ON THE LIMITING SENSITIVITY OF WEAK SIGNAL VARICAP METERS

Babayan R.R.

V. Trapeznikov Institute of Control Problems, RAS, Moscow

The paper deals with the calculation of the input stage noise of the amplifier of weak low-frequency signals with a varicap-based modulator. The modulator was designed by the circuit of a controlled feedback oscillator. The parameters of the input circuit providing the achievement of ultimate sensitivity were determined.

Keywords: low current amplifier, feedback oscillator, varicap-based modulator.

 

CALCULATION OF THE RADIATION CHARACTERISTIC OF THE CYLINDRICAL RADOME WITH THE DIPOLE INSERTED INTO IT

 

Kevanishvili G.Sh., Kevanishvili I.G.,  Kekelia G.V., Robitashvili A.G., Chikhladze G.G.

and Mushkudiani G.G.

 

Georgian Technical University

 

Abstract. The paper deals with the electrodynamic analysis of the complex antenna consisting of a dipole placed in a cylindrical radome with metallic faces and a dielectric layer wall. The dipole height is less than that of the radome. The formula for calculation of the radiation characteristic was derived and the corresponding radiation patterns were constructed.

Keywords: antenna, dipole, radome,  radiation pattern, dielectric layer.

 

 

BUILDING OF THE OPTIMAL STRUCTURE OF AN INTEGRAL AGGREGATE

Demurashvili Sh.M., Macharadze T.D. and Milnikov A.A.

Georgian Technical University

International Black Sea University

In the absence of  a priori information about the location of the bench-points (the bench- prices) in the aggregate models of multiple non-linear regression analysis, it is necessary to filter out statistically nonsignificant ones.  It is shown that this problem can be reduced to the problem of choosing the best regression equation, which was solved by the elimination method. The latter consists in calculating the successive partial F-criteria for all tested bench-points. The efficiency of the developed method is demonstrated by the example of the seven-pointed Integral Agregate approximating the parabolic configuration of observed points. It is shown that, of the seven selected points, statistically significant are only three: two extreme and one internal ones. Comparative ANOVA of seven- and three-point Agregates showed the optimizing nature of the sifting process: the adequacy of the three-point unit is not less than that of the seven-point aggregate.

Keywords: Integral Aggregate, partial F-criteria, hypothesis testing, bench-points, multiple non-linear regression. 

 

PREDICTION OF A DISEASE BY A BIO-RESONANCE METHOD

 

Kadagishvili L.G.

 

V.V. Chavchanidze Institute of Cybernetics, Georgian Technical University

Georgian Engineering Academy

 

Abstract. The paper deals with possible heuristic modeling by using the bio-resonance relationship between the patient and the bio-corrector. The complexity of the séance allows us to describe the course of the process as a macro-model. In fact, this is probabilistic modeling. Application of this model in the analysis of a real procedure needs vast information to be processed as simple it may seem. This means that the diversity before reaching the goal of procedure (séance) has extended a lot as compared to the traditional models used to calculate the losses.

In our model, the subjective factor will also play a role. The old traditions considered a bio-corrector as an organizer of a séance. Now, the conditions have changed, and the data bank must be as accurate as possible for both participants. Otherwise, the bio-resonance balance may be disturbed.

Keywords: bio-resonance, modeling, disease prediction.

 

 

IMPROVEMENT OF ENERGY INDICES OF THE MULTI MOTOR ASYNCHRONOUS

ELECTRIC DRIVE

Tchunashvili B.M., Petrosyan A.M., Shavelashvili G.V. and Tugushi M.A.

Georgian Technical University

A method is suggested for controlling the reactive power compensation to improve the energy performance of multimotor asynchronous electric pumping stations by  total compensation of reactive power consumed from the network. The loss of reactive power in the power transformer of the power supply network substation is taken into account. The block diagram of the developed system is given. The  methodology of  calculating the parameters of the system elements is suggested.

Keywords: asynchronous drive, compensation, reactive power, energy efficiency.

