bluuebunny/crossref_metadata_2025 huggingface dataset:
Dc‐link capacitor voltage control for the NPC three‐level inverter with a newly MPC‐based virtual vector modulation
Authors: Yuan Qingqing , Li An , Qian Jinyue , Xia Kun
Published: December 2019

Dc‐link capacitor voltage unbalance would affect the performance of the neutral‐point clamped (NPC) three‐level inverter. With the traditional virtual space vector modulation (VSVPWM) method, the dc‐link capacitor voltage could be kept balance under the different modulation indexes or power factors. With the virtual medium vector being set as an adjustable one, the voltage balance could be better guaranteed no matter there might have some non‐linear factors However, whether the traditional or improved VSVPWM method has a complicated trigonometric calculation, thus, a newly MPC‐based virtual vector modulation has been proposed in this paper. With the 19 virtual space vectors being in roll optimisation, a nice current trajectory, dc‐link capacitor voltage balance, even a relative low switch losses have been implemented. Considering that the optimised virtual space vector could not be taken as a direct output, the distribution of the basic vectors has been generated to make it being favourable for modulation. The effectiveness of this MPC‐based virtual vector modulation is verified in comparisons with other methods, which can save over 67.3% execution time of the traditional SVPWM method, and over 46.6% of the improved VSVPWM way while provide a better dc‐link capacitor voltage balance and output current quality.
Dynamic testing and analysis of turbine generator shafting
Authors: Tang Changliang , Wang Liyong , Chen Tao
Published: December 2019

With the world's energy shortage, the scholars all over the world have done a lot of research work on the efficient use of energy, energy‐saving emission reduction, and the development of new energy. Turbine generators have a wide range of applications in energy recovery. In this study, a new type of turbine generator structure is proposed. Four disc‐type permanent magnet motors are symmetrically mounted on the shafting, and are supported by gas hydrostatic bearing. The vibration tests of the shafting were carried out. The vibration characteristics of the shafting were analysed by using the bode diagram, the time‐waterfall map, the bifurcation diagram, the shaft orbits at the typical speeds, and the Poincare maps, which can provide references for developing high‐speed turbine generators.
A novel technique for hypersonic vehicle control
Authors: Mitridis Dimitrios , Bliamis Chris , Panagiotou Pericles , Yakinthos Kyros
Published: December 2019

A novel control technique is investigated for hypersonic aerial vehicles. The technique is based on the use of active shock bumps (SBs) as a form of control device. The SBs deflect to create shockwaves on–demand, at specific locations around the aerial vehicle. As a result, a force is applied on the aerial vehicle, which in turn is used to provide the necessary moment for pitch and roll manoeuvres. In this work, a preliminary aerodynamic analysis of the SB device technique is made by means of CFD. For this purpose, and taking the large corresponding Reynolds numbers of the flow into consideration, the two–dimensional Euler equations are solved. A parametric investigation is carried out, by examining the effect of key parameters, namely the Mach number (M) and device deflection angle (δSB) on the produced force acting on the vehicle, serving as a proof of concept. Using a specific interpolation method, the resultant force is presented as a function of the Mach number and the device deflection angle, on three–dimensional charts, where the effect of each parameter is shown (force–Mach–deflection maps). Furthermore, a preliminary feasibility study is performed, including a kinematic analysis and some key material considerations. Additionally, a kinetic analysis is also conducted to secure the dynamic rigidity of the actuating mechanism and provide an initial estimation concerning weight and basic geometrical parameters of the SB mechanism components.
Aircraft Maintenance Professionals: Stress, Pressure and Fatigue
Authors: Dias Nicole G. , Santos Luis F.F.M. , Melicio Rui
Published: December 2019

The objective is to emphasize on the environmental and organizational pressure, namely, the pressure and fatigue induced in aircraft professionals. Safety is the main driver of aviation; environmental and organizational conditions, including extended working hours, have a negative impact on the performance of aircraft maintenance professionals and on aircraft safety. Just as aircraft crews and air traffic controllers have their work schedules highly monitored by aviation regulators; but regulators do not monitor the work schedules of professionals and they are subject to extended working timetables required by aeronautic players. The authors, through an international survey aimed at aeronautical professionals, demonstrate that errors are linked to stress, pressure and fatigue, environmental and organizational. This work also intends to demonstrate the need for regulators to monitor the work schedules of aircraft professionals to avoid that extended working hours having a negative impact on aircraft safety. The authors give the possible diagnostics and recommendations, which can be used to help the aeronautical players and aircraft maintenance staffs to create a safety culture and a decision and validation matrix of the aircraft maintenance.
Comparison of Reactive Flow Simulations for a LOX/CH4 Multi-element Rocket Engine
Authors: French Ainslie D. , Cutrone Luigi , Schettino Antonio , Marini Marco , Battista Francesco , Natale Pasquale
Published: December 2019

This study details the reactive flow simulations of a LOX/CH4 Multi-element rocket engine. The work has been conducted within the framework of the HYPROB-BREAD project whose main objective is the design, manufacture and testing of a LOX/LCH4 regeneratively cooled ground demonstrator. Numerical simulations have been carried out with both commercial software and CIRA software developed in house. Two sets of boundary conditions, nominal and experimental, have been applied from which a code-to-code validation has been effected with the former and a code-to-experiment validation with the latter. The results presented include both flow data and heat fluxes as well as parameters associated with engine performance, and indicate an excellent agreement with experimental data of a LOX/CH4 Multi-element rocket engine.
Angst in der Kunst. Ikonographie einer Grundemotion
Authors: Hillert Andreas
Published: December 2019

