bluuebunny/crossref_metadata_2025_split huggingface dataset:
The photon trajectories around black hole with moving light source
Authors: Radjaroendee Nattawat , Jamraschai Thammatorn , Hirunsirisawat Ekapong 
Published: December 2023

Abstract
The influence of curved spacetime around a black hole on photon trajectory has been widely studied recently. This study focuses on numerical simulations and some theoretical analysis to characterize the photons emitted from a moving light source around a Schwarzschild black hole. The results show that photon trajectories can be categorized based on the unique features of the light path caused by a variation in emitting angle (β). We propose three types of trajectories, including 1) the return angle (βret
): the photon from this angle orbits around the black hole and returns to the light source 2) the escaping angle (βesc
): the photon from this angle escapes to infinity parallel to the horizontal axis 3) the critical angle (βph
): the photon coming from this angle of initial condition enters a critical photon orbit. The escaped photons can be subclassified by computing the lensed ratio which is the difference between the angular position of the photon escaped to infinity and the initial emitting angle. This study reveals the characteristics of photons from light source moving around a black hole and can be further used to analyze the behavior of light from compact stars or other glowing objects in more complicated systems.
The effect of temperature on absorbance of rubidium atoms in a vapor glass cell
Authors: Kaewko A , Parkprom P , Ketaiam K , Chaiwongkhot P , Chattrapiban N , Sompet P , Thaicharoen N 
Published: December 2023

Abstract
Glass cells containing neutral atoms are commonly employed in spectroscopy experiments and have potential applications in metrology. The temperature of the vapor plays a vital role as it directly influences the absorption rate of rubidium atoms. In this research, we study the effect of vapor temperature on the absorption spectrum of rubidium atoms. We observed the broadening of the spectral line and increased absorption, enabling us to determine the absorbance of atoms within the cell. These results provide valuable insights for our future work to characterize absorbance of homemade vapor cells for portable quantum device applications.
Magnetic structure of the S = ½ staircase kagome lattice PbCu3TeO7
Authors: Jansawang J , Techathitinan S , Nambu Y , Matan K 
Published: December 2023

Abstract
The crystal and magnetic structure characterization of geometrically distorted PbCu3TeO7 with S=1/2 Cu2+ spins forming a staircase kagome lattice was investigated using x-ray and neutron diffraction on a powder sample. The distorted kagome lattice of antiferromagnet PbCu3TeO7 exhibits a quasi-two-dimensional spin network. The x-ray diffraction data show that PbCu3TeO7 crystallizes in the orthorhombic system in the space group Pnma (No. 62). The lattice parameters a = 10.488(1) Å, b = 6.353(1) Å, and c = 8.814(2) Å. Our temperature-dependent x-ray diffraction data show that there is no structure phase transition between 12 and 298 K. From our powder neutron diffraction data at 2 K, we observed two distinct magnetic Bragg peaks at low angles, confirming the magnetic transition to the ordered state at low temperatures. In previous work, the ordering vector for the magnetic structure was determined using simulations to be (0,1/3,0). However, in this work, we found that based on the neutron diffraction data the ordering vector is in fact (0,1/3,1/3). The magnetic structure of PbCu3TeO7 exhibiting an antiferromagnet with noncollinear spin order is proposed.
Thickness dependence of optical properties of sputtered AZO film on borosilicate glass
Authors: Khamee Wattana , Niyom Kanchanee , Rattanasakulthong Watcharee 
Published: December 2023

