SUMMARY
CHARACTERISTICS OF DOUBLE
DELTA-DOPED AlGaAs/InGaAs/GaAs PSEUDOMORPHIC HEMT
Khuchua
N.P., Chakhnakia Z.D., Melkadze R.G., Wieck A.D.,
Reuter D.,
Ksaverieva M.S., Sakharova T.B. and
Tutunjyan A.A.
Research
and Production Complex (RPC)
“Electron Technology”, Iv. Javakhishvili
Tbilisi State University, Georgia
Lehrstuhl
fuer Angewandte Festkoerperphysik, Ruhr-Universitaet
Bochum, Germany
Institute
of Micro- and Nanoelectronics, Tbilisi, Georgia
Abstract. A
correlation of properties of molecular-beam epitaxy
(MBE)-grown double delta-doped AlxGa1-xAs/In0.23Gao.77As/AlxGa1-xAs
pseudomorphic heterostructures
(with different mole fractions x = 0.2 and 0.34 and barrier thicknesses Lg of 17.0nm and 20.2nm, respectively) with
static parameters of PHEMTs on their basis has been studied. The transistors
with the gate length of 0.8mm and
the channel width from 100 to 800mm
were fabricated by the identical reproducible technology. Special attention is
paid to the influence of the leakage current in the subgate
region of a heterostructure on parameters of
transistors, which can be detected only at the initial stages of device
processing. The presence of these leakages in the material deteriorates device
characteristics even if a heterostructure itself has
obvious advantages.
Keywords: AlGaAs/InGaAs/GaAs
heterostructures, molecular-beam epitaxy,
pseudomorphic high electron mobility transistor
(PHEMT), PHEMT technology, static parameters, leakage currents, transistor modeling.
THERMOELASATIC EQUILIBRIUM OF THE THICK TRANSVERSELY ISOTROPIC PLATE IN
THE CYLINDRICAL COORDINATE SYSTEM
Ozbetelashvili N.B.
and Tsitskishvili Z.A.
Georgian Technical University
The paper deals with the thermoelastic equilibrium of the thick transversely isotropic
plate. There is considered the case when the conditions of symmetry are
fulfilled at the side faces, while desired conditions are set specified for the
upper and lower bounds. The exact solution of the given problem was
found by using the general solutions and the variable separation method. The problem under consideration is
nothing but a bend of the pendular hinged plate
caused by tangential load. The obtained general solution supports this
statement.
Keywords: transversely isotropic plate, thermoelastic
equilibrium, cylindrical coordinate system, pendular
hinged load, bend, tangential load.
THERMODYNAMIC
EMISSION LOSS
Gvetadze V.E., Lomidze A.N., Purtskhvanidze G.N.
and Gogisvanidze L.G.
The article
deals with the investigation results on the exergy
loss of exhaust gases associated with the exhaust resistance. It was found that
the exergy loss of exhaust gases varied in direct
proportion to the second degree of pipe compressor capacity and inversely to
the second degree of the effective flow section of the valve-exhaust port
system. The resistance of the exhaust manifold and of the gas-collecting snail
of the pipe compressor insignificantly affects the value of the exergy loss of the gas in the exhaust line and its share in
the loss is less than 0.2%.
Keywords:
exhaust
gases, thermodynamic loss, exergy, exhaust line.
LASER
WITH DOUBLE DISTRIBUTED FEEDBACK
Vardosanidze Z.V., Chanishvili
A.G., Petriashvili G.Sh., Chilaya
G.S., Aronishidze M.N., Tavzarashvili
S.P. and Tevdorashvili
K.G.
V.
Chavchanidze Institute of Cybernetics, Georgian
Technical University
Lasing in a dye-doped
cholesteric liquid crystal layer was experimentally
studied. A new type of a holographic laser was developed. The
pumping was performed with an interference pattern obtained by superposition of
two beams of the second harmonic of a Nd:YAG laser.
The emission field of the obtained laser is similar to that of diffraction from
the grating. Thus, the laser operates as a laser and a dynamic hologram
simultaneously.
Keywords:
cholesteric
liquid crystal laser, distributed feedback, holography.
