bluuebunny/crossref_metadata_2025 huggingface dataset:
A development of a low-cost pyranometer for measuring broadband solar radiation
Authors: Tohsing K , Phaisathit D , Pattarapanitchai S , Masiri I , Buntoung S , Aumporn O , Wattan R
Published: December 2019

In this work, the design of an inexpensive and reliable pyranometer used for measuring broadband solar irradiance is proposed. A BPX43 – 4 phototransistor is used as a light detector, which has the spectral response in the range approximately 450 to 1100 nm. This system is controlled by an Arduino pro mini ATmega328P (5 V, 16 MHz) microcontroller and all components are located inside a FB05 black box. Due to a high level of solar radiation in the different environmental conditions, the pyranometer encountered the voltage saturation. Therefore, a 0.25 mm thick of Teflon is selected for attenuating the sunlight. After investigating against a reference sensor, the transmittance of this attenuator is found to be about 12.5%. Finally, the experimental results from the system are compared with a standard pyranometer performed at Physikalisch-Meteorologisches Observatorium Davos/World Radiation Center (PMOD/WRC, 46.80 °N, 9.83 °E and 1, 610 meters above sea level), Switzerland. The results demonstrate a satisfactory agreement between the global irradiance obtained from our proposed pyranometer and the standard pyranometer.
Extracting overlapping 2D-images by central-derivatives-based algorithm
Authors: Palasak Hataiwat , Pholsen Natthajuks , Tianprateep Montian , Wannadelok Orapin
Published: December 2019

Usual algorithms, such as, 5-steps and a backward-derivatives-based (BDB) method, could extract an image of a top layer from a one of a base layer in a 2D full-field optical coherent tomography (FFOCT). Those both algorithms still give the robust images. For improving the quality of the image in 2D-FFOCT, in this research a central-derivatives-based (CDB) algorithm is introduced to apply for investigating two overlapping 2D images. According to our simulation, it shows that the performance of CDB-algorithm is as good as the one of 5-step algorithm in case a phase difference between each fringe images is not more than 40 degree. It is also less robust by comparing with the one of BDB-algorithm. By our experimental results, it can also be concluded that the CDB-algorithm can separate two overlapping 2D images with more brightness than the ones applied by BDB-algorithm.
Effect of static magnetic field on ripening of Thai cavendish bananas
Authors: Mahathaininwong N , Chucheep T , Thitithanakul S , Wandee S , Karrila S , Narakaew J
Published: December 2019

This study aimed to investigate the effects of static magnetic fields on the ripening of Thai cavendish banana fruits. The cavendish bananas were received from an agriculturist in Kanchanadit District, Surat Thani province, Thailand. NeFeB magnets were used to generate the maximum static magnetic fields of 300 mT and 600 mT. The ripening of the banana fruits was recorded in terms of weight loss, color change and firmness after exposure to a magnetic field. The results showed that the weight loss of the banana fruit when exposed to magnetic field was higher than in the not exposed control group. Increasing the magnetic field strength to 600 mT increased the weight loss further from that with 300 mT. The effects of magnetic field on weight loss of bananas were statistically significant, but there were no statistically significant differences in color or firmness from the control group.
A causal model of factors affecting azimuth and altitude learning by smart phone in astronomy
Authors: Wimuttipanya J
Published: December 2019

In present, physics learning management has developed into learning technology from easy to complex levels with many developed media increased. Smart phone is one of all media use in many automatically. In this paper, researcher used instruction of a causal model of factor affecting azimuth and altitude learning by smart phone in astronomy using by rotating the position, finding the angle of the star in the sky which tells the coordinates of the star from applications created used by cell phones and Wi-Fi. It was suggested that student using their phones to download a free app that would monitor frequencies and send data to a processing facility. Methods for teaching and learning that students have analysed solve problems that are linked to the problems of everyday situations and conclusions through the team’s idea to solving problems of inequality in access to quality education of students who are far away and the practice of research practices that can be used to develop educational institutions. The results indicated that the adjusted model was consistent with empirical data. Goodness of fit measures were found to be: χ2 = 271.59, df = 149, p-value = 0.00063, GFI = 0.95, RMSEA = 0.042.
Present status of 4 MeV electron beam accelerator system for natural rubber irradiation
Authors: Suphakul S , Rhodes M W , Saisut J , Rimjaem S , Thongbai C
Published: December 2019

Electron beam accelerator system for natural rubber irradiation is under developing at the Plasma and Beam Physics (PBP) Research Facility, Chiang Mai University (CMU). The system aims to improve the natural rubber latex properties by using energetic electrons to induce cross-linking between polymer chain or called vulcanization process. Due to no chemical added as a conventional way (usually sulphur), the rubber product produced by this method has good mechanical properties with lower toxicity that is suitable for many applications. The system consists of a DC thermionic cathode electron gun, a 5-cell radio-frequency (RF) linear accelerator (linac), an RF modulator, an adjustable speed conveyer and a control system. The expected electron beam energy from the simulation is in the range from 0.5 to 4 MeV with a maximum pulse current of 100 mA and a pulse repetition rate is adjustable from 20 to 400 Hz. This beam condition provides a calculated average absorbed dose between 160 and 640 Gy. The system has been complete assembled and the RF modulator has been tested. The RF processing has been performed and some of electron beam properties has been measured. The present status of development and the results are reported in this contribution.
Calibration of energy slits and simulation of electron trajectories in the alpha magnet’s 3D field
Authors: Techakaew K , Rimjeam S
Published: December 2019