Katharina Domschke. Angst in der Kunst. Ikonographie einer Grundemotion. Stuttgart: Kohlhammer 2019. 200 Seiten, 49,00 Euro, ISBN 978–317–035–150–9
Cannabis, Cannabinoide und Cannabiskonsumstörungen
Authors: Hoch Eva , Preuss Ulrich W.
Published: December 2019

Keine Droge führt derzeit zu so intensiven, teilweise leidenschaftlich geführten Diskussionen wie Cannabis. Welche gesundheitlichen und sozialen Risiken birgt die Substanz, wenn sie zu Rauschzwecken gebraucht wird? Dieser Beitrag beschreibt die wichtigsten Cannabinoide, das endogene Cannabissystem sowie mögliche kurzund langfristige Risiken. Er zeigt zudem psychotherapeutische Behandlungsoptionen von Cannabismissbrauch und -abhängigkeit auf.
What You Need to Know About AQP4, MOG, and NMOSD
Authors: Prasad Sashank , Chen John
Published: December 2019

Neuromyelitis optica (NMO) is an antibody-mediated inflammatory disease of the central nervous system with a predilection for the optic nerves, spinal cord, and certain brain regions. While NMO was previously considered a variant of multiple sclerosis (MS), it is now known to have distinct clinical, pathological, and immunological features. The identification of AQP4-IgG, a pathogenic antibody against aquaporin-4 (AQP4), delineated NMO from MS and markedly advanced insights into the unique features of this disease. The specificity of this antibody has allowed an expanded view of the clinical presentations of NMO-spectrum disorders (NMOSD), without requiring all the clinical features that were previously essential to make a clinical diagnosis. Early, accurate diagnosis of patients with NMOSD permits treatment with appropriate acute and long-term immunosuppressive agents that are critical to mitigate the risk of disability associated with this disease. More recently, a subset of patients with the NMOSD phenotype have been found to have autoantibodies targeting myelin oligodendrocyte glycoprotein (MOG), which has a different pathogenesis and expected outcome. Better understanding of the distinct pathophysiology of these disorders has laid the foundation for targeted efforts to develop novel, disease-specific treatments. In this review, we discuss the revised diagnostic criteria for NMOSD, appraise the diagnostic significance of the AQP4-IgG and MOG-IgG tests, review evidence supporting the use of available treatments for acute episodes and long-term disease modification, and highlight key emerging immunotherapies.
Effect of ZrO2 interfacial layer on forming ferroelectric HfxZryOz on Si substrate
Authors: Lee Sang Jae , Kim Min Ju , Lee Tae Yoon , Lee Tae In , Bong Jae Hoon , Shin Sung Won , Kim Seong Ho , Hwang Wan Sik , Cho Byung Jin
Published: December 2019

Ferroelectric HfxZryOz (HZO) with an average polarization switching window of 32 µC/cm2 was demonstrated on a Si substrate with a ZrO2 interfacial layer (IL). It is suggested that the ZrO2 IL below HZO crystallizes in the form of an o-phase prior to HZO crystallization, during rapid thermal annealing, thereby promoting the vertical growth of an o-phase HZO layer. HZO with the ZrO2 IL consists mainly of an o-phase that exhibits an in-plane tensile stress of 2.68 GPa, resulting in superior ferroelectric characteristics. This technology has the potential to expedite the realization of ferroelectric Hf-based dielectrics in advanced memory and logic technology.
Micro-MOKE with optical interference in the study of 2D Cr2Ge2Te6 nanoflake based magnetic heterostructures
Authors: Ma Zongwei , Zhu Wang , Lin Gaoting , Liu Yinan , Jin Feng , Yang Yang , Wu Tong , Luo Xuan , Sun Yuping , Chen Jianhao , Sun Yan , Zhou Chun , Sheng Zhigao
Published: December 2019

Due to its high sensitivity and sub-micrometer spatial resolution, the microscopic magneto-optical Kerr effect (micro-MOKE) technique has been widely utilized in the study of two-dimensional (2D) magnetic materials and heterostructures. Here, by taking 2D Cr2Ge2Te6 nanoflakes on a silicon wafer substrate as a model system, we present the effect of optical multilayer interference induced “optical artifacts” on the effective micro-MOKE measurements in such a system. It is found that not only the magnitude but also the sign of the micro-MOKE signal could be modulated by the “optical artifacts” with the variation of either the Cr2Ge2Te6 nanoflakes’ thickness or probe light wavelength. The detailed analysis based on the multilayer interference model reveals that there are two kinds of MOKE signals, sign reversal and magnitude modulation behavior, and the interference effect on the MOKE response can be easily predicted from unpolarized optical images. Our findings provide instructional principles on the promotion of micro-MOKE characterization as well as the optical studies in van der Waals magnets.
Quantifying the photothermal conversion efficiency of plasmonic nanoparticles by means of terahertz radiation
Authors: Breitenborn H. , Dong J. , Piccoli R. , Bruhacs A. , Besteiro L. V. , Skripka A. , Wang Z. M. , Govorov A. O. , Razzari L. , Vetrone F. , Naccache R. , Morandotti R.
Published: December 2019

