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Detectability of exomoons by examining the signals from a model of transiting exoplanets with moons

Journal of physics: Conference Series 2022年第1期2145卷

作者： P Cherdwongsung S Awiphan P Kittara K Matan N Nakharutai Master's Degree Program in Physics Department of Physics Faculty of Science Mahidol University Bangkok 10400 Thailand National Astronomical Research Institute of Thailand (Public Organization) Chiang Mai 50180 Thailand Department of Physics Faculty of Science Mahidol University Bangkok 10400 Thailand Department of Statistics Faculty of Science Chiang Mai University Chiang Mai 50200 Thailand

Exomoons are natural satellites of exoplanets. Nowadays, none has been confirmed. However, a number of detection techniques have been proposed, including Transit Timing Variations (TTV) and Transit Duration Variations (TDV) techniques. From a recent study, fitting observed transit with the traditional photocentric fitting model shows unique features around the primary and secondary exomoon transits in TDV and transit depth signals, which might reduce the detectability. The aim of this work is to retrieve the variation of TTV, TDV and transit depth signals of exomoon systems with the photocentric fitting model. One year star-planet-moon transit light curves are simulated with LUNA algorithm and fit with TransitFit. The results show that neglecting the TDV and transit depth data with phase around exomoon's primary and secondary transits improve the exomoon detectability by a factor of ten and the systems with large moon orbital semi-major axis with nearly edge-on orbit around low mass stars can be detected.

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Investigation of electron energy spread effects on the intracavity MIR-FEL power at the PBP-CMU electron linac laboratory

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Journal of physics: Conference Series 2021年第1期1719卷

作者： S Sukara H Ohgaki S Rimjaem Master Degree Program in Physics Faculty of Science Chiang Mai University (CMU) Chiang Mai Thailand Plasma and Beam Physics (PBP) Research Facility Department of Physics and Materials Science Faculty of Science Chiang Mai University Chiang Mai (CMU) Thailand Thailand Center of Excellence in Physics Ministry of Higher Education Science Research and Innovation Bangkok 10400 Thailand Institute of Advanced Energy Kyoto University Kyoto Japan

At the PBP-CMU Electron Linac Laboratory, the existing linear accelerator system is under developing to produce electron beams with suitable properties for generation of oscillator mid-infrared free-electron laser (MIR-FEL) and super-radiant terahertz (THz) undulator radiation. This work focuses on the simulation of the oscillator MIR-FEL with expected electron beam energy of 20 – 25 MeV to evaluate the required electron beam parameters. To achieve FEL saturation, the single-pass FEL simulation using the code GENESIS 1.3 was performed to estimate the laser wavelength, FEL gain and electron macro-pulse duration. In the simulation, electron beams with energy spread of 0, 0.5 and 1.0 %, and the electron peak current of 25 and 50 A were considered. As a result, the electron beam with energy of 20 – 25 MeV can produce the FEL wavelengths of 13.5 – 21.2 µm using a 1.6-m undulator with maximum undulator parameter of 1.07. The largest FEL gain is 216% when using electron beam energy and peak current of 20 ± 0% MeV and 50 A, which requires the electron macro-pulse duration of 1.6 µs to saturate FEL. Due to the possible macro-pulse duration at our facility of 6 µs, the operation of electron beam with energy spread of 0.5% and peak current of higher than 25 A is required to saturate FEL. Results from this single-pass simulation can be used as a based information for further practical consideration with multi-pass simulation.

