Head- candidate of physical and mathematical sciences, pro-rector on correspondence course Ponomarev Sergey Mikhailovich.

Direction "Astronomy, astrophysics, the history of astronomy" of scientific work in NSPU is possible to consider traditional. Historically it existed from the moment of creation of high school and conducts the beginning from activity of the Nizhniy Novgorod circle of the fans of physics and astronomy (year of the basis 1888). Though, certainly, from the point of view of the contents it constantly underwent some changes.

  1. As the Basic themes, submitted within the framework of the given direction, it is possible to consider:
  2. Not classical problems of the heavenly mechanics;
  3. Cosmogony of bodies of Solarsystem;
  4. Separate problems of comet astronomy;
  5. Astrophysics of the Sun and interplanetary environment;
  6. Elements of outer-galaxy astronomy;
  7. An astronomical calendar - year-book;
  8. Historical and astronomical researches;

First three themes are connected to a name of the deserved figure of a science of RSFSR, doctor's of physical and mathematical sciences, professor's Vladimir Vyacheslavovich Radzievsky.

For the first time V.V.Radzievsky has arrived on work in the Gorky's state pedagogical institute on a post of the head by chair of physics in 1957. However in 1959 he leaves for Yaroslavl. In May, 1965 he is nominated as the order of the Ministry of education to a post of the pro-rector on scientific work of this institute. Working the pro-rector, in 1966 V.V.Radzievsky achieves creation chair of astronomy (modern name - chair of astronomy and history of natural sciences) and opening of physical and astronomical branch (1967). By the head by chair of astronomy he has worked down to 1983, then remained in a post of the professor of the same faculty till 1995.

V.V.Radzievsky has brought the invaluable contribution to development of astronomical education in Russia and, in particular, in the Nizhniy Novgorod region. During 20 years (since 1966) he was the vice-president All-Union of a astronomy and geodetic society, more than 15 years - chairman of a commission on astronomy in pedagogical high schools of the Ministry of Education of RSFSR, 10 years - vice-president of Council on preparation of the astronomical staff at an Academy of sciences USSR. He was the member of the specialized councils on protection of the dissertations and within 40 years the Astronomical calendar" (M. entered in editorial boards of a magazine "the Earth both universe "and year-book": a science).

He is distinguished by extraordinary breadth of scientific interests. During the scientific activity which is not stopping, by the way to tell, till now, V.V.Radzievsky has published about 230 works of academic, scientific - methodical and critical- bibliographic character. The directions of his scientific activity defined subjects of scientifically research work of chair of astronomy during all history of its existence. Itself Vladimir Vyacheslavovich the proceedings subdivided into 3 types:

  • Works pawning bases of new sections of a science;
  • works which are bringing in novelty to separate sections of a science;
  • works having local scientific meaning;

The works put in pawn bases of the photogravitational heavenly mechanics and cosmogonic of comet statistics concern To the first type. In doctor's dissertation "the Heavenly mechanics of radiating bodies"(1955).

No-classical problem of the heavenly mechanics.
V.V.Radzievsky, reconsidering the basic equations of the classical mechanics in view of reduced weight of a body, finds out a line of new effects.

In particular, it is possible to note:

  1. In a task of two bodies the movement has appeared possible on all to seven conic sections;
  2. Valid of a noconservative photogravitational field has appeared to possible capture in a task of two bodies;
  3. Was found out, that the law of photogravitational interaction does not submit to the third axiom of Newton. Therefore probably accelerated movement of the isolated system of two bodies;
  4. In the limited task of three bodies 7 points of vibration (instead of five) are found;
  5. Was found out, that the most powerful mechanism of change of an orbit in a task of two bodies is the change of reduced weight of a radiating body at the expense of change of the sizes, of a Midavev's section or of a albedo small body;
  6. use of a solar sail for change of an orbit of a space vehicle Is offered;

In a numerous series of clauses (Report of an Academy of sciences USSR. 1950. № 5; 1953. № 3; an astronomical magazine 1953, Vol. 30. № 3; 1956. Vol. 33 №2 etc.) the reasons of occurrence no-central of photogravitational force and following from here effects were considered:

  1. Planet-centrical effect of beam braking at the expense of absorption of solar radiation. This effect was included in the world literature under the name of effect Radzievsky's, has appeared planet-centrical analogue of effect Pojntig-Robertson's;
  2. Effect turn of meteoric bodies at the expense of heterogeneity of a albedo surface;
  3. Effect anti-izotropic re-radiation, on two order the superior effect Pojntig-Robertson's, is known in the world literature as effect Yarkovsky-Radzievsky's;
  4. Parachute effects at movement in a photogravitational field of a massive body connected with by a dispersion matter, as the possible mechanism of education of double stars by capture;

For researches of a problem of use of a solar sail V.V.Radzievsky was awarded with the Centre on preparation cosmonaut by the Y.A.Gagarin diplom and the S.P.Korolev medal.