The accurate determination of the photothermal response of nanomaterials represents an essential aspect in many fields, such as nanomedicine. Specifically, photothermal cancer therapies rely on the precise knowledge of the light-to-heat transfer properties of plasmonic nanoparticles to achieve the desired temperature-induced effects in biological tissues. In this work, we present a novel method for the quantification of the photothermal effect exhibited by nanoparticles in aqueous dispersions. By combining the spatial and temporal thermal dynamics acquired at terahertz frequencies, the photothermal conversion efficiency associated with the geometry of the plasmonic nanoparticles can be retrieved in a noncontact and noninvasive manner. The proposed technique can be extended to the characterization of all those nanomaterials which feature a temperature-dependent variation of the refractive index in the terahertz regime.
Enteroendocrine and tuft cells support Lgr5 stem cells on Paneth cell depletion
Authors: van Es Johan H. , Wiebrands Kay , López-Iglesias Carmen , van de Wetering Marc , Zeinstra Laura , van den Born Maaike , Korving Jeroen , Sasaki Nobuo , Peters Peter J. , van Oudenaarden Alexander , Clevers Hans
Published: December 2019

Significance

The stem cell niche is the in vivo microenvironment in which stem cells both reside and receive stimuli that determine their fate. Intestinal Paneth cells produce an arsenal of molecules involved in numerous biological processes, including critical support of the intestinal stem cell niche via the expression of niche ligands, growth factors, and cytokines. The relevance of the niche function of Paneth cells has been challenged, however. Here we show that specific, acute ablation of Paneth cells in mice does not affect the stem cell population, because alternative niche cells derive enteroendocrine and tuft cells. These cells serve as an alternative source of Notch signals, which are essential for intestinal stem cell maintenance.
The study effects of the characteristics of hydraulic oil on calibration of hydraulic pressure balance
Authors: Khamnounsak C , Likit S
Published: December 2019

One of the sources of an anomaly in the calibration of a hydraulic pressure balance is a various kind of working fluids that is employed in an operation. Therefore, the pressure and vacuum laboratory at National Institute of Metrology (Thailand), also known as NIMT, has been studied the effects of using different types of working fluids. The purposes of the study are to find piston effective area and study effectiveness of hydraulic pressure balance by observing falling rate and piston rotating time. The studies were performed in two ranges which are between 40 bar to 70 bar, and 600 bar to 700 bar. The results illustrate that the effective area of piston in the range of 40 bar to 70 bar has the maximum difference of 14 ppm, and in the range of 600 bar to 700 bar, it has the maximum difference of 5 ppm which will not affect the accuracy of hydraulic pressure balance. In addition to that, hydraulic pressure balances that use DHS oil have a falling rate approximately double of hydraulic pressure balances that use ISO VG 22 oil. Regardless, this does not affect the calibration result also the usage of the equipment. As the result, these two oils can be used interchangeably in calibration of hydraulic pressure balance that used in industry sector.
The mass distribution and the rotation curve of the Milky Way Galaxy using NARIT 4.5 m small radio telescope and the 2.3 m Onsala radio telescope
Authors: Mingmuang Y , Tummuangpak P , Asanok K , Jaroenjittichai P
Published: December 2019

This study was aimed to make the neutral hydrogen (HI) mapping and rotation curve of the Milky Way at galactic longitude 0° to 90° in the galactic plane by using the 4.5 m Small Radio Telescope (SRT) of National Astronomical Research Institute of Thailand (NARIT) and the 2.3 m Onsala radio telescope. The HI spectra at wavelength of 21 cm can be used to analyze the dynamical properties of the Milky Way with Gaussian fitting software, which was developed by using Python programming language. SalsaJ is another free astronomical software which was also used in this study by analyzing the Gaussian spectra of the Onsala radio telescope. For making sure the performance of developed software, therefore, it will be tested between their observation spectra of NARIT 4.5 m SRT and the Onsala radio telescope together with the public international archive. The results showed that the positions of HI are distributed in a spiral - arms shape and the rotation curve is constant at the galactic distance (R) > 3 kpc. The spherical mass distribution (in terms of the surface mass density) was approximated by directly using rotation curve. Our results are in good agreement with the standard values.
Study of carbide composites processed by spark plasma sintering for Gen IV reactors
Authors: Kwamman T
Published: December 2019

The variant of TiC/SiC interfaces was successfully fabricated by SiC powder (P) and lump SiC (L) by spark plasma sintering (SPS) at 1800 °C. There were no chemical reactions between SiC and TiC at that temperature. The larger TiC/SiC interfaces can be created by lump SiC. In contrast, the uniform distribution of TiC/SiC was found when using SiC powders. A network of micro-pores still appeared in both TiC with 30 % SiC and TiC with 50 % SiC composites, stress fields developed at the interface between TiC and SiC grains due to their differences in thermal expansion coefficients, confirmed by the peak shift about 2 cm-1 from Raman peak of 969 cm-1. Thermal diffusion of TiC/SiC composites was significantly higher than TiC monolith and varied regard to SiC contents.
Initial pointing model of the 40m Thai National Radio Telescope with an 8-inch optical telescope
Authors: Phakam A , Jaroenjittichai P , Prasert N , Asanok K , Singwong D
Published: December 2019

