bluuebunny/crossref_metadata_2025 huggingface dataset:
Layered Transition Metal Electride Hf2Se with Coexisting Two-Dimensional Anionic d-Electrons and Hf–Hf Metallic Bonds*
Authors: Wang Xihui , Qiu Xiaole , Sun Chang , Cao Xinyu , Yuan Yujie , Liu Kai , Zhang Xiao
Published: January 2021

Electrides are unique materials, whose anionic electrons are confined to interstitial voids, and they have broad potential applications in various areas. In contrast to the majority of inorganic electrides, in which the anionic electrons primarily consist of s-electrons of metals, electrides with anionic d-electrons are very rare. Based on first-principles electronic structure calculations, we predict that the layered transition metal chalcogenide Hf2Se is a novel electride candidate with anionic d-electrons. Our results indicate that the anionic electrons confined in the Hf6 octahedra vacancy between [Hf2Se] layers mainly come from the Hf-5d orbitals. In addition, the anionic electrons coexist with the Hf–Hf multiple-center metallic bonds located in the center of neighboring Hf4 tetrahedra. The calculated work function (3.33 eV) for the (110) surface of Hf2Se is slightly smaller than that of Hf2S, which has recently been reported to exhibit good electrocatalytic performance. Our study of Hf2Se will enrich the electride family, and promote further research into the physical properties and applications of electrides.
Numerical simulation of the soliton solutions for a complex modified Korteweg–de Vries equation by a finite difference method
Authors: Xu Tao , Zhang Guowei , Wang Liqun , Xu Xiangmin , Li Min
Published: January 2021

In this paper, a Crank–Nicolson-type finite difference method is proposed for computing the soliton solutions of a complex modified Korteweg–de Vries (MKdV) equation (which is equivalent to the Sasa–Satsuma equation) with the vanishing boundary condition. It is proved that such a numerical scheme has the second-order accuracy both in space and time, and conserves the mass in the discrete level. Meanwhile, the resulting scheme is shown to be unconditionally stable via the von Nuemann analysis. In addition, an iterative method and the Thomas algorithm are used together to enhance the computational efficiency. In numerical experiments, this method is used to simulate the single-soliton propagation and two-soliton collisions in the complex MKdV equation. The numerical accuracy, mass conservation and linear stability are tested to assess the scheme’s performance.
Study of K*(892)0 and ϕ (1020) meson production in proton–proton and Pb–Pb collisions at

sNN

= 2.76 TeV
Authors: Ali Y , Ahmed M , Arif A , Ali Q , Tabassam U , Rubab U , Suleymanov M
Published: January 2021

In this paper, we describe a study of charged particle yield as a function of p

T
for K
*(892)0 and ϕ (1020) mesons in proton–proton (pp) and Pb–Pb collisions at

s

N
N

 = 2.76 TeV in the central rapidity region of ∣y∣ < 0.5, in a p

T
range of 0 < p

T
< 15 GeV c
−1 in pp collisions and in a p

T
range of 0 < p

T
 < 20 GeV c
−1 in Pb-Pb collisions. We also investigated a very important ratio, the nuclear modification factor, to study the effects of the medium in the most central region, i.e. 0%–5% centrality. For data simulation, we used the EPOS-LHC and EPOS-1.99 models. To check the validity of these models’ simulations, we compared the data obtained from these Monte Carlo simulation programs with ALICE experimental data for

s

N
N

 = 2.76 TeV. It was concluded that the models’ predictions for the ϕ-meson in pp and for the most central Pb-Pb collisions disagreed with the ALICE data, and that the difference increased with p

T
. This may be connected with the essential role of collective parton behaviors which could not have been taken into account by the models. For K
*0 mesons, both programs gave almost the same predictions, and with p

T
in the interval p

T
 > 3 GeV c
−1, the predictions were very close to the experimental data. Both models gave higher predictions for the soft p

T
interval and lower predictions for the hard interactions. The values of the R
AA distributions were lower than unity and both models were very close to the ALICE data. It is very interesting that the models were not able to describe the p

