Ex) Article Title, Author, Keywords
pISSN 0374-4914
eISSN 2289-0041
pISSN 0374-4914
eISSN 2289-0041
Ex) Article Title, Author, Keywords
Abstract : As an essential feature of doing science or physics, inquiry and laboratory work have been emphasized as both pedagogical goals and strategies. The discussion on what constitutes physics inquiry and laboratory work has philosophical, cultural and historical aspects and also reflects the relatively recent development of science curriculum. In this paper, I have reviewed how the notion of science inquiry and laboratory work has changed and elaborated on the recent emphasis on scientific practices in doing physics. The review has shown that students’ doing science or physics entails their epistemic agency while participating in scientific practices and sensemaking. Following the review, I have presented an empirical analysis of middle school science teachers’ facilitation, or lack thereof, of students’ sensemaking during scientific practices. The analysis revealed several strategies that facilitated students' sensemaking during scientific practices and underscored the critical role of teacher noticing in supporting students’ sensemaking. Further research topics are suggested in the conclusion.
Abstract : We present a quantitative three-dimensional (3D) measurement technique with an extended axial range using a partial coherence digital holography microscope (DHM). This method enables the extraction of 3D information from specimens by analyzing the reconstructed amplitude images, which inherently contain optical path difference (OPD) data modulated by the degree of coherence in the hologram plane. By utilizing partial coherence illumination, the proposed DHM approach effectively mitigates coherence noise, allowing for precise 3D measurements even for samples with step heights exceeding the wavelength of the light source used. As a proof of concept, we conducted 3D measurements on a stepwise sample, demonstrating the capability of our method to resolve fine structural details and measure significant height variations. This technique offers significant advantages for applications requiring accurate 3D profiling in the presence of coherence noise and large step heights.
Abstract : Ion trap is emerging as one of the key techniques in the field of quantum computing due to its high precision and long coherence time. This review covers recent research trends in quantum computing technologies based on ion trap, discussing the technological advancements in the control and operation of quantum bits (qubits). We deal with quantum state preparation, Rabi oscillations, and decoherence suppression methods within ion trap systems. Additionally, the potential and commercialization prospects of ion trap for realizing next-generation quantum computers are examined, along with its contributions to enhancing the performance of quantum computers. Compared to other quantum computing implementations, ion trap offers remarkable accuracy and scalability, and it is expected to play a crucial role in the development of next-generation high-performance quantum computers.
Abstract : In high-energy experiments, photo detectors using photomultiplier tubes require detection materials that absorb the energy of incident particles and convert it into an optical signal. These materials must exhibit high geometric efficiency, scintillation efficiency, and light output. The most common detection materials that satisfy these characteristics are utilized in the form of liquid scintillators where certain organic scintillation solutes are dissolved in a solvent. In order to achieve a high signal-to-noise ratio, this paper is focusing efforts on the development of next-generation liquid scintillators as detection materials and the saturation response of photomultiplier tubes to high-energy gamma rays as photo detector response characteristics. As a preliminary step towards achieving a high signal-to-noise ratio, to date, basic several research that has not been reported was performed on the recognition of detector output signal patterns and predictive maintenance of triggered detectors through signal preprocessing studies.
Abstract : Recently, researches on the various types of neuromorphic synaptic devices are attracting attention. In this paper, a synaptic device was fabricated and its characteristics were analyzed using a mesh-type platinum floating gate that mimics nanoparticles. Compared with single floating gates, mesh-type floating gates have a wider memory window and excellent electrical characteristics with improved operation speed and retention. Appropriate thickness conditions were set by checking the EOT (equivalent oxide thickness) and breakdown voltage of the tunnel oxide and control oxide using capacitance-voltage curves and a current-voltage curve. Excellent program and erase operation, synaptic weight, repeatability, reproducibility and memory window width were confirmed using the capacitance-voltage curves. It was compared whether the same performance was achieved even if part of the floating gate was damaged, suggesting the possibility of a synaptic device.