  1. Among other significant results, which has received V.V.Radzievsky in the field of the heavenly mechanics, it is possible to note:
  2. The general decision of a unlimited task of three bodies at Nyuton-Guk's interaction (Report of an Academy of sciences USSR. 1953. Vol.91. № 6);
  3. Reception of the new decisions of a task of two bodies of variable weight (Astronomical magazine. 1957. Vol.34 № 4);
  4. Reception of integral of bipolar elements in a task of two bodies (Astronomical magazine 1970. Vol.47 № 1).
  5. Reception of second integral in to a half-limited task of three bodies (Astronomical magazine 1976. Vol.53 № 3).
  6. Research of empirical laws in movement of the Moon (Astronomical bulletin. 1976. Vol.10 № 1; the collection of works of All-Union a astronomy- geodetic society. 1977. № 6);
  7. Reception of integral Yakobi at any sedate law of the central force in the limited task of three bodies and application of results to system a Galaxy - Sun - comet (Letter in an Astronomical magazine 1980. Vol.6 № 1);

The research of interaction of stars with interstar environment has resulted in occurrence of a series of works on star astronomy. About ten clauses were devoted to research of effect anizotropic of shine of stars caused by education of a dusty cloud in apex of a flying star (an Astronomical magazine 1969. Vol.46 № 1 etc.). Among other works on star astronomy it is possible to note clauses on research of effect Barr's, work about the new theorems of star statistics, opening of a star whirlwind in area apex of the Sun (Astronomical magazine 1969. Vol.46 № 3; 1971. Vol.48 № 1; 1973. Vol.50 № 4 etc.). Many works V.V.Radzievsky's carry cosmogonic character. In particular, a little his joint with the senior lecturer A.V.Artemev of works on an origin of axial rotation of the Earth (Astronomical magazine 1965. Vol. 42 № 1 etc.).

Cosmogony of bodies of Solar system.
Separate problems of comet astronomy.
From the end 60 years Radzievsky take a great interest in questions of comet cosmogony. On this problem he published more than 100 clauses. Together with A.V.Artemev's, S.M.Ponomarev's etc. was prepared and some catalogues of comets in various systems of coordinates (Problem of research of the universe are statistically processed. M. - L., 1979. Release. 8; the statistical catalogue of parameters of orbits of long periodic comets in Laplas's coordinates. M., 1985 etc.). In result some laws of comet dynamics and new effects (for example, unknown earlier "parachute effect") are established. The interpretation of the found out laws has resulted in a conclusion about existence in Solar system two unknown and enough massive of trance-Puton's planets (Analysis of movement of bodies of Solar system. Riga, 1986). The hypothesis about presence of such planets is supported in works both domestic, and foreign scientists.

For merits in the field of the heavenly mechanics, cosmogony and origin of comets the World centre on small planets has named astroid № 3923 (1976 SN3) as a name "Radzievskij". In the honourable certificate is marked: "Namend in honor of Vladimir Vyacheslavovich Radzievsky, professor at the Nizhegorodsky pedagogical institute, known for his work in celestial mechanics, the cosmogony of the Solar system and the origin of comets".

A theme "the Astrophysics of the Sun and interplanetary environment" has received active development in NSPU rather recently - from the end 80 years. The largest and successful direction in its frameworks is "Remote wave diagnostics and the neuron- network forecast in Solar- terrestrial communications". The given direction has based and the professor by chair of Theoretical physics NSPU N.A.Barchatov is headed by the doctor of physical and mathematical sciences. Distribution madnet-hydro-dynamic perturbations in a solar wind - theme of his doctor's dissertation.

