Simple function form for n+208Pb total cross section between 5 and 600 MeV

The total cross section for neutron scattering from 208Pb with energies between 5 and 600 MeV has been analyzed extending a previously defined simple function of three parameters to reveal a Ramsauer-like effect throughout the whole energy range. This effect can be parametrized in a simple way so that it may be anticipated that the complete function prescription will apply for total cross sections from other nuclei.Comment: 9 pages, 4 firgure

Charge-exchange reaction cross sections and the Gamow-Teller strength for double beta decay

The proportionality between single charge-exchange reaction cross sections in the forward direction as found, for example from $(p,n)$ and $(^3$He,$t)$ and from $(n,p)$ and $(d,^2$He) reactions, and the Gamow-Teller (GT) strength into the same final nuclear states has been studied and/or assumed often in the past. Using the most physically justified theory we have at our disposal and for the specific example of the ${}^{76}$Ge-${}^{76}$Se system that may undergo double beta-decay, we demonstrate that the proportionality is a relative good assumption for reactions changing a neutron into a proton, i.e. ${}^{76}$Ge$(p,n){}^{76}$As. In this channel, the main contribution to the GT strengths comes from the removal of a neutron from an occupied single-particle (SP) state and putting a proton into an unoccupied SP state having either the same state quantum numbers or those of the spin-orbit partner. In contrast to this, in the second leg of the double beta decay a single proton must be taken from an occupied SP state and a neutron placed in an unoccupied one. This second process often is Pauli forbidden in medium-heavy nuclei and only can be effected if the Fermi surface is smeared out. Such is the case for ${}^{76}$Se$(n,p){}^{76}$As. Our results suggest that one may not always assume a proportionality between the forward-angle cross sections of the charge-exchange reactions and the GT strength in any such medium-heavy nuclei. The discrepancy originates from a pronounced effect of the radial dependence of the nucleon-nucleon ($NN$) interaction in connection with the Pauli principle on the cross sections in the $(n,p)$ reaction channel. Such a radial dependence is completely absent in the GT transition operator.Comment: 14 p., 7 fig

Pendidikan Kristen & Pembaratan: Kajian Terhadap Pendidikan Misi Protestan di Minahasa, 1830 - 1916.

The history of Christianity in Minahasa is closely related to colonialism. But colonialism not only affects the socio-political side of Minahasa society, but also the education system and schools. The history of Minahasa education is closely related to the activities of the Dutch Missionary Union or Nederlandsch Zendeling Genootschap (NZG). The implementation of educational programs, systems, and practices in Minahasa were carried out and pioneered by NZG, especially in the era of 1830 - 1918. Furthermore, we can see how Western-style education and NZG support intersect with various political dynamics in Dutch East Indies. Through historical research, this article examines the relationship between Western-style education and political dynamics of the Dutch East Indies in Minahasa society. This article offers an explanation and reflection in particular on mission education in Minahasa in relation to colonialism, the Western-style education system, the contribution of education, to the impact of education on the Minahasa community.Sejarah kekristenan di Minahasa berkelindan dengan kolonialisme. Tetapi kolonialisme bukan hanya mempengaruhi perkara sosial politik dalam masyarakat Minahasa, tetapi juga sistem pendidikan dan sekolah-sekolah yang terdapat di Minahasa. Sejarah pendidikan Minahasa begitu lekat kaitannya dengan kegiatan Serikat Misionaris Belanda atau Nederlandsch Zendeling Genootschap (NZG). Pelaksanaan program, sistem, dan praktik pendidikan yang di Minahasa banyak dilakukan dan dirintis oleh NZG, terutama dalam era 1830 - 1918. Lebih jauh lagi, NZG juga menjadi penyokong pendidikan ala Barat di Minahasa dengan menyediakan berbagai sarana hingga sumbangan pendidikan. Sehingga kita bisa melihat bagaimana pendidikan ala Barat dan dukungan NZG beririsan dengan berbagai dinamika politik Hindia Belanda. Melalui penelitian sejarah, artikel ini mengkaji relasi pendidikan ala Barat dengan dinamika politik Hindia Belanda dalam masyarakat Minahasa. Artikel ini menawarkan eksplanasi dan refleksi khususnya mengenai pendidikan misi di Minahasa dalam relasinya dengan kolonialisme, sistem pendidikan ala Barat, sumbangan pendidikan, hingga pengaruh pendidikan tersebut bagi masyarakat Minahasa

Approximate solution to the CGHS field equations for two-dimensional evaporating black holes

Callan, Giddings, Harvey and Strominger (CGHS) previously introduced a two-dimensional semiclassical model of gravity coupled to a dilaton and to matter fields. Their model yields a system of field equations which may describe the formation of a black hole in gravitational collapse as well as its subsequent evaporation. Here we present an approximate analytical solution to the semiclassical CGHS field equations. This solution is constructed using the recently-introduced formalism of flux-conserving hyperbolic systems. We also explore the asymptotic behavior at the horizon of the evaporating black hole

The future of annotation/biocuration

Talk given at 3rd International Biocuration Conference. Berlin 200

Charged null fluid and the weak energy condition

Uses the Einstein-Maxwell field equations to derive the fundamental equation of motion for charged null fluid. This equation of motion includes a Lorentz force term. Using this equation, it is shown that charged null fluid always satisfies the weak energy condition. This result is in contrast to previous interpretations of the charged Vaidya solution (a special case of a charged null fluid), which produced violations of the weak energy condition. The errors in the previous interpretations are explained. The new interpretation is then applied explicitly to the charged Vaidya solution