DESIGNING
AND PRODUCTION OF COATED LENSES-CONCENTRATORS FOR ENHANCING THE POWER
EFFICIENCY OF THE PHOTOVOLTAIC UNIT
Avaliani I.M., Chikovani R.I., Khachidze T.I. And
Berishvili Z.V.
Institute
“Optica”
The article
deals with the possibility of enhancing the power efficiency of the
photovoltaic unit by using the coated lenses-concentrators. Specifically, there
was fabricated a coating of the lens-concentrator consisting of three layers:
1. SiO2, 85 nm (g=1.47); 2. ZrO2, 63 nm (n=1.98); 3. SiO2,
85 nm (g=1.47). It was experimentally revealed that the electric power
generated by the photovoltaic unit with the coated lens-concentrator
considerably increased (by 7.4% according to the provisional data).
Keywords:
coated
lens, light concentrator,
photovoltaic unit, power efficiency.
ELABORATION OF THE METHOD OF LOCAL
THERMAL OXIDATION FOR DESIGNING OF INTEGRATED MULTIELEMENT LIGHT-EMITTING
INDICATORS
Jghenti M.I., Trapaidze I.T., Berakchian V.O.
and Chulukhadze N.C.
Georgian Technical University
Abstract. One of the most important tasks of
modern optoelectronics is the designing of emitting devices with high scale
integration. The heteroepitaxial structures pGaAs-pGa1-xA1xAs-nGa1-yAlyAs, which are
characterized by high efficiency of radiation, are the most suitable for this
purpose. . However, the development of isoplanar
technology based on these structures requires the elaboration of relevant
technological processes and carrying out a number of investigations. In this
respect, the key task is obtaining of the native oxide of GaAlAs
solid solution, by means of which the electric and optical isolation of
emitting elements from each other is realized. This article deals with a unique
method of local thermal oxidation for obtaining the native oxide of the solid
solution. The electrical and optical properties of the oxide were studied. The
efficient multielement light-emitting indicator was
designed.
Keywords: light-emitting indicator, local thermal oxidation, heterostructure, native oxide, isoplanar
technology.
DEVELOPMENT OF THE UNIQUE METHOD OF LOCAL THERMAL OXIDATION FOR
DESIGNING OF INTEGRATED MULTIELEMENT LIGHT-EMITTING INDICATORS
Jghenti M.I.
The
structures pGaAs-pGa1-xA1xAs-nGa1-yAlyAs,
which are characterized by high efficiency of radiation, are most suitable for
processing of semiconductor multielement
light-emitting indicators. However, for application of these structures for the
abovementioned purposes, it is necessary to develop isoplanar
technology, which has not been available so far. In this connection, the key
task is to obtain the native oxide of the GaAlAs
solid solution, by means of which the electric and optical isolation of
emitting elements from each other is realized. This paper deals with the
development of a unique method of local thermal oxidation for
formation of the emitting elements in light-emitting heteroepitaxial
pGaAs-pGa1-xA1xAs-nGa1-yAlyAs
structures.
Keywords: isoplanar technology, heterostructure, native oxide, light-emitting indicator,
local thermal oxidation.
FABRICATION of THIN thulium sesquisulfide films by
discrete evaporation and their mechanical properties
Teteloshvili M.G., Jabua Z.U., Gigineishvili A.V., Iluridze
G.N., Minashvili T.A. and Davitadze K.D.
Georgian
Technical University
Georgian
Aviation University
Abstract. The
technology of production of thin films from the pre-synthesized material by
discrete thermal vacuum evaporation on different substrates (pyroceramic, quartz, leucosapphire
and single-crystalline silicon) was developed. The relative mechanical strength
of the fabricated films was
studied by the method of complete attrition. It was determined
that the mechanical strength of the films depended on the time of annealing.
The time of annealing longer than 170 h hardly affected the mechanical strength
of the films.
Keywords: thin
films, discrete evaporation, thulium sesquisulfide,
mechanical strength, annealing.
INVESTIGATION
OF THE ISOTOPIC ABUNDANCE RATIO IN THE SUPERPURE (7N+) GALLIUM MELT
OBTAINED BY THE METHOD OF MEMBRANE PURIFICATION
Kutelia
E.R., Kvinikadze G.M. and Dzigrashvili
T.A.