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Effects of heat treatments on the microstructure and hardness of thermally sprayed Ni-Cr-Mo-Al alloy coating

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Journal of physics: Conference Series 2021年第1期1719卷

作者： A Srichen C Banjongprasert Master's Degree Program in Materials Science Faculty of Science Chiang Mai University Chiang Mai Thailand Department of Physics and Materials Science Faculty of Science Chiang Mai University Chiang Mai Thailand Center of Excellence in Materials Science and Technology Chiang Mai University Chiang Mai Thailand

Thermal spray coating is one of the technologies used to prevent corrosion and wear by creating a protective layer on the substrate. From previous research, the microstructure of arc-sprayed nickel-chromium-molybdenum-aluminium (Ni-Cr-Mo-Al) after heat treatment at 1100°C was investigated. It was found that the corrosion rate of this coating under 20vol%H2SO4 was reduced by 97%. However, the heat treatment at high temperatures is still limited to industrial applications. Therefore, this research will focus on studying microstructure and properties after heat treatment at moderately high temperatures, which are in a range of service temperature. Specimens were arc sprayed and heat treated at 300, 400, 500, 600 and 700°C and characterized by Scanning Electron Microscopy (SEM) with Energy Dispersive X-ray Spectroscopy (EDS) technique. Phases were analyzed by X-ray diffraction (XRD). There was no significant change of γ-Ni grains after heat treated at 600°C for 10 days from the Electron Backscattered Diffraction (EBSD) study. The hardness of the coatings increased after heat treatments due to a reduction in porosity, an increase of oxides and the formation of MoSi2.

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Effects of processing parameters on microstructure and properties of aluminum-silicon alloy ADC12 7th

Effects of processing parameters on microstructure and prope...

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7th International Conference on Advanced Materials and Engineering Materials, ICAMEM 2018

作者： Charoenrut, Kasem Banjongprasert, Chaiyasit Master's Degree Program in Materials Science Department of Physics and Materials Science Faculty of Science Chiang Mai University Chiang Mai50200 Thailand Department of Physics and Materials Science Faculty of Science Chiang Mai University Chiang Mai50200 Thailand

ISBN: (纸本)9783035713718

Aluminum-Silicon Alloy, ADC12 is one of the most popular alloys for pressure die casting due to its high castability and high productivity. ADC12 is a hypoeutectic aluminum-silicon alloy that contains 10-12wt% of Si and has an occasional problem for a mechanical properties failure such as crack and shrinkage porosity. This study presents the investigation of the microstructure of ADC12 parts produced by pressured die casting with different process parameters and chemical compositions. The microstructure was observed using optical microscopy (OM) and scanning electron microscopy (SEM) with energy - dispersive X-ray (EDX) and electron backscatter diffraction (EBSD) to determine phases, grain, and crystallographic information in order to understand the microstructural evolution after die casting with different process conditions. Changes in casting pressure and a reduction of iron content contributed to enhanced mechanical properties and less shrinkage porosity. This was due to different processing parameters, mainly casting pressure. The average grain size of aluminum matrix was also reduced due to a higher pressure during casting with a moderately fast cooling rate. © 2018 Trans Tech Publications.

关键词： Die casting

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Microstructure and properties of arc sprayed Zn-Al alloy coatings

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Journal of physics: Conference Series 2021年第1期1719卷

作者： T Kaewpradit D Yutthakamthon W Pongsaksawad P Sheppard H Koiprasert C Banjongprasert Master's Degree Program in Materials Science Faculty of Science Chiang Mai University Chiang Mai Thailand Department of Physics and Materials Science Faculty of Science Chiang Mai University Chiang Mai Thailand National Science and Technology Development Agency Pathum Thani Thailand Center of Excellence in Materials Science and Technology Chiang Mai University Chiang Mai Thailand

In this study, zinc-aluminum alloy coatings were deposited on low carbon steel substrates by arc thermal spraying with different current and spraying distances. Optical microscope (OM) was used to characterize the deposited coatings. From the experiment, it is found that the samples that use different electric currents and spraying distances result in the different microstructure of the coating surfaces and different mechanical properties. The sample that uses higher current tends to have a higher hardness than the sample with a lower electric current at the same spraying distance.

