bluuebunny/crossref_metadata_2025_split huggingface dataset:
Canonical quantization of neutral and charged static black hole as a gravitational atom
Authors: Senjaya David , Rivera Alejandro Saiz 
Published: January 2021

Abstract
The gravitational field is usually neglected in the calculation of atomic energy levels as its effect is much weaker than the electromagnetic field, but that is not the case for a particle orbiting a black hole. In this work, the canonical quantization of a massive and massless particles under gravitational field exerted by this tiny but very massive object—both neutral and charged—is carried out. By using this method, a very rare exact result of the particle’s quantized energy can be discovered. The presence of a very strong attractive field and also the horizon make the energy complex valued and force the corresponding wave function to be a quasi–bound state. Moreover, by taking the small scale limit, the system becomes a gravitational atom in the sense of Hydrogenic atoms energy levels and its wave function can be rediscovered. Moreover, analogous to electronic transitions, the transition of the particle in this case emits a graviton which carries a unique fingerprint of the black hole. If it can be detected, this essential information such as black hole’s mass and charge can be known.
Paper-based colorimetric sensor for potassium ion detection in urine by crown ether modified gold nanoparticles
Authors: Chitbankluai Khwanrudee , Buranachai Chittanon , Limbut Warakorn , Thavarungkul Panote 
Published: January 2021

Abstract
Detection and identification of potassium ion (K+) level in urine is essential for diagnosis of several deseases or for guiding treatments. We have developed a simple, rapid, low cost and naked-eye quantitative method for K+ analysis in urine using a paper-based colorimetric array test strip. The array comprised three sensing elements printed using a wax-printing technique and filled with different amounts of crown ether (4-aminodibenzo-18-crown-6) modified gold nanoparticles (AuNPs). The detection is achieved by measuring the color change (from red to violet) when AuNPs aggregated following crown ether-K+ complexation. Furthermore, the detection sensitivity could be controlled by changing the amount of the crown ether. The strip sensor array based on crown ether modified AuNPs successfully detected K+ level in the ranges of 5-1000 µM by naked eye. Thus, the developed sensor is very simple yet has a potential to be of real use in detecting K+ in real urine samples.
Finding optimal hyperparameters of feedforward neural networks for solving differential equations using a genetic algorithm
Authors: Boonthanawat C , Boonyasiriwat C 
Published: January 2021

Abstract
In this work, feedforward neural networks are used to solve 2D Laplace equation on rectangular domains. Optimal values of weights and biases of a network are recursively computed during the network training by minimizing a least-squares loss function using data at collocation points to approximate the true solution. The performance of the network largely depends on network architecture and model capability. In this work, an optimal set of hyperparameters is searched on various values of relative error. The genetic algorithm is used to find the optimal activation function, optimization algorithm, and weight initialization. In addition, we also searched for the optimal value of the number of hidden layers for a specific value of total parameters. Numerical results show that we can successfully obtain an optimal set of hyperparameters that is consistent across many values of relative error.
Numerical study on characteristics of sound and wake generated by flow past triangular cylinder at various incident angles
Authors: Chanthanasaro T , Boonyasiriwat C 
Published: January 2021

Abstract
Characteristics of sound and wake generated by flow past a triangular cylinder with Mach number 0.3 at various incident angles are studied by numerically solving the compressible Navier-Stokes equations using Open FOAM. The Reynolds number in this study is varied from 140 to 180. Vortex streets behind the cylinder are observed to have different patterns as the Reynolds number and the angle of incidence are varied. The mean lift coefficient has zero value when the cylinder is symmetric and maximum value at incident angle approximately 30°. The mean drag coefficient is observed varying when incident angle increaes. The Strouhal number observed has the value in the range of 0.15 − 0.21. Sound is generated mainly from a fluctuation in the lift and drag forces due to the shedding of vortices. The frequency of sound in far field is observed shifting when the incident angles is increased because of the different behavior of the fluctuating lift and drag forces.
Using wavelet analysis to study floods in Bangkok
Authors: Juthasirorat Narin , Anusasananan Panatcha , Suwanarat Suksan , Thangprasert Nipon 
Published: January 2021

