The Internal Dynamics of Globular Clusters

Galactic globular clusters are ancient building blocks of our Galaxy. They represent a very interesting family of stellar systems in which some fundamental dynamical processes have been taking place for more than 10 Gyr, but on time scales shorter than the age of the universe. In contrast with galaxies, these star clusters represent unique laboratories for learning about two-body relaxation, mass segregation from equipartition of energy, stellar collisions, stellar mergers, core collapse, and tidal disruption. This review briefly summarizes some of the tremendous developments that have taken place during the last two decades. It ends with some recent results on tidal tails around galactic globular clusters and on a very massive globular cluster in M31.Comment: An invited review (32 pages, 7 figures) in "The Chaotic Universe: Theory, Observations, Computer Experiments", Proceedings of the ICRA Rome-Pescara workshop, eds. V.G. Gurzadyan and R. Ruffini (Singapore: World Sci.), in pres

A variation equation for the wave forcing of floating thin plates

A variational equation is derived for a floating thin plate subject to wave forcing. This variational equation is derived from the thin plate equations of motion by including the forcing due to the wave through the integral equation derived using the free surface Green’s function. This equation combines the optimum method forsolving the motion of a thin plate (the variational equation) with the optimum method for solving the wave forcing of a floating body (the Green’s function method). Solutions of the variational equation are presented for some simple thin plate geometries using polynomial basis functions. The variational equation is extended to the case of plates of variable properties and to multiple plates and example solutions are presented

Heterodon simus

Number of Pages: 2Integrative BiologyGeological Science

Partisipasi Perempuan Dalam Pengelolaan Lingkungan Hidup

Women have strong links with the environment. In his role as manager of the household, they are more interacting with the environment and natural resources. The era of globalization has indirectly resulted in increasing the development of environmental pollution and environmental damage. Women and children are part of the citizens who have a direct impact of pollution. Women's health impaired due to unhealthy living environment will result indirectly on the health of children as the future generation. Law No. 32 of 2009 on the Protection and Management of Living (UUPPLH) has given the changes that are democratic; give broad authority to local governments and community involvement in giving priority to control environmental damage. The role of women is implicitly described in article 70 of the role of the community. The role of women in environmental protection under the act protection and environmental management can be a social control and the role of women in environmental policy-making through the legislature

Palomar 13: a velocity dispersion inflated by binaries ?

Recently, combining radial velocities from Keck/HIRES echelle spectra with published proper motion membership probabilities, Cote et al (2002) observed a sample of 21 stars, probable members of Palomar 13, a globular cluster in the Galactic halo. Their projected velocity dispersion sigma_p = 2.2 +/-0.4 km/s gives a mass-to-light ratio M/L_V = 40 +24/-17, about one order of magnitude larger than the usual estimate for globular clusters. We present here radial velocities measured from three different CCD frames of commissioning observations obtained with the new ESO/VLT instrument FLAMES (Fibre Large Array Multi Element Spectrograph). From these data, now publicly available, we measure the homogeneous radial velocities of eight probable members of this globular cluster. A new projected velocity dispersion sigma_p = 0.6-0.9 +/-0.3 km/s implies Palomar 13 mass-to-light ratio M/L_V = 3-7, similar to the usual value for globular clusters. We discuss briefly the two most obvious reasons for the previous unusual mass-to-light ratio finding: binaries, now clearly detected, and more homogeneous data from the multi-fibre FLAMES spectrograph.Comment: 9 pages, 2 Postscript figure