Novel Diazole/Triazole and Dibenzothiophene Dioxide Containing Pentacyclic Systems with Promising Biological Activities

The aim of the current work is to synthesize the new heterocyclic pentacyclic condensed systems that combine benzothiophen and benzimidazole/triazole into one molecule. The dibenzothiophene was taken as an initial compound and by consistent “extension” was annihilated the imidazole and triazole nucleuses. As a result two new pentacyclic systems were produced: 3H-, 7H-diimidazole[4,5-b][5,4-g] dibenzothiophene-5,5-dioxide and 3H-, 7H-ditriazole[4,5-b][5,4-g] dibenzothiophene-5,5-dioxide with the promising antimi-crobial activity. Their spectral characteristics were studied.

Obtaining of Nanocomposites in SiC-SiAlON and Al₂O₃-SiAlON System by Alumothermal Processes

Composites were obtained in the in SiC-SiAlON and Al2O3-SiAlON system. Physical-chemical processes going on at the obtaining of SiALON within the range of 800°C - 1500°C were studied. Charge compositions and sintering regime were selected. It was proved that X-SiALON was obtained at the sintering of kaolin-aluminum powder at 1500°C, while β-SiALON was formed at the sintering of SiC-Aluminum powder, silicium and Al2O3-aluminum powder, silicium at 1500°C. Corrosion properties of the materials were studied. Investigations were performed by the methods of X-Ray structural and microscopical analysis.

Some New Derivatives of 3H-benzo[b]Furo[3,2-f]- Benzimidazole with Expected Biological Activity

On the base of benzimidazole and benzofuran containing heterocyclic system, several derivatives with expected biological activity were synthesized. 2,3-diaminodibenzofuran was the primary substance. Adding various cyclic agents, 2-phenil was got, 2-（o-chlorophenil）, 2-（o-oxyphenil）, 2-chlorometyl- and 2-hydroximethyl-3H-benzo[b[furo（3,2-f] benzimidazoles. The aforementioned substances were characterized by IR and NMR spectroscopy.

Controlled Local Hyperthermia and Magnetic Hyperthermia of Surface (Skin) Cancer Diseases

Average size of hematite and magnetite micro and nanopowders and polydispersity index, zeta potential and distribution of particles were studied. Analysis showed that average size of the obtained particles for magnetite is 740.9 nm, for hematite particles 30 - 35 nm. Alternate current feed source was created for hyperthermia. Proceeding from the requirements of the objectives, the U type MnZn material magneto conductors were selected, in which 10.0 and 8.0 mm width gaps were cut and glass test tubes with magnetite or hematite suspensions were placed in them. Series of experiments at various field intensity and frequencies showed that for efficient magnetic hyperthermia therapy more powerful device was needed with frequency of up to 10 Mega Hertz to achieve the temperature 43°C - 45°C necessary for full activation of Neel and Brown mechanisms in particles. At the next stage, on the basis of experimental material the anticancer mono-therapeutic effect of hyperthermia and its adjuvant action in poly chemotherapeutic treatment was presented by the use of a device created by us “Lezi”. As a result of the experiment it was shown that in all animals (outbred albino mice, 3 months old) inhibition of cancer growth was fixed and intratumoral necrosis was developed, while after 7 and 10 sessions tumors were ulcerated, which refers to positive effect of the experiment (Conclusion of Pathologicanatomical Laboratory “PATGEO”, Tbilisi, Georgia ).

Improvement of Boron Carbide Mechanical Properties in B₄C-TiB₂and B₄C-ZrB₂Systems

Experimental works have been conducted the objective of which was to improve mechanical properties of boron carbide by introduction of doping elements into the system. Titanium and Zirconium were selected as doping elements, which were introduced into the system in the form of TiB2 and ZrB2. Four types of boron carbide-titanium and zirconium mixture with various titanium and zirconium diboride content were used in experiments. Optimal process parameters, as well as doping elements concentration, necessary to provide required high mechanical parameters in the composite were defined.

Obtaining of SiAlON Composite via Metal-Thermal and Nitrogen Processes in the SiC-Si-Al-Geopolymer System