As a part of the mega-project, known as “Radio Astronomy Network and Geodesy for Development (RANGD)” by National Astronomical Research Institute of Thailand (NARIT), the fully steerable 40m Thai National Radio Telescope (TNRT) is under construction in the eastern region of Chiang Mai. From December, 2019, commissioning stage of TNRT includes the determination of pointing and aperture efficiencies, which are expected at no wind condition as 2 arcsec (rms) and 60 percent at K-band, respectively. Perfect alignment between the antenna pointing system with on-sky coordinates system, e.g. equatorial, is very crucial in obtaining such high pointing accuracy. In the initial step without the K-band receiver, this can be partially achieved with the installation of an optical telescope with an imaging system on the antenna structure and the initial pointing offset can be determined by tracking planets or other celestial sources in the optical. Here, we present the complete design of the system consisted of an 8-inch reflective telescope, a focuser and 20 MP camera, which results in the field of view of 22.67 by 15.15 sq. arcmin and the resolution of 0.25 arcsec. The complete measurement procedure for such approach and discussion on the advantages and limitations are also included.
CALLISTO spectrometer for solar radio bursts monitoring in Chiangmai
Authors: Prasert N , Phakam A , Asanok K , Jaroenjittichai P , Chumthong A , Thongmeearkom T
Published: December 2019

Solar radio bursts are important phenomena for studying solar activities such as flares and coronal mass ejections (CMEs). A worldwide network is ∼ 90 stations, known as, e-CALLISTO, has been developed such purpose. This CALLISTO spectrometer was installed at Princess Sirindhorn AstroPark, National Astronomical Research Institute of Thailand, Chiangmai, in January 2019. The instrument has been designed for monitoring and collecting the data of solar radio activities at the frequency range between 45 and 870 MHz. In this paper, we report the installation and preliminary measurements of the CALLISTO spectrometer. The data collected will be stored in Radio Astronomy Center of NARIT and transferred to the ETHZ data archive.
Physical properties and thermal conductivity of soil geopolymer block
Authors: Jittabut Pongsak
Published: December 2019

This research aimed to study the mixing ratios of fly ash and rice husk ash on the physical properties and thermal conductivity of soil geopolymer block. Fly ash to rice husk ash ratios for this experiment were 100:0, 80:20, 70:30, 50:50, 30:70, 20:80 and 0:100 %wt, respectively. The properties analysis of soil geopolymer block such as the compressive strength, water absorption, apparent porosity, bulk density and thermal conductivity were tested. The results indicated that soil geopolymer block of 80:20 %wt at 28 days of curing gave the maximum compressive strength of 131.43 kg/cm2. The minimum water absorption of 7.70 %, minimum bulk density of 2, 056.34 kg/cm3, minimum apparent porosity of 15.64 %, minimum thermal conductivity of 1.8674 W/m.K, were obtained. The compressive strength of soil geopolymer block increased up to 87 % and the thermal conductivity has decreased to 35 % compared to commercial cement block. The compressive strength, the water absorption and the bulk density of 80:20 %wt mixtures was in accordance with the standard product community at 602/2547 that can be used in construction applications.
Measurements of tin-palladium catalyst concentration by an optical method
Authors: Promsawang C , Jansukra P , Meechan W , Luengviriya C
Published: December 2019

Electroless plating on plastics is a technology that changes the plastic surfaces to appear like metals for decoration as well as specific applications. The plastic surfaces are commonly treated in a catalysing process by using a tin-palladium catalyst whose concentration is in a specific range. Since the concentration of the tin-palladium catalyst strongly affects the catalysing process as well as the plating quality, its concentration is regularly monitored. We present a study on measurements of the concentration of the tin-palladium catalyst with red-brown color based on an optical method. Its absorption spectrum monotonously decreases when the wavelength of the incident light increases. For a given wavelength, the absorbance increases with the concentration. Five standard concentrations are used to construct several calibration equations between the absorbance and the concentration by linear fits for different wavelengths. The calibration equations are verified by eight tested solutions. The results show that wavelengths in the range of 310 – 500 nm are suitable for the concentration measurements of tin-palladium catalyst since the errors are less than 5%.
Long-term with short-intervals monitor of 6.7 GHz CH3OH masers using Hitachi 32-m radio telescope to statistically research the periodic flux variability around high-mass protostars
Authors: Sugiyama K , Yonekura Y , Motogi K , Saito Y , Momose M , Honma M , Hirota T , Uchiyama M , Tanaka K E I , Kramer B H , Asanok K , Jaroenjittichai P , Fujisawa K
Published: December 2019

We initiated a long-term with short-intervals monitoring project toward 442 CH3OH masers at 6.7 GHz (Dec > -30 deg) using Hitachi 32-m radio telescope of Japan in Dec 2012. Our observations have been carried out daily, monitoring a spectrum of each source with intervals of 9-10 days. In Sep 2015, the number of the targets sources and intervals were redesigned into 143 and 4-5 days to detect periodic variations with periods shorter than 30 days. We have so far obtained new detections of periodic flux variations in 31 CH3OH sources with periods of 22-409 days. These periodic flux variability with timescale between a few months and a few years must be a unique tool to study high-mass protostars themselves and their circumstellar structures on a tiny spatial scale of 0.1-1 au (∼1.5 x 107-8 km). We will also present the future prospect via monitoring of OH and H2O masers in these periodic sources using 40-m Thai National Radio Telescope that is under construction by NARIT.
Fall detection system with 3-axis accelerometer
Authors: Aphairaj D , Kitsonti M , Thanapornsawan T
Published: December 2019

