Cooling of Hybrid Stars with Spin Down Compression

We study the cooling of hybrid stars coupling with spin-down. Due to the spin-down of hybrid stars, the interior density continuously increases, different neutrino reactions may be triggered(from the modified Urca process to the quark and nucleon direct Urca process) at different stages of evolution. We calculate the rate of neutrino emissivity of different reactions and simulate the cooling curves of the rotational hybrid stars. The results show the cooling curves of hybrid stars clearly depend on magnetic field if the direct urca reactions occur during the spin-down. Comparing the results of the rotational star model with the transitional static model, we find the cooling behavior of rotational model is more complicated, the temperature of star is higher, especially when direct urca reactions appear in process of rotation. And then we find that the predicted temperatures of some rotating hybrid stars are compatible with the pulsar's data which are contradiction with the results of transitional method.Comment: 8 pages, 5figures, accepted by RA

Hurst parameter analysis of radio pulsar timing noise

We present an analysis of timing residual (noise) of 54 pulsars obtained from 25-m radio telescope at Urumqi Observatory with a time span of 5~8 years, dealing with statistics of the Hurst parameter. The majority of these pulsars were selected to have timing noise that look like white noise rather than smooth curves. The results are compared with artificial series of different constant pairwise covariances. Despite the noise like appearance, many timing residual series showed Hurst parameters significantly deviated from that of independent series. We concluded that Hurst parameter may be capable of detecting dependence in timing residual and of distinguishing chaotic behavior from random processes.Comment: 7 pages, 3 figures, 2 tables, Submitted to MNRA

Model Rute dan Peta Interaktif Posyandu di Kota Semarang Menggunakan Geolocation dan Haversine Berbasis Mobile Android

Users of mobile phones with android operating system is increasing from year to year as more affordable. Thisgives the potential use of mobile phones as a means of disseminating information. As the capital of Central Java,Semarang has a variety of health care facilities which include Posyandu is always used by the surroundingcommunity. However, not all locations Posyandu known by the public because they lack information about thelocation. It is necessary for the navigation application Posyandu in Semarang. The purpose of this research ishow to design the application model and the location of Posyandu in real time with the geolocation methods andformulas Haversine. The method used is the Systems Development Life Cycle. System analysis model using UseCase Diagrams, Activity Diagrams, Sequence Diagrams and Class Diagrams. Results of this research is theapplication of navigation map based on Android mobile can provide information about the existence of thelocation, route and distance Posyandu. Results of this application is important for people who need drivingdirections Posyandu location. With this application is expected the results will help the public to obtaininformation and the location of the neighborhood health center (posyandu) in the city of Semarang can be met