Abstract
Sputtered AZO film with different thicknesses (98, 141, 206, 249 and 306 nm) was deposited on a borosilicate substrate. The XRD pattern indicated that the deposited AZO films showed the prominent peak of the AZO phase in the (002) direction, and the (004) plane was also observed on the 141, 206, 249 and 306 nm films. The peak intensity was increased with film thickness. AFM images reveal that all films show a granule surface and columnar structure with different sizes and distributions depending on thickness. In addition, the surface roughness and electrical resistance of the films were increased with increasing thickness. The 98 nm film exhibited a constant transmission, but the optical transmission of the rest of the films fluctuated with the wavelength in the 400-1000 nm range, and their transmission was thickness-dependent. The maximum mobility and carrier concentration was observed on the 306 and 249 nm, respectively. The energy bandgap of the film ranged from 3.5-3.6 eV and was increased with the film thickness. The results attribute that the thickness significantly modifies structural phase, surface morphology, and roughness, strongly affecting the optical properties of sputtered AZO films.
Universality of flux quantum in an s-wave superconducting ring
Authors: Nisaisue C , Krunavakarn B 
Published: December 2023

Abstract
A problem of the crossover of the flux periodicity in an s-wave superconducting ring whether a period hc/e arises instead of hc/2e is studied in the basis of the linearized Ginzburg-Landau equation for the order parameter. We analyze the behavior of the Little-Parks oscillations for a one-dimensional superconducting ring threaded by an external magnetic flux and find the period of the magnetic flux is strictly hc/2e independent of the radius of the ring. The obtained result shows the universality of a superconducting flux quantum.
Analyzing asymmetry in the Wolf-Villain model via the study of the persistence of various initial height fluctuations
Authors: Chatraphorn P , Chanphana R 
Published: December 2023

Abstract
The Wolf-Villain (WV) model, which, in some literature, has shown trait of up-down asymmetry, is investigated through the study of the persistence probability of height fluctuations in simulated film surfaces. The persistence probability is the probability that the height fluctuation of each site does not cross its initial value (h
0) along a time interval. When averaged over all possible values of h
0, the probability is known to exhibit a power law decay behavior with the exponent called persistence exponent. In this work, instead of averaging over all h
0, we consider a fixed value of h
0 and find that the persistence probability of the WV model still decreases with time as a power law if the fixed value meets a necessary condition, i.e. h
0 is roughly equal to or larger than the saturated roughness of the film. The persistence exponent for each h
0 is measured and found to decrease as the value of h
0 increases. Scaling form of the persistence probability at a specific h
0 is also studied. Notably, all results obtained here are in agreement with those of the up-down symmetric models appeared in literatures despite the fact that the WV model is an asymmetric model. These results support the idea from other studies that the asymmetry in the WV is very weak.
Crystallographic rotation effect on the particle and spin across a half metal/semiconductor junction with Dresselhaus spin-orbit interaction
Authors: Siripanadorn A , Onsri T , Jantayod A 
Published: December 2023

Abstract
Theoretical studies were conducted on probability, conductance and spin polarization through a junction between a half metal (HM)/semiconductor with Dresselhaus spin-orbit coupling (DSOC), using the scattering theory and the continuous model in a two-dimensional system. The focus was on how the bulk orientation of the DSOC affects the charge and spin polarization. Results showed that the crystal face (100) makes a negative perpendicular to the normal wave vector of the system, resulting in a maximum value of the conductance spectrum and the spin polarization. However, the maximum value of the spin polarization can occur with any crystallographic orientation when the applied voltage reaches the crossing point of the DSOC. Moreover, the electron incident angle injection can cause a gap between in the transmission probability with spin up and spin down, corresponding to higher charge and spin polarization across the junction.
Boosting the electrical output of cement-based triboelectric nanogenerator by surface treatment technique
Authors: Kaewsrithong Kanisorn , Kaewpoonsuk Anucha , Torkittikul Pincha , Wongkeo Watcharapong , Chaipanich Arnon , Rianyoi Rattiyakorn , Nochaiya Thanongsak 
Published: December 2023