 

SOME ASPECTS OF FORMATION OF NONPENETRATING OHMIC CONTACTS TO SHALLOW NANOSCALE SILICON LAYERS 

Tutunjyan A.A.

Institute of Micro- and Nanoelectronics

The paper represents a brief review on the formation of nonpenetrating ohmic contacts based on refractory metal silicides to shallow nanoscale silicon layers. The main characteristics of ohmic contacts using titanium, cobalt, nickel and platinum as well as aluminium silicides obtained by various technological methods are assessed.

Keywords: shallow silicon layers, nonpenetrating ohmic contacts, refractory metal silicides, aluminium.

 

PREPARATION  OF TmSe THIN FILMS AND THEIR  ELECTROPHYSICAL PROPERTIES

Teteloshvili M.G., Jabua Z.U. and Gigineishvili A.V.

Georgian Technical University

The technology of preparation of thin crystal films of thulium selenide on various substrates (polycrystalline glassceramic, leucosapphire, single-crystal silicon) by a method of discrete vacuum thermal evaporation of previously synthesized volume material was developed. The dependences of conductivity and Hall mobility of current on the thickness of films were measured at room temperature. It was revealed that the conductivity and the Hall mobility of electrons  essentially  depended on the thickness of films.

Keywords: films, thulium selenide, discrete evaporation, thickness, electroconductivity, Hall mobility.

 

 

POLYMER FILM HOLOGRAPHIC LASER

 

Wardosanidze Z.V., Aronishidze M.N., Chanishvili A.G., Chilaya G.S.,

Tavzarashvili  S.P. and Tevdorashvili K.G.

 

V. Chavchanidze Institute of Cybernetics of the Georgian Technical University

 

Abstract. A new type of a holographic laser with transversally distributed excitation was developed. A dye-doped polymer film as an active medium was sandwiched between two interference mirrors forming an optical cavity. An optical contact between the mirrors and the film surfaces was provided. The pumping was performed by an interference pattern formed with two mutually coherent beams of the second harmonic of the Nd:YAG laser (532nm). The cross-section of the generated laser beam represented a pattern similar to the diffraction pattern of the grating with a pitch equal to that of the pumping interference pattern. Thus, the obtained laser operated as an elementary hologram.

Keywords: dye lasers, coherent double-beam pumping.

 

A METHOD OF MEASUREMENT OF THE GEOMETRIC AND OPTICAL PARAMETERS OF LENSES BY USING A MICROSCOPE

Shalamberidze D.M., Zardiashvili D.G., Kordzakhia I.I., Abramishvili G.G. and Avaliani I.M.

Institute `Optica~

The paper deals with a method of measurement of the geometric and optical parameters of lenses by using a microscope. The radii of the lens curvature and the refractive index of the optical material were calculated by measuring  the distances from the front and back surfaces of the lens to the point of the image with the help of an optical microscope.

Keywords: optics, lens, refractive index, curvature radius.

 

QUANTITATIVE EVALUATION OF THE ABRASIVE WEAR OF A HYDRAULIC TURBINE AND THE MEASURES OF ITS CONTROL BY THE EXAMPLE OF RACHA HYDRO

Lomidze Yu.B., Khelidze G.K. and Kantaria A.M.

Georgian Technical University

The paper deals with the quantitative evaluation of the abrasive wear by the example of the Francis turbine of Racha Hydro constructed on the River Ritseula (Georgia). The tubine operated for 1,248 hours under the conditions of high concentration (0.788 g/l), hardness (more than 4 units of Mohs’ scratch hardness) and  content (55%) of solid particles in the water. Based on the instrumental measurements and casts taken, the loss in weght of the metal in the areas subjected to abrasive wear was determined. It made up 31.0 kg at the front cover, 9.23 kg at the back cover and 3.99 kg at the guide vanes, which gave 44. 22 kg in total. Comparing the obtained results with the literature data on the results of investigations of the abrasive wear of hydraulic turbines of a number of hydraulic power stations, it was established that  the turbine of Racha Hydro worked in a hazardous area from the wear standpoint (in accordance with the head and the concentration of solid particles). These circumstances determined putting the turbine under repair after half a year of its operation.

