, which consists of three layers: ectoplasm, granular layer and hyaloplasm. Myelin-like bodies having the granular, vesicular and drop-like formations in the centre appear to be the special structure of the cytoplasm. In the cytoplasm there are areas, saturated with electron dense glycogen granules. On the electronograms sometimes it is observed how the pinocytic vesicles in the supporting cells are created from the diverticulum of plasmatic membrane of sensitive cells. The boundary areas of plasmatic membrane of adjacent cells (sensitive cells with supporting or supporting cells with the support) are also characterized by the presence of specialized contacts, which are analogous to desmosomes in the epithelial tissues, as well as by the existence of cellular desmosomes, interdigitations. Numerous lacunas have been revealed in the intercellular space, which are connected by the thin tubules and ducts resulting in the formation of a complicated configuration of extensive system of communicating with each other lacunae, which have the exit in statocyst cavity.

Statocysts H. Lucorum appear to be the paired formations having a spherical form and locating on dorsolateral surface of pedal ganglia of subesophageal ganglionic complex. Using the method of reconstruction, as well as the method of scanning electron microscopy on paraffin and semithin slices it has been revealed that the epithelial lining of H. Lucorum appears to be a spatially ordered complex, consisting of 13 cell assemblies. in each of them one sensory cell is surrounded by the satellite cells. The sensory cell has a star shape on the front pole of statocyst because of many protoplasmic processes branching off from its body. The other 12 cells have polygonal shape and form three belts around the inside perimeter of statocyst: interior, middle or equatorial and posterior. There are 4 cells in each belt. The sensory cells forming anterior and posterior belts turned out to be displaced in relation to the cells of equatorial belt and for this reason the whole cell structure resembles a brickwork. The distribution of sensory cells on the inner surfce of statocyst creates the structural polarization of this formtion. First of all, this is evidenced by the presence of the sensory cell on the anterior pole of statocyst and by the absence of those on opposite, posterior pole. The topography of each sensory cell on the inner surface of statocyst, the sizes and shapes of the nuclei, the quantity of nucleoli, the peculiarities of cytoplasm vacuolation and interrelation of sensory and supporting cells have been established.

Statocyst epithelial lining of terrestrial pulmonary snail Helix lucorum is a spatially arranged structure consisting of 13 cell ensembles. Each ensemble has a sensory cell surrounded by companion cells. The sensory cell on the anterior statocyst pole is star-shaped due to multiple protoplasmatic protrusions on its body. The remaining 12 polygon-shaped cells form 3 tires along the statocyst internal perimeter: anterior, middle or equatorial and posterior. There are 4 cells in each tire. Topography of every sensory cell on the statocyst internal surface was described as well as cell nuclei size and form, nucleoli number and patterns of cytoplasm vacuolization. Space free of sensory cells is occupied by supporting or intercalary cells. Exposure to space microgravity over 40, 43, 102 and 135 days aboard the orbital station MIR affected morphology of the sensory cells. Specifically, this appeared as reductions in cell height and, consequently, extension of the statocyst cavity internal diameter and volume in the space-flown snails.

Light and scanning electron microscopy was used to study the morphological parameters and ultrastructure of Helix lucorum statocysts and statoliths in Pomatias rivulare statocysts after 56, 93 and 110-day exposure to microgravity aboard the ISS. Increased gravity was simulated by 30-d centrifugation at 6 g. On the first day of recovery, many statoconia and statoliths were found to carry numerous warts. Moreover, statoconia grew in number significantly as compared with the ground control. On the contrary centrifugation caused massive destruction of statoconia. In a month after orbital flight and centrifugation morphology of both statoconia and stastoliths was nearly normal. These results evidence, that the gravitational field is an important factor for the abiotic medium responsible for building up the inertial mass in the equilibrium organ of animals.

Prior to examining and describing pelvic organ support defects in females, all clinicians should use optimal pelvic prolapse classification. We proposed our original classification which includes both the prolapse grade and etiopathological causes. In our classification crucial point of descent is isthmus of uterus. Such conception will aid in providing a comprehensive and correct surgical treatment to reduce prolapse recurrence. According to ethiopathologic principles in pelvic prolapse surgery, in our study success was obtained in 97.3%.