Mechanics Colloquim

PROGRAM

PROGRAM ZA OKTOBAR 2006.

Pozivamo Vas da učestvujete u radu sednica Odeljenja i to:

SREDA, 04. oktobar 2006. u 18 sati:


Prof. Ingo Mller Technische Universitat Berlin Germany
ENTROPY IN THERMODYNAMICS AND IN THE KINETIC THEORY

In the work of Clausius the entropy emerged as a state function with the extraordinary property of growing in adiabatic processes. And Boltzmann found a molecular interpretation of entropy in the kinetic theory of gases. Boltzmanns discovery marked the beginning of the appreciation of stochasticity in physics and,-- at the same time of quantization. When the law of conservation of energy is combined with the law of entropy growth, it turns out that equilibria define a compromise between energy, that tends to a minimum, and entropy that tends to a maximum. Temperature determines the influence of these tendencies. Three examples are given:

i.) Planetary atmospheres.
ii.) A rubber molecule.
iii.) Phase transition in a shape memory alloy.


SREDA, 11. oktobar 2006. u 18 sati:


Prof. Tommaso Ruggeri, Research Center of Applied Mathematics, C.I.R.A.M., University of Bologna, Italy
ON THE RIEMANN PROBLEM FOR HYPERBOLIC SYSTEM OF BALANCE LAWS

In this talk I will present first the historical Riemann problem in fluid dynamics and than I will give a brief survey on the well know results of Riemann problem for conservation laws. Then I will present the open problem concerning balance law systems like Extended Thermodynamics and Mixtures and some preliminary results. The origin of the problematic is of mechanical interest but is also interesting for mathematicians.



SREDA, 18. oktobar 2006. u 18 sati:


Prof. Branislav Baclic, Fakultet tehnickih nauka, Novi Sad
OPTIMALNI OBLIK ATLETSKOG KOPLJA ILI SLOBODNOG ROTIRAJUCEG STAPA

Pokazuje se analogija poblema odredjivanja optimalnog oblika atletskog koplja i problema optimalnog oblikovanja slobodnog rotirajuceg tapa. Analogija je iskoriscena da se Pontrjaginovim principom problem optimalnog oblikovanja svede na nelinerni singularni granicni problem. Optimalni oblik je odre?en numeri?kom integracijom tog granicnog problema uz koriscenje prvog integrala sistema i jedne apriorne ocene. Ova svojstva reenja su nadjena zahvaljujuci cinjenici da granicni problem poseduje cak tri razlicite varijacione formulacije.

SREDA, 25. oktobar 2006. u 18 sati:


Aleksandar S. Tomic, Narodna observatorija, Beograd
POSSIBLE CONNECTION BETWEEN THE EARTHQUAKES AND COSMICAL NANOGRAVITY

In this paper we investigate the correlation between calculated tidal gravity variation on the Earth's surface (vector amplitude, vertical and horizontal component, and baricentric velocity) with data of the earthquakes, especially in Los Angeles -San Francisco area foci in period 1986-2006. Besides standard method the singular spectrum analysis method were used. In computer modeling of tidal gravity field were obtained the waves of the amplitude110 pg and period 91 s, produced on the Earth's surface by Solar system body dynamics. We explained data on the magnetic field variation in the Loma Prieta, California earthquake from Oct 18, 1989 by expulsion of electrons, mechanism described in Savi?-Kaanin theory, caused by nonlinear accumulation of this wave action on atomic level in molecular clusters.

Sednice se održavaju u zgradi SANU, Knez Mihailova 35, u sali 2 na prvom spratu.