T
distributions, but they gave good predictions for their ratios. This may possibly be due to parton collective behaviors. We observed some additional suppression of K
∗0 at low values of p

T
with respect to ϕ-mesons, which may be related to the role of the masses of the particles in soft interactions. The rising trend for R
AA in the region from p

T
= 10 GeV c
−1 to 20 GeV c
−1 observed by the ALICE experiment was absent for the ϕ-mesons.
Stable quantum interference enabled by coexisting detuned and resonant STIRAPs*
Authors: Liu Dan , Gao Yichun , Xu Jianqin , Qian Jing
Published: January 2021

Inspired by a recent experiment [Phys. Rev. Lett.
122 253201(2019)] that an unprecedented quantum interference was observed in the way of stimulated Raman adiabatic passage (STIRAP) due to the coexisting resonant- and detuned-STIRAPs, we comprehensively study this effect. Our results uncover the scheme robustness towards any external-field fluctuations coming from laser intensity noise and imperfect resonance condition, as well as the persistence of high-contrast interference pattern even when more nearby excited levels are involved. We verify that an auxiliary dynamical phase accumulated in hold time caused by the presence of the quasi-dark state in detuned-STIRAP can sensitively manipulate the visibility and frequency of the interference pattern, representing a new hallmark to measure the hyperfine energy accurately. The robust stability of the scheme comes from the intrinsic superiority embedded in the STIRAP mechanism that preserves the coherence of population transfer, which promises a remarkable performance of quantum interference in a practical implementation.
Fabrication and characterization of Al-Mn superconducting films for applications in TES bolometers*
Authors: Yu Qing , Zhang Yi-Fei , Zhao Chang-Hao , He Kai-Yong , Huang Ru-Tian , He Yong-Cheng , Wu Xin-Yu , Liu Jian-She , Chen Wei
Published: January 2021

Superconducting transition edge sensor (TES) bolometers require superconducting films to have controllable transition temperatures T
c in different practical applications. The value of T
c strongly affects thermal conductivity and thermal noise performance of TES detectors. Al films doped with Mn (Al–Mn) of different concentrations can accomplish tunable T
c. A magnetron sputtering machine is used to deposit the Al–Mn films in this study. Fabrication parameters including sputtering pressure and annealing process are studied and their influences on T
c and superconducting transition width ΔT
c are optimized. The Al–Mn films with ΔT
c below 1.0 mK for T
c in a range of 520 mK–580 mK are successfully fabricated.
α-decay study of 218Ac and 221Th in 40Ar+186W reaction *
Authors: Hua Wei , Zhang Zhiyuan , Ma Long , Gan Zaiguo , Yang Huabin , Huang Minghui , Yang Chunli , Zhang Mingming , Tian Yulin , Zhou Xiaohong , Yuan Cenxi , Shen Caiwan , Zhu Long
Published: January 2021

In this study, 218Ac and 221Th nuclides were produced via the heavy-ion induced fusion evaporation reaction 40Ar + 186W. Their decay properties were studied with the help of the gas-filled recoil spectrometer SHANS and a digital data acquisition system. The cross section ratio between 222Pa and 218Ac was extracted experimentally, with measured value 0.69(9). Two new possible α decay branches to 221Th are suggested. The valence neutron configurations for the daughter 217Ra are discussed in terms of the hindrance factors.
The 15th SIAM PHYSICS CONGRESS (SPC2020)
Authors: Soonthornthum B , Aukkaravittayapun S , Kittara P
Published: January 2021

The 15th Siam Physics Congress (SPC2020) was successfully held online during June 4–5, 2020. Initially, the Thai Physics Society with Mahidol University and Prince of Songkla University had planned to co-host the SPC2020 in Trang province in Southern part Thailand. Unfortunately, due to the coronavirus (COVID-19) pandemic throughout many countries all over the world and also in Thailand, the organizing committee had seriously considered this unexpected, serious and intense crisis on the health issue. Therefore, there came a decision that the congress should not be held physically, but the congress should instead utilize online internet connections through hubs hosted at the Thai Physics Society and its co-hosts. This is to keep up to the highest standard of health regulation and self-practice (from WHO) in avoiding the extremely serious pandemic. Consequently, the Thai Physics Society, Mahidol University and Prince of Songkla University had facilitated and hosted the SPC2020 as national teleconference during June 4–5, 2020.