Him last researches are connected to development of methods of remote wave diagnostics of parameters of interplanetary environment and magnetic field, forecast of dynamic events in the near-Earth space space being the important section of Solar- errestrial physics. Considered in these methods ultra low-frequency (ULF) of a wave of a range of 0,01-1 hertz (the geomagnetic pulsations) on frequency border with by classical variations (magnetic storms). Their minimal frequency - frequency own magnet-hydro- dynamic (MHD) of fluctuations terrestrial magnet-realm as resonator. As the conditions of distribution and generation of these waves are closely connected to key processes in space space and directly in magnet-realm, the waves contain the information on their condition. The regular registration, adjusted per last decade, a component of a vector of perturbations of a magnetic field ULF of fluctuations is provided with application sensitive megnet-metrs, which are placed on a terrestrial surface and on space vehicles. The efforts of the researchers are directed on, that re-create on these measurements a general picture of near-Earth plasma processes, i.e. to establish space "weather". It is accepted to name it as remote diagnostics of space space and magnetrealm. It is clear, that the synchronous registration of fluctuations in several points on a terrestrial surface and directly in space space is especially useful to such diagnostics.

Diagnostics of parameters of space space has the direct relation to forecasting solar and geomagnetic storms. The similar forecasts are extremely important and can be used at the decision of various questions connected to a condition ionosphere, magnetspheres and of near-Earth space, and, in particular, of questions of distribution of radiowaves. The strong influence of the electromagnetic phenomena on biological objects, including the man is known, the medical forecast made on the basis of forecasting of changes in to near-Earth environment therefore is possible also.

The real physical picture occurring in near-Earth space of events is complex), therefore attempts of the further perfection of physical and mathematical models on ways of the account of the greater circle of processes can withdraw from authentic diagnostics and forecasting of the observable phenomena. Therefore alongside with the "classical" methods based on the formulation of models of influence indignant of a magnetizing solar wind, indignant, nagnetosphere of the Earth, spelling and subsequent decision of the physical equations for particles of plasma and electromagnetic waves, methods of the correlation analysis of conditions in space space and methods of artificial neuron networks (ANN) actively develop. The neuron-network approaches are universal for the most various complex systems, when the construction of detailed mathematical model or is impossible, or is unjustified because of excessive complexity. Of a neuron network during training weight factors between the elements ("neurons") on available experimental data automatically arrange, then can successfully predict processes. So the man and, almost always, animals - to attributes and precedents, without construction of abstract models predicts events.

The marked above methods of study of Solar- terrestrial communications are basic for scientifically research work spent NSPU for cooperation with such organizations, as the Nizhniy Novgorod research radiophysical institute(NRRI), Institute of applied physics of an academy of sciences, Institute of terrestrial magnetism, ionosphere and distribution of radiowaves of the Russian academy of sciences etc., last years. Its urgency is defined by close communication with the decision of applied scientific problems and, first of all, with search of geoeffective parameters of a solar wind and interplanetary magnetic field. It is natural, that in case of use ULF of waves for the purposes of diagnostics the study of their evolution is necessary at distribution in near-Earth space and opportunity of penetration in magnet-sphere. In this connection within the framework of the first approach the theoretical bases of formation and carry of a field low-frequency MHD perturbations in driven space plasma are considered: In a solar wind, on left to a terrestrial shock wave and in magnet-sphere of the Earth. Thus the basic and usually not taken into account features of space are consistently taken into account, in which the wave phenomena are studied. The solar wind is considered as non-uniform environment with over-alven by speeds and spiral interplanetary field, left a shock wave as area with the certain structure, and transitive area behind a terrestrial shock wave as environment with advanced by turbulentus movement.