Abstract : As an essential feature of doing science or physics, inquiry and laboratory work have been emphasized as both pedagogical goals and strategies. The discussion on what constitutes physics inquiry and laboratory work has philosophical, cultural and historical aspects and also reflects the relatively recent development of science curriculum. In this paper, I have reviewed how the notion of science inquiry and laboratory work has changed and elaborated on the recent emphasis on scientific practices in doing physics. The review has shown that students’ doing science or physics entails their epistemic agency while participating in scientific practices and sensemaking. Following the review, I have presented an empirical analysis of middle school science teachers’ facilitation, or lack thereof, of students’ sensemaking during scientific practices. The analysis revealed several strategies that facilitated students' sensemaking during scientific practices and underscored the critical role of teacher noticing in supporting students’ sensemaking. Further research topics are suggested in the conclusion.
Abstract : The effects of sintering conditions, such as sintering temperature and cooling rate, on the piezoelectric properties of BiFeO3 (BFO) ceramics were investigated when preparing BFO piezoelectric ceramics using the solid-state reaction method. The BFO ceramics were sintered at 810 °C, 830 °C, and 850 °C, with cooling rates controlled by furnace cooling and air cooling at each temperature. BFO ceramics sintered at temperatures above 830 °C exhibited higher direct piezoelectric coefficients (d33) than those sintered at 810 °C, suggesting that piezoelectric properties are related to grain size. For BFO ceramics sintered above 830 °C, a faster cooling rate resulted in a higher d33 value. In contrast, for BFO ceramics sintered at 810 °C, a slower cooling rate produced a higher d33 value, due to difficulties in achieving polarization alignment during poling caused by the suppression of domain wall movement by charged defects.
Abstract : Herein, effect of p-GaN gate/u-GaN cap layer grown on AlGaN/GaN heterostructure was studied by dynamic conductance measurement. U-GaN cap layer thickness can give a strong effect on transfer curves, which is related to the AlGaN/GaN interface trap states. A thick u-GaN cap layer relaxes the strain across the AlGaN barrier, reducing the piezoelectric field, thereby lowering the two-dimensional electron gas (2DEG) density at the AlGaN/GaN interface. On the other hand, the thin u-GaN layer below 20-nm induces the shallow interface on the AlGaN/GaN interface. The inhomogeneous surface interface states due to the thin u-GaN causes the reduction of electron mobility, thereby results in a deterioration of drain current. Furthermore, the increased inhomogeneous interface trap states of the thin u-GaN cap layer appear to contribute to the relatively increased gate leakage current by the trap assisted tunneling.
Abstract : The scintillator of the small animal PET detector is very small and a long shape, so excellent spatial resolution can be achieved. However, this scintillation pixel causes a decrease in spatial resolution in the outskirts of the field of view. To solve this problem, in a previous study, we stacked scintillator blocks in four layers and inserted light guides with different reflector patterns between each layer to design a depth of interaction detector. In this study, we attempted to find the optimal combination of light guide thicknesses to obtain optimal flood images by composing various combinations of the thickness of the light guide used for each layer. For this, A detector was designed using DETECT2000, and the flood images evaluated for the degree of separation according to each light guide thickness combination. As a result, it was possible to find the optimal combination of light guide thicknesses, which improved the degree of separation by 52.26% compared to the original case.
Abstract : The differential cross sections of 386 MeV α-particles elastic scattering on 32S and 58Ni are analyzed within the framework of the eikonal model using the tangential velocity at the distance of closest approach. The calculation results successfully reproduce the structure of the experimental angular distributions, and are in good agreement with the measured data. The oscillatory structures observed around the crossing angle in angular distributions are explained in terms of the strong interference between the near-side and the far-side scattering amplitudes. The effect of using tangential velocity on the differential and reaction cross sections is investigated. Furthermore, the critical angular momentum, the strong absorption radius and the reaction cross section are examined.
