179 research outputs found
Spectral properties of the surface reflectance of the northern polar region of Mercury
We analyse MESSENGER reflectance measurements covering the northern polar
region of Mercury, the least studied region of the northern mercurian
hemisphere. We use observations from the Mercury Dual Imaging System Wide-Angle
Camera (MDIS/WAC) and the Mercury Atmospheric and Surface Composition
Spectrometer (MASCS/VIRS) to study the spectral dependence of the surface
reflectance. The results obtained from the observations made by both
instruments are remarkably consistent. We find that a second degree polynomial
description of the measured reflectance spectra gives very good fits to the
data and that the information that they carry can best be characterized by two
parameters, the mean reflectance and the mean relative spectral slope, averaged
over the explored range of wavelengths. The properties of the four main types
of terrains known to form Mercury's regolith in the northern region, smooth
plains (SP), heavily cratered terrain (HCT), fresh ejecta/materials and red
pitted ground (RPG) are examined in terms of these two parameters. The results
are compared, and found consistent with those obtained by earlier studies in
spite of difficulties met in obtaining accurate reflectance measurements under
the large incidence angle condition characteristic of polar regions. These
results will help with the preparation of the BepiColombo mission and with
supporting its observational strategy.Comment: 21 pages, 15 figures, accepted for publication in Research in
Astronomy and Astrophysic
Further Discussion On Applying Case Study Method In Investment Law Course – A Case Of Education Investment In Vietnam
Purpose: The aim of this study is to focus on clarifying using case study method to improve taching
law course. Currently, many universities around the world are applying a new teaching method. It
can help students absorb knowledge more efficiently and faster. That is the case study. Using a Case
Study allows a deeper understanding of cases as a unit, through comparing the similarities and
differences of individual cases.
Design/methodology/approach: The study uses qualitative analysis, synthesis and inductive
methods, together with studies and references from CPTPP, FTA Agreement, as well as Regulations
on assurance of business investment activities.
Findings: The application of this method to teaching helps learners to approach very applicable
situations. The situations or problems close to the theory will also help them to systematize all the
knowledge they have learned to apply to solve the assigned problem. Not only use the knowledge
learned, but also learn related knowledge outside the program to solve the problem. Case Study is
an extremely interesting and interesting learning method, helping us to associate reality and apply it
to solve problems and help us remember longer. If you really understand what a case study is, then
apply it to your life and work. The results show the regulations on guaranteeing ownership rights as
well as ensuring investors' business investment activities have been clearly stipulated in the 2020
Labor Law of Vietnam. These regulations have concretized the constitutional principle of investors'
freedom to invest and do business in industries that are not prohibited by la
The VATLY Radio Telescope
A small radio telescope (SRT) has been installed on the roof of the Hanoi astrophysics laboratory VATLY. It is equipped with a 2.6 m diameter mobile parabolic dish remotely controlled in elevation and azimuth and with super-heterodyne detection around the 21 cm hydrogen line. First results of observations of the Sun and of the centre of the Milky Way are presented. They demonstrate the high quality of the telescope performance and are used to evaluate lobe size, signal to noise ratios, anthropogenic interferences and measurement accuracies. Particular attention is given to the measurement of the pointing accuracy. The rich measurement programme that is now at hand is briefly sketched
Simulation of proton-induced and iron-induced extensive air showers at extreme energies
The development of extensive air showers at extreme energies is studied using
a simulation model much simpler and cruder, but also more transparent and
flexible, than existing sophisticated codes. Evidence for its satisfactory
performance is presented. As an illustration, shower elongation rates are
evaluated in the to eV region and compared with recently
published data. Lateral distribution functions of both muons and
electrons/photons are also briefly discussed. Reliable results are obtained in
the comparison between proton-induced and iron-induced showers.Comment: 22 pages, Preprint submitted to Astroparticle Physic
Numerical modeling of thermal dust polarization from aligned grains in the envelope of evolved stars with updated POLARIS
Magnetic fields are thought to influence the formation and evolution of
evolved star envelopes. Thermal dust polarization from magnetically aligned
grains is potentially a powerful tool for probing magnetic fields and dust
properties in these circumstellar environments. In this paper, we present
numerical modeling of thermal dust polarization from the envelope of IK Tau
using the magnetically enhanced radiative torque (MRAT) alignment theory
implemented in our updated POLARIS code. Due to the strong stellar radiation
field, the minimum size required for RAT alignment of silicate grains is . Additionally, ordinary paramagnetic grains can achieve
perfect alignment by MRAT in the inner regions of due to
stronger magnetic fields of mG - 1G, producing thermal dust
polarization degree of . The polarization degree can be enhanced
to for grains with embedded iron inclusions. We also find that
the magnetic field geometry affects the alignment size and the resulting
polarization degree due to the projection effect in the plane-of-sky. We also
study the spectrum of polarized thermal dust emission and find the increased
polarization degree toward due to the alignment of
small grains by MRAT. Furthermore, we investigate the impact of rotational
disruption by RATs (RAT-D) and find the RAT-D effect cause a decrease in the
dust polarization fraction. Finally, we compare our numerical results with
available polarization data observed by SOFIA/HAWC+ for constraining dust
properties, suggesting grains are unlikely to have embedded iron clusters and
might have slightly elongated shapes. Our modeling results suggest further
observational studies at far-infrared/sub-millimeter wavelengths to understand
the properties of magnetic fields and dust in AGB envelopes.Comment: 27 pages, 23 figures, 1 table, to be submitte
Evaluation of Lecture Hall Service and Infrastructures Construction Rules of Vietnam Universities Via A Case of Neu in Hanoi
Building a university design regulations and standards is not only necessary for units in the industry but also contributes to bringing to society modern educational models, suitable to the economic conditions of the country. The standard applies to the design, renovation and new design of university buildings throughout Vietnam, based on the document issued by the Ministry of Construction No. TCVN 3981:1985. This paper also suggest: Improve the quality of the teaching /lecture service staff. First, Develop a reasonable monitoring, evaluation and reward mechanism to motivate people to work hard; Second, Each faculty member on duty has a job description with clear responsibilities, rights and obligations; Third, Conduct ongoing training. It is necessary to regularly organize training and training courses on serving, communicating, and dealing with customers
Factors affecting ecotourism loyalty with the moderating role of social influence - Empirical evidence in Vietnam
Today, ecotourism has become more common and attractive for tourists who love to explore nature and experience the cultural heritage. In the 4.0 age of technology, social networking not only helps visitors find suitable destinations to visit easily but also provides visitors with a place to leave comments or reviews after the trips. This study aims to qualify the relationships between electronic-worth-of-mouth (eWOM), social influence (SI), destination image (DI), tourist satisfaction (SAT), and ecotourism loyalty (EL). The study applied the PLS-SEM model to estimate 499 observations at ecotourism sites in Vietnam as empirical evidence. The research results show that all the factors in the research model have positive and significant effects on EL. In particular, DI and SAT, directly and indirectly, affect EL; while eWOM and SI only have direct effects on EL. Additionally, it was found that the effect of eWOM on EL increased with the moderating role of SI. © 2022 Editura Universitatii din Oradea. All rights reserved.Univerzita Tomáše Bati ve Zlín
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