List of titles Track(Session), Organizing Committee, Scientific Committee, Editorial Committee, Plenary Speakers, Organizing Institutions, Sponsors are available in this pdf.
Characteristic of Fe in tektite observed from XANES and UV-Vis spectroscopy
Authors: Paisarnsombat S , Monarumit N , Aimploysri S
Published: January 2021

Tektite is a geological sample formed as a result of a collision of the meteorite on the surface. An energy from the collision results in an excavation of the melted material into the Earth’s atmosphere and landed back on the surface further away from the impact site having glassy or crystalline textures. Tektite was deposited in Thailand and was identified as part of the Australasian strewn field. Chemical compositions of tektites have previously been studied. However, there is no study has established a relationship between composition and color of tektites. Thus, this study aims to relate the characteristic of color-center element, Fe, to the color of tektites using X-ray Absorption Near Edge Structure (XANES) and UV-Vis spectroscopy. Nine tektite samples were collected from Korat plateau and purchased from Thailand and Vietnam gem markets. XANES spectra of all (nine) samples show similar Fe K-edge pattern with pre-edge and E0 at 7080-7089 and 7118 eV, respectively. The spectrum is 100 percent matched with XANES structure of FeO standard suggesting Fe component of Fe2+ oxidation state in the sample. Seven, out of nine, samples establish similar UV-Vis broad absorption peak at 492-539 nm, which corresponds to absorption peak of Fe2+. The UV-Vis absorption spectrum cannot be obtained from two samples possibly due to high Fe-content in the samples. The calculated energy band gaps (E

g
) of the samples are in between 1.35 eV to 1.76 eV with maximum absorption in between 1.88 eV to 1.95 eV. The result is in consistent with a black color of the tektite. It indicates that cause of color in tektites is related to Fe-content and can be explained by the energy band. This study can be furthered compare with moldavite (green variety of tektite) in order to identify cause of color in impact-related materials like tektites, as well as to provide information for identification of synthetic and genuine moldavites and also for characterization of tektites sources using the component of various Fe oxidation states.
Constraints on dark matter annihilation from several IACTs’ cosmic ray electron spectrums
Authors: Duangchan Chaimongkol , Wechakama Maneenate
Published: January 2021

In dark matter self-annihilation events, highly energetic electron and positron pairs can be created in several different annihilation channels and propagate through space while losing their energies. The electrons can lose their energies by these mechanisms; the interaction with low-energy photons via inverse Compton scattering, synchrotron radiation due to interstellar magnetic fields, and ionization with neutral hydrogen atoms, resulting in high energy cosmic electron fluxes at the Earth’s location. Adopted electron spectrums from H. E. S. S., MAGIC, and VERITAS which are Imaging Atmospheric Cherenkov Telescopes (IACTs), we have found the constraints on dark matter annihilation in a range of TeV energies. The results show the stringent constraint on electron channels, and there are no significant differences in constraints between IACTs’ data sets.
A global view of stellar populations in M82
Authors: Suwannajak C , Duangphumek S
Published: January 2021

We present photometric and spectroscopic studies of the stellar content of M82, including the resolved halo stellar population and the halo globular clusters. M82 is a nearby peculiar galaxy that recently went through a close encounter with its more massive companion, M81. As a result, M82 has a high star formation activity and unusual stellar content. We studied the resolved stellar population using the imaging data from the Hubble Space Telescope (HST) data archive. Then, their metallicities were analyzed to understand a global view of the stellar populations in M82. We found that the old stellar population in M82 shows typical characteristics for a disk galaxy, while the young stellar population shows a sign of disruption as a result of the recent interactions.
Kepler-TESS light curve analysis of KIC 10417986 as a practical example for astronomical research in schools
Authors: Aindang A , Inkum R , Sarotsakulchai T , Surina F
Published: January 2021