Republic
Center for Structure Research of the Georgian
Technical University
Abstract. The
paper deals with the comparative study of Isotopic Abundance Ratio in the melts
of commercially available 6N-purity gallium and superpure
7N+ gallium samples produced from it by the membrane purification
technology by using Secondary Ions Mass-Spectrometry (SIMS). It is shown that,
in the 7N+-purity non-crystallized gallium melt, discorrelation
of the natural ratio of
gallium isotopes takes place, and it is equal to Ga69/Ga71=1.415-1.450
versus Ga69/Ga71=1.505-1.527
measured for the initial sample.
Keywords: isotopic ratio, superpure
gallium, membrane purification, SIMS.
THERMO-
AND GASODYNAMIC ANALYSIS OF THE LIQUID-PISTON STIRLING ENGINE
Kevkhishvili N.A. and Javshanashvili N.B.
Georgian
Technical University
The article deals with the theoretical analysis of physical processes
of the liquid-piston Stirling engine. It was assumed that the operation of the heat exchanger was ideal; the gas temperature in
the cylinders was constant and
equal to the
amount of external heat sources. The hydraulic resistance in the gas path was neglected; the dead volume in the devices was also neglected. Based on these assumptions, the relation between the supplied and taken off
heat, and the work performed by the engine was
derived. Besides, the geometric
dimensions
of the engine were established.
Keywords: Stirling engine, liquid piston,
thermodynamics, gasodynamics.
DATABASE DESIGN BY USING MS ACCESS
Namchevadze T.V.
Akaki Tsereteli State University, Kutaisi
Currently
the database management system Ms Access is actively used in database design.
The paper deals with the stages of designing the simple databases. The sense
and the ways of implementation of all stages are explained. A particular
example of the database is considered. The database is called Winery.
The sense model, and then the logical one were constructed. During construction
of the models, the principles of data normalization were observed.
Keywords: database design,
conceptual model, logical model, normalization.
Bioresonance relationship between the patient and the
biocorrector
Kadagishvili L.G.
V.V.
Chavchanidze Institute of Cybernetics,
Abstract. The article deals with
positive and negative effects of the bioresonance relationship established
between the patient and the biocorrector. Sometimes, the patient dies because
of a doctor’s failure to diagnose correctly and hence maltreatment. There are
many examples when an intelligent so-called biocorrector diagnosed correctly
and the patient recovered due to proper treatment. It should be noted that the
relationship between the patient and the healer depends on the bioresonance
moment, which occurs depending on the attittude. The bioresonance communication
between two people, established via physical fields at a small distance or at a
certain ditsnace without contact, is unique and is characterictic of biological
organisms only. In order not to become a negative rlationship, such a relationship
requires the compatibility between the two individuals. There is still much to study in this
field. It is evident that biofields are an objective
reality and need scientific research.
Keywords:
bioenergy, biofield, information, bioresonance,
biocorrector.
PROMOTION OF THE DEVELOPMENT OF RENEWABLE ENERGY IN
GEORGIA
Arabidze N.T., Arabidze M.T. and Grigalashvili A.Sh.
Georgian Technical University
Georgia is a country with transition economy. Hence, it is expected to
achieve international grants for implementation of the projects aimed at
mitigation of the consequences of the global climate change. The development of
renewable energy is one of the ways of such mitigation. This paper deals with
the problems of promotion of renewable energy in Georgia.
Keywords:
renewable energy, global climate change.
THE
POSSIBILITIES FOR EFFICIENT AND HIGH-QUALITY EXECUTION OF PROJECT ROADWORK
Baratashvili M.P.
The paper deals
with the possibilities for efficient and high-quality execution of roadwork by
using special computer programs. The methods providing the execution of project
roadwork with high quality and high saving rate and relevant software are
discussed.
Keywords:
roadwork, high quality, efficiency, software.
THE
IMPACT OF SHIP’S MOTIONS ON THE PEOPLE AND CARGO ON BOARD
Saginadze I.S. and Pkhakadze
M.D.
Akaki
Tsereteli State University, Kutaisi
Georgian
Engineering Academy
The
paper deals with the impact of ship’s motions on the cargo on board. The
inertial forces acting on the cargo under motion were calculated. For different
values of
the parameters of the ship-cargo system, the values of
cargo acceleration were computed by using program MathCAD.