In this work, the designed and developed process of a fall detection system using a NodeMCU microcontroller is described. A 3-axis acceleration sensor is used to obtain the data of the movement of humans and changes in acceleration are used to determine trends in falling. The ESP8266 microcontroller is used to the receive the data in real time and alert the family through the LINE application. Experimental results show that the system is capable of precisely producing alarms for falling actions and has a high detection precision and effectiveness.
Chemical agent monitor simulator (CAMSIM): prototype
Authors: Torasa C , Won-in K , Dararutana P
Published: December 2019

Chemical Agent Monitor Simulator or CAMSIM is used for training the trainees of the Royal Thai Army Chemical School in the Chemical Warfare Detection Course to familiarize, and to expert for using detection and identification. This research is aimed to design and produce a prototype of the CAMSIM which uses in the military training. The designed system is operated using ultrasound with the difference intensity for training to detect chemical residues in the field and on the body or clothing. The product is composed with the Chemical Agent Monitor Simulator (CAMSIM) which can be detected 4 different ultrasonic signals simultaneously and 4 different ultrasonic sources. The CAMSIM can present both in type (ultrasonic frequencies) and intensity of the chemicals (ultrasonic intensities). It can be concluded that this is real, safe and amenable to deliver and validate the high quality training. It is simultaneously signal detection. And the trainees are also familiar with the operations.
Physical and chemical characterization of Lopburi clay before and after calcination
Authors: Chomyen P , Sinthupinyo S , Chamnankid B , Hanpongpun W , Chaipanich A
Published: December 2019

Supplementary cementitous materials (SCMs) may be used as a substitution of Portland cement to reduce CO2 emissions in the cement industry. One of promising Supplementary cementituous materials for practical use in the construction industry is calcined clay. Clay must be calcined to form high reaxtivity pozzolanic materials from mineral addition known as amorphous metakaolin (AS2). Calcined clay may be used to improve mechanical properties, durability and some characteristic. This research aimed to study clay mineralogy and chemical composition of Lopburi clay in Thailand. Physical and chemical characterizations of Lopburi clay before and after calcination were investigated using X-Ray Diffraction, Qualitative X-Ray Diffraction (QXRD), Scanning Electron Microscopy (SEM) and X-Ray Fluorescene. The results showed that Lopburi clay main major oxides aed silicon dioxide (SiO2), alumina oxide (Al2O3) and iron oxide (Fe2O3) furthermore, Lopburi clay is kaolinite clay.
Application of pivoting adversarial networks in search for four top quark production in CMS
Authors: Wachirapusitanand V , Srimanobhas N , Blekman F
Published: December 2019

One burden of high energy physics data analysis is uncertainty within the measurement, both systematically and statistically. Even with sophisticated neural network techniques that are used to assist in high energy physics measurements, the resulting measurement may suffer from both types of uncertainties. Fortunately, most types of systematic uncertainties are based on knowledge from information such as theoretical assumptions, for which the range and behaviour are known. It has been proposed to mitigate such systematic uncertainties by using a new type of neural network called adversarial neural network (ANN) that would make the discriminator less sensitive to these uncertainties, but this has not yet been demonstrated in a real-life LHC analysis. This work investigates ANNs using as a benchmark the search for the production of four top quarks, an extremely rare physics process at the LHC and one of the important processes that can prove or disprove the Standard Model. The search for four top quarks in some cases is sensitive to large systematic uncertainties. The expected cross section upper limit for four top quark production is calculated using traditional neural networks and adversarial neural networks based on simulated proton-proton collisions within the Compact Muon Solenoid detector within Large Hadron Collider, and are compared to existing results. The improvement and further considerations to the search for rare processes at the LHC will be discussed.
Development of the greenhouse solar dryer for germinated parboiled Thunya-Sirin glutinous rice dried
Authors: Sarobol Mali , Teeta Suminya , Pharanat Wanida , Guson Watthanawong , Chaimatchim Supasit , Sarobol Preedok
Published: December 2019

The objective of this work was to describe the development of greenhouse solar dryer for germinated parboiled Thunya-Sirin glutinous riced ried. Parameters studied were germinated parboiled Thunya-Sirin glutinous rice, drying temperatures at 40°C. The drying process was carried out until the final moisture content was below 8 % (dry basis, d.b.). The moisture ratio, the color difference (ΔE) and physical propertiesof the product were determined. The results revealed that the greenhouse solar dryer showed the drying time for 5 hr. The greenhouse solar dryer maintains color and nutrients of rice, this technique better prices, higher affordability level, better payback power of farmers. Therefore, drying germinated parboiled Thunya-Siring lutinous rice using greenhouse solar dryer is more suitable than unsanitary.
Influence of hydrothermal time on structural properties of ZnO nanorods grown on spin-coated ZnO seeding layer
Authors: Mahamu Hambalee , Srinonate Wuttichai , Pecharapa Wisanu
Published: December 2019