Teachers and students in schools have been struggled to accomplish astronomical researches themselves in Thailand, but lacked off equipment and method. The aim of this paper is to provide methods to determine physical parameters of a given Kepler eclipsing binary, without any radial velocity curves, as an example for possible school projects. Unpublished light curves of KIC 10417986 from Kepler and TESS online archives were analysed simultaneously by using the Wilson & Devinney code to derived relative photometric parameters. On an assumption of the system is a contact binary system whose components are main-sequence stars, absolute dimensions including T
1 = 6751 ± 900 K, T
2 = 6804 ± 907 K, R
1 = 1.48 ± 0.05 R⨀, R
2 = 1.4 ± 0.3 R⊙, M1 = 1.64 ± 0.07 M⊙, M2 = 1.6 ± 0.4 M⨀, and L
1 ∼ L
2 ∼ 4L⨀, were determined. The semi-major axis a = 3.7 ± 0.4 R⊙ and a mass ratio q = 1.0 ± 0.2 were calculate tracing backward from the derived dimensions. We found that such a very short period (0d.073731) KIC 10417986 might not play such a good example for school project due to its very low amplitude of variation in light curves (∼0.0007 magnitude) even one may conclude it is not a variable star. However, we found the system interesting since it might have high mass transfer rate from the primary onto the secondary star.
Theoretical calculation of saturated absorption spectroscopy of atomic ytterbium beam
Authors: Jayjong N , Phoonthong P , Pruttivarasin T
Published: January 2021

Saturated absorption spectroscopy is a technique of measuring the transmission of a probe beam induced by a counter-propagating pump beam, which can achieve a nearly Doppler-free spectral resolution. In this study, the saturated absorption spectra of individual isotopes of ytterbium atoms are calculated using rate equations for various polarizations of the probe and pump beams under an assumption that the distribution of velocities for atoms within the atomic beam is a Maxwell-Boltzmann distribution. The fourth-order Runge-Kutta method is used for calculation of the rate equations, then the absorption coefficient in the vicinity of the atomic transitions is calculated, and the transmission of the probe beam is obtained by Beer-Lambert law. We compare the calculations with an experimental result from the literature and obt ain a good agreement.
Theoretical study of intermolecular interactions in protic ionic liquids: a single ion pair picture
Authors: Nanthanasit P , Chattrapiban N , Jitvisate M , Nimmanpipug P , Rimjaem S
Published: January 2021

Protic ionic liquids are made via intermolecular transfer between cation and anion. This research employs theoretical calculation to gain understanding of the intermolecular interactions at single-ion-pair level and their consequences to the macroscopic properties of the ionic liquids. The protic ionic liquids used in this study are ethylammonium nitrate (EAN), propylammonium nitrate (PAN), and butylammonium nitrate (BAN). Molecular structures of ions and ion pair of each liquid are optimized using the density functional theory. The ion pair binding energies and infrared spectra of optimized structures are investigated. Infrared spectra of separated cation and anion are compared with cation-anion ion pair to specify the vibrational band shifts due to intermolecular interactions. The infrared-spectra show the hydrogen-bond stretching modes in the far-infrared region at the wavenumber between 108-252 cm−1 and the red shifts of four vibrational bands due to intermolecular interactions between the ions. Three vibrational band shifts are mainly due to Coulomb force, and the other shift is caused by combination of intermolecular interactions. Moreover, the energy calculations show that the binding energy decreases as the alkyl chain length increases.
First-principles calculation for water purification of Pb, Sn and Zn ions adsorption on graplidiyne surface
Authors: Singsen S , Tangpakonsab P , Tussamee N , Kaewmaraya T
Published: January 2021