At the PBP-CMU Electron Linac Laboratory, high-brightness electron beams are produced from the radio-frequency (RF) linear accelerator (linac) system that consists of a thermionic RF electron gun, an alpha magnet, a traveling-wave linac structure, quadrupole magnets and steering coils. Several diagnostic devices are installed in the accelerator system to characterize electron beam properties. In this work, we study on measurement of electron beam energy downstream the RF gun using the alpha magnet equipped with energy slits in the vacuum chamber and a current transformer. Calibration of the energy slits’ posit ions for various stepper motor encoder numbers was conducted before installing the slits in the magnet’s vacuum chamber. The calibration result was imported into the energy calculation software that links to the stepper motor encoder and the energy value will then be automatically calculated. Moreover, dynamic simulations using a software ASTRA were performed to investigate electron’s trajectories in the alpha magnet’s field with different initial electron positions and angles. The results from this study will be used to estimate the result and accuracy of energy measurement using the alpha magnet. It was found that, for different initial horizontal and vertical positions at the alpha magnet entrance, the energy of electron will be measured to be lower than its actual energy by around 0.5% and the measured energy will decrease when the initial position is moving away from the middle point. In case of horizontal particle’s angle, the error of energy measurement increases up to 1% at the angle of 3° before the beam hitting the alpha magnet chamber. For the vertical particle’s angle, the electron that has the initial angle less than or larger than 1.5° will hit the vacuum chamber.
Heat transfer rate of close-loop oscillating heat pipe with check valve using NiO as working fluid
Authors: Saengmart O , Meena P
Published: December 2019

This Research studied the heat transfer characteristics of the closed-looped oscillating heat pipe with check valves (CLOHP/CV), examining effectiveness, considering the effects of heat transfer rates and studying the internal pressure of the (CLOHP/CV). That install the fins and do not install the fins by using a heat pipe made of copper pipe, inner diameter of 5 mm, with two check valves. The evaporator section, condenser section and adiabatic section lengths were 20, 20 and 10 cm, respectively. Heat pipe had two check valves and 24 turns. Nickel oxide (NiO) was used at a working filling ratio and concentration 50% by volume and 0.14 g of the tube respectively. Hot air was at 60 70 and 80 degree Celsius, at a wind speed of 1.0 m/s. The fins were copper with radian size of 0.5 cm, and thickness of the fins was 1 mm. From the experiment, it was found that the heat flux of the CLOHP/CV heat exchanger set with the fins was the highest at 80 degree Celsius, with a value of 9, 743.11 W/m2. The effectiveness is 0.3 and the internal pressure is 123.59 kPa.
Experimental apparatus and methods for synthesizing 1D single-atom array
Authors: Srakaew K , Phrompao J , Anukool W
Published: December 2019

We present apparatus and methods for laser cooling and trapping of single rubidium-85 atoms. The setup consists of a magneto-optical trap and identical optical microtraps lined up by using a programmable acousto-optic defector. The apparatus designs and systematic arrangement are described in conjunction with the limitations of the techniques and the scope for future improvement. Individual control over the position and power of each trap attained in our work is the key to addressable and scalable quantum system.
Development of a highly sensitive label-free DNA based fluorescent sensor for cisplatin detection
Authors: Niammusik Anusorn , Thammakhet-Buranachai Chongdee , Thavarungkul Panote , Kanatharana Proespichaya , Srisintorn Wisarut , Buranachai Chittanon
Published: December 2019

Cisplatin, or cis-diamminedichloroplatinum (II), is a platinum-based chemotherapeutic drug. It is widely used against many types of cancer. However, there are various side effects in patients taking cisplatin. The side effects are also found in chemotherapists or health workers exposed to contaminating cisplatin in workplace. Therefore, there is a need for sensors for cisplatin contamination detection. This work reports the development of a highly sensitive fluorescent sensor using single stranded ssDNA as a sensing element. It contains consecutive guanine bases to allow an efficient cisplatin binding. Then, an enzyme-free DNA amplification technique called catalyzed hairpin assembly (CHA) was employed to increase the sensor sensitivity. It comprises two hairpin DNAs (H1 and H2) which are in meta-stable states and can form a hybrid only in the presence of the cisplatin sensing ssDNA described above. H1 is designed such that after the hybrid formation, a newly exposed overhang forms a G-quadruplex (GQ). The GQ formation can be monitored by mixing a GQ binding dye called Thioflavin T (ThT) in the solution. ThT fluorescence quantum yield is negligible if ThT is free in solution but increases over 1000 folds when bound to GQ. The formation of H1:H2 hybrid and ThT-GQ complex is disrupted if cisplatin binds to the sensing ssDNA. Therefore, the decrease in ThT fluorescence signifies the increase in cisplatin concentration and vice versa. The developed sensor capable to detect the cisplatin in the range of 500 – 7500 nM and the limit of detection is 182 nM. The merit of this novel sensor is that it is label-free therefore economical yet highly sensitive. It is expected that the sensor can help monitor cisplatin contamination in chemotherapeutic workplaces.
Characterizations of carbon nanotubes grown on clay
Authors: Aodkeng S , Sinthupinyo S , Chamnankid B , Hanpongpun W , Chaipanich A
Published: December 2019