Abstract
Floods in Bangkok are regular natural disasters that happen nearly every year during the monsoon season. Many streets of the city may turn into canals and seriously worsened rush-hour traffic causing many commuters to arrive late at work or school. Therefore, in this research, we will study floods in Bangkok area both seasonal flooding and occasional flooding due to the effect from La Nina cycles using the wavelet spectrum analysis and the cross wavelet method. The result from cross wavelet transform (XWT) shows that the standard precipitation index (SPI) (wet) and the oceanic index (ONI) (La Nina) have significant common power mainly in the 20-40 month band from 1967-1974 during the strong La Nina cycle. There is, however, a large area with common power outside the significance level around 32-80 month band from 1982-2002 but depicts a highly significant local correlation. The corresponding wavelet coherence spectra showed that SPI and ONI co-varied mostly in the 32-60 month band from 1966-1981 with the arrow pointing to the right and in the 64-80 month band from 1986-1994 with the arrows also pointing to the right. Although flooding is a common and annual occurrence in Bangkok, the La Nina climatic phenomenon can cause a higher than average rainfall. The intense extremely wet period during strong La Nina years was observed in 1955-1956, 1998-1999 and 2007-2008. In a La Nina years, Bangkok will receive more rain than normal years. In general, this work may contribute to the improvement of the understanding of how climate variability may impact flooding in Bangkok. Knowing of the La Nina years in advance will help the government in better planning and preparation to prevent flooding areas more than normal.
Physical properties of termite mound soil in para rubber plantation of southern border provinces
Authors: Seetapong N , Chulok S , Thongkhong V 
Published: January 2021

Abstract
Most farming areas in southern part of Thailand are predominated by the para rubber plantation and termite mound are generally found in almost plantation area. Termites have peculiar activities in the soil and also lead to the significant changes in the soil properties. The objective of this research was to study the physical properties of termite mound soils in para rubber plantations. The soil in the area of southern border provinces i.e. Pattani, Yala, and Narathiwas was investigated. The collected samples were divided into top, center, and base. Additionally, the soil samples were collected at the distance of 5 meters away from the mound base. It was found that the termite mound soil was comprised of silty and clay soils with high moisture and density. Most of the soil particles were sandy soil and had good water absorption coefficient. The termite mound soils were weakly acidic and by this reason the electrical conductivity was at a level that does not affect the growth and production of plants. For agriculture improvement, termite mound soils can be mixed with other soils to retain moisture, absorb water and nutrients.
Collaboration between TISTR and NIMT: An application of the pressure metrology in an air speed measurement
Authors: Pitakarnnop J , Chaiyapat U , Piromgraipak P , Luanghirun K 
Published: January 2021

Abstract
This paper describes a collaboration between Thailand Institute of Science and Technological Research (TISTR) and National Institute of Metrology Thailand (NIMT) in an application of a differential pressure measurement to an air speed measurement. The aim of the collaboration is to link the measurement of an air speed by a pitot static tube anemometer at TISTR to the measurement of a differential pressure at NIMT. Upon completing the project, TISTR’s pitot tube anemometer is traceable to NIMT’s force balance piston gauge. TISTR’s pitot tube anemometer in combination with its Eiffel-type wind tunnel can be employed as a calibration system for an anemometer. The result of the collaboration leads to a lower cost of maintaining TISTR’s traceability in air speed measurement.
The determination of correction factors for free-air ionization chamber calculation using monte carlo method
Authors: Rindhatayathon P , Koonkana K , Pungkun V 
Published: January 2021

Abstract
A free-air ionization chamber is used as the primary standard instrument for absolute measurement of air kerma for of X-ray beams. The evaluation of correction factors is a key importance for establishing the standard. Photon-scattering, and diaphragm transmission and scattering were taken into the accounts to reduce some photon phenomena. On the other hand, electron-loss factor which scatter from an electrode were used for electron compensates. In this research, Correction factors were calculated for each mono-energetic photon from 2 to 60 keV for low energy x-rays and 10 to 320 keV for medium energy x-rays by EGS5 code. The calculated corrections from a mono-energetic photon of W/Mo mammography x-rays were compared between effective energy and spectrum method. There is no significant difference between two methods.
Calibration of whole body counter for assessment of internal dose in the human body
Authors: Dararutana C , Abdullah N 
Published: January 2021