Heavy metals contaminated in water supply are of environmental concern. An efficient filter is essentially required for removing them from water before safe use. Here, first-principles calculations based on the density functional theory (DFT) have been employed to study the atomistic mechanisms of the heavy metals (i.e., Pb, Sn and Zn ions) trapped on a novel material carbon graphdiyne (GDY) surface. Fundamental properties, including the adsorption energies, preferential sites, density of states (DOS) and band structures are examined. The findings show that the adsorption energies of Pb and Sn ions are much greater than that of Zn ion. In addition, the energy gap of GDY vanishes after being adsorbed by Pb and Sn ions, whereas its semiconducting gap remains unchanged by Zn adsorption. This mean that GDY strongly attracts Pb and Sn ions by chemical bonds while it interacts weakly with Zn ions by van der Waals forces. As a result, GDY can be a promising candidate as an adsorbent material for water purification of Pb and Sn ions.
An interpretation of a simple portal dark matter model on Fermi-LAT gamma-ray excess
Authors: Klangburam Tanech , Pongkitivanichkul Chakrit
Published: January 2021

Dark matter is one of the main components of the universe. Due to its weak interaction with other particles, dark matter cannot be identified as a particle that we know of. We are interested in a simple particle physics scenario where dark matter is identified with the fermion in the dark sector and the standard model sector is connected to dark matter via the portal scalar field. One of the promising signals from these models are gamma-rays from dark matter annihilation processes. In 2016, the Fermi-LAT collaboration detected a gamma-ray excess signal coming from Milky Way’s galactic center which was immediately regarded as a possible candidate for the first detection of dark matter. In this project, we study an interpretation of the signal from Fermi-LAT as a dark matter annihilation from portal dark matter model. First, we calculated gamma-ray fluxes from dark matter annihilations as subsequent decays of portal scalars where the astrophysical factor is calculated from the Navarro-Frenk-White (NFW) dark matter density profile. We found that the simplest model does not fit adequately with chi-squared per degree of freedom,

χ

ν

2

∼
19.9

. We proposed that a part of the Fermi-LAT excess might come from another source of gamma-ray. The dark matter model combined with an unknown astrophysical source is then studied. The combined model is able to provide a reasonable fit

(

χ

ν

2

∼
10
)

indicating that scalar mass is 130 GeV, where dark matter mass is in the range of 150 − 350 GeV and 〈σν〉 is around 7 × 10−26 cm3/s.
Simulation of cut off characteristics of 2.45 GHz microwave inside the open-ended conductor cylindrical pipe
Authors: Rachpibul Apassara , Nisoa Mudtorlep
Published: January 2021

For a realtime measurement of moisture contents and temperature profiles of a sample inside a microwave oven, Sensors and open-ended pipes are equipped to the microwave system, allowing to measure those parameters from other ends of the pipes. The main role of the pipes is to reduce the microwave wave from leaking out to the environment and the interference with measuring equipment. In this research, a model of a microwave system with five installed pipes is simulated using COMSOL Multiphysics. The microwave cavity is modelled to be a cube with equal lengths of 33 cm. A pipe with diameter of 1.5 cm is installed on the top of the microwave and the other four pipes with diameter of 2.5 cm are installed at the bottom. The system is designed so that an infrared sensor can be attached to one end of the top pipe to measure temperature and a load cell is equipped under the bottom four pipes to measure the moisture content. The simulation result shows an exponential decay of electric field norm along the pipes away from the microwave chamber. For the pipes with diameters of 1.5 cm and 2.5 cm, the microwave wave is reduced to virtually zero at the distance of 3 cm and 4 cm away from the chamber, respectively.
Preliminary results from a feasibility test of mixed alpha source detection by prototype bare silicon devices
Authors: Chaiwongkhot Kullapha , Ruffolo David , Yamwong Wittawat , Prabket Jirawat , Tippawan Udomrat
Published: January 2021