Keywords: hydraulic turbine, abrasive wear, loss in weight, Racha Hydro.

 

 

DESIGN AND INVESTIGATION OF THE METALWORK AND FOUNDATIONS FOR BRIDGE MECHANISMS

Purtskhvanidze G.N., Chabukiani R.R., Uriadmkopeli T.D. and Purtseladze I.G.

Akaki Tsereteli State University, Kutaisi

The paper deals with the design of the foundation for the agricultural bridge mechanism and of the metalwork of the horizontal truss for this mechanism. The materials and metalwork which would provide safe and efficient operation of the bridge mechanism during its service are discussed.

Keywords: bridge mechanism, metalwork, rail, drive wheel, drive.

 

CHARACTERISTICS OF THE POWER SOURCES OF BRIDGE MECHANISM DRIVES AND SELECTION OF THE BEST VERSION

Purtskhvanidze G.N., Chabukiani R.R. and Purtseladze I.G.

Akaki Tsereteli State University, Kutaisi

The paper deals with the power sources of the drives of agricultural bridge mechanisms. Both renewable and unrenewable power sources are considered. The basic diagram and the operation of the bridge mechanism drive are given.

Keywords: bridge mechanism, drive, solar energy, photocell, accumulator, gearing.

 

CLEANING OF THE SURFACE, LAYERS AND BOTTOM OF WATER BODIES POLLUTED WITH PETROLEUM AND PETROLEUM PRODUCTS

 

Molodinashvili Z.F., Khetsuriani N.T., Goderdzishvili Q.G., Usharauli E.A., Topuria E.N., Mchedlishvili I.J. and Chkhaidze M.N.

 

Iv. Javakhishvili Tbilisi State University

P. Melikishvili Institute of Physical and Organic Chemistry

 

 

Abstract. The paper deals with the development of the thechnology of simultaneous cleaning of the surface, layers and bottom of water bodies polluted with petroleum and petroleum products, and the obtaining and investigation of a new polymeric composite matrix. For water treatment, a polyacrylamide gel fraction was used. With its help, the sorption of 85% of the petroleum substrate during 168 hours was performed.

Keywords: petroleum pollution, water treatment, water bodies, polymeric composite, biomass.

 

PHENOLIC COMPOUNDS IN RED WINES OF DIFFERENT TYPES

 

Kekelidze I.A., Ebelashvili N.V. and Japaridze M.Sh.

 

Institute of Viticulture and Oenology, Georgian Agricultural University

 

Abstract. The paper deals with the research of phenolic compounds in red wines of different types  produced from Saperavi grape, and the comparison and assessment of  the obtained results. The objects of the study were: dessert, dry table, semi-sweet, liqueur and fortified wine samples from Saperavi (Kindzmarauli area); Alaverdi Monastery and Teliani Valley dry wine samples; Badagoni semi-sweet wine sample. The content of catechins, phenolcarbonic acids, flavonols, resveratrol and vanillin aldehyde was studied by High Performance Liquid Chromatography (HPLC).  It is shown that the objects of the study differ significantly  in the content of phenolic compounds. The high content of catechins was found in dry, semi-sweet and dessert wine samples. In the samples most of all from flavonols was detected quercetin glucoside; while from phenolcarbonic acids – gallic acid. In red wines produced from Saperavi, the content of  monomeric phenolic compounds is quite high, which explains their antioxidant activity.

Keywords: red wines, catechins, phenolcarbonic acids, flavonols.

 

 

ACCUMULATION AND DISTRIBUTION OF Cd, Zn, Cu AND Mn IN BARLEY

 

Rcheulishvili O.A., Metreveli N.O., Kalabegishvili T.L., Rcheulishvili A.N.,

Rcheulishvili N.A., Korpela T., Tugushi L.S. and  Abashidze A.I.

