Pusan National University

About: Pusan National University is a education organization based out in Busan, South Korea. It is known for research contribution in the topics: Population & Catalysis. The organization has 24124 authors who have published 45054 publications receiving 819356 citations. The organization is also known as: Busan National University & Pusan University.

Azimuthal anisotropy of D-meson production in Pb-Pb collisions at √sNN=2.76 TeV

Abstract: The production of the prompt charmed mesons D0, D+, and D*+ relative to the reaction plane was measured in Pb-Pb collisions at a center-of-mass energy per nucleon-nucleon collision of √sNN=2.76TeV with the ALICE detector at the CERN Large Hadron Collider. D mesons were reconstructed via their hadronic decays at central rapidity in the transverse-momentum (p_T) interval 2–16 GeV/c. The azimuthal anisotropy is quantified in terms of the second coefficient v2 in a Fourier expansion of the D-meson azimuthal distribution and in terms of the nuclear modification factor R_AA, measured in the direction of the reaction plane and orthogonal to it. The v2 coefficient was measured with three different methods and in three centrality classes in the interval 0%–50%. A positive v2 is observed in midcentral collisions (30%–50% centrality class), with a mean value of 0.204+0.099−0.036 (tot. unc.) in the interval 2

Inclusive charged hadron elliptic flow in Au + Au collisions at √sNN=7.7–39 GeV

Abstract: A systematic study is presented for centrality, transverse momentum (p(T)), and pseudorapidity (eta) dependence of the inclusive charged hadron elliptic flow (v(2)) at midrapidity (vertical bar eta vertical bar < 1.0) in Au + Au collisions at root s(NN) = 7.7, 11.5, 19.6, 27, and 39 GeV. The results obtained with different methods, including correlations with the event plane reconstructed in a region separated by a large pseudorapidity gap and four-particle cumulants (v(2){4}), are presented to investigate nonflow correlations and v(2) fluctuations. We observe that the difference between v(2){2} and v(2){4} is smaller at the lower collision energies. Values of v(2), scaled by the initial coordinate space eccentricity, v(2)/epsilon, as a function of p(T) are larger in more central collisions, suggesting stronger collective flow develops in more central collisions, similar to the results at higher collision energies. These results are compared to measurements at higher energies at the Relativistic Heavy Ion Collider (root s(NN) = 62.4 and 200 GeV) and at the Large Hadron Collider (Pb + Pb collisions at root s(NN) = 2.76 TeV). The v(2)(pT) values for fixed pT rise with increasing collision energy within the pT range studied (<2 GeV/c). A comparison to viscous hydrodynamic simulations is made to potentially help understand the energy dependence of v(2)(pT). We also compare the v(2) results to UrQMD and AMPT transport model calculations, and physics implications on the dominance of partonic versus hadronic phases in the system created at beam energy scan energies are discussed.

An approach to developing domain requirements as a core asset based on commonality and variability analysis in a product line

Abstract: The methodologies of product line engineering emphasize proactive reuse to construct high-quality products more quickly that are less costly. Requirements engineering for software product families differs significantly from requirements engineering for single software products. The requirements for a product line are written for the group of systems as a whole, with requirements for individual systems specified by a delta or an increment to the generic set. Therefore, it is necessary to identify and explicitly denote the regions of commonality and points of variation at the requirements level. In this paper, we suggest a method of producing requirements that will be a core asset in the product line. We describe a process for developing domain requirements where commonality and variability in a domain are explicitly considered. A CASE environment, named DREAM, for managing commonality and variability analysis of domain requirements is also described. We also describe a case study for an e-travel system domain where we found that our approach to developing domain requirements based on commonality and variability analysis helped to produce domain requirements as a core asset for product lines.

High volumetric energy density annealed-MXene-nickel oxide/MXene asymmetric supercapacitor

Abstract: A Ti3C2Tx MXene electrode decorated with NiO nanosheets was synthesized by a facile and cost-effective hydrothermal method. The NiO nanosheets were grown and immobilized on the carbon-supported TiO2 layer which was derived from Ti3C2Tx-MXene during a thermal annealing process. An electrode based on the NiO-grown derived-TiO2/C-Ti3C2Tx-MXene nanocomposite (Ni-dMXNC) exhibited a remarkable maximum specific capacity of 92.0 mA h cm−3 at 1 A g−1 and 53.9 mA h cm−3 at 10 A g−1. Furthermore, an asymmetric supercapacitor (ASC) device composed of Ni-dMXNC as the positive electrode and Ti3C2Tx MXene as the negative electrode was demonstrated to be better with a high energy density of 1.04 × 10−2 W h cm−3 at a power density of 0.22 W cm−3, and cycling stability with 72.1% retention after 5000 cycles, compared to ASCs using previously reported Ti3C2Tx MXene materials. The enhanced capacitive performance is attributed to the newly formed high-surface-area multilayers of the Ni-dMXNC architecture, the active surface of NiO layer, and a favourable synergetic behaviour of the Ti3C2Tx MXene negative electrode.