A project on development of a satellite-borne silicon-based cosmic ray ion detector was started. Semiconductor detectors based on P-I-N junctions are widely used in space experiments due to their light weight, compact design and high stopping power. The position-sensitive parts of the detector are designed to be silicon-based detectors. A prototype silicon detector without the outermost layer of insulators was prepared. The detector is expected to have the potential to identify the elements of high energy ions using the ΔE-E technique. Thus, for the beginning step of this project, a detector response proportional to the deposited energy has to be confirmed. We set up a detection system of a mixed standard alpha source including Am-241, Pu239 and Cm-244 with our devices and a photodiode (Hamamatsu S1223 with glass removed). The detector response is indicated by the digitized signal pulse height distribution from a 2048-channel ADC. The feasibility of our devices to distinguish the difference of energy in terms of several hundred keV was confirmed. A linear relation between the pulse height peaks and the emitted energy of each radiation source was also indicated.
Uncertainty evaluation of crystallite size measurements of nanoparticle using X-Ray Diffraction analysis (XRD)
Authors: Mongkolsuttirat K , Buajarern J
Published: January 2021

Crystallite size is one of the critical powder characteristics to determine nano-scale properties used in many industrial applications. The crystallite size can be extracted by X-ray Diffraction (XRD) analysis since it is one of the simplest and the most convenient method among numerous characterization techniques. However, the lack of suitable uncertainty evaluation for determining crystallite size makes the measurement questionable. Therefore, this paper has presented the uncertainty evaluation for crystallite size measurement based on the method of JCGM 100:2008. The main contributions according to the Scherrer equation consist of the Scherrer constant (K), the X-ray wave length (λ), the full width of the peak at half maximum intensity (FWHM), the diffraction angle (θ), and also the resolution and repeatability effect. The measurement process, statement of the standard uncertainty of the component sources, sensitivity coefficient and the combined standard uncertainty of crystallite size measurement have been explained in detail. A numerical example presents how to estimate the uncertainty budget for the nanoparticle of TiO2 or P25 which is a commercially available powder.
Multipole resonance probe measurement in plasma
Authors: Jampaiboon N , Sirithipvanich C , Paosawatyanyong B
Published: January 2021

In the study of low-temperature plasma, the plasma parameters such as plasma density and plasma temperature are required. Recently, a multipole resonance probe (MRP) which utilized an active plasma resonance concept was proposed. The probe consists of two hemispheres, insulated by a thin dielectric sheet. The advantages of the probe include simple setup and localized measurements similar to those of the conventional Langmuir probe. The probe does not cause plasma contamination, one of the Langmuir probe disadvantages since the probe conductors are covered in the dielectric. However, it can only determine plasma density. The MRP is usually connected with a Network Analyzer for measuring the reflection coefficient spectrum which can be analyzed to obtain the plasma density. In this experiment, the constructed MRP is used to measure the plasma density comparing to the Langmuir probe. The results of the experiment showed that the plasma density result of the MRP gives a similar tendency as that of the Langmuir probe. However, the plasma density determined by the MRP was deviated when compared with the Langmuir probe. In order to explore the idea that MRP does not need to be constructed in hemisphere shape, MRP in different shapes have been assembled and verified.
Electric field effect on electrospun fiber alignment using a parallel electrode plate
Authors: Oncheurn Karnjana , Infahsaeng Yingyot
Published: January 2021

The nanofiber has been applied to various technologies such as textile technology, medical production, filtration devices or electronic devices. Nanofiber by electrospin preparation has been extensively studied. In particular, the structural properties of the fiber such as fiber diameter and alignment were mainly focused. Here, the electrospining with two parallel plate collectors was used to fabricate the PVA nanofiber. The result shown that the minimum fiber diameter was obtained when using the parallel plate gap of 2.0 cm, the plate-to-tip height of 15.0 cm and applied voltage of 15 kV. From SEM results, the average diameter of nanofibers at approximately 135.55±5.79 to 340±29.91 nm was obtained and fiber alignment was investigated. In addition, the light absorption of nanofiber in wavelength range of 300-1100 nm was investigated. Therefore, the electrospinning method with parallel plate collector can be applied for low fiber diameter and high ordering alignment, which may be applied for optoelectronic development.
Enhancing the supercapacitor performance of NiCo2O4 microflowers by reduced graphene oxide nano-sheets
Authors: Saei Worawee , Buranasiri Prathan , Karaphun Attaphol , Ruttanapun Chesta , Sriwong Chaval
Published: January 2021