 

E. Andronikashvili Institute of Physics of Iv. Javakhishvili Tbilisi State University

 Ilia State University

  Iv. Javakhishvili Tbilisi State University

University of Turku, Turku, Finland

J. Gogebashvili State University, Telavi

 

Abstract. The paper deals with the accumulation and distribution of chemical elements in edible plants. The edible plants growing in the polluted environment absorb large amounts of chemical elements and accumulate them in different organs. Such plants could be a hazard to people’s health  when they are used as food. Hence it is of great importance to study the concentrations of various elements in edible plants. In this work, the accumulation and distribution of Cd, Zn, Cu and Mn in barley was studied. The  averange concentrations of these elements in the roots, stems and leaves of the plant were determined at different stages of its growth. The obtained results allow assessing the risks associated with intaking the plants grown in the polluted environment.

Keywords: edible plants, chemical elements, accumulation, distribution, environment, pollution.

 

A MEASURING DEVICE FOR CHEMICAL MICRO CONCENTRATIONS IN NATURAL WATERS

Padiurashvili  V.N.,  Dzagania T.B.,   Semionov R.V., Makhashvili  K.A., Dolidze A.V. and   Iashvili N.G.

Georgian Technical University

There are the methods of determination of the coagulant in drinking water and appropriate devices that are just for measuring the big doses of the coagulant (or flocculent), i.e. for determination of significant changes in the electroconductivity of drinking water. A new method of determining the microconcentration of the coagulant in drinking water and the design of the device are offerred. The operation of the device is described.

Keywords: chemical reagents, measuring device, microconcentration, drinking water, coagulant.

 

 

THERMOGRAVIMETRIC STUDY OF COMPLEX COMPOUNDS OF SILVER (I) WITH TERTIARY ARSINES

Kikalishvili M.I.

Akaki Tsereteli State University, Kutaisi

Behavior of silver (I) tetra (triphenylarsine) perchlorate under heating conditions was studied by means of the thermogravimetric analysis. It was revealed that firstly the ligand broke from the compound. The final product of thermal decomposition was silver.

Keywords: silver, tertiary arsines, complex compounds, thermolysis, thermogravimetric study.

 

 

BIOLOGICAL ASPECT OF BORON

Kikalishvili M.I. and Bakradze-Guruli M.Sh.

Akaki Tsereteli State University, Kutaisi

The paper deals with the role of boron in vegetable and animal organisms and vital biochemical processes. In plant  organisms, boron is involved in carbohydrate, carotene and vitamin changes. It activates enzymes and promotes the assimilation of molecular nitrogen in legume plants.

Keywords: boron, biological aspect.

 

VARIATIONS OF BIOACTIVE SUBSTANCES IN RED WINES PRODUCED BY DIFFERENT TECHNOLOGICAL TECHNIQUES OF ENZYME MACERATION

 

Ebelashvili N.,  Shubladze L. and Kekelidze I.

 

Institute of Viticulture and Oenology Georgian Agrarian University

 

Abstract. Biologically active substances play a crucial role in the evaluation of red wine quality. Their concentration is greatly influenced by the grape variety, grape growing site and the applied technological techniques of enzyme maceration. The authors have elaborated a technological technique of maceration for preparation of red wines enriched with biologically active substances. By using the HPLC method it was established that the application of the technology of production of red wines we offer provides much more extraction of bioactive substances: catechins, phenolcarbonic acids, flavonols, vanillin, unsubstituted amino acids etc., as compared with the existing one.

Keywords: red wines, maceration, catechins, phenolcarbonic acids, flavonols, amino acids.

 

PHENOLIC COMPOUNDS IN RED WINES OF DIFFERENT TYPES

 

Kekelidze I., Ebelashvili N. and Japaridze M.

 

Institute of Viticulture and Oenology, Georgian Agricultural University

 

Abstract. The paper deals with the research of phenolic compounds in red wines of different types  produced from Saperavi, grape cultivar, and the comparision and assessment of  the obtained results. The objects of the study were: dessert, dry table, semi-sweet, liqueur and fortified wine samples from Saperavi (Kindzmarauli area); Alaverdi Monastery and Teliani Valley dry wine samples; Badagoni semi-sweet wine sample. The content of catechins, phenolcarbonic acids, flavonols, resveratrol and vanillin aldehyde was studied by High Performance Liquid Chromatography (HPLC).  It is shown that the objects of the study differ significantly  in the content of phenolic compounds. The high content of catechins was found in dry, semi-sweet and dessert wine samples. From flavonols, most of all quercetin glucoside was detected in the samples; while from phenolcarbonic acids – it was gallic acid. In red wines produced from Saperavi, the content of  monomeric phenolic compounds quite high, which explains their antioxidant activity.