Abstract
In the Malaysian Nuclear Agency (Nuklear Malaysia), the ORTEC Whole Body Counter System, bed type was used for assessing internal dose due to intake of gamma radionuclides in the human body. In this study, the performance of ORTEC Whole Body Counter System includes energy calibration, counting efficiency, validation test and minimum detectable activity (MDA) for the radionuclides of interest (ROI) has been investigated using ORTEC whole body counter phantom and mixed standard sources having gamma energies between 59.5 keV and 1836.2 keV. Later, the whole body counting was performed to determine the existence of any gamma radionuclides in the body. The result of the energy calibration was within the tolerance limit of ± 5%. The counting efficiency varies between 0.0000881 cps/Bq and 0.000332 cps/Bq. The results of the validation test show that the bias (Br) and repeatability (SBr) are within the acceptable range of -0.25 ≤ Br ≤ +0.50 and SBr ≤ 0.40, respectively. The MDA for each ROI of I-131, Cs-137 and Co-60 were 165.4 ± 10.0 Bq, 144.6 ± 11.5 Bq and 167.3 ± 30.5 Bq, respectively. A total of 14 volunteers from Postgraduate Educational Course in Radiation Protection and Safety of Radioactive Sources (PGEC-16) were invited to perform the whole body counting. Each volunteer was scanned for 1200 s with the bed speed of 0.065 inch/s. The results show that there is no internal exposure found for all monitored person. Consequently, it can be concluded that the ORTEC Whole Body Counter System (WBC) is now ready to be used for internal dose assessment.
Laser excitation spectroscopy of beryllium heat treatment in synthetic ruby
Authors: Keawdonree Nuttapong , Monarumit Natthapong , Chomkokard Sakchai , Jinuntuya Noparit , Wongkokua Wiwat 
Published: January 2021

Abstract
Ruby is a gem variety of corundum (α-Al2O3) that is colored red by trivalent chromium (Cr3+) substituting for Al3+ in the corundum structure. Recently, the beryllium (Be) heat treatment has been practiced as a technique to enhance the color of ruby. The ruby will turn orange to be an orange sapphire as a result of the enhancement. Some advanced technics to identify the Be heat-treated orange sapphire have been developed such as laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), secondary ion mass spectrometry (SIMS) and laser-induced breakdown spectroscopy (LIBS). We studied the effect of Be atoms in the corundum structure using the red, green, blue and purple laser excitation spectroscopy with the wavelengths of 634 nm, 545 nm, 452 nm and 408 nm respectively. The fluorescence spectra were analyzed for unheated, normal heat treatment and Be heat treatment synthetic ruby samples. The fluorescence intensity of the Be-heated samples was lowest compared to the unheated and normal treated ones for both high and low Cr content.
Activated carbon derived from coconut shell chars for use as a cathode material in aluminium-ion batteries
Authors: Thanwisai P , Phuenhinlad P , Chaiyapo N , Kanaphan Y , Nash J , Chotsuwan C , Rattana-amron T , Klamchuen A , Meethong N 
Published: January 2021

Abstract
Aluminium-ion batteries (AIBs) are a promising energy storage system due to their significant advantages of low cost, high anode capacity and safety. Nevertheless, the critical challenge limiting AIB performance is an inadequate cathode capacity that diminishes their cell energy density. To overcome this limitation, it is important to develop novel cathode materials with high cathode capacity for AIBs. Herein, we report an activated carbon derived from coconut shell chars for use as a cathode material in AIBs. The activated carbon was synthesized via KOH activation and carbonization. The prepared cathode material exhibits a high specific capacity of 38 mAh g−1 at a high current density of 1 A g−1 due to its high specific surface area of 2686 m2 g−1, which is beneficial for chloroaluminate-ion accommodation. This result indicates that the activated carbon derived from coconut shell chars with its high surface area is electrochemically active and is likely to be a promising cathode material for AIBs.
Preparation and enhanced electrical breakdown strength of PVDF-TrFE-CTFE/PVDF-HFP film composites
Authors: Chaipo S , Putson C 
Published: January 2021