Goal: obtaining of composite in the SiC-SiAlON system with the metal thermal method in the nitrogen medium. Method: SiALON-s are solid metal oxide solutions in nitrides. Area of their presence is considered in four-component system-Si3N4-ALN-AL2O3-SiO2. In the present paper SiALON-containing composite was obtained through alum-thermal process in the nitrogen medium on the base of Geopolymer (kaolin and pologycley-Ukraine), SiC, aluminum nano-powder and Si powder with small additives of perlite (Aragatz, Armenia) by the reactive baking method. The advantage of this method is that compounds, which are newly formed thanks to interaction going on at thermal treatment: Si3N4, Si, AlN are active, which contributes to SiALON formation at relatively low temperature, at 1250°C - 1300°C. Results-β-SiAlON was formed at the sintering of SiC-aluminium and silicium powder, geopolymer at 1450°C. Porosity of carbide SiAlON composite obtained by reactive sintering, according to water absorption, equals to 13% - 15%. The samples were fragmented in a jaw-crusher and were powdered in attrition mill till micro-powder dispersion was obtained. Then samples were hot-pressed at 1620°C under 30 MPa pressure. Hold-time at the final temperature was 8 min. Sample water absorption, according to porosity, was less than 0.4%. Further studies were continued on these samples. Conclusion: the paper offers processes of formation of SiC-SiAlON composites and their physical and technical properties. Phase composition of the composites was studied by X-ray diffraction method, while the structure was studied by the use of optic and electron microscope. Electric properties showed that the specimen A obtained by hot-compression is characterized by 2 signs lower resistance than the porous material B, which was used to receive this specimen. Probably this should be connected with transition of the reactively baked structure of the hot-compressed material into compact structure. Obtained materials are used in protecting jackets of thermo couples used for melted metal temperature measuring (18 - 20 measuring) and for constructions used for placing objects in factory furnaces.

Preparation of Composites by Nitro Aluminothermic Processes, over β–SiAlON Matrix in the SiAlON-SiC-Al2O3 System

Goal: The goal of the research is preparation of SiAlON-containing composite through nitro aluminothermic processes, by the methods of reactive sintering and hot compaction. Method: The composite CH-6 was obtained by the method of reactive sintering, with further grinding and hot compression in vacuum furnace at 16000°C, under 30 MPa pressure and 10-12 min standing at the final temperature. Precursor was prepared in a thermostat at 150°C temperature by double compression. Pressure equaled to 20-25 MPa. Results: Physical-technical properties of specimens prepared via hot compaction were investigated. Mechanical strength at compression is 1940 MPa;mechanical strength at bending is 490 MPa;elastic module is 199.5 GPa, HV-11.6 GPa. X-Ray diffraction analysis, electron microscopic and X-ray diffraction Microspectral analysis were used to investigate composite microstructure and phase composition. Composite formulation was defined, the main phases of which were: β-SiAlON, corundum and silicium carbide. Conclusion: Composite CH-6 has been selected from the obtained composites, which is characterized by relatively high physical-technical properties: strength, density and hardness. Materials can be used for making high refractory articles, such as jackets to secure thermocouples, furnace bedding, cutting tools for metal and wood treatment, in rocket spatial technology and others.

Composite Stable to Corrosive Media in SiC-AL₂O₃-Si_2ON₂System

The object of the research was to study the composite received in impure nitrogen medium from silicon carbide, silicon and refractory clay mixture. With X-ray diffraction, petrographic and electron microscope methods the chemical processes happening at burning of the mentioned mixture in technical nitrogen medium and the kind of received binder, phase composition and basic properties are studied. It is stated that silicon carbide composite with complex binder is received, the main phases being: Si2ON2, 3Al2O3· 2SiO2 and SiO2. SiC-Al2O3 composite is also received and studied. Water and acid resistance of composites (H2SO4, r—1.84 g/sm3) and resistance to nonferrous metals and slag are studied. The received composites can be used for production of protective envelope of thermocouple for measuring of temperature of ferrous and nonferrous metals at high temperatures.

Metal-Ceramic Smart Composite in Ti(C,N)-Ni-Mo-W System

Goal: Low wolfram-containing cutting composite was obtained by fusion of titanium carbonitride and high melting temperature binding metallic phase. Method: The composite was obtained via compaction and further sintering in vacuum furnace at 1600°C under 10-3 Pa pressure. Phase analysis was performed on X-ray apparatus “DRON-3”;microstructure was determined by electron microscope NANOLAB-7, microhardness by MUCKE-mark microhardness meter;relative resistance of cutters was evaluated at similar modes of cutting according to distances they passed;experiments were carried out on turning lathe. Results: Physical-mechanical characteristics of the obtained composite are: σbend, = 1000 - 1150 MPa, σbend1000°C = 600 MPa, HV = 14 GPa;HV1000°C = 6.5 GPa. High speeds of cutting and high temperatures resistance of cutters made by the obtained composites exceeds 1.5 - 2-folds that of cutters made of the known BK8 and KNT20 hard alloys. Conclusion: Its application is recommended in hot steel treatment by cutting, for removal of the so-called burrs, as well as in steel treatment by cutting during pure and semi-pure operations. It can also be used in jet engines, chemical industry apparatuses, electric-vacuum devices, in industry of responsible details of rockets, nuclear reactors, flying apparatuses.