Among achievement within the framework of the given direction it is possible to note the following. The new mechanism of easing MHD of waves in space plasma connected to their resonant dispersion on not-uniforms of parameters of interplanetary environment (of News of high schools is offered. Radiophysics. 1988). This mechanism explains features registered wave perturbations in a solar wind. In non-uniform a over-alven solar wind for low-frequency waves the phenomenon of double refraction of beams with simultaneous amplification MHD of waves is revealed at the expense of an exchange of energy with driven plasma of a solar wind. The method of definition of area of generation of waves under the analysis of an observable spectrum is developed. (News of high schools. Radiophysics. 1988). The conditions of an enlightenment strongly of turbulentus transitive area behind a terrestrial shock wave for low-frequency waves of a solar wind (Geomagnetism and airnomy are found. 1989), which has basic meaning at use outer-magnet-sphere's perturbations for remote diagnostics of parameters of near-Earth space. The influence of various mechanisms dissipation on dynamics strongly nonlinear and shock MHD of waves in driven to near-Earth plasma (News of high schools is investigated. Radiophysics. 1996). The case of strong nonlinearity is analysed, where the traditional classification of waves is inadequate. The new sources geoeffective MHD perturbations in to near-Earth lasma (News of high schools are found. Radiophysics. 1998). The analysis of parametrical interaction MHD perturbations with perturbation of other types on a background turbulentus of a solar wind by a method of the kinetic equation for function of distribution plasmons in non-uniform environment is carried out. The sizes of effective attenuations MHD of waves are calculated at the account of real features of distribution of parameters of interplanetary environment and magnetic field along a trajectory of carry of waves and account over-alven of a flow of a solar wind. The layers of near-Solar space are determined which are responsible for MHD of a wave of various scales registered in a vicinity of the Earth (Int. Journ. of Geom. Aeron. 2000). The conditions of formation and arrival to magnet-sphere of the Earth of geoeffective parameters of a solar wind are revealed depending on a kind of indignation near to the Sun and condition of interplanetary environment. The spatial - temporary pictures of distribution of fields large-scale magnet-hydro-dynamic perturbations on a line the Sun - Earth connected to solar activity are constructed and the degree of efficiency of influence investigated perturbations on terrestrial magnetsphere is specified. The numerical modeling of consequences of passage of low-frequency waves of a solar wind through left a terrestrial shock wave for different conditions of its flow and orientation of an interplanetary magnetic field is carried out. The arising modulation of low-frequency waves and dependence of their amplitudes on parameters of a solar wind closely connected to solar activity is analysed. Thus the swapping of energy of falling waves in waves of other types (Geomagnetism and airnomy is appreciated. 1998). The consideration of reflection MHD perturbations from of magnet-attended areas ionosphere has allowed to find out effect of left of plasma from areas near to reflecting borders, i.e. occurrence of slow magnet-sound waves having the relation to redistribution of plasma in magnet-sphere of the Earth (News of high schools. Radiophysics. 2000). For these purposes the original computer programs allowing to carry out modelling computing experiments on research of non-uniform flat waves in interplanetary plasma were created.

The technology ANN also is successfully used by us for the decision of a line of applied geophysical tasks. The method ANN considers questions of forecasting of dynamics of a geomagnetic index Dst on parameters of plasma and magnetic field in a solar wind on the basis of given of satellite system OMNI. The parameters of a solar wind rendering the greatest influence on formation geomagnetic storms are revealed. The question on influence of architecture ANN on quality of the forecast global perturbations of a ground magnetic field is investigated. Is shown, that ANN with return distribution of a mistake after the appropriate adjustment and training allow effectively to carry out the hour forecast of dynamics global geomagnetic perturbations on parameters of near-Earth plasma received from space vehicles, taking place in a solar wind, (of News High schools. Radiophysics. 2000). The engineering ANN is used also for restoration of blanks in record by one observatory of a world network of magnetic stations by use of supervision in another observatory, located in same a latitudimal zone.

The work spent by scientific group, which supervises N.A.Barhatov over, has by high practical value, as is directed on creation of methods of diagnostics of space weather and revealing of key Solar- terrestrial communications with use already to existing network of geomagnetic services. Developed neuro-network methods of diagnostics of near-Earth space space have appeared useful addition for radical improvement of the forecast of the important phenomena in magnet-sphere of the Earth caused by various displays of solar activity.

The given work was supported by the grants of the Russian fund of basic researches, grant of the International scientific fund (1993), grant INTAS - CNES and program "Universities of Russia, 2000".

It is necessary to note, that the direction "strophysics of the Sun and interplanetary environment"is not limited to the above-stated theme. The independent character is carried "By supervision of active educations of solar photosphere in optical and radiorange ", carried out in 1990-1994 years within the framework of economics-contractual subjects together with scientifically research radio by physical institute (executors from NSPU - A.V.Artemev, S.M.Ponomarev, A.P.Poroshin, from scientifically research radio of physical institute Y.I.Medvedev, V.F.Melnikov etc.). Besides the senior lecturer A.M.Shutov realizes a separate theme "Methods and devices for research of objects with varied polarization of optical radiation".

