“Everything is theoretically impossible, until it is done.”
Robert A. Heinlein
The advantages of using foam concrete.
Energy saving. Compared with other building materials, non-autoclaved foam concrete can dramatically reduce the cost of insulating walls and roofs of houses and significantly reducing construction time. This is achieved at the expense of energy savings in the production of foam concrete, reducing the number of workers, low cost components of foam concrete and the lack of sophisticated construction equipment.
Fire and environmental safety. Foam concrete is non-flammable, has a high fire resistance, which makes it an attractive material for the construction of fire-resistant structures. When exposed to intense heat such as a blowtorch on the surface of foam concrete, it does not split and does not explode, as is the case with heavy concrete. For example if to heat the outer side of the wall of foam concrete with a thickness of 150 mm to 1200 ° C, the internal heated only to 46 ° C after 5 hours of testing. The material is non-toxic and has no harmful secretions when heated, peculiar to insulating materials made of plastic or basalt wool.
Thermal insulation. Due to its cellular structure, foam concrete has a very low heat transfer. This means that in most cases the use of additional insulation in floors and walls is not necessary.
Acoustic properties. The acoustic properties of foam concrete are such that sound is absorbed without being reflected, unlike walls made of heavy concrete or brick. Low noise frequencies are particularly well absorbed by foam concrete. Therefore, it is often used as a soundproofing layer on structural concrete slabs to limit the noise transmission of floors in multi-story residential or office buildings.
Durability. Foam concrete, in contrast to mineral wool and foam plastics that lose their properties, over time, only improves its thermal insulation and strength properties, which is associated with its long internal maturation.
ANTIDOTES FOR EMERGENCY CARE FOR ACUTE AND CHRONIC INTOXICATIONS WITH RADIOACTIVE SUBSTANCES AND HEAVY METAL COMPOUNDS
There is the possibility of the nuclear or radiological weapons using by enemy, as well as the possibility of contamination of food products and water sources with toxic compounds of heavy metals. In this regard, the civil and Armed Forces medical service are facing the tasks related to the development of reliable methods and means of protecting a person from the harmful effects of penetrating radiations and toxic metals. One of such ways of protection is to use the special drugs - antidotes. Antidotes prevent the absorption of radioactive isotopes and ions of toxic metals from the digestive tract, in case of their ingestion with food and water. Strontium Sr90 and Cesium Cs137 are long-lived isotopes of uranium fission products which have the greatest danger. These elements are well absorbed from the digestive tract by 30÷40 % and 100%, respectively. When ingested, they are permanently deposited in tissues and organs.
The present work is devoted to the antidotes development for emergency care for acute and chronic intoxications with radioactive substances and heavy metal compounds. The basis of these antidotes are highly selective inorganic ion-exchange materials. The author took part in the development of the composition and technology of obtaining an antidote, named «Ferrocyn». «Ferrocyn» selectively absorbs isotopes Cs137. «Ferrocyn» is a chemical-pharmaceutical preparation intended as a medicine for excretion of incorporated radioisotopes from the body Cs137. «Ferrocyn» is a finely dispersed powder of dark blue color, without taste and smell, the chemical composition is ferriferrocyanide of potassium.
A temporary pharmaceutical article was developed for «Ferrocyn». All necessary preclinical and clinical studies were performed. The basis of the pilot-industrial technology for the production of «Ferrocyn» was the technological scheme for the preparation of the inorganic electron-ion exchanger FS-10 developed by us. In accordance with the developed technology, the production of experimental lots of the «Ferrocyn» preparation was organized. The products were transferred to the Institute of Biophysics of the Ministry of Health to conduct research. It also comes at a pharmaceutical factory for packaging and delivery to consumers.
The highly selective to strontium inorganic sorbent ISMA-2 was developed for selective absorption of Sr90 isotopes. By analogy with the «Ferrocyn» preparation, it selectively promotes the excretion of Sr90 isotopes from the body. ISMA-2 sorbent is non-toxic and resistant to the action of aggressive media in the gastrointestinal tract. This product also passed a full cycle of tests in the profile organizations of the healthcare system and radiochemical laboratories in the structure of the nuclear industry. Also as antidotes in radioactive Sr90 damage, we investigated inorganic polymeric antimony compounds. High selectivity of these drugs allowed obtaining the biological effect with significantly reduced therapeutic doses. Inorganic polymeric cation exchangers based on antimony compounds also have no toxicity. We also developed a technique that allowed the stabilization of freshly precipitated barium sulphate BaSO4 and to delay the aging process for its use as an antidote. Barium sulphate preparations obtained by a new method reduced the deposition of strontium Sr90 in the body by 20÷40 times and also created a real protection against this dangerous radioisotope.