Abstract : This study proposes a novel scientific inquiry model utilizing open data, developed through a review of relevant literature and the researchers’ direct engagement and reflective practice. The practical feasibility of this model was examined by conducting inquiry activities in collaboration with science teachers. The model is structured into three primary phases: ‘preparation’, ‘conducting scientific inquiry’, and ‘sharing and reflecting inquiry results’ with each phase further subdivided into multiple steps. Based on detailed feedback provided by the teachers regarding the open data inquiry model, the researchers offer several recommendations for the implementation and broader dissemination of scientific inquiry utilizing open data.
Abstract : In this study, we designed a system that quickly and accurately detects the location of a radiation source using a radiation spectroscopy detector. Since the use of a collimator is essential in conventional imaging systems, the imaging time is long due to very low sensitivity. To solve this problem, we designed a position measurement system that does not use a collimator. We used a method of measuring the location of a radiation source by placing a radiation spectroscopy detector at multiple locations and calculating the location based on the counts of the radiation. For the location evaluation, a Cs-137 was used and placed at multiple locations to measure the radiation, and the photoelectric peak was used as the counts and applied to the calculation formula. The location evaluation was performed at all 5 × 5 array, and as a result, the overall location accuracy was measured to be 82.65 ± 5.26% on average. If this system is installed in places where people gather and places where radiation sources are used, it is expected that it will be possible to establish a safe place by minimizing exposure to radiation sources through rapid detection of radiation sources.
Abstract : We present a quantitative three-dimensional (3D) measurement technique with an extended axial range using a partial coherence digital holography microscope (DHM). This method enables the extraction of 3D information from specimens by analyzing the reconstructed amplitude images, which inherently contain optical path difference (OPD) data modulated by the degree of coherence in the hologram plane. By utilizing partial coherence illumination, the proposed DHM approach effectively mitigates coherence noise, allowing for precise 3D measurements even for samples with step heights exceeding the wavelength of the light source used. As a proof of concept, we conducted 3D measurements on a stepwise sample, demonstrating the capability of our method to resolve fine structural details and measure significant height variations. This technique offers significant advantages for applications requiring accurate 3D profiling in the presence of coherence noise and large step heights.
Abstract : We present analytical solutions of susceptibility for the probe beam in open two-level atoms when co-propagating coupling and probe beams interact with atoms at weak laser intensities. The susceptibility for a stationary atom is averaged over the Maxwell–Boltzmann velocity distribution to calculate the susceptibility for Doppler-broadened atoms. The terms corresponding to electromagnetically induced absorption or transparency in susceptibility are calculated in an analytical form. In addition, it is confirmed that in order for electromagnetically induced absorption to appear, the decay rate from the excited state to the non-ground state must be smaller than that of the ground state.
Abstract : A Proton beam therapy is an advanced method of external radiation therapy that takes advantage of the Bragg peak. In this study, we used the Particle and Heavy Ion Transport code System (PHITS) simulation software to analyze how a proton beam interacts with a water phantom, an alternation of human tissue. A proton beam therapy has been used for several decades as the external radiation therapy method to benefit from the dose distribution of the linear energy transfer (LET). As LET increases there are more energetic electrons deposited closely together and thus damage to DNA is more likely. Therefore, even with the same radiation dose a high LET radiation will cause more damage (x-rays provide low LET; alpha particle and neutrons provide high LET). Suppose the radiation has a high LET. It means it gives off a large amount of energy quickly. The results show that a proton beam creates a strong peak, named the Bragg peak, at a specific depth, with minimal energy deposition before and after this peak.
Aekyung Shin, Donggeul Hyun, Jeongwoo Park
New Phys.: Sae Mulli 2023; 73(1): 37-43
https://doi.org/10.3938/NPSM.73.37
Geon Park, Inseo Kim, Hojung Sun, Yongjei Lee, Kimoon Lee, JungYup Yang
New Phys.: Sae Mulli 2023; 73(1): 23-28
https://doi.org/10.3938/NPSM.73.23
Sangwoo Ha
New Phys.: Sae Mulli 2023; 73(9): 734-749
https://doi.org/10.3938/NPSM.73.734
pISSN 0374-4914