Abstract
Triboelectric nanogenerators have the potential to convert mechanical energy to electric energy through electrostatic induction thus they are promising alternative cleaning energy sources for human beings. The objective of this work is to increase the electrical outputs of cement-based triboelectric nanogenerators (C-TENGs) by using a surface polishing treatment technique. The hand-mixed cement pastes with water-to-cement ratios of 0.3, 0.4, and 0.5 by weight were cast in the molds and cured in saturated lime water. A study was conducted to investigate the electrical output, which included voltage and current, under a single vertical contract-separation mode with a constant force and a frequency of 3 Hz. To improve the electrical generating performance, all samples were subjected to a surface treatment by polishing with sandpaper. After electrical investigations, the electrical outputs were remeasured. The results showed that the modified surface samples have significantly higher electrical outputs than that of the pristine sample due to the increased contact surface area. Moreover, the cement paste with a water-to-cement ratio of 0.3 after a polished-surface treatment exhibits the highest power density for an external resistance of 10 MΩ, improving around 70% higher than the pristine sample. The study successfully presents a low-cost and simple technique for improving the performance of cement-based triboelectric nanogenerators.
Influence of Coulomb interactions on Einstein phonons in a three-dimensional electron gas and superconductivity
Authors: Phatcharasirinawakun Worapon , Robkob Udom 
Published: December 2023

Abstract
This study investigates the influence of Coulomb interactions on Einstein phonons in a three-dimensional electron gas (3DEG) and their impact on superconducting properties. By considering Coulomb effects in all contributions to the phonon self-energies, we explore the renormalization of phonons and its implications for superconductivity. Numerical solutions of the isotropic Eliashberg equations are used to determine the gap functions, providing valuable insights into the behavior of renormalized phonons. Our analysis reveals that while the frequencies of renormalized phonons are lower compared to non-interacting Einstein phonons, their inclusion leads to higher superconducting critical temperatures and maximum gap functions. However, as the strength of Coulomb interactions increases, a decrease in the superconducting critical temperature and gap is observed. These findings highlight the significant role of Coulomb interactions in determining the behavior of phonons and the emergence of superconductivity in three-dimensional electron gases.
Physicochemical properties of PSF/SiO2-NH2 composite membranes incorporated by polymeric additives
Authors: Ellis T , Sricheewin C , Yuenyao C 
Published: December 2023

Abstract
This research aims to study the effects of PVP and PEG on the morphological structure, hydrophilicity and mechanical properties of PSF/SiO2-NH2 composite membranes. PSF/SiO2-NH2 membranes with and without the addition of PVP and PEG are fabricated by phase inversion process and used to study the physical and chemical properties as mentioned. Change of the structure and wettability properties of prepared membrane samples are determined by different scientific techniques. Hydrophilic properties are evaluated through the measurement of water contact angle (WCA) while morphology and pore size, as well as the creation of pore on the top surface of membrane samples are analyzed through the SEM micrographs. Additionally, alteration of hydrophilic functional groups on the top skin surface of the membrane is measured by FTIR technique. Experimental results illustrated the effects of PVP and PEG on the morphological and porous structures of PSF/SiO2-NH2 composite membranes. Internal porous structure have clearly changed from the sponge-like structure with macrovoids to finger-like structure. Macrovoids disappeared with the addition of PVP and PEG into the matrix of PSF/SiO2-NH2 composite membranes. Experimental results also showed that nanopore created on the top surface of PSF/SiO2-NH2 membranes incorporated with PVP and PEG. Importantly, PVP and PEG show the influence to the hydrophilic properties of PSF/SiO2-NH2 membranes. The effect on the hydrophilic properties as mentioned is confirmed by the increasing of hydrophilic group on the membrane surfaces and decreasing of WCA. DMTA results showed that PVP and PEG affect the glass transition temperature and mechanical properties of PSF/SiO2-NH2 composite membranes.
Purifying VO2 phase synthesized by sol-gel method via annealing process
Authors: Chongprasit Rattachanok , Kittiwatanakul Salinporn 
Published: December 2023