As antidotes from salts of heavy metals, we developed a whole series of sorbents that selectively absorb ions of various metals. We used an inorganic electron-ion exchanger FS-10 as an antidote when poisoning by Thallium salts. This sorbent was synthesized on the basis of mixed ferrocyanides of nickel and potassium. Sorbents for lead, arsenic, cadmium, copper, mercury and selenium have also been synthesized. Sorbents for selenium can be used as antidotes for radioactive polonium damage Po210.
HIGH TEMPERATURE INSULATION COATINGS FOR WIRES
State of work
Electrical machines (electric motors, generators, electromagnets, sensors etc.) for aerospace applications and nuclear reactors are located closer to sources of the energy, and need to function at high temperature. Therefore, the upper limit of the use of copper wires is the melting point of copper – 1085 °C. Temperature of the electrical machines can be increased up to Curie point of the core materials, temperature of 630 °C. However, the operating temperature of the winding wires is limited by decomposition of polymers that are used for the insulating wires. Most heat-resistant polymer insulation is capable of withstanding temperatures up to 300 °C.
The objective of the work is to develop an isolating material and a coating process that the winding wire will be suitable to resist against heating up to the temperature of Curie point of the core material or the temperature of melting of the conductor used for winding wires.
This problem can be solved by using inorganic materials like a silicon dioxide (SiO2) with melting point of 1600 °C. However, the silicon dioxide is very hard and brittle material. In connection with this primary insulation must be flexible. However, after some heat-treating it should become hard, dense and strong. After that, it must withstand high temperatures and be resistant to electrical breakdown.
Such scheme may be implemented within sol-gel process. The sol-gel proses are well known for synthesis composite materials for aerospace and rocket technology .
Coating of the winding wire will be based on the soluble organic silicates. These compounds are similar to alkali metal silicates, in its properties. In addition, they do not contain in their composition the alkali metals, which reduce melting point of silicates and reduce their resistance. Above a certain temperature, organic silicates are decomposed to form pure silica SiO2, and volatile compounds.
Soluble organic silicates can have viscosity necessary for coating the metal wire. The coating obtains after drying, and can withstand a certain bending force. It’s sufficient for winding induction coils predetermined shape and size. Finished coils are thermally treated as finished product. Then, it’s possible to carry out additional impregnation of finished coils with organic silicate. What impregnation need to further thickness increase of coating, reducing empty interturn gaps and healing, ability to cover defects on surface of the wire. Thereafter, secondary heat treatment is necessary to carry out for final fixation of silica coating.
The coating on wire surface is possible to use install. Similar installation is used for protective coating on surface of fibers in preparation of composite materials.
Acid and alkaline hydrolysis of tetraethoxysilane. This variant sol-gel process allows to form three-dimensional polymer network. Carrying out controlled hydrolysis of tetraethoxysilane we get products which are precursors to silica coatings. The viscosity of solution can be adjusted. The technology is similar to previous embodiment.
The purpose of this research is to develop new group of the insulating coatings that will increase electromechanical properties of insulation of the winding wire for operation at high temperatures. This topic is patentable.
PRODUCTION ESTABLISHMENT OF AROMATIC METAL OXIMATES AND THEIR DERIVATIVES
State of Work
In recent years, studies of synthetic reactions and the biological activity of organometallic compounds of various oximes have been widely developed. In this regard, the complexes of various metals with aromatic derivatives of various oximes are of the greatest interest and diversity. This is due to the diversity of functional groups that may be part of such compounds. Derivatives of various metals were synthesized, located in periodic table of Mendeleev.
In the formation of complex compounds of various metals with oximes, the latter perform the function of a ligand in a complex compound. To fulfill this role, the ligand must demonstrate remarkable selectivity for the complexation of the corresponding metal compared to other metals in solution when leaching from solutions rich in other components. The formation of the complex should be favorable at relatively low pH values necessary to ensure that the iron remains in solution. Such bond strength and selectivity of the complexation of aromatic oximes with metals such as copper, nickel, and some platinum metals are due to the very favorable structural correspondence for the electron cavity in the ligands and the structure of the electronic shells of the corresponding metal ions. These properties are additionally determined by the hydrogen bond between the two units formed during complexation. Such intramolecular hydrogen bonds in the complexes lead to special stability as a result of the appearance of macrocyclic systems. Thus, this effect is a structural feature that is of great practical importance for determining the effectiveness of complex formation processes during extraction, precipitation, and in other applied fields.