The theme "Outer-galactic astronomy" was submitted by works of the doctor of physical and mathematical sciences of the professor head by chair of astronomy in 1983 - 1989 B.I.Fesenko. In the works, using methods of mathematical statistics, he investigated distribution and orientation of galaxies in congestions (Dynamics and evolutions of star systems. An academy of sciences USSR. M.- L., 1975; an astronomical magazine 1978. Vol. 56. № 2; 1980. Vol. 57 № 5; the letters in an Astronomical magazine 1982. Vol.8 № 8; astrophysics. 1981. Vol.17 № 4; 1986. Vol.24 № 3; 1986. Vol.25 № 1). The received data have allowed to find some laws in distribution of the characteristics of galaxies in congestions and to make the certain conclusions concerning structure of the observable universe.

The theme "an Astronomical calendar a year-book" is the oldest and traditional theme of scientifically research work of the given direction. An astronomical calendar (AC) - first edition, similar in Russia, - beginnings to be let out by the Nizhniy Novgorod circle of the fans of physics and astronomy (NCFPA) in 1895. The initiator of the edition was the chairman of government NCFPA the director of a 1-st area grammar school S.V.Sherbakov. Subsequently such employees NSPU participated in preparation of materials AC, as the professor K.K.Dubrobsky, professor K.L.Baev, professor V.I.Turansky, senior teachers of chair of astronomy E.G.Demidovich and S.N.Parshin etc. His history is in detail covered in S.M.Ponomarev's to clause "One century and 10 years" (AC for 1998. N.Novgorod, 1998. Page.138). Let's note only, that since 1952 his release was transferred in Moscow. However approximately 50 % of its contents prepared The inhabitants of Nizhni Novgorod, including members of chair of astronomy NSPU. In 1994 under the initiative of the chairman of government NCFPA, member editorial board AC S.M.Ponomareva the Nizhniy Novgorod edition AC was renewed and proceeds now under his edition. The basic work on preparation AC is the account efermids (tables of seen rules) heavenly bodies of Solar system. Though efermids for forthcoming year pay off on the basis of traditional methods, the accounts in themselves represent new result. Besides on faculty for these purposes the special computer program is developed. The release AC is carried out in cooperation with Institute of applied astronomy of the Russian academy of sciences, Nizhniy Novgorod planetarium and other organizations. The year-book can be used as a help management for the scientific employees working in the field of astronomy, astrophysics and geodesy, and also in educational process in high schools and average educational institutions. His average volume makes about 13 printed sheets.

СIt is necessary to note, that now all above-stated themes of scientifically research works on chair of astronomy and the histories of natural sciences are incorporated under the general name "Physics and dynamics of bodies of Solar system". Is a uniform theme, which represents a multiplane scientific problem including development of the theories, their numerical and graphic interpretation, creation of methods of account of various elements describing a condition and dynamics of change of some physical parameters of objects of Solar system and environment between them. Within the framework of same theme in astronomical observatory of chair the supervision of such astronomical phenomena, as solar and lunar eclipses, bright comets, silvery (mezo-spherial) of a cloud, covering of stars and planets by the Moon is carried out. The basic executor of these supervision is the director observatory the senior lecturer of faculty of astronomy and history of natural sciences A.P.Poroshin. The results of supervision are published. The received data on coverings are directed to the International centre of lunar supervision in Tokyo.

Astronomical observatory NSPU, its history and scientific work on its base represent independent interest. More in detail about it is possible to due in S.M.Ponomarev's clauses published in an Astronomical calendar on 1995 and 1998, and A.P.Poroshin's to clause "Small observatory, known to all world", printed in Works of physical faculty NSPU (1998).