The criteria of the immobility of loose cargo were obtained. The influence of
ship’s motions on the people on board is also discussed.
Keywords: ship’s motions, cargo, cargo acceleration, inertial forces.
THE RESEARCH
TECHNIQUE OF THE SEISMIC ACTIVITY OF TECTONIC STRUCTURES: AN EXAMPLE OF THE
BORJOMI-KAZBEGI “FRACTURE”
Lursmanashvili N.D.
Iv. Javakhishvili Tbilisi State University
The paper deals
with the geomorphological and geodesic exploration of the Borjomi-Kazbegi
“fracture”. Since the Borjomi-Kazbegi fracture is
considered to be a large curst structure, it was essential to perform its
comprehensive exploration. Precision GPS instrumentation was used to reveal
lots of local topographic marks along the given “fracture” base. The
comprehensive exploration did not reveal any data supporting the existence of this
“fracture”. All topographic marks are continuous along the “fracture”.
Moreover, no structure evidenced about its displacement due to tectonics.
Keywords:
tectonic
structure, seismic activity, research technique, geodesic exploration,
geomorphological exploration.
WASTES OF THE
ORE-DRESSING PLANT AND THEIR COMPLEX RECYCLING
Geleishvili T.P. and Geleishvili I.T.
Georgian Technical University
The paper deals with complex recycling of the wastes of the ore-dressing
plant. The proposed scheme provides for application of the useful components of
industrial wastes in various fields.
Keywords: ore dressing,
wastes, recycling.
INFRARED ABSORPTION SPECTRA OF
METHIONINE-CONTAINING CITRATES
Beshkenadze I.A., Zhorzholiani
N.B. and Gogaladze M.A.
Petre Melikishvili Institute of Physical and Organic Chemistry, Iv. Javakhishvili Tbilisi
State University
Based on the study on the IR absorption spectra of methionine-containing
citrates, it was determined that that, acting as a bidentate
ligand, the molecules of methionine coordinate with complex-forming metals via
oxygen atoms of the carbonyl group and nitrogen of the amino group, forming the
pentamerous metal cycles. As for citric acid, acting
as a quadribasic ligand and deprotonating three
carboxyl groups and one hydroxyl group, it forms tetradentate
citrate ions (L4). These ions coordinate with complex-forming metals
via oxygen atoms of three carboxyl groups and one hydroxyl group.
Keywords: citrates, methionine, infrared
absorption spectra, complex-forming metals.
The Content of Heavy Metals in
Soil and in the Leaves of bilberry bush Vaccinium
Kacharava T.O. and Koiava L.N.
Georgian
Technical University
Nowadays,
heavy metals pollution of ecosystems is one of the most serious and nearly
irreversible ecological problems for
any country. Hence, its study is important for protection of living organisms,
as well as of the biodiversity of the vegetation cover and the soil. The
toxicity of heavy metals is manifested in the interference with the development
of plants and microorganisms, their excessive content causes the damage of the
central nervous system of humans and animals, changes the composition of blood,
has an adverse effect on the function of internals, causes severe physiological
changes, etc. The paper deals with a series of experiments aimed at the
determination of the heavy metals content in the soil and in the leaves of
bilberry bush Vaccinium.
Keywords: heavy metals pollution,
soil, bilberry bush.
ON
THE ELECTROPHILIC BONDING OF BICYCLOBUTYLIDENE WITH CARBONIC ACIDS AND THEIR
PRODUCTS
Eremeishvili M.G.
Bicyclobutylidene reacts with alcohol, acetic acid,
chloracetic acid and fluoroacetic
acid in the presence of H2SO4. Without the catalyst, bicyclobutylidene reacts with trichloracetic
acid and trifluoroacetic acid. The reaction is
exothermic. Corresponding adducts were produced.
Keywords:
electrophilic bonding, bicyclobutylidene, carbonic acids.
REGROUPING OF BICYCLOBUTYLIDENE IN THE PRESENCE OF THE ACID CATALYST
Eremeishvili M.G.
Akaki Tsereteli State University, Kutaisi
Regrouping
of bicyclobutylidene takes place due to the presence of 60% H2SO4 and
H2O. Regrouping proceeds by the Wagner-Merveyn
rule. Compound 1-hydroxy (bicyclo 3,3,0)-octane
(melting point – 47-47.5ºC) was extracted as an individual one.