Abstract
Poly(vinylidenefluoride-trifluoroethylenechlorotrifuoroethylene), PVDF-TrFE-CTFE composite films with addition poly(vinylidene fluoride-co-hexafluoropropylene), PVDF-HFP at different copolymer loading was prepared by using the tape casting solution method. Electrical breakdown strength (Eb) was measured by the dielectric breakdown test system and fitting the Eb by the Weibull model. The experimental results illustrated that the breakdown probability, P(E) of the neat terpolymer and copolymer film was 316 V/μm and 495 V/μm, respectively. In addition, the breakdown probability of composite films between terpolymer and copolymer is higher than the neat PVDF-TrFE-CTFE film, in which the value of Eb is almost double when compared with terpolymer film. We will discuss on their crystallinity, material homogeneity and crystalline size to provide the method to improve the electrical breakdown strength with addition copolymer for energy storage applications.
Preparation and characterization of nanostructured TiCrN thin films deposited from Ti-Cr mosaic target by reactive DC magnetron sputtering
Authors: Alaksanasuwan Siriwat , Buranawong Adisorn , Witit-Anun Nirun 
Published: January 2021

Abstract
In this research work, nanostructured thin films of TiCrN have been deposited on Si by reactive DC magnetron sputtering from a mosaic Ti-Cr target. The effects of nitrogen gas flow rates on the structure of the as-deposited TiCrN thin films were examined. The crystal structure, microstructure, surface morphology, thickness, and composition were characterized by GI-XRD, FE-SEM and EDS technique, respectively. The results revealed that the thin films were formed as a (Ti, Cr)N solid solution. The as-deposited thin films showed a nanocrystalline structure of TiCrN with the crystal sizes less than 45 nm. The lattice constants were in the range of 4.144 to 4.181 Å. The thickness of the TiCrN films decreased from 379 to 276 nm with increasing of the nitrogen gas flow rates. The nitrogen content of the as-deposited films was increased with increasing of the nitrogen gas flow rates, while the titanium and chromium content in the films were decreased. Finally, the TiCrN thin films showed compact columnar and dense morphology as a result of various the nitrogen gas flow rate.
Development of cornstarch-based hydrogel drug delivery patch controlled by the electric field for hypertension
Authors: Jaruchalermrat Phitchaphon , Niamlang Sumonman 
Published: January 2021

Abstract
To study electrical controlling drug delivery from poly(vinyl alcohol) (PVA), PVA was prepared at various crosslink ratio. Hydrochlorothiazide (HCTZ), which is used to treat high blood pressure, was selected as a model drug. The release characteristic of hydrochlorothiazide from PVA matrix was a studied by using modified franz diffusion cells at pH 7.4 and temperature of 37 °C for 48 h. The amounts of drug permeation was characterized by UV-vis spectrophotometry. The degree of swelling and mesh size of crosslinked PVA was investigated. The degree of swelling increase with decreasing crosslinking ratio. The amount of drug permeation is decreased with increasing crosslinking ratio which corresponded to degree of swelling. When external electric filed was applied, the amount of HCTZ increases with increasing electrical voltage due to electro-repulsion force and generation of micropore in pigskin. To increase solubility and biodegradability of hydrogel matrix, corn starch (CS) was blend with PVA hydrogel. For passive permeation, the amount of HCTZ permeation from PVA/CS and PVA at similar crosslinking ratio is 7.56 and 7.93%, respectively. Thus presenting of CS do not affect the permeation characteristic.
X-ray spectroscopy study of ancient glass beads at Hor-Ek, Thailand
Authors: Won-in K , Dararutana P 
Published: January 2021