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Design and development of photonic-based non-invasive hemoglobin level detector

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AIP Conference Proceedings 2020年第1期2314卷

作者： Suryani Dyah Astuti Ikhsan Rino Wijaya Osmalina Nur Rahma Alfian Pramudita Putra Muhammad Fahmi Akif Rahmatillah Riries Rulaningtyas 1Biomedical Engineering Master Degree Department of Physics Faculty of Science and Technology Universitas Airlangga Surabaya Indonesia 2Department of Physics Faculty of Science and Technology Universitas Airlangga Surabaya Indonesia 3Biomedical Engineering Study Program Department of Physics Faculty of Science and Technology Universitas Airlangga Surabaya Indonesia

Hemoglobin is the protein molecule that binds oxygen in the blood. Hemoglobin level can be used as a benchmark of the human physiological condition, such as anemia, hypoxia, and postoperative bleeding. Generally, measurement of hemoglobin levels is performed by an invasive method that takes blood samples to be tested. This study offers a tele-monitoring system for measuring the hemoglobin level non-invasively, so it could reduce the possibility of infection or contamination to the body and can be monitored anywhere by using a website. This tele-monitoring device of non-invasive hemoglobin and oxygen saturation levels were designed by integrating the pulse oximetry sensor with signal conditioning circuit, Arduino Uno as a microcontroller, Ethernet module, an internet network, cloud server, and website. Pulse oximetry measured the oxygen saturation in the blood that indicate the vital state of human and became essential to determine the amount of hemoglobin level. The system performance in this study was tested on participants who had a good daily exercise and participants who never had daily activities to discover the correlation between hemoglobin levels with human physical activity and obtained 89% of accuracy. This system can be implemented as a personal device for monitoring the hemoglobin level and the oxygen saturation in daily used.

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Physical properties distribution of galaxy population in Abell 2142 cluster

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Journal of physics: Conference Series 2019年第1期1380卷

作者： Kledsai Poopakun Wichean Kriwattanawong Master's Degree Program in Astronomy Faculty of Science Chiang Mai University Chiang Mai 50200 Thailand Department of Physics and Materials Science Faculty of Science Chiang Mai University Chiang Mai 50200 Thailand

In this work, we investigate the physical properties of galaxies in Abell 2142 using photometric and spectroscopic data from the Sloan Digital Sky Survey (SDSS). The sample was selected by two criteria: redshift of 0.0781 ≤ z ≤ 0.1038 and the location within a radius of 100 arcminutes from the cluster centre. We found that the sample distributes into 2 groups, a foreground filament galaxies with z ≤ 0.085 and the cluster members with z > 0.085. The relation between apparent magnitude in g filter band and u – z colour suggests that we can use the u – z equals 3.2 as a criterion to separate galaxies into blue (u – z ≤ 3.2) and red (u – z > 3.2) sequence galaxies. Moreover, blue sequence galaxies have higher value of equivalent width of hydrogen alpha corresponding to higher star forming activity than red sequence galaxies. The nearby filament contains higher fraction of star forming galaxies (65%) than the cluster Abell 2142 galaxy members (46%). This could be due to difference of the environmental effect.

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Impedance measurement system simulation for trapped cell model in various microwell geometries

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Journal of physics: Conference Series 2019年第1期1380卷

作者： Sorawit Sanin Chupong Pakpum Nirut Pussadee Master's Degree Program in Physics Faculty of Science Chiang Mai University Chiang Mai 50200 Thailand Program in Applied Physics Faculty of Science Maejo University Chiang Mai 50290 Thailand Plasma and Beam Physics Research Facility Department of Physics and Materials Science Chiang Mai University Chiang Mai 50200 Thailand Thailand Center of Excellence in Physics Commission on Higher Education Bangkok 10400 Thailand