Carbon nanotubes (CNTs) are nano materials that have unique physical and mechanical properties. Carbon nanotubes grown on clay (Clay-CNTs) are new hybrid material based on clay mineral. Clay minerals were used as catalyst for CNTs synthesis by chemical vapor deposition at 700 °C for 1 hour. In this work, Clay-CNTs were investigated by various analytical techniques such as X-ray diffraction (XRD), scanning electron microscope (SEM) and electron diffraction spectrometer (EDS) and Raman spectroscopy to analyse the phase identification of crystalline, morphology and crystallinity quality of Clay-CNTs. Moreover, thermogravimetric analysis (TG) was studied to ident ify phase deco mposition. XRD results indicate crystallites of the CNTs have (002), (101) and kaolinite and quartz from clay mineral catalyst. SEM images of Clay-CNTs showed cluster of CNTs on carbon fiber and their wormlike morphology. The intensity of Raman spectra of Clay-CNTs reveals the defect of CNTs structure. TGA derivative profile indicated decomposition of CNTs and kaolin.
Mechanical and physical properties of particleboard made from scirpus grossus and coconut fiber
Authors: Kongkaew P , Sila W , Saiying S , Pharanat W
Published: December 2019

In this research of study mechanical and physical properties of particleboard made with scirpus grossus and coconut fiber. The particles were manually mixed at a weight ratio of C1 (100:0), C2 (90:10), C3 (75:25), C4 (25:75), C5 (10:90) and C6 (0:100) and glued adhesive with methylene diphenyl diisocyanate (MDI) 7% (by weight). Physical and mechanical properties were evaluated following Thai industrail standard (876-2547). To measure the mechanical properties, 6 samples were tested to determine the modulus ofrupture – MOR and modulus of elasticity – MOE by using samples with a nominal size of 250×50 mm and physical properties, 3 samples were tested to determine the were determined: density, water absorption (WA) and thickness swelling (TS). The physical properties result of all ratio is according to the standard, which the highest density, thickness swelling and water absorption are C3 (849.01 kg/m3), C6 (6.55 %) and C6 (9.92 %) respectively. The mechanical properties result of Modulus of rupture (MOR) for proportion to C4, C5 and C6 have a higher than standard, while C1, C2 and C3 are lower. All ratio for modulus of elastic (MOE) are lower than standard. The ratio of C6 is the highest modulus of rupture (21.60 MPa) and the highest of modulus of elastic is C1 (360.20 MPa). The experimental investigation indicated that the excellent particleboard properties are obtained with a mixture ratio of C5 (10:90).
Training science teachers in using guided inquiry-based learning to develop experimental design skills in laboratories
Authors: Sujarittham T , Yeung A , Tanamatayarat J
Published: December 2019

It is well accepted that the purpose of physics laboratory classes is to not only help students gain an understanding of physics concepts, but to also help them develop their scientific laboratory skills. One such skill is the ability to undertake science inquiry to design an experiment to investigate a research question, thereby enhancing students’ higher order thinking skills. Engaging in science inquiry and experimental design consists of five sub-skills. These include identifying the variables to be measured, developing an experimental procedure, selecting equipment and materials, minimizing possible errors, and making links to known physics concepts. The aim of this study was to train teachers to enhance their students’ experimental design skills through inquiry based learning. A training program was conducted, in which 22 teachers participated. These teachers had over 5 years’ experience in teaching science and physics. The concept of heat capacity was chosen, as it was of interest to all the teachers in the group. The training also involved teachers using guided worksheets, which were designed to help them assist their students in developing each of the five sub-skills using a guided inquiry approach. It is expected that such an approach will allow students to solve problems that they had encountered previously. From observations of teacher practices and analysis of teacher worksheets completed in the training course, we found that most teachers spent most time on linking physics knowledge to solve the problem. Many teachers had misconceptions about heat transfer and closed system. Only 6 teachers could design and conduct their experiment to solve the problem correctly. However, all of them could reflect that the need for designing experiments that can enhance students’ experimental design skills and the five sub-skills.
A period-based measurement for grounding capacitance meter with arduino using a relaxation oscillator
Authors: Gasosoth Thitinun , Lianghiranthaworn Traitot , Unai Somrit
Published: December 2019

This paper focus on the development of a simple and low-cost capacitance measurement for Arduino microcontroller. The working principle of the circuit is based on the period changes of the square-wave signal, which is generated by relaxation oscillator, causes by RC values in the circuit. The relaxation oscillator is based on two different types of op-amp, rail-to-rail and comparator. The output frequency of the oscillator is about 2 kHz to 100 kHz. The range of test capacitors is approximately from 1 pF to 33 pF. The percent error of each type of op-amp due to nonlinearity and parasitic capacitance is presented. Finally, the comparison of the experimental results and theoretical analysis as well as precision LCR meter are investigated and discussed.
L-Cysteine/Graphene oxide for electrochemical determination of ascorbic acid in the presence of dopamine and uric acid
Authors: Prongmanee W , Asanithi P
Published: December 2019

