Indestructibility of compact spaces

In this article we investigate which compact spaces remain compact under countably closed forcing. We prove that, assuming the Continuum Hypothesis, the natural generalizations to $\omega_1$-sequences of the selection principle and topological game versions of the Rothberger property are not equivalent, even for compact spaces. We also show that Tall and Usuba's "$\aleph_1$-Borel Conjecture" is equiconsistent with the existence of an inaccessible cardinal.Comment: 18 page

Models for the 3-D axisymmetric gravitational potential of the Milky Way Galaxy - A detailed modelling of the Galactic disk

Aims. Galaxy mass models based on simple and analytical functions for the density and potential pairs have been widely proposed in the literature. Disk models constrained by kinematic data alone give information on the global disk structure only very near the Galactic plane. We attempt to circumvent this issue by constructing disk mass models whose three-dimensional structures are constrained by a recent Galactic star counts model in the near-infrared and also by observations of the hydrogen distribution in the disk. Our main aim is to provide models for the gravitational potential of the Galaxy that are fully analytical but also with a more realistic description of the density distribution in the disk component. Methods. From the disk model directly based on the observations (here divided into the thin and thick stellar disks and the HI and H$_2$ disks subcomponents), we produce fitted mass models by combining three Miyamoto-Nagai disk profiles of any "model order" (1, 2, or 3) for each disk subcomponent. The Miyamoto-Nagai disks are combined with models for the bulge and "dark halo" components and the total set of parameters is adjusted by observational kinematic constraints. A model which includes a ring density structure in the disk, beyond the solar Galactic radius, is also investigated. Results. The Galactic mass models return very good matches to the imposed observational constraints. In particular, the model with the ring density structure provides a greater contribution of the disk to the rotational support inside the solar circle. The gravitational potential models and their associated force-fields are described in analytically closed forms, and in addition, they are also compatible with our best knowledge of the stellar and gas distributions in the disk component. The gravitational potential models are suited for investigations of orbits in the Galactic disk.Comment: 22 pages, 13 figures, 11 tables, accepted for publication in A&

Monte Carlo Simulations of Ultrathin Magnetic Dots

In this work we study the thermodynamic properties of ultrathin ferromagnetic dots using Monte Carlo simulations. We investigate the vortex density as a function of the temperature and the vortex structure in monolayer dots with perpendicular anisotropy and long-range dipole interaction. The interplay between these two terms in the hamiltonian leads to an interesting behavior of the thermodynamic quantities as well as the vortex density.Comment: 10 figure

Proses Pembelajaran Seni Musik Bagi Siswa Tunanetra

Tujuan penelitian ini adalah untuk mengetahui, mendiskripsikan, dan menganalisis metode dan pelaksanaan pembelajaran musik bagi siswa tunanetra kelas VIII SMP Di SLB Negeri 1 Pemalang. Penelitian ini menggunakan pendekatan kualitatif. Hasil penelitian yang telah dilaksanakan menunjukan bahwa metode pembelajaran siswa tunanetra hampir sama dengan metode pembelajaran pada siswa awas pada umumnya, yaitu sama-sama menggunakan metode ceramah, metode tanya jawab, metode demonstrasi, dan metode pemberian tugas. Namun cara penyampaian dan pelaksanaannya berbeda dengan siswa awas. Ada 3 tahap proses pembelajaran, yaitu: tahap perencanaan yang meliputi penentuan alokasi waktu, persiapan materi dan buku pembelajaran, juga persiapan media yang akan digunakan dalam proses belajar mengajar Tahap pelaksanaan meliputi penyajian materi dengan menggunakan metode ceramah, metode tanya jawab, metode demonstrasi, dan metode pemberian tugas. Tahap evaluasi meliputi waktu pemberian ujian, dan pelaksanaan evaluasi. Remedial tidak dilaksanakan. The goals of this research are to find out, describe, and analyze methods and implementation of music learning for the visually impaired students of VIII class at I Public Junior High School for the Physically Impaired at Pemalang. This research used qualitative approach. The finding shows that learning method of the visually impaired students is almost the same with that of regular public secondary schools, by means of lecturing, interview, demonstration method, task-assigning method. However, the deliverance and implementation of the learning is different from those of the regular students. Among the three stages of learning process include: planning which includes time allocation, material preparation, and learning materials, as well as media preparation for the learning and teaching process. The implementation stage includes topic presentation by lecturing, interview, demonstration and task-assigning methods. The evaluation stage includes time allocation for tests and evaluation implementation. Remedial test is not conducted