Single cell analysis is a measurement or detection of individual cell properties and responses. The method is of significance due to stimulated responses of any individual cell are different depending on their morphology and functionality. Therefore, detected properties from a group of cells cannot be used to represent that of the individual cell. Since cells can move freely in a microfluidic system, a trap must be added to the system to fix the cell position at the detection region for long period observation and assay. One of the most popular used cell trap in the biomedical field is a microwell array. A sensitive technique for measuring single cell properties is an impedance measurement, in which small change in electrical properties of the cell and the surrounding medium between excitation and pick-up electrodes is recorded. However, the microwell placed between two electrodes acts as an electrical insulator to reduce the signal passing through the system. This paper focuses on the effect of microwell geometry parameters generated from the design of experiments (DOE) software on detected signals using finite element simulation software. The study found that the microwell wall thickness affects the detected current signal most significantly and the optimized geometry that minimally reduces measured current signal was 20 µm height, 5 µm well thickness, and 16 µm gap size.

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Simulation of square-frame dipole coils for steering of electron beam

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Journal of physics: Conference Series 2019年第1期1380卷

作者： K Kongmali S Rimjaem Plasma and Beam Physics Research Facility Department of Physics and Materials Science Faculty of Science Chiang Mai University Chiang Mai 50200 Thailand Master Degree Program in Physics Department of Physics and Materials Science Faculty of Science Chiang Mai University Chiang Mai 50200 Thailand Thailand Center of Excellence in Physics Commission on Higher Education Bangkok 10400 Thailand

This study focuses on magnetic field simulation of a square-frame steering magnet and electron beam dynamic simulations in its magnet's field at the PBP-CMU Electron Linac Laboratory, Chiang Mai University. The small dipole magnets with the same design were constructed from four identical iron bars winding with 70 turns of copper-wire. They are used for steering electron beam with a maximum kinetic energy of about 2.0 MeV in the pre-injectors system of the electron accelerator. The magnetic field simulations were conducted by using computer programs POISSON and RADIA for two-dimensional and three-dimensional models, respectively. The maximum magnetic fields at an excitation current of 1 A were 44.30 and 57.32 Gauss for the 2D and 3D models, respectively. The magnetic effective length was 10.45 cm. The electron beam dynamic simulations in the 3D magnetic field map was performed by utilizing a computer program ASTRA to investigate the transverse electron beam distribution along the magnetic axis. The achievement of this study will be used as an important information for proper operation of the magnets at our facility.

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Design of radiation shielding for the 4-MeV RF linac using the Monte Carlo simulation

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Journal of physics: Conference Series 2019年第1期1380卷

作者： P Jaikaew S Rimjeam Plasma and Beam Physics Research Facility Department of Physics and Materials Science Faculty of Science Chiang Mai University Chiang Mai 50200 Thailand Master Degree Program in Physics Department of Physics and Materials Science Faculty of Science Chiang Mai University Chiang Mai 50200 Thailand Thailand Center of Excellence in Physics Commission on Higher Education Bangkok Thailand 10400

A radio-frequency (RF) linear accelerator (linac) and related system for irradiation of electron beam on natural rubber is under the commissioning at the PBP-CMU Electron Linac Laboratory, Chiang Mai University. The maximum kinetic energy of electron beam that can be achieved from the accelerator is about 4 MeV. The bremsstrahlung radiation in the x-ray regime is produced when electrons interact with materials in the beam path. The radiation with the dose exceeding the regulation limit can be harmful for the personnel in the laboratory and public area. This research concentrates on design of radiation shielding to prevent the leakage of radiation from the accelerator area. Calculation of the photon's energy deposition per volume due to the interactions of electron beam with materials in the irradiation system and surrounding area including the collision and bremsstrahlung processes was performed by using a Monte Carlo simulation software GEANT4. Shielding walls of the 4-MeV linac and its irradiation system consists of iron plates with the thickness of 2 cm for the side walls and 3 cm for the top wall. Results of the radiation calculation suggested that the photon's energy deposition per volume outside the accelerator hall reduces by more than 99.5% after the shielding walls were added.

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