Ascorbic acid (AA), also known as vitamin C, has many roles in biological systems, such as prevention of cancer and common cold. Determination of AA is essential for food and pharmaceutical industries. Nowadays, electrochemical method is a potential method for detecting AA. However, detection of AA in presence of biological compounds, e.g. dopamine (DA) and uric acid (UA), is big challenge because these compounds are commonly found in biological samples and interfere the oxidation peak potential of AA. To overcome this problem, electrochemical coating of cysteine on graphene oxide decorated screen-printed electrode (Cys/GO/SP) was newly used for determination of AA. Field emission scanning electron microscope, energy dispersive x-ray and EIS were used to characterize the composites. AA of different concentrations were determined in phosphate buffer saline that has 10-µM DA and 10-µM UA using by differential pulse voltammetry (DPV). Cys/GO/SP presented three oxidation peaks corresponding to AA, DA and UA, whereas GO/SP and SP provided single peak. The oxidation peak currents of AA showed good linear relationship with AA concentrations of 0.5 - 5 mM with the detection limit of 0.26 mM. The results suggest that Cys/GO/SP can be used for electrochemical determination of AA in the interference of DA and UA.
Thai Hom Mali rice purity test by using digital image analysis
Authors: Kleawphaipan T , Somprasong S , Srahongthong T , Pattanasiri B
Published: December 2019

The mixing of non-aromatic rice is one of the major problems that impact directly to Thai Hom Mali Rice export markets. Thus, to preserve the Thai Hom Mali Rice quality and reputation of exporting, the National Bureau of Agricultural Commodity and Food Standards (ACFS) establishes a manual of Thai Hom Mali Rice standards, where the rice grain must have at least 92% of Thai Hom Mali. Nowadays, the DNA-based method has been proved to be a robust and accurate tool for testing rice purity. However, this adulterants detection technique is expensive and unfit for a small scale of commercial. In this work, we applied image analysis by using the computer together with a flatbed scanner to characterize the rice grain and classify different rice varieties. We found that some rice grain morphological features, such as chaff-tip width, right concave depth, chaff-tip angle, and interior angle, are possible to be used for distinguishing between Khao Dawk Mali 105, Chainat 1, Pathum Thani 1, and RD 23.
Simulation and measurement of electromagnetic undulator prototype for production of THz radiation
Authors: Kitisri P , Suphakul S , Thongbai C , Rimjaem S
Published: December 2019

This research focused on magnetic field simulation and measurement of an electromagnetic undulator prototype for generation of terahertz (THz) radiation from electron beam with energy of about 10 MeV at the PBP-CMU Electron Linac Laboratory of the Plasma and Beam Physics Research Facility. This undulator prototype has 6.5 periods with a period length of 64 mm. Its magnetic field was measured by using a Hall probe with a measuring system, which its position movement can be precisely controlled with automatic computer interface. The magnetic field of end-poles was compensated by adjusting the end-pole currents. It was found that at the main-pole current of 0.76 A, the optimal end-pole currents at the entrance and exit o f the undulator were 0.27 A and 0.19 A, respectively. At these currents the undulator has the transverse good field region of 19 mm. For magnetic field simulation, the computer program RADIA was used to model the undulator prototype for the ideal design. This was done for comparing the magnetic fields from the simulation and the measurement. The magnetic field of the two cases were not the same because the constructed prototype has different gaps for different lo ngitudinal positions. However, they could give the radiation in the THz regime, which were 97.6 μm for the simulation and 96.7 ± 0.1 μm for the measurement.
Study on electron and hole states in tilted quantum well structures
Authors: Bukaew W , Sivalertporn K
Published: December 2019

In this study, the energy states of electron and hole in GaxIn1-xNyAs1-y/GaAs tilted quantum well structure have been theoretically investigated. The content of x and y are 0.65 and 0.005 respectively. The energy states and wave functions have been calculated by solving the Schrödinger equation in real space. The well width of 2-10 nm, barrier width of 2-10 nm and tilted layer width of 1-3 nm are considered in this work. The results show that the electron and hole energies decrease with increasing the well width and tilted layer width. The wave functions are both symmetric (ground state) and anti-symmetric (the first excited state), and spread out as the well width increases. In addition, the barrier width of couple tilted quantum well structure has also been studied. It is found that the probability of finding electron and hole are equal in both wells and the wave function within barrier layer decreases with increasing the barrier width as well. The ground state energy increases and the first excited state energy decreases as the barrier increases. As a result, the two states tend to the same level when the barrier is more than 8 nm. This is because the wide barrier can decrease the interaction between two quantum wells and makes each quantum well acts as an isolated quantum well with no interaction between them.
Local glass transition of polyisoprene induced by graphene planes observed in silico through atomistic molecular dynamics simulations
Authors: Yolong Thipjula , Sutthibutpong Thana
Published: December 2019