Most of the recent nanodevices are fabricated by using high-efficiency deposition methods and patterned via high-resolution lithography. However, there are drawbacks for the methods including small-scale product, high cost consumption, and multi-step processes. To reduce these disadvantages, this work focuses on the usage of sol-gel synthesis and spin coating method to fabricate ZnO seed layer onto glass substrates. All of substrates were patterned by conventional UV photolithography at exposure time of 7 seconds, then ZnO nanorods were hydrothermally grown at 90°C for 2, 3, and 4 hours, respectively. All of samples were characterised by scanning electron microscope (SEM) which revealed the sharp and smooth tip hexagonal structure at different hydrothermal time. The evolution of the nanorods’ growth was investigated, and the diameters were estimated. Moreover, crystal quality was revealed by x-ray diffractograms. It was clear that the domination of c-axis plane occurred for all the samples associates with the crystallinity of the nanostructures. This indicated escalating of the non-monodirectional growth plane in increasing nanorods’ diameter as the nanorods are polycrystal. Furthermore, the optical properties of the samples were observed by UV-visible spectroscopy and photoluminescence technique (PL). UV-visible spectroscopic data showed diminishing of the energy band gap when the diameter grew up. PL data revealed the reduction of the intensity ratio at near-band-edge peak versus oxygen vacancy peak. This information pointed to the decreasing trend of the crystal quality with escalating growth time.
Matter-wave interferometry from near-field to far-field diffraction
Authors: Srisuphaphon S , Temnuch W , Buathong S , Deachapunya S
Published: December 2019

A simplified explanation of near-field and far-field diffraction with matter-wave is described using the path integral formulation. Our approach is demonstrated with cold Rb atoms in single-, double-, and multiple-slit configurations. With the use of an initial wave for the particle beam that corresponds to the slit opening and the number of slits, the transition from near-field to far-field diffraction can also be explored. Identifying the boundary between near-field and far-field diffraction is the first priority for implementing matter-wave diffraction experiments.
Numerical investigation of effect of central gap’s width and length of magnetic material on heat transfer and pressure loss of water flow using computational fluid dynamics
Authors: Thongjamroon J , Techapiesancharoenkij R , Chaiworapuek W
Published: December 2019

This research studied heat transfer and pressure loss due to water flow through the compressed magnetic powder using Computational Fluid Dynamics. The Reynolds number was determined, ranging from 3, 000 to 7, 000, corresponding to the working flow-rate range in the magnetic refrigeration system. To model the compressed magnetic powder as porous media, the porosity and permeability, calculated from experimental results, were 0.1684 and 3.3076×10-10 m2, respectively. In this research, porous media which have constant heat flux, were in a cylindrical shape. They had a diameter of 0.012 m and 0.05, 0.10 and 0.15 m in length. The width of the central gap was 0.001, 0.002, 0.003, 0.004 and 0.005 m. The numerical results showed that the Nusselt number and the friction factor increased when the width decreased and the length increased. The maximum friction factor and the Nusselt number were 27.85 and 16.83, respectively at 0.001 m in width and 0.15 m in length under the Reynolds number of 3, 000. However, the highest thermal performance was 1.91 at 0.004 m in width and 0.15 m in length under the Reynolds number of 7, 000. The results obtained in this research could be utilized for the geometric design of magnetic material for the magnetic refrigeration system in the future.
The evolution of stellar and dark matter density in EAGLE brightest cluster galaxies
Authors: Tangpakonsab Parinya , Muanwong Orrarujee
Published: December 2019

We use the EAGLE (Evolution and Assembly GaLaxies and their Environments) simulations, with the 50 co-moving Mpc a side box, with and without the effect of active galactic nuclei (AGN) to study dark matter distribution and stellar density in central galaxies. The simulations allow us to study cosmological structures at various redshifts which are chosen at 0, 0.27 and 0.87. We study the brightest cluster galaxy (BCG) in the largest galaxy cluster at these redshifts. The dark matter profile of the galaxy in the simulation with AGN exhibits a flat core, while its counterpart in the simulation without AGN is cuspy at all redshifts. The stellar density in the galaxy resembles the corresponding dark matter profile at all radii. At outer radii, the stellar density profile in the simulation with AGN changes dramatically from high to low redshift. We conclude that the energetic process of AGN in the simulation can effect both the stellar and dark matter components in central galaxies. As the box size is relatively small and the result is based on only central galaxies of small clusters, the study does not cover a wide dynamic range. The baryonic feedback effect on dark matter needs to be further explored on larger scales for cosmologists to correctly constrain cosmological parameters.
Modeling and simulation of a LaCoO3 Nanofibers /CNT electrode for supercapacitor application
Authors: Chinnasa P , Ponhan W , Choawunklang W
Published: December 2019

