Ex) Article Title, Author, Keywords
pISSN 0374-4914
eISSN 2289-0041
pISSN 0374-4914
eISSN 2289-0041
Ex) Article Title, Author, Keywords
Abstract : New Physics searches using a high energy collider experiment should be performed systematically, especially when interpreting a new signal with a specific new Physics model among different possibilities. A data-driven method should be used in a model-independent way to capture all scenarios. In this article, we demonstrate how one can achieve a systematic and model-independent data analysis by separating an analysis on a new Physics signature into a phase space structure and matrix amplitude of a process. For instance, we consider a process with two visible particles and dark matter candidate signal at the high energy hadron collider. Finally, we recommend a proposed method to combine with a machine learning network and an algorithm to probe the broad scope of Physics beyond the standard model efficiently.
Abstract : The radiative proton capture on 15N targets, i.e., 15N(p, γ)16O, is an important thermonuclear reaction of the CNO cycle in stellar environments. This reaction is a key process in the cycle because it initiates the NO cycle by producing 16O. In this study, we investigated the 15N(p, γ)16O reaction within the framework of cluster effective field theory. We construct an effective Lagrangian to describe the reaction at stellar energies and calculate the astrophysical S factor. The parameters of our calculations, such as low-energy constants, resonance energy, and decay width of the 16O resonance are determined by fitting empirical data of the S factor at the range of 72.8 keV ≤ Ecm ≤ 368.3 keV. The S factor value for this reaction at extremely low energy is then determined to be S(E=0) = 30.4 keV·b, which is consistent with the estimates of R-matrix approaches.
Abstract : Epitaxial nickel cobaltite (NiCo2O4) (110) films were grown on magnesium aluminate (MgAl2O4) (110) at oxygen pressures ranging from 5 to 200 mTorr using pulsed laser deposition. Using X-ray diffraction, a shift in the (110) peak to a lower angle was suggested to have occurred as the oxygen pressure increased with a relatively large change in interplanar spacing at approximately 20 mTorr. The rocking curve supported the view that NiCo2O4 films had high crystallinity, and atomic force microscopy images suggested that films had few irregularities below 1 nm. The measurement of the magneto-optic Kerr effect suggested that the NiCo2O4 films were ferrimagnetic at room temperature and possessed a distinctive uniaxial in-plane magnetic anisotropy. As the oxygen pressure increased, the ferrimagnetic-to-paramagnetic transition temperature increased from ~305 to ~365 K. All of the films displayed metallic and ferrimagnetic properties. Consequently, an increase in oxygen pressure is likely to induce a decrease in oxygen defects and an increase in nickel(III) ion occupation of the octahedral sites, resulting in strengthening of the ferrimagnetic properties. In addition, this will presumably enhance lattice strain, resulting in a reinforcement of the magnetic anisotropy due to spin-lattice coupling.
Abstract : This study aimed to explore the potential and likely significance of introducing the action concept to college physics education. To do so, this study theoretically examined the usefulness of the action concept for learning physics, and then tested 39 pre-service physics teachers' understanding of the action concept. Their mean score for understanding a list of concepts related to the action concept was only 27%, and their understanding of action concepts that were related to possibility, path, and complex functions was particularly low. Although the most frequent question pattern was random model, in which both the score and concentration were low, some questions were analyzed into two model pattern, thereby highlighting the potential for misunderstanding occurring. There was a significant difference in the mean scores according to the physics-related subjects that the respondents had taken. The introduction of the action concept in college physics education has significance in that it can serve as an alternative explanation tool in both classic and quantum mechanics, and it is a concept that cuts across and connects classic and modern physics.
Abstract : SND@LHC is a new LHC experiment that measures neutrino production at the LHC and searches for feebly interacting particles. The experiment detects neutrinos with energies of 100 GeV - TeV using a hybrid detector of ECC composed of emulsion interleaved with tungsten target followed downstream by a muon system. SND@LHC measures neutrino production cross sections for three flavors and allows the examination of neutrino interactions in a pseudo-rapidity region of 7.2 < η < 8.6. The detector also functions to search for feebly interacting particles. SND@LHC is operated to collect 150 fb-1 of data for three years during Run 3 of the LHC to observe about 2,000 neutrinos.
Abstract : Nitrogen-doped molybdenum disulfide (N-MoS2) was synthesized using melamine as the nitrogen source to be used as a catalyst for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The as-synthesized N-MoS2 had an atomic nitrogen composition of 13%, and it exhibited a low overpotential of -0.20 V at -10 mA/cm2 for HER and 1.43 V at 10 mA/cm2 for OER, with small Tafel slope values of 97 and 117 mV/dec for HER and OER, respectively. The enhanced HER and OER performances observed as a result of the nitrogen doping of MoS2 is attributed to N-MoS2 being characterized by a higher electrochemical active surface area (9.1 × 10-4 cm2) and lower charge transfer resistance (8.1 Ω) than its precursor.