A study on the molecular mechanisms of natural rubber reinforcement due to the addition graphene planes was carried out by molecular dynamics simulations. Simulations of pure natural rubber (Polyisoprene; PI) and Polyisoprene-graphene composite (PI-GRA) were performed and analyzed for their glass transition temperatures (Tg). In the simulations, simulated annealing technique was used to change the temperature from 100 K to 300 K in order to observe the glass transition from the point where the sudden increase in volume and sudden decrease in density were observed. Glass transition temperature (Tg) from the molecular dynamics trajectory of pure PI was 207.9 K, close to the value Tg = 211 K obtained from the experiment. Also, we found that glass transition temperature (Tg) increased to 220.1 K when adding graphene planes into the PI matrix. In addition, further analysis of MD trajectories showed that the overall density of pure 16-mer cis-1, 4-polyisoprene at low temperature (100 K) is higher than the density at high temperature (300 K) and the threshold density for glass transition was 929.4 kg/m3. For PI-GRA at 100 K, density of the whole system was higher than the threshold density, which showed that the whole polymer was in glass phase. However, at 300 K, the network of PI molecules nearby the graphene planes were orderly organized and possessed higher density than the threshold density, which showing the properties of glass. In the middle area, PI molecules were arranged disorderly and has a lower density than the threshold, showing the properties of rubber.
Photometric study of the short-period contact binary CW Canis Minoris
Authors: Panpiboon P , Chinasa P , Punon M , Pharanud W , Sutthapintu A , Duangsopa A , Promsri C , Nilakhon C , Nontasee K , Nontachan N , Antapanya N , Saengnam T , Lawan T , Choawanklang W
Published: December 2019

We present the new BV light curves of the short-period contact binary CW Canis Minoris. The (O-C) diagram was fitted with times of minima for a new linear ephemeris which the period of the contact binary is found to be 0.313152 (±0.000053) days. The orbital period of the eclipsing binary is found to show a long-term increase at a rate of 3.34 (±0.50) × 10-7 days per year. The light curves were analyzed by the Wilson-Devinney code which has a mass ratio of 0.710 (±0.003) and a degree of contact about 0.013 (±0.989) %. The geometric structures of CW CMi are obtained with the components exactly filling its limited lobe.
Effects of hydrogen peroxide on 304 stainless steel in high temperature water
Authors: Makjan S , Boonsri P , Channuie J , Kanjana K
Published: December 2019

Hydrogen peroxide (H2O2), an oxidizer produced by water radiolysis, is considered one of the main contributors to corrosion of the stainless steel (SS) components in the cooling system of nuclear reactors. The detailed understanding of this chemical system is however still missing. The present research aimed to study the effects of H2O2 on 304 SS. The surface morphology and the chemical composition of the SS specimens after experiment were examined using Scanning Electron Microscope – Energy Dispersive X-ray (SEM-EDX). The change in atomic % of Fe, Cr, Ni, and O as a function of temperature will be reported. The corrosion type and possible corrosion products will be proposed and discussed.
Reverberation mapping of the disc wind in ultraluminous X-ray source NGC 5408 X-1
Authors: Loekkesee S , Chainakun P , Luangtip W
Published: December 2019

Recent observational evidences suggested that ultraluminous X-ray sources (ULXs) which are in supercritical accretion rate might release the outflowing wind and change the geometry to slim disc. However, the exact structure of the disc is still unclear. In this work, we develop a simple reverberation model to analyse the X-ray time lags of the ULX NGC 5408 X-1, in order to determine the geometry of the disc and the outflowing wind. The data of NGC 5408 X-1 from the XMM-Newton archive are binned into three groups based on the instrument count rates, i.e. low, medium and high count rates. The lag profiles are then extracted from each group. Fitting the models to the lag data suggests that the wind-launching radius tends to increase with the count rates, which is in agreement with the super-Eddington framework that prefers a stellar mass black hole (sMBH). The wind-launching radius for the sMBH is constrained to be in the order of ∼ 105rg. We also report a degeneracy between the black hole mass and the wind launching radius. A more realistic geometry and model might be required to explain the time lags in NGC 5408 X-1.
Characteristic of DBD plasma for ozone synthesis and its application on disinfection of chilli
Authors: Rodsong Puthita , Tirawanichakul Supawan , Tirawanichakul Yutthana
Published: December 2019

The main objectives of this work are to study effect of high voltage power supply on plasma dielectric barrier discharge (DBD) system to amount of ozone concentration and to preliminary study effect of ozone on disinfection of microorganism. The amount of ozone concentration generated by the plasma DBD was determined by the KI standard ASTM method while on-site research work, ozone concentration was measured by the Liverbond test kit. The experimental result showed that ozone concentration was relatively dependent on the voltage supply. The produced ozone concentration was varied between 10 and 100 mg/l of air flow rate relating to voltage supply. The characteristics of plasma discharges was also presented. For feasibility study of disinfection of microorganism on chili by ozonated water bubbling, the results showed that the dissolved ozone with 8 kV can reduce E.coli from 9×105 MPN/100 ml to 1×105 MPN/100 ml in 120 min duration time.
Dark matter from the inert Higgs doublet model
Authors: Treesukrat W , Uttayarat P
Published: December 2019