The supercapacitors are expected to represent the future of energy storage unit equipment due to their good performance on both the energy density and the power density. This paper is the first presentation of the mathematical form of the supercapacitor, which consists of LaCoO3 nanofibers electrodes and carbon nanotube electrode (CNT) as well as the electrical and concentration channels, the dynamic model used to determine the impact of the thickness of CNT electrode on the performance of supercapacitors in COMSOL Multiphysics. The results showed that when changing the voltage scan rate from 0.001, 0.01, 0.1 and 1.0 V/s, current and voltage increased. But the time to change the current density is reduced by a voltage scan rate of 0.001 V/s. The range of voltage changes from -0.4 to 0.4 V in the period of 1, 500 s and when adding the position of the length, the concentration will gradually decrease. The present model is conclusively verified to be effective and successfully provides a methodology to optimize the cell size in various applications.
A case study of a teaching and learning sequence for Newton’s third law of motion designed by a pre-service teacher
Authors: Sujarittham T , Tanamatayarat J
Published: December 2019

Over several decades, many physics teachers have taken a crucial responsibility for improving conceptual understanding of students. To enhance students’ understanding, generally they have adopted an alternative teaching approach to classes. However, such that approach does not always yield positive learning outcomes. Many researchers reported that a teaching and learning sequence was one of the essential factors needed to take into account. In this study, the teaching and learning sequence was proceeded by 5E inquiry-based learning which was grouped as active learning. Therefore, the goal of this study was to analyze the teaching and learning sequence for Newton’s third law designed by a pre-service teacher together with the physicists’ comments on that sequence. This was viewed as the initial phase of research in finding a suitable framework for future training pre-service teachers about how to design a teaching-learning sequence. The teaching and learning sequence was implemented to the two classes of grade 9 students. From the analysis, we found that the teaching and learning sequence were complicated and some physics situations were not clear. To help support the students’ conceptual understanding, all unclear physics situations were refined and corrected in line with physicists’ comments to be used in the classes but remained the primary structure of such that designed sequence. The standardized test about force was administered to the students after completing the lesson. The results were found that the designed sequence yielded low learning outcomes even were taught with the interactive engagement. This was the evidence shown that the teaching and learning sequence affected students’ leaning and there was a need about seeking a framework to help pre-service teachers in a process of designing a teaching and learning sequence.
The projectile tube experiment for improving high-school physics conceptual understanding
Authors: Rachniyom S , Sujarittham T , Wuttiprom S
Published: December 2019

This research aimed to design the simple apparatus to improve students’ conceptual understanding in projectile motion. The projectile tube experiment was a simple apparatus that consisted of a one-meter PVC tube, a 1200-watt hair dryer, a hard sheet of paper, and a ping pong ball. The participants were 30 grade 10 students who were selected by non-random sampling in the second semester of the academic year 2018. The research tools consisted of learning lesson plans and a multiple-choice learning achievement test. The class activity was conducted by using the Interactive Lecture Demonstrations (ILDs) method with Tracker Video Analysis. The results showed that the experiment set worked perfectly and could be used for learning the projectile concept. The students’ achievement score was significantly increased at a statistical level of .05 and the average of students’ normalized gain was in a medium gain regime.
Testing of car speed approximation equation from yaw mark using radio control car simulator
Authors: Pengyot A , Nanthanasit P , Wattanakasiwich P
Published: December 2019

In forensic science, yaw mark is one of the interesting evidences from the traffic accident. It caused by a vehicle wheel slides on the surface of the road when the speed before braking of the vehicle is high enough. Therefore, prediction of the vehicle speed is important to compare with the legal maximum speed. This research focused on the simulation of a car’s braking on a curve using the radio control car. High-speed video and Tracker Video Analysis (Tracker) software were used to investigate the positions and speeds of the radio control car. The braking path from Tracker software was assumed as the yaw mark in the real accident scene. The equation of the braking path was investigated using the total least-squares spiral curve fitting. The speeds of the car for each position of the braking path were calculated by the method from Daily’s research and the new method modified from Daily’s research. The predicted speed was compared with the one measured from Tracker. The results were similar at the beginning of the braking path, but increasingly different when the speed of the radio control car decreased. Moreover, the modified Daily’s method can investigate the speed better than the Daily’s method for the speed based on a clothoid spiral fitting and Archimedean spiral fitt ing. Findings from this study can be used to develop instructional materials for intermediate mechanics to demonstrate a real application.
Determination of radiation attenuation coefficients of BaSO4/PVC and BaSO4/PS for X-ray shielding
Authors: Jaiyen S , Phunpueok A , Thongpool V
Published: December 2019

The X-ray radiation shielding properties of PVC and PS containing BaSO4 at different concentrations were investigated using the beam transmission method for X-ray tube with a CdTe detector. The mass attenuation coefficients (μm) of these shielding materials were calculated. It was found that the μm increased with the increasing of BaSO4 content up to a value of 60% by weight. The highest value of mass attenuation coefficients at 50 kV tube voltage was 5.985 cm2/g for the BaSO4/PVC sheet and 3.991 cm2/g for the BaSO4/PS sheet. The μm values were compared between BaSO4/PVC and BaSO4/PS. The results showed that BaSO4/PVC had better X-ray shielding performance than that for BaSO4/PS.
Study on gamma-ray shielding properties of lead tellurite glass systems using PHITS
Authors: Sriwunkum C , Nutaro T
Published: December 2019