Abstract : Sonication is the process of agitating particles in many applications. In particular, electrochemical measurements need homogeneous solutions; thus, samples must be sonicated for 5 min, sometimes up to 1 h. Herein, we investigated the sonication effect on MoS2 particles systematically. MoS2 particles (2 μm) were sonicated for different times from 0 to 1 h, and the sonication effect was investigated using optical microscopy, scanning electron microscopy, X-ray diffraction, and electrochemical measurements. The results show an average particle size of ~2.07 ± 0.13 μm. Furthermore, the dispersion of MoS2 increased just after the sonication, but it returned to the initial state after some time, where the particles are distinguishable from the solvent. Therefore, researchers concluded that the 1-hr sonication does not affect the particle size of MoS2 particles.
Abstract : New Physics searches using a high energy collider experiment should be performed systematically, especially when interpreting a new signal with a specific new Physics model among different possibilities. A data-driven method should be used in a model-independent way to capture all scenarios. In this article, we demonstrate how one can achieve a systematic and model-independent data analysis by separating an analysis on a new Physics signature into a phase space structure and matrix amplitude of a process. For instance, we consider a process with two visible particles and dark matter candidate signal at the high energy hadron collider. Finally, we recommend a proposed method to combine with a machine learning network and an algorithm to probe the broad scope of Physics beyond the standard model efficiently.
Abstract : The radiative proton capture on 15N targets, i.e., 15N(p, γ)16O, is an important thermonuclear reaction of the CNO cycle in stellar environments. This reaction is a key process in the cycle because it initiates the NO cycle by producing 16O. In this study, we investigated the 15N(p, γ)16O reaction within the framework of cluster effective field theory. We construct an effective Lagrangian to describe the reaction at stellar energies and calculate the astrophysical S factor. The parameters of our calculations, such as low-energy constants, resonance energy, and decay width of the 16O resonance are determined by fitting empirical data of the S factor at the range of 72.8 keV ≤ Ecm ≤ 368.3 keV. The S factor value for this reaction at extremely low energy is then determined to be S(E=0) = 30.4 keV·b, which is consistent with the estimates of R-matrix approaches.
Abstract : A trend analysis was conducted on content knowledge problems in the Secondary School Physics Teacher Selection Test (SSPTST). The basic completion subjects in the SSPTST comprised classical mechanics, electromagnetism, quantum mechanics, wave and optics, thermal and statistical physics, and modern physics. We analyzed 384 problems during the academic period 2002–2021 based on the “Evaluation Areas and Evaluation Content Elements” developed by the Korean Institute of Curriculum and Evaluation. Furthermore, comparative analyses between the SSPTST and 2015 Revised National Science Curriculum (RNSC) as well as the SSPTST and curricula of Colleges of Education were conducted. The main results are as follows. (1) The most and least frequently tested subjects in the SSPTST are classical mechanics and modern physics, respectively. (2) There are some differences between the proportion of achievement standards for each subject in the 2015 RNSC and problems for the corresponding subject in the SSPTST. (3) The proportion of problems for each subject in the SSPTST is not in line with the number of credits for the corresponding subject offered in teachers’ colleges.
Abstract : Isomorphic multiple-choice items (IMCI) are a potential tool to diagnose students' misconceptions. This survey research aimed to identify the characteristics of students' responses on IMCI and diagnose students' misconceptions. The relationship between students' responses to diagnostic results and their success in solving open-ended items was also investigated. The IMCI consisted of nine multiple-choice items that were categorized into three IMCI groups according to the force and motion concepts covered in the questions. To evaluate the accuracy of IMCI diagnosis, an open-ended problem was also developed. Referring to their responses to the IMCI, students were classified into three groups: those who understand the concept, those who hold misconceptions, and those who are inconsistent. It was found that students who understand the concept well also demonstrated a high ability to solve the open-ended problem as shown by the average score of those students, which was the highest among the groups. The isomorphic scores were correlated sig¬nificantly with open-ended scores, while conventional scores did not show any significant correlation.
Abstract : This study aims to examine the considerations in Physics education in the era of the fourth industrial revolution, which will lead to rapid changes. This study addresses the lack of definition of the fourth industrial revolution. Thus, we focused on the features of hyper-convergence, hyper-connection, and super-intelligence, which characterize the future society. First, in the era of hyper-convergence, Physics education must be flexible enough to go beyond its original boundaries and pursue convergence with more diverse and heterogeneous disciplines. Second, in the hyper-connected era, Physics education must involve comprehensive learner diagnosis systems using big data and artificial intelligence as well as augmented and virtual reality. Finally, in the era of super-intelligence, Physics education must nurture creativity, sensitivity, and human character, which are unique human characteristics. In particular, it is imperative to think about the role of physical education in establishing human identity in the fourth industrial revolution era when a loss of humanity is expected.
Byeong-Hyeon JEONG, Ji-Sang PARK*
New Phys.: Sae Mulli 2020; 70(8): 630-636
https://doi.org/10.3938/NPSM.70.630
Woo Tae Hong, Hyun Kyoung Yang
New Phys.: Sae Mulli 2021; 71(3): 236-241
https://doi.org/10.3938/NPSM.71.236
Hyeong Seon PARK, Seong-Heum PARK, Hyunbok LEE, Heung-Sik KIM*
New Phys.: Sae Mulli 2020; 70(11): 920-927
https://doi.org/10.3938/NPSM.70.920
pISSN 0374-4914