Dark matter is a clear evidence of new physics beyond the Standard Model. In this work, we consider the inert doublet model where dark matter is a member of a new Higgs doublet. In this scenario, dark matter properties can be calculated. We then test model predictions against experimental results such as the LHC Higgs data, the electroweak precision measurements and dedicated dark matter searches. In addition, we subject the model to theoretical constraints: perturbativity, vacuum stability and unitarity. Finally, we identify the viable parameter space of the model.
van der Waals parameters of inert, polar and non-polar gas molecules obtained from atomistic molecular dynamics simulations
Authors: Saeteaw Akarachai , Sawang Nuttawat , Sutthibutpong Thana
Published: December 2019

A series of atomistic molecular dynamics simulations were performed on the systems of gas molecules within an NVT ensemble, where the number of molecules, the volume and the temperature were controlled. For each simulation, simulated annealing technique was used to gradually vary the temperature and the change in gas pressure was measured within the simulation box at constant volume. Simulation results and regression analysis on the relationships between pressure and temperatures showed that two van der Waals parameters, representing interaction strength and effective size of the gas molecules, depended on shape, size and polarity of the molecules. This study provided an alternative way of demonstrating the basic thermodynamics of gas, and bridging the gap between information from microscopic and macroscopic scales.
An Arduino board with ultrasonic sensor investigation of simple harmonic motion
Authors: Buachoom A , Thedsakhulwong A , Wuttiprom S
Published: December 2019

An Arduino, one of the most popular microcontroller platforms, is widely used in teaching and learning STEM. It is really open source software and hardware, huge community, low cost boards and peripherals, and simple programming language. This research aims to develop an Arduino-based physics investigation of the simple harmonic motion (SHM) of mass on a spring. This rich cross curricular STEM activity integrates electronics, computer programming, physics, and mathematics in a way that is both experimentally exciting and intellectually rewarding. The experimental data are collected with the help of an HC-SR04 ultrasonic distance sensor and an Arduino Uno board. The data are then graphed and analysed using Microsoft Excel in real-time. The experiment data can be used to investigate Hooke’s law. The elastic constant of the spring, k = 16.54 N/m, is very close to the value determined from the period of the SHM. This Arduino-based investigation of SHM can be helped the students to improve both their experimental and theoretical skills.
Application of free surface synthetic schlieren method in determining surface tension from a light floating object
Authors: Pathommapas C , Yapo S , Seesomboon E , Pussadee N
Published: December 2019

Free surface synthetic schlieren (FS-SS) is a liquid surface topography visualization technique relying on apparent dot pattern displacement due to liquid surface deformation. It has gained attention in the fluid visualization field due to its relatively simple and inexpensive setup. One of the most powerful features of the FS-SS technique is the 3D topography of deformed liquid surface, in which submillimeter scale changes can be readily observed in great detail. The visualization of liquid meniscus at the solid interface is proposed in this study to calculate surface tension by equating the surface tension force with weight of light, floating object with circular geometry. It was found that surface tensions of liquids are much greater than anticipated, suggesting that the effect of buoyant force of displaced liquid due to deformed interface cannot be neglected. When the buoyant force is included, the calculated surface tension of liquids are within 10% of the reference values.
Motion Blitz: a new card game for assessing students’ thinking level about physics
Authors: Thunyaniti T , Wuttiprom S
Published: December 2019

Critical thinking and problem-solving skills are crucial for the 21st century. Game-based learning (GBL) is a powerful teaching strategy for fostering these skills amongst students. GBL can reinforce knowledge and bridge the gap between what is learned by creating dynamic, fun, and exciting learning environments. This research developed a card game called “Motion Blitz” for teaching the physics concept of motion in one and two dimensions. Motion Blitz is a quick matching card game that consists of a deck of “Motion Cards” which picture motions in daily life and a selection of “Motion Symbols” displaying a path of motions: linear, projectile, circular, rotational, rolling, and simple harmonic motions. To play the game, one player starts by flipping over one of the “Motion Cards”, then simultaneously everyone tries to figure out the proper “Motion Symbol” to grab. Figure it out and grab the right one to get the card/point. After playing, the teacher uses questions to stimulate student thinking and help students construct scientific knowledge. Finally, 12 questions according to Bloom’s taxonomy are administrated to students. These questions are classified according to different cognitive levels ranging from low-level thinking (knowledge, comprehension) to high-level thinking (application, analysis, synthesis, and evaluation). Data analyses showed Motion Blitz’s ability to elevate students’ thinking level, over 90% of students scored well at a low level and 59% at a high level approximately. In addition, data indicated that students’ thinking scores became lower at a higher level of thinking.
Effects of time delay in no-knowledge quantum feedback control
Authors: Saiphet Jirawat , Chantasri Areeya , Suwanna Sujin
Published: December 2019