The gamma-ray shielding properties, mass attenuation coefficient, mean free path and half value layer of lead tellurite glass systems were investigated in the photon energy range of 0.015–15 MeV using particle and heavy ion transport code system (PHITS) with the use of narrow beam transmission technique. The gamma shielding efficiency of studied glass systems was compared to that of standard concretes in terms of mean free path and half value layer. The obtained results show that PHITS is very capable for investigation of radiation shielding properties to good accuracy with maximum percentage differences of less than 2% comparing to the results by XCOM database. This will make a useful alternative technique for studying radiation parameters of other glasses, for which no experimental results are available.
Preparation and thermochromic behaviors of polydiacetylene/indium or gallium doped zinc oxide nanocomposites
Authors: Htet Htet Lynn Tin , Jaisutti Rawat , Tivakornsasithorn Kritsanu , Traiphol Rakchart , Osotchan Tanakorn
Published: December 2019

Polydiacetylene (PDA) is one of the well-known thermochromic materials having a high potential in applications such as displays and sensor technology. Many research groups have been working on controlling thermochromic reversibility of PDA-based materials. In this research, the colorimetric response of PDA assembled with indium or gallium doped zinc oxide was studied with various concentrations. Indium or gallium doped zinc oxide was prepared by hydrothermal method. The compositions of 5, 10, and 15% of indium and 5, 12, and 24% gallium, respectively. Undoped zinc oxide and gallium doped zinc oxide exhibited the nanoflowers composed of nanosheets while the indium doped zinc oxide showed the nanorod structure and combined to be nanoflowers. Monomer of PDA composing 10, 12-pentacosadiynoic acid in ethanol was mixed with indium and gallium doped zinc oxide precursor solution at 20% weight. Ultra-violet light source was used to photo-polymerize for five minutes after incubation at low temperature for a prolong cooling. For nanocomposites of poly(PCDA) and undoped and gallium doped zinc oxide, the color of nanocomposite changed from blue to light-purple at above 70°C and the color can be reversible when cooling down to room temperature. However, for nanocomposites of PCDA and indium doped zinc oxide, the color change from blue to light-purple at above 50°C then become red than those in gallium doped PDA nanocomposite. In addition, the color of PCDA nanocomposite with indium doped zinc oxide cannot be reversible back to the original color.
Calibration of pyroelectric infrared detectors using a light bulb as a black body radiation source
Authors: Pakluea S , Jitvisate M , Rimjaem S
Published: December 2019

The pyroelectric detector is used for measuring infrared radiation. It has uniform response covering wide wavelength from 0.001 µm to 1000 µm and can measure the high-power level of radiation at room temperature operation. In this research, we calibrated the pyroelectric detector by using a tungsten light bulb as an infrared source. Properties of blackbody radiation from the light bulb are investigated. The interested properties include the spectral distribution and the relation of radiation intensity to heating temperature. The most radiation emitted from the light bulb lies in infrared wavelength. The pyroelectric detectors were calibrated against a pyroelectric Joulemeter with known responsivity. The results of this study will be applied to the measure of the radiation produced from the accelerator-base radiation source at the PBP-CMU Electron Linac Laboratory.
Effect structure in physics and hints to economics equation of state
Authors: Gumjudpai Burin , Sethapramote Yuthana
Published: December 2019

We point out that, there is effect structure in physical laws which is noticed from both phenomenological and postulate points of view. Here we consider effect structure in equations of state (EoS). Effect of one variable to the other variables are expressed as a diagram. Formal criteria to judge a status of EoS of an empirical relation is proposed here for classifying the EoS into classes. The framework shades light on testing of existence of an EoS in economics system. Demand-side EoS in perfect-competitive market is proposed employing hints given by the criteria. The demand-side EoS turns to be new class of EoS.
Effect of using geopolymer flyash on torsion capacity of hybrid high-strength reinforced concrete beams containing fine and coarse aggregates substitution which added iron ores as filler
Authors: Aulia T B , Muttaqin M , Afifuddin M , Zaki M , Nastiti G
Published: December 2019

High demand for advanced infrastructure leads to the use of high-strength concrete. Complex, futuristic and asymmetrical building construction may create dangerous torsional load and moment, mainly due to earthquake. Using large amount of cement makes high-strength concrete not environmentally friendly. The use of natural aggregates continuously reduced its availability. Efforts to substitute cement and aggregate from abundant and environmentally-friendly natural materials could be smart solution. This study aims to analyze the torsional capacity of high-strength cantilever reinforced concrete beams having L configuration with a torque arm. Three hybrid beams were cast with substitution of 15% coal flyash (CFA), 15% palm oil blast furnace slag (POSFA) and 10% pozzolanic flyash (PFA) from cement weight, added with 10% pozzolanic sand as fine aggregate substitution and 40% palm oil blast furnace slag as coarse aggregate substitution. One beam without flyash and aggregate substitution (NPBHSC) was tested as comparison. All four beams added with iron ore as filler. The best torsion capacity achieved by PFA beam with maximum load (P) 2.83 ton, maximum torsion moment (M) 10.4 kNm, maximum torsion angle (Θ) 0.0225 rad, ductility (µ) 3.941 and cylinder compressive strength (σ) 59.48 MPa, when compared to NPBHSC beam which produced P = 2.65 ton, M = 9.638 kNm, Θ = 0.0069 rad, µ = 1.008 and σ = 44.40 MPa. POSFA beam followed then by CFA beam resulted in slightly smaller P and M, but generated greater σ, Θ and µ than NPBHSC. It can be concluded that geopolymer flyash can increase compressive strength, torsion capacity and ductility of high-strength reinforced concrete beams.