Keywords: regrouping, bicyclobutylidene, catalyst.
ON THE PROBLEMS OF REGIONAL ECONOMY AND MANAGEMENT
Chubinidze
L.G.
Akaki Tsereteli State University,
Kutaisi
Georgia’s policy of regional economy needs further improvement. This is
especially topical for the countries being in the period of reforms and
transition to close ties with the European Union. In this connection, of
primary importance is the improvement of the efficiency of local
self-government and control bodies, which essentially depends on their staffing
with highly qualified specialists.
Keywords: regional economy, management, local self-government.
ON THE MANAGEMENT OF THE DEVELOPMENT OF A NEW PRODUCT
Chubinidze L.G. and Karchava M.S.
The development of technologically perfect and high-quality product does
not mean its immediate success on the consumer market. The analysis of the
experience of the developed countries in this field shows that such success
strongly depends on the perfect management.
Keywords: management, product development, consumer market.
SOME ISSUES OF
THE CREATION OF THE KNOWLEDGE SCORE TEST AND THE ESTABLISHMENT OF ITS
PARAMETERS
Jaadze S.V.
Georgian
Technical University
The paper deals with the methods of creation of the knowledge score
test and establishment of the parameters characterizing its quality. Two methods
of this kind are considered, their advantages and drawbacks are discussed.
Besides, some parameters characterizing the test quality and the rules of
determination of their values are described.
Keywords: estimation of knowledge, test, correlation coefficient, test
reliability, test validity.
KINETIC
REGULARITIES OF MASS TRANSFER OF THE MEDICINE WITH ONSIDERATION FOR ENTRAINMENT
FROM THE EXTERNAL ENVIRONMENT (REPORT I)
Buadze E.P., Pailodze N.O., Abuladze N.B., Bochorishvili R.I. and Khurtsilava
I.A.
The paper deals
with the investigation of the kinetic regularities of mass transfer of the
medicine with consideration for its entrainment from the external environment. Nitrofural (furacilin), a
slightly soluble antimicrobial agent, was used as a basic medicine. The general
analytical solution describing the desorption of the
medicine from a textile material with a prolonged therapeutic effect on the
wound was obtained. Assumption I denotes that we neglected the medicine
sorption on the surfaces of the polymer layer and the carrier. Then we
confirmed experimentally that the sorption processes matter both at the initial
stage of the use of the material and, to a greater extent, at the final one.
However, the concentration of the medicine retained on the surfaces of the
polymer-thickener and the fiber-forming polymer did
not exceed 10%.
Keywords:
medicine,
mass transfer, kinetic regularities, textile material, medicine sorption.
KINETIC
REGULARITIES OF MASS TRANSFER OF THE MEDICINE WITH ONSIDERATION FOR ENTRAINMENT
FROM THE EXTERNAL ENVIRONMENT (REPORT II)
Buadze E.P., Pailodze N.O., Abuladze N.B., Bochorishvili R.I. and Khurtsilava
I.A.
The paper is the
continuation of the previous work (Report I) and deals with the problems of modeling of the sorption of medicine from a textile
material. The investigation results allow obtaining the computation data that
sufficiently approximate the experiment, and their set does not contradict the
physical interpretation of the experiment. At the same time, the model with
entrainment does not clarify the mechanism of desorption and its regularities
when polymer thickeners are used, and hence needs perfection.
Keywords:
medicine,
mass transfer, kinetic regularities, textile material, desorption.
DISINFECTANT-
STERILIZING MEANS AND THEIR CHARACTERISTICS
Padiurashvili Z.V.
Foreign and local
disinfectant-sterilizing means are reviewed. Their advantages and drawbacks are
discussed.
Keywords:
disinfectant,
sterilizing agent.
THE BIOLOGICAL ROLE OF MAGNESIUM IN THE PROCESS OF
RESUSCITATION OF LIVING ORGANISMS
Kikalishvili M.I. and Bakradze-Guruli M.Sh.