Abstract
Vanadium dioxide (VO2) film has significant interesting phase transition properties called metal-semiconductor transition (MST) which occurs at 68 °C. This transition behavior makes it suitable for various applications, including thermochromic materials for smart windows, sensors, and electronics devices. In this study, we aimed to focus on the purification of VO2 through the sol-gel synthesis method from vanadium alkoxide (VO(OC3H7)3. To analyze the effects of annealing temperature (500 °C-600 °C) on the resulting structural, morphology, and electrical properties, x-ray diffraction (XRD), Raman spectroscopy, atomic force microscopy (AFM), temperature dependent resistance, and infrared (IR) thermal image were considered. The resistance as a function of the temperature shows an abrupt change confirming the phase transition. However, XRD shows an impurity of other vanadium oxides such as V6O13. In addition, the sample annealed at 600 °C shows a non-uniform surface filled with island clusters, while the sample annealed at 500 °C has a smooth and uniform surface. Raman spectra further supports the formation of VO2 (M) clusters mixed with V6O13 in smooth area, resulting in a decrease in electrical properties, significant reduced resistance change at the excessive annealing temperature.
Quantum oscillations of pseudomagnetoresistance in tunable tilt-mismatch Dirac-cone junction
Authors: Rakrong Phachara , Choopan Wachiraporn , Liewrian Watchara 
Published: December 2023

Abstract
This paper presents research on the quantum oscillation of pseudomagnetoresistance (PMR) in tilted Dirac cone material junctions. Dirac cones are linear energy dispersions that arise in materials like graphene, which is a two-dimensional material with unique electronic properties. The presence of a tilted Dirac cone in the energy spectrum of these materials introduces interesting phenomena such as pseudomagnetism and anisotropic quantum transport. By applying strain, we can control the direction of the tilted Dirac cone in graphene and investigate the pseudomagnetotransport properties of this system. Magnetoresistance is a real effect that arises from the Lorentz force acting on the charge carriers, while PMR is a geometric effect that arises from the tilted Dirac cone and the crystal lattice structure of the material. Using computational methods for finite-superlattice materials and the transfer-matrix method, our results show that the quantum beating pattern of PMR is more pronounced with an increased number of barriers. Additionally, we observe that the amplitude and period of the modulation depend on the strength and orientation of the tilted-induced pseudomagnetic field. We demonstrate that the PMR behavior can be tuned and optimized for specific applications, potentially leading to improvements in the design and optimization of graphene-based devices such as sensors, transistors, and quantum computers, which rely on the PMR behavior of graphene.
Real-time radiation monitoring of high energy 1.2-GeV synchrotron accelerator using experimental physics and industrial control system
Authors: Aim-O P , Manasatitpong K , Sumano N , Ruengpoonwittaya S , Suradet N , Kampitak W , Thongwat A , Pamungkas N S , Wangnok K 
Published: December 2023

Abstract
The high energy 1.2-GeV electron accelerator facility’s radiation detection and monitoring system (RDMS) has greatly evolved to be the effective backbone of real-time radiation monitoring for the new light source 3-GeV synchrotron facility. Experimental Physics and Industrial Control System (EPICS), ethernet hardware connections (Optic fibers), and Web-based software interfaces make up the new RDMS framework, built on well-liked network technology. The problems of monitoring i.e., a lot of manpower, poor monitoring accuracy, and inability to monitor continuously in the high radiation dose are eliminated. EPICS, composed of an Input/Output Controller (IOC) and Client Workstations which can communicate with a Local Area Network (LAN), were applied for remote control and radiation measurement. EPICS has been able to transport and store massive amounts of data for large-scale systems with a wide range and high accuracy. The monitoring data were sent to the server through the optic fibers network system, which is more advantages such as no distance restrictions, low attenuation of the signal, faster responding times, and particularly electromagnetic resistance. The data can be accessed anywhere from client monitors with graphical user interfaces. This system is successfully developed and tested for the high energy 1.2-GeV electron accelerator. The RDMS is useful for radiation safety to monitor the radiation dose level during machine operation to protect occupational workers and the public from radiation hazards.
Modeling simulation of nitric oxide and ozone generated by the Compact Air Plasma Jet: Nightingale®
Authors: Palee Nattawut , Thana Phuthidhorn , Wijaikham Apiwat , Pussadee Nirut , Boonyawan Dheerawan 
Published: December 2023