The no-knowledge quantum feedback, introduced in Phys. Rev. Lett., 113, 020407 (2014), is a measurement-based feedback protocol for decoherence suppression in a quantum system coupled to noisy environment. By continuously measuring the environmental noise, without directly gathering any information about the system, the decoherence effect can be suppressed by feeding back quantum controls proportional to the measured signal. In the original work, the feedback control was assumed instantaneous, leading to perfect cancellation of noise backaction on the quantum system. However, the instantaneous feedback is difficult to achieve in practice, and close-loop feedback protocols are always associated with finite delayed time. Therefore, in this work, we consider the effects of the delay between the time at which the measurement signal is acquired and the time that such signal is fed back to the system. We investigate the problem with an example of a two-level system (qubit) coupled to a Markovian reservoir, via a Hermitian coupling operator, where a homodyne detection is used to measure the environmental noise. We numerically simulate quantum stochastic trajectories of the qubit and analyse their averaged dynamics. We find that the feedback control with time delay can either enhance or reduce the decoherence effects, depending on whether the delayed time is in-phase or out-of-phase with the unitary dynamics of the qubit system.
Electronic structures of CsPb(XxY1–x)3 perovskites
Authors: Wanwieng Nontapat , Kaewmeechai Chaiyawat , Laosiritaworn Yongyut , Punya Jaroenjittichai Atchara
Published: December 2019

We investigated electronic structures of CsPb(X
x
Y1–x
)3 perovskites, where X, Y = Cl, Br, or I, and x = 0, 1/3, or 2/3, based on the density functional theory (DFT) with generalized gradient approximation (GGA). The results show that these materials exhibit direct and inverted gaps, in the sense that the character of electronic states near the valence band maximum (VBM) is derived from atomic s-like orbital of Pb and p-like orbital of halide atom, whereas the character of states near the conduction band minimum (CBM) is derived from atomic p-like orbital of Pb in contrast with the electronic band structures of other common semiconductors. Their density of states also indicates that the optical transition in both absorption and luminescence are stronger.
Fabrication and properties of flexible CaCl2/P(VDF-HFP) composite films
Authors: Yuennana Jureeporn , Muensit Nantakan
Published: December 2019

An emerging trend in the development of smart electronics has great attracted the interest of scientists and engineers to fabricate hydrofluorpolymer composites that provide the large dielectric property and electroactive phase. This work has investigated the effect of calcium chloride (CaCl2) on morphology, structure and dielectric properties of poly (vinylidenefluoride-hexafluoropropylene) (P(VDF-HFP)). The CaCl2/P(VDF-HFP) composite films was prepared by a solution casting method. The addition of CaCl2can obviously induce the formation of the electroactive β-phase in P(VDF-HFP) films without any modification of P(VDF-HFP) chains or mechanical stretching treatment. The microporous composite films have better properties, such as high flexibility, thermal stability, β-phase fraction (97%) and dielectric constant (17), than the unfilled one.
Physical properties of RR Lyrae variables in Galactic globular clusters and dwarf spheroidal galaxies
Authors: Benkortem S , Tanakul N , Suwannajak C , Pattarakijwanich P , Yuma S
Published: December 2019

We propose a tool to distinguish between Galactic globular clusters (GCs) and dwarf galaxies based on physical properties of RR Lyrae (RRL) variables in the systems. Normally, these two systems show various distinctive properties; for instance, mass, size, and luminosity. Nevertheless, these properties overlap each other in recently discovered systems. The subsequent classification between GCs and dwarf spheroidal (dSph) galaxy is ambiguous. An RRL variable is a pulsating variable star with a short period of 0.2-1 days. It is relatively easy to observe the complete period of its light curve. The age of RRL stars is typically more than 10 Gyr; therefore, they can provide information of the host system at its early stage. In this study, we provide an extensive data collection of RRLs in 96 GCs, 23 dSphs, and 10 dwarf irregular (dIrr) galaxies. Based on public catalogs, we analyze various RRL properties such as Oosterhoff dichotomy, fraction of high amplitude short period (HASP) variables, metallicity, and specific frequency of RRLs (SRR). We examine correlations among all properties in an attempt to distinguish between GCs and dSphs.
Study of the relation between torsional shear stress and transverse torsion angle of cable
Authors: Mukdapitak S , Kasayapanand C , Trakulhun P , Puntree J
Published: December 2019

The relation between torsional shear stress and transverse rotational angle of earphone cable was investigated due to hypothecated to play an important role in the cable entanglement. The cable was hung with a circular plate and attached to force sensor on top. The experiment was carried out by rotating the plate stepwise at 90 degrees each for 80 times reaching 7200 degrees in total. Experimental results exhibit the fluctuation of longitudinal force with period almost exactly equals to a complete circle of transverse rotational displacement. It is also found that average longitudinal force tends to increase with counter clockwise rotation while decreasing in clockwise direction. We then conclude that the relationship between torsional shear stress and transverse torsion of the cable can be described by trigonometric function with linear changing of average amplitude.
Scintillation response of CdWO4 scintillator for gamma-ray detection
Authors: Phunpueok Akapong , Thongpool Voranuch , Jaiyen Sarawut
Published: December 2019

