Bulk viscosity of Mixed nucleon-hyperon-quark Matter in Neutron stars

We calculate the coefficient of bulk viscosity by considering the non-leptonic weak interactions in the cores of hybrid stars with both hyperons and quarks. We first determine the dependence of the production rate of neutrons on the reaction rate of quarks in the non-leptonic processes, that is $\Gamma_{n}=K_{s}\Gamma_{s}+\Gamma_{\Lambda}+2\Gamma_{\Sigma^{-}}$. The conversion rate, $K_{s}$ in our scenario is a complicated function of baryon number density. We also consider medium effect of quark matter on bulk viscosity. Using these results, we estimate the limiting rotation of the hybrid stars, which may suppress the r-mode instability more effectively. Hybrid stars should be the candidates for the extremely rapid rotators .Comment: This paper contains 17 pages,8 figures and 1 table and is accepted by Monthly Notices of the Royal Astronomical Societ

Facebook's Mobile Career

At the end of its first decade, Facebook’s identity, popularity, and characteristics are shaped in important ways by its becoming a form of mobile media, as much as it as platform associated with Internet and social media. This paper seeks to explore and understand Facebook as the important force in mobile media and communication it now is. It draws upon and combines perspectives from technology production, design, and economy, as well as user adoption, consumption, practices, affect, emotion, and resistance. The paper discusses the beginnings of mobile Facebook, and the early adoption of mobile Facebook associated with the rise of smartphones. The second part of the paper explores Facebook’s integration with photography (with Instagram) and social games (such as Zynga’s Farmville). The paper argues that Facebook’s mobile career is an accomplishment that has distinctively melded evolving affordances, everyday use across a wide range of settings, as well as political economies, corporate strategy, and design.Australian Research Counci

The Big Meaning of Small Messages : The Use of WhatsApp in Intergenerational Family Communication

This study explores the use of WhatsApp instant messenger in extended families in two countries, Finland and Italy, that represent different family and communication cultures. Qualitative research material was collected in 2014/2015 from families consisting of three or more generations and living either in the same or different households. A directed approach to qualitative content analysis was applied in the analysis of the research data. The results of the study show that WhatsApp is considered to facilitate family interaction across generations. The success of WhatsApp in the family context accounts for two main factors: first, for the possibility to reach the whole family at once; and secondly, for its capacity to promote “phatic communion” via small messages. While utilizing various communicative modalities of WhatsApp (text and voice messages, photos, videos), family members take into account others’ preferences and communication skills.peerReviewe