Keywords: red wines, catechins, phenolcarbonic acids, flavonols.

 

DEVELOPMENT OF THE EQUIPMENT-PRODUCTION PROCESS SCHEME FOR THE PRODUCTION OF MUSCAT FORTIFIED WINES

Kituashvili T.A., Khositashvili M.L., Gotsiridze O.G., Buishvili G.T.,

Gorgiladze M.R. and Ardzenadze M.D.

Jakob Gogebashvili Telavi State University

The paper deals with the development of the technology of production of fortified wines from the Muscat Rkatsiteli grape variety. The production process scheme was developed. The implementation of this scheme provides the preservation of taste and flavor of the Muscat grape in wine.

Keywords: fortified wine, Muscat, production process

 

INVESTIGATION OF AROMATIC COMPOUNDS IN THE WINE PRODUCED BY KAKHURI TECHNOLOGY

Buishvili G.T., Khositashvili M.L., Matiashvili Sh.I. and Shildelashvili I.I.

Jakob Gogebashvili Telavi State University

The paper deals with the research of  aromatic compounds in the wine which was produced by Kakhuri technology. The aromatic components  of  wines Rkatsiteli, Kakhuri Mtsvane and Khikhvi were studied.  It was found that the amount of aromatic components in wine Rkatsiteli was more than in wines of Kakhuri Mtsvane and Khikhvi.

Keywords: wine, aromatic compounds, Kakhuri technology.

 

THE ROLE AND PLACE OF FOOD SCIENCE IN THE FOOD SAFETY MANAGEMENT SYSTEM

Karchava M.A. and Kintsurashvili N.J.

Akaki Tsereteli State University, Kutaisi

The development of HACCP (Hazard Analysis and Critical Control Points) plan for an effective preventive integrated system of ensuring food safety is time-consuming work. By using scientifically justified approaches, it is possible to optimize  highly complex, critical and highly skilled work for developing the HACCP plan. The HACCP plan for technological process safety management of “the sterilized drinking milk” has been elaborated. This plan does not envisage the GMP and GHP requirements. Despite this, it can be successfully used as “the basis” for own HACCP by any enterprise which produces “the sterilized drinking milk”. Based on the achievements of modern food science, it is possible to develop the same Package of HACCP Bases that should considerably facilitate the activities of Georgian enterprises for performing such  complex work.

Keywords: food science, food safety, management.

 

THE MECHANISM OF SOME MODERN DISINFECTANTS

Padiurashvili Z.V., Gvasalia L.I., Tsverava M.K. and Padiurashvili V.N.

Georgian Technical University

The paper deals with modern disinfectants. The mechanism of some of them is briefly discussed.

Keywords: medicine, disinfectants, mechanism.

 

 

CHANGES IN WOMA’S  POSTURE DEPENDING ON THE HEIGHT OF THE HEEL

Ugrekhelidze I.I., Dolidze N.A. and Grdzelidze M.G.

Akaki Tsereteli State University, Kutaisi

The paper deals with the information how the changes  in woman’s    posture depend on of  the height of shoe heels. The evolution of the center of gravity of the body and the spinal configuration with raising the foot is discussed.  The results of anthropometric studies  for determination  characterizing the woman’s  posture when using  high-heeled shoes are analyzed. The  sketches of  the woman’s posture without shoes and in the  shoes on the heels  7 cm and 9 cm high are presented. The analysis showed that it is essential to take into consideration the changes in dimensional parameters  characterizing the woman’s  posture when designing clothes.

Keywords: posture, dimensional  parameters, heeled shoes, clothes.