328 research outputs found
Equation of state of the neutron star matter, and the nuclear symmetry energy
The nuclear mean-field potentials obtained in the Hartree-Fock method with
different choices of the in-medium nucleon-nucleon (NN) interaction have been
used to study the equation of state (EOS) of the neutron star (NS) matter. The
EOS of the uniform NS core has been calculated for the np composition in
the -equilibrium at zero temperature, using version Sly4 of the Skyrme
interaction as well as two density-dependent versions of the finite-range M3Y
interaction (CDM3Y and M3Y-P), and versions D1S and D1N of the Gogny
interaction. Although the considered effective NN interactions were proven to
be quite realistic in numerous nuclear structure and/or reaction studies, they
give quite different behaviors of the symmetry energy of nuclear matter at
supranuclear densities that lead to the \emph{soft} and \emph{stiff} scenarios
discussed recently in the literature. Different EOS's of the NS core and the
EOS of the NS crust given by the compressible liquid drop model have been used
as input of the Tolman-Oppenheimer-Volkov equations to study how the nuclear
symmetry energy affects the model prediction of different NS properties, like
the cooling process as well as the gravitational mass, radius, and moment of
inertia.Comment: To be published in Physical Review
Post-mortem Reproduction from a Vietnamese Perspective—an Analysis and Commentary
Post-mortem reproduction is a complex and contested matter attracting attention from a diverse group of scholars and resulting in various responses from a range of countries. Vietnam has been reluctant to deal directly with this matter and has, accordingly, permitted post-mortem reproduction implicitly. First, by analysing Vietnam’s post-mortem reproduction cases, this paper reflects on the manner in which Vietnamese authorities have handled each case in the context of the contemporary legal framework, and it reveals the moral questions arising therefrom. The article then offers an account of Vietnamese social norms as an explanation for the tendency to conduct post-mortem reproduction. In arguing that a deeper and more thorough examination of the moral and ethical reasoning is required, the paper advocates in favour of supportive post-mortem reproduction regulation. In doing so, the paper seeks to reconcile the Vietnamese legal framework and post-mortem reproduction experiences of other countries. The article concludes that Vietnam and countries sharing the similar cultural traits should permit post-mortem reproduction explicitly. This would require full engagement with the ethical and legal issues arising, and careful promulgation of regulations and guidelines based on comparative experiences of a range of countries in handling this matter
Drift-diffusion modeling, analysis and simulation of organic semiconductor devices
We discuss drift-diffusion models for charge-carrier transport in organic semiconductor devices. The crucial feature in organic materials is the energetic disorder due to random alignment of molecules and the hopping transport of carriers between adjacent energetic sites. The former leads to so-called Gauss-Fermi statistics, which describe the occupation of energy levels by electrons and holes. The latter gives rise to complicated mobility models with a strongly nonlinear dependence on temperature, density of carriers, and electric field strength. We present the state-of-the-art modeling of the transport processes and provide a first existence result for the stationary drift-diffusion model taking all of the peculiarities of organic materials into account. The existence proof is based on Schauder's fixed-point theorem. Finally, we discuss the numerical discretization of the model using finite-volume methods and a generalized Scharfetter-Gummel scheme for the Gauss-Fermi statistics
Startup Learning Community Approach: Case Study in Vietnam
Group B: Quality of Education and Educational Polic
Teacher Professional Development in the Context of Education Reform in Vietnam: Policy and Practice
Teacher Professional Development (TPD) plays an important role in the Fundamental and Comprehensive Education Reform in Vietnam. The goal of this study is to describe the situation of TPD in the context of education reform in Vietnam: Describe both the reform policies and practice in school. This study emphasized that Vietnam has actively implemented education policies relating to TPD. Three-dimensional evaluation of TPD included: (i) Teaching plans and materials; (ii) Organization of learning activities; and (iii) Students’ activities. The research results showed a positive moderate to the high correlation between teaching plans and materials and organization of learning activities and Students’ activities. The research results showed an inverse correlation between the average teacher age and the Organization of learning activities. The older teachers tended to underestimate the extent of implementation of Organization of learning activities. This finding led to recommendations to provide older teacher groups with professional development activities
The situation and solutions to develop Green Building in Vietnam
Housing in Vietnames megacities is quite expensive due to limited land availability. Besides, green housing investment requires higher implementation costs than non-green housing investments, plus a Green Building certification fee implemented by international organizations. Despite specific difficulties and problems, green real estate projects bring economic benefits to both investors and users in the long run.
Green building development is a trend that is particularly interested in by governments and real estate developers.
Through analyzing the current status of Green Building development in Vietnam, the authors have discovered barriers, limitations, and proposed solutions.
To develop green buildings effectively, investors need to operate a 5-step process throughout the project life cycle, including Green planning — Green design — Green construction — Green operation — Green lifestyle. Using environmentally friendly materials, energy-saving efficiency in green housing is no longer an unattainable dream for urban residents in Vietnam
Effects of different feeds and stocking densities on growth and survival rates of mud crab (<em>Scylla paramamosain</em>) at the stage from megalopa to crablet-1
Mud crabs (Scylla genus) are luxury foods in high demand internationally. The efficient techniques for mud crab hatcheries are vital for providing breeds for their aquaculture, which is rapidly growing in many countries. This study aims to investigate the effects of different feeds and stocking densities on mud crabs' growth and survival rates (Scylla paramamosain) in the stage from megalopa to crablet-1 stage. Two separate experiments were conducted indoors in the 60-liter round plastic tanks (containing 50 liters of water at a 28‰ salinity). Experiment 1 investigated four feeds: frozen Artemia biomass, pureed shrimp meat, Lansy pellet feed (48% protein), and NRD pellet feed (55% protein). Megalopae (mean weight of 5.8 mg) were stocked at a density of 10/L. In experiment 2, the megalopae (mean weight of 5.4 mg) were stocked at densities of 20, 30, and 40/L and were fed the Lansy pellet feed, which was the best one selected from experiment 1. High survival rates were obtained at all four feeds (82.2–87.5%) and three stocking densities (88.4–90.1%). The growth performances in Lansy feed and frozen Artemia biomass were better than those in pureed shrimp meat and NRD pellet feed, which was seen through higher indicators of daily weight gain (DWG) and specific growth rate in weight (SGRw) (p p > 0.05). The investigated feeds and stocking densities suit the nursing mud crab (S. paramamosain) megalopa. In contrast, the Lansy pellet feeds had a stocking density of 20/L, resulting in the highest nursing efficiency
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