At present, scintillation materials are playing a major role in medical radiation detection. They are being used for various scans including CT scan, PET scan and SPECT scan. In this work, the researchers studied the scintillation response of the CdWO4 (CWO) crystal compared with the Bi4Ge3O12 (BGO) crystal. The energy resolution and light yield values were tested using a photomultiplier tube (PMT) readout. The gamma source was aligned along the cylindrical axis of the crystal and the PMT. The energy spectra were then recorded using a PC-based multichannel analyser (MCA). From the results, it was found that the energy resolution of 6.5 % obtained from the CWO crystal was superior than that of 9.3 % obtained from the BGO crystal of 662 keV gamma-ray energy. The CWO crystal displayed about two times greater light yield than the BGO crystal. In the energy range from 32 keV to 1, 408 keV, the degree of the light yield non-proportionality of 0.13 obtained from the CWO crystal was also more exceptional than that of 0.19 obtained from the BGO crystal. The photo-fraction of both crystals was also discussed.
3D printing of interdigital sensor based conductive ABS for salt and sucrose concentration sensing
Authors: Ponan W , Harnsoongnoen S
Published: December 2019

This paper reports the application of three-dimensional (3D) printing to the fabrication of an interdigital sensor based conductive acrylonitrile butadiene styrene (ABS) for salt and sucrose concentration sensing. The substrate and interdigital sensor are fabricated by 3D printing based ABS and conductive ABS filament, respectively. The interaction between the samples and interdigital sensor was analyzed based on a direct current circuit. The proposed sensor was tested for the electrical current response to salt and sucrose at various concentrations ranging from 0 to 10 % (W/V) with steps of 2 % (W/V). The experimental results confirmed that the electrical currents were linearly changed when the concentration of salt and sucrose was changed. Moreover, it has a wide dynamic range and offers rapid lower-cost measurement. The proposed technique offers an opportunity for the development of salt and sucrose meter systems.
The effects of atmospheric plasma jet treatment to the germination and enhancement growth of sunflower seeds
Authors: Nantapan J , Sarapirom S , Janpong K
Published: December 2019

Using the plasma technique, the sunflower seed was treated by means of argon plasma. The argon plasma was driven by high voltage DC pulse at 25 kHz. Plasma dissipated power was varied at 0.41, 0.51, 0.61 and 0.72 watts and argon gas flow rate was fixed at 4 liters per minute for 15 sec. The experiment analyzed the physical properties, chemical properties and growth rate. Concerning the physical properties, the morphology was checked via the contact angle and roughness by SEM. The chemical properties were analyzed via contact angle. The growth rate was checked using 4 processes: the 1st is the water uptake, the 2nd is germination count rate within 5 days, the 3rd is seeding length within 7 days and the 4th is dry weight of seeding with 80 °C in the oven for 24 hrs. The results show the contact angle of control is 41.08 degree. After treatment using plasma jet the contact angle decreased, henceforth the wettability increased. Using increased plasma power the surface roughness increased. The water uptake of plasma with dissipated power at 0.41 watts gave the best result. Following plasma dissipated power at 0.41 and 0.61 watts respectively the germination count rates are 68% and 56%. The seeding length as well as the dry weight decreased when the power increased.
Roles of driven current locations on ETB and ITB based on three-field bifurcation concept
Authors: Dang-iad A , Chatthong B
Published: December 2019

This work investigates the roles of external current source on the formation and effectiveness of an internal transport barrier (ITB) and an edge transport barrier (ETB) in fusion plasma using bifurcation approach. Thermal, particle and toroidal momentum transport equations are solved simultaneously for the spatiotemporal profiles of plasma pressure, density and toroidal velocity, respectively. The transport effects include neoclassical and turbulent terms with constant coefficients assumption. The turbulent suppression, leading to intrinsic formation of transport barriers, is driven by the magnetic shear and the flow shear. Residual stress effect is included in this work. Thermal, particle and torques sources are locally provided based on Gaussian shape distribution at plasma center, plasma edge and plasma center, respectively. The effects of off-axis driven current locations on ITB and ETB formations are investigated. In particular, width and height of ETB and ITB are shown to be affected by the source. It is found that off-axis of driven current can increase plasma temperature, density and toroidal velocity at its core because ITB is formed and expanded. However, size of ETB pedestal is slightly affected by the location of driven current. When the location of driven current is changed from r = 0.00 to 0.60, ITB width changes from r = 0.00 to 0.12 of plasma profile and ITB top formation location changes from r = 0.00 to 0.80.
The students’ basic conceptions of buoyant force
Authors: Wongsuwan Wachirawut , Huntula Jiradawan
Published: December 2019

The conception of buoyant force is an advanced concept. If students need to solve the problem on the buoyant force, they have to understand basic concepts which are mass, volume, force, pressure, and density. For solving the problems about buoyant force, students need to make a decision and use many concepts to solve the problems. The difficulty of solving a problem about buoyant force is students cannot construct and link their own related knowledge to solve the problem. In this study, the purpose was to study students’ basic concept in buoyant force of grade 10 and grade 11 students. The target group consisted of 18 students in Phangwittayayhon school. Two-tier multiple choice was used as a conceptual test in this research consisting of eight items. All of students were taught about the buoyant force concepts before doing the conceptual test. The data were analyzed by descriptive statistic. The results showed that more than 80 percent of students have many alternative basic concepts which are related to buoyant force including mass, volume, depth, pressure, and density even they have already studied buoyant force since they were in grade 9.