Abstract
In ancient time, it is well known that glasses have been used in ornament and decorative objects in Thailand for several hundred years as implied by archaeological evidences such as glass beads and decorative glasses. In this work, the blue and red colored glass beads selected from the Hor-Ek archaeological site in Nakhon Pathom province (central Thailand) have been characterized chemical composition using a scanning electron microscope coupled with energy dispersive X-ray spectroscopy (SEM-EDS) and a particle induced X-ray emission spectroscopy (PIXE). Cu-K-edge XANES (X-ray absorption near edge structure) of the selected samples is also carried out in fluorescent mode in order to determine the oxidation state. The results showed that the beads are all the LMHK-based glass (low magnesia, high potash). The red and blue tonalities are affected by copper with different oxidation states, and/or the summation of copper and cobalt. The shape and composition of these ancient glass beads are similar to those collected from other four sites in southern Thailand such as Khlong Thom, Phu Khao Thong, Nang Yon, and Thung Thuk and the foreign countries such as India, China, and Vietnam. These detailsindicate the long-distance trade and exchange network in ancient maritime.
Concentrations of 238U in selected Thai spices and the related dose assessment
Authors: Nochit P , Kulsawat W , Khunsamut J 
Published: January 2021

Abstract
Finger root, galangal, turmeric, and lemon grass are commonly used in Thai cuisine as spices and herbs. The radionuclide uranium accumulates in human diet can has toxic effects in human health such as kidney damage and neurological disorders. In this study, the concentrations of 238U in some selected spices commonly used in Thailand were determined and the annual effective doses (AED) were assessed. Four spices consisted of galangal, turmeric, lemon grass and finger root were sampling from Bang Krathum district, Phitsanulok during 2017-2018. The radioactivity of 238U in these spice samples were varied from 0.015 (below detection limit) to 2.79 Bq/kg fresh. The highest activity was recorded in finger root (2.79 ± 0.14) while the lowest was lemon grass (0.34 ± 0.06). The estimated AED determined in this study due to consumption of spices ranges from 0.004 to 0.781µSv/y and the total value for all four spices was 1.934 µSv/y. It was found that AED in this study is far below the International standard of average radiation dose of 290 µSv/y received per person worldwide due to intake of natural radionuclides in food. The results revealed insignificant radiological health hazard to the public due to the consumption of spices via foods. Based on these results, the spices samples from the studied area are considered radiological safe for human consumption. The results provide baseline values which may be useful in establishing rules and regulations relating to radiation protection.
A novel vibration sensor based on the near-field Talbot effect
Authors: Buathong S , Srisubphaphon S , Deachapunya S 
Published: January 2021

Abstract
A novel technique for vibration measurement is proposed using the near-field Talbot effect. The sensor is based on monitoring intensity modulation of interference patterns deviated from that at the Talbot distance. To achieve high sensitivity to mechanical vibrations, an asymmetric grating is employed to provide a small grating open fraction. Our theoretical outcomes show that the sensor resolution can be at micro and even nano scales. This practical vibration sensor can be useful in metrology and many industrial applications.
Development of a cost-effective remote explosives detection system based on Raman spectroscopy
Authors: Thongrom S , Kalasuwan P , van Dommelen P , Daengngam C 
Published: January 2021

Abstract
Near real-time detection and identification of explosives from safe distances remains a challenging defense technology that requires both scientific and engineering perspectives in the design and development. Here, we demonstrated a cost-effective standoff Raman system for detecting explosive materials from distances up to 30 m. The optical system consists of an 8-inch Schmidt–Cassegrain telescope for Raman scattering light collection, while a compact grism was used to generate Raman spectrogram. An image intensifier from night vision technology was incorporated for amplifying the extremely weak Raman spectrum to a level detectable by a thermoelectric-cooled CMOS camera. A nanosecond pulsed laser at 440 nm with peak power of 0.41 MW was used as an excitation source, and the standoff Raman measurement was performed for test samples, including Ba(NO3)2, BaSO4 and NaNO3 powders. The spectral resolution and signal-to-noise ratio performance of the system were evaluated for the samples placed at distances of 10, 20 and 30 m. It was found that the standoff Raman system can resolve such Raman spectra, showing clear characteristic peaks of Ba(NO3)2, BaSO4 and NaNO3 at 1,045.9, 986.4 and 1,066.5 cm−1, respectively. These spectrum results agree well with the Raman spectra obtained from a standard close-range Raman system.