Constant entropy hybrid stars: a first approximation of cooling evolution

We aim to study the possibility of a hadron-quark phase transition in the interior of neutron stars, taking into account different schematic evolutionary stages at finite temperature. We also discuss the strange quark matter stability in the quark matter phase. Furthermore, we aim to analyze the astrophysical properties of hot and cold hybrid stars, considering the constraint on maximum mass given by the pulsars J1614-2230 and J0348+0432. We have developed a computational code to construct semi-analytical hybrid equations of state at fixed entropy per baryon and to obtain different families of hybrid stars. An analytical approximation of the Field Correlator Method is developed for the quark matter equation of state. For the hadronic equation of state we use a table based on the relativistic mean field theory, without hyperons. We solved the relativistic structure equations of hydrostatic equilibrium and mass conservation for hybrid star configurations. For the different equations of state obtained, we calculated the stability window for the strange quark matter, lepton abundances, temperature profiles and contours profiles for the maximum mass star depending on the parameters of the Field Correlator Method. We also computed the mass-radius and gravitational mass-baryonic mass relationships for different hybrid star families. We have analyzed different stages of hot hybrid stars as a first approximation of the cooling evolution of neutron stars with quark matter cores. We obtain cold hybrid stars with maximum masses $\geq 2 M_\odot$ for different combinations of the Field Correlator Method parameters. In addition, our study based on the gravitational mass - baryonic mass plane shows a late phase transition between hadronic and quark matter during the proto-hybrid star evolution, in contrast with previous studies of proto-neutron stars.Comment: 12 pages, 14 figures, published in A&A 601, A21 (2017

Manajemen Kelompok Tani Petani Sayuran dalam Mendukung Ketahanan Pangan Kota Banjarbaru

Banjarbaru Municipality, from a spatial perspective, has a strategic role as a primary node of commodities distribution chain in South Kalimantan Province, because it is located between two main consumption centers, that are: Banjarmasin (the biggest consumption center) and Martapura. Beside as a consumption center, Banjarbaru also plays as an agricultural production center, especially vegetables. The study is purposed to know the management of the vegetable farmer group in order to promote food security in Banjarbaru Municipality. The population in the study was vegetable farmer groups. The samples were selected trough random sampling method. Generally, the management of the vegetable farmer group is in good condition (77.84%), planning (64.66%), organizing (85.89%), actuating (77.13%), and evaluation (65.55%). This shows that farmer group management able to support food security in Banjarbaru. For better management in a vegetable farmer group, it is suggested to increase the capability of planning in yields processing and marketing; and in recording farm activities

Dirichlet's and Thomson's principles for non-selfadjoint elliptic operators with application to non-reversible metastable diffusion processes

We present two variational formulae for the capacity in the context of non-selfadjoint elliptic operators. The minimizers of these variational problems are expressed as solutions of boundary-value elliptic equations. We use these principles to provide a sharp estimate for the transition times between two different wells for non-reversible diffusion processes. This estimate permits to describe the metastable behavior of the system

Fractional charges in pyrochlore lattices

A pyrochlore lattice is considered where the average electron number of electrons per site is half--integer, concentrating on the case of exactly half an electron per site. Strong on-site repulsions are assumed, so that all sites are either empty or singly occupied. Where there are in addition strong nearest--neighbour repulsions, a tetrahedron rule comes into effect, as previously suggested for magnetite. We show that in this case, there exist excitations with fractional charge (+/-) e/2. These are intimately connected with the high degeneracy of the ground state in the absence of kinetic energy terms. When an additional electron is inserted into the system, it decays into two point like excitations with charge -e/2, connected by a Heisenberg spin chain which carries the electron's spin.Comment: 10 pages, 4 eps figures. To appear in Decemeber issue of Annalen der Physi

Praktik Senam Hamil Hubungannya dengan Kelancaran Proses Persalinan

Maternal Mortality Rate (MMR) in Indonesia is higher than other countries, even among Asian countries. Exercise during pregnancy is the one of method to prepare delivery process and further is to prevent maternal death. The objective of this research is to analyze relationship between knowledge and practice of pregnancy exercise, also relationship between practice of pregnancy exercise and delivery process. This was a cross sectional research. Moreover, the population involve in this research were all primi para (mother that having first pregnancy) that recorded at Jagir Public Health Service Centre in Surabaya. The samples were taken by simple random sampling method. Furthermore, the relationship among variables was analyzed using chi square and fisher exact test. The result shows that there was no relationship betweenknowledge and practice of pregnancy exercise (p = 0.060), but there was a relationship between practice of pregnancy exercise and delivery process (p = 0.000). According to result of the research, its suggested that health promotion by doing pregnancy exercise should be developed because it can prepare physically and psychologically of delivery process and reduce the risk of maternal death.Key words: knowledge, pregnancy exercise, delivery proces