Abstract
This study aimed to model and investigate the distribution characteristics of NO and O3 produced by a Compact Air Plasma Jet device using 0D and 2D fluid models. The 0D global model was employed to calculate densities in the plasma volume before constructing the 2D model for the distribution of densities via boundary conditions. As the feeding gas flow rate increased from 3 to 11 slm, the NO and O3 densities predicted by the 0D model decreased from 10 ppm to 1 ppm and from approximately 12 ppm to 1 ppm. In comparison with the gas detector measurements, the NO densities exhibited the same values and trends with respect to the number of pulses and flow rate, but O3 concentrations from the 0D model simulations were higher than those measured by the gas detector. With a 20 ms simulation time, NO concentrations decreased along the axial length, whereas O3 concentrations increased. Additionally, O3 concentrations from both models were higher than the measurements from the gas detector, which did not align with the experimental results. The incorporation of dominant humidity reaction sets improved the alignment between the modeling results and specific experimental observations. The model equipped with these additional humidity reaction sets can be effectively employed to predict the NO and O3 density generated by the Compact Air Plasma Jet device.
The effect of meteorological parameters on air particulate matter
Authors: Anusasananan Panatcha , Suwanarat Suksan , Thangprasert Nipon 
Published: December 2023

Abstract
The conditions of the weather have an effect on both the amount of emissions and the quality of the air. A change in meteorological conditions has a substantial effect on particulate matter (PM) levels. In this study, we will first use statistics and wavelet calculations to look at the links between particulate matter (PM10 and PM2.5) and relative humidity (RH). RH influences the natural deposition of PM concentrations. Then, we’ll examine how wind direction (WD) and wind speed (WS) affect PM. The results show that both PM10 and PM2.5 are high in February and that July and August have the lowest levels. In contrast, RH is low in February and maximum in October. Whenever the RH increases, the PM concentration decreases, and vice versa. The correlation coefficients between PM10 and RH are 0.3433 during the winter, 0.7181 during the summer, and 0.0052 during the rainy season. This illustrates the significant seasonal correlation between PM and RH. The results from wavelet coherence analysis indicate that PM and RH have close negative correlations. Significantly high wavelet power in the 8–30 day waveband exists in winter each year in the observed time horizon. There is also another common power found throughout the spectrum. PM and RH in these wavebands are out of phase with one another, with RH slightly leading PM. Moreover, the WS and WD also have an effect on PM concentration. If the wind speed is high and exceeds a specific threshold, the wind will take PM away, causing the PM concentration to decrease. In February 2023, the NE and NNE winds carried the most PM into the Bangkok region, followed with less concentration, by the WSW, SW, and W winds. Since PM is one of the primary air contaminants that has been linked to a deterioration in human health, it is extremely important to have a solid understanding of how PM concentrations change over time.
Chemical and electrical properties of activated carbon from Samui Island young coconut waste
Authors: Pinchaipat R , Koedthong P , Boonpian P , Vitidsant T , Owkusumsirisakul J 
Published: December 2023

AbstractSolid coconut waste has been a chronic issue that can lead to an environmental problem in Samui Island. Therefore, we are interested in processing this waste into a more valuable product. Many previous studies have evaluated the characteristics of activated carbon (AC) using chemical properties, but not electrical properties. In this work, we analyze the electrical properties of AC to identify a wide range of potential applications. The whole coconut with husk was turned into AC under different activation parameters (temperature, impregnation ratio of KOH and time) using one-factor-at-a-time method. The results showed that with higher activation temperature (750-850°C), the iodine adsorption number increased but the yield decreased. Excessive impregnation ratio and longer activation time could lower the iodine adsorption number due to the collapse of micropores into larger pores. The SEM images revealed that after activation process, a well-developed pore structure is achieved. The highest iodine adsorption number was obtained at 1356.80 mg/g at activation condition of 800°C, impregnation ratio of 1:2 and activation time of 2 hrs. The electrical property of activated carbon was remarkably improved from the initial char, in accordance with the iodine number result. The lowest resistivity was also achieved at the same condition as above.