The paper deals with the biological role of magnesium. Its participation
in the processes proceeding in living organisms is discussed. Magnesium is a
central ion in chlorophyll cluster. Photosynthesis proceeds with its
participation due to solar energy. It enters into the composition of bone
tissue. It interferes with the breath centers and
circular regulation in the brain. It reduces arterial pressure. Magnesium is
quite effective in controlling convulsions.
Keywords:
magnesium,
biological activity, living organism.
ON THE POSSIBLE PESTICIDES
POLLUTION OF THE CHAKVI AND CHAISUBANI AGRICULTURAL AREAS IN AJARA
Varshalomidze J.G., Mumladze N.G., Danelia
G.Sh.,
Mumladze K.M. and Kavtaradze
M.L.
Georgian
Technical University
The role of soil in the processes proceeding in the biosphere and
anthropogenic sources of soil pollution are considered. The problems of
pollution of the soil with pesticides are discussed. The hazard level of chloroorganic pesticides was assessed. The content of chloroorganic pesticides in the soil of the Chakvi and Chaisubani
agricultural areas was determined by using the mass-spectrometer (GC/MS)
system.
Keywords: pesticides,
pollution, soil agricultural area.
INVESTIGATION
OF THE EXTENT OF SPREAD OF YEAST PHENOTYPES KILLER, NEUTRAL AND SENSITIVE IN
SPONTANEOUS POPULATIONS OF THE CHKHAVERI GRAPE CULTIVAR
Salia E.Sh.
The
investigation of the phenotypic composition of spontaneous yeast populations of
the Chkhaveri grape cultivar revealed a low content
of the strains of phenotypes killer and sensitive, which forms the
prerequisites for manifestation of the competitive edge of the pure wine yeast
culture of the killer phenotype.
Keywords:
wine
yeast, yeast phenotype, killer yeast, spontaneous population.
ESTABLISHMENT OF
THE CONDITIONS OF USING THE PURE CUKTURE WINE YEAST CHKHAVERI 5 DURING
FERMENTATION
Salia E.Sh., Melikishvili M.V., Makhatadze M.F., Papava Z.M. and Mdinaradze M.B.
Institute
of Viticulture and Oenology,
Research was
performed in laboratory with the aim of establishment of the conditions of
efficient use of the pure culture wine yeast Chkhaveri
5 in production. Namely, the objective was the optimization of the process of
fermentation and the production of high-quility
product. The best result was achieved under the conditions of semi-aerobiosis, at the sulfation dose of 100 mg/l free sulfurous acid and 3% pure yeast starter.
Keywords:
wine
yeast, pure culture, fermentation, optimization, aerobiosis.
PRODUCTION OF THE DRY FORM OF THE PURE CUKTURE WINE YEAST CHKHAVERI 5 AND THE STUDY ONITS ACTIVITY
Salia E.Sh. and Makhatadze M.F.
Institute of
Viticulture and Oenology,
By liophilic drying of pure culture wine yeast Chkhaveri 5, a dry form of this yeast was produced.The investigation of the activity (fermentation
and intensity and sulfation resistance) of reactivated cells, and also of the
fermentation time showed that the pure culture wine yeast Chkhaveri
5 retained its activity after drying.
Keywords:
wine
yeast, pure culture, dry form, yeast activity.
ANTIOXIDANT
ACTIVITY OF WHITE MULBERRY VODKA
Bedianidze L.M.
Jakob Gogebashvili State University, Telavi
The
article deals with the experimental research on the antioxidant activity of
white mulbery vodka. It was revealed that, after
fermentation and vodka distillation in a traditional way, its antioxidant
activity was 4%. After aging of white mulberry vodka (40 g per liter for 6 months) on grape seeds, its antioxidant
activity increased up to 18.9%. In the
result, the flavor and useful properties of the vodka
improved, and the
vodka gained a nice straw color. This was due to the
transfer of phenol compounds from the seeds into the vodka.
Keywords: vodka, white mulbery, antioxidant activity, grape seeds, phenol
compounds.
SCIENTIFIC ASPECTS OF THE IMPROVEMENT OF THE SAFETY OF GERMINATING GRAIN
Pruidze
E.G., Khutsidze T.Z. and Khetsuriani G.S.
Recently the tendency of using the germinating grain for food has
increased. Special attention is paid to the germinating wheat grain, as this
culture is widely spread in
Keywords:
germinating
grain, wheat, grain safety.