"Historical astronomical researches" - theme which has served with the reason of change of the name of chair of astronomy. Since 1996 it began to refer to as chair of astronomy and history of natural sciences. The chief of the given theme is the head by chair the candidate of physical and mathematical sciences, senior lecturer Sergey Mikhailovich Ponomarev. Within the framework of the given theme the researches on a history of development of separate directions of astronomy, astronomical education, public astronomical organizations in Russia and Nizhniy Novgorod region are conducted. One of the basic projects - "Formation of experimental radioastronomy in city Gorky (social and cultural aspect)", chief S.M.Ponomarev. The project was maintained by the grant of the Russian humanitarian scientific fund. The realization of the given project was carried out in close cooperation of such organizations, as NSPU, scientifically research radio physical institute, Nizhniy Novgorod state university, Nizhniy Novgorod state technical university. The basic executors of the project: the doctor of philosophical sciences the professor by chair of philosophy NSPU A.A.Kasyan, candidate of physical and mathematical sciences, senior lecturer of the Nizhniy Novgorod technical university B.V.Bulyubash, candidate of physical and mathematical sciences conducting employee NRRI V.M.Fridman, candidate of physical and mathematical sciences conducting employee NRRI V.F.Melnikov.

Within the framework of the project the following work is done :
The bank of commential interview of conducting a science carried out in 1998 - 1999 is created. Is complemented and the list of the domestic and foreign references on a history of radioastronomy is analysed with the purpose of definition of a role and place of these researches in city Gorky in scientific, social and cultural aspects. The selection of the archival documents revealing a role of the separate persons in a history of radioastronomy in city Gorky, help and interaction with administrative, industrial and public organizations both in city Gorky, and behind its limits is carried out. On the basis of interview, archival and references materials for the materials for materials for materials for materials for materials for materials for materials for the analysis of the assembled materials of interview determining formation of a new scientific direction, influence of individual sights on methods and ways of development of experimental radioastronomy. The results of the analysis answer basic the conducting a science concepts formation of new scientific directions. Features inherent in events in at the same time are marked city Gorky, connected with an organizing and scientific role of the persons who have defined fast and effective development of experimental radioastronomy. The selection of photomaterials on organization by first radioastronomical observatory's "Zimenki" is carried out and the comment to them is made. The analysis of discussion is carried out which passed in the beginning 50-th years XX of century in the Gorky's state university on G.S.Gorelik's to the book "Fluctuations and waves" (M. - L. 1950). The discussion was by original reflection of ideological campaigns which were taking place in the Soviet science per these years. For the first time is paid attention to specificity of such campaign which was taking place in a province.

By results of the done work it is possible to note, that for the first time object of special historical and scientific research became formation and development of scientific discipline located within the limits of one region. The new names and facts are entered into a history of a domestic science and engineering. The process of formation of scientific discipline successfully uniting fundamental and tool aspects of scientific knowledge is investigated. It defines novelty and urgency of research.

As the contribution of theoretical character it is possible to consider: the analysis of development of radioastronomy in city Gorky in a context of modern problems of a history of astronomy and social history; revealing of mechanisms of mutual influence of tool methods of researches and fundamental science; realization of the analysis of a role "of scientific management" in development of a science in separately taken region during the end 40 - 50 years XX of century.

During work above the project the methods of historical and scientific research applied in works on a social history of the Soviet nuclear project are used. With reference to the assembled file of the facts and documents the adequacy of methods of historical and scientific research used in English works on a history of astronomy is checked up. All this is the contribution of methodical character to development of a science.

As the contribution of character of conducting a history it is possible to consider formation of the systematized file of the documents and interview of conducting a science on a social history of experimental radioastronomy in city Gorky. Preparation of the electronic version of a file for connection to a database of the electronic project of Institute of a history of natural sciences and engineering of the Russian academy of sciences "a Social history of a domestic science and engineering".

The contribution of applied character is defined by that the results of the carried out research can be used by preparation of generalizing researches on a history of the Russian science and engineering of the Soviet period and on a history of astronomy./p>

Results of research have also educational and methodical meaning: by preparation of educational rates of a history of astronomy, history of natural sciences, and also study of local lore, study of region, philosophy and methodology of a science.

The methodological contribution: the idea of welfare definition of scientific knowledge is concretized with reference to a history of radioastronomy; the model of the analysis of aspects of activity of the scientific radioastronomer is offered; is revealed and the circle of social - methodological and philosophical and methodological problems of development of radioastronomy is formulated. The concept "moscowcentrizm" in a history of a science is entered, the positive and negative aspects of this phenomenon are revealed. Clauses are published: "Formation of experimental radioastronomy in Nizhni Novgorod"(Works of physical faculty. N.Novgorod, 1998.); "a Provincial echo of great shocks" (Questions of a history of natural sciences and engineering. 2001. №1).

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