This work presented the preparation and supercapacitor performance of a spinel nickel-cobalt oxide (NiCo2O4) microflowers mixed with nano-sized reduced graphene oxide (rGO) sheets. The hybrid material (NiCo2O4/rGO), pure NiCo2O4 and nano-sized rGO samples were characterized and confirmed by several techniques, such as XRD, SEM and EDS. The supercapacitive properties of all prepared samples were also studied using an electrochemical measurement technique (CV and GCD). The results revealed that the NiCo2O4/rGO (484.1 F.g−1) hybrid electrode exhibited much higher specific capacitance than those of pristine NiCo2O4 (358.3 F.g−1) and nano-sized rGO (113.8 F.g−1) electrodes, respectively. Hence, this work indicates that the supercapacitor performance of NiCo2O4 mixed rGO hybrid materials is more superior to the pure NiCo2O4 microflowers and nano-sized rGO sheets.
Fabrication of 3D surface-enhanced Raman scattering (SERS) substrate via solid-state dewetting of sputtered gold on fumed silica surface
Authors: Pengphorm P , Nuchuay P , Boonrod N , Boonsit S , Srisamran P , Thongrom S , Pewkum P , Kalasuwan P , van Dommelen P , Daengngam C
Published: January 2021

Raman spectroscopy is a potent and widespread optical analytical technique thanks to its non-invasive and high-specification for the detection of targeted molecules. However, for the case of trace detection, it is common that a weak Raman signal is easily swamped by noise and thus unable to be resolved. Here, we demonstrated a facile fabrication of a three-dimensional surface enhanced Raman spectroscopy (SERS) substrate, based on low-vacuum sputtering of gold nanofilm on hierarchically rough fumed silica monolayers deposited by layer-by-layer self-assembly technique. Due to the much lower surface energy of the silica-air heterostructure compared to metallic materials, deposited gold layers dewetted the surface spontaneously, forming nano-sized spherical gold particles without the requirement of an extra annealing process. Plasmonic effects were studied through optical absorption measurements, while the surface morphology and topography were examined using SEM and AFM for various sputtering durations. Furthermore, the enhancement of Raman spectrum was investigated for 10−4 M of methylene blue (MB), using 532 nm and 0.57 mW excitation laser. An initial Raman enhancement factor of 17 was observed at 1645 cm−1 peak, even with yet to be optimized fabrication procedures.
Quantum approximate optimization and k-means algorithms for data clustering
Authors: Saiphet Jirawat , Suwanna Sujin , Chotibut Thiparat , Chantasri Areeya
Published: January 2021

Noisy intermediate-scale quantum (NISQ) devices are cutting-edge technology expected to demonstrate potential and advantages of quantum computing over classical computing. Its low number of qubits and imperfection from noises restrict running full-scale quantum algorithms on such devices; however, quantum advantages can still be obtained. To achieve quantum advantages from NISQ devices, the hybrid quantum-classical algorithms were introduced. Quantum approximate optimization algorithm (QAOA) is a variational hybrid algorithm, which utilizes a NISQ device as a sub-unit for specific tasks and performs most calculations on a classical computer. QAOA provides an approximate solution, with arbitrary precision as the number of operations increases, for optimization problems. In this work we investigate the possibility of applying QAOA to a clustering problem and compare its performance with the classical k-means algorithm. It turns out that the weights in graph connectivity can degrade the algorithm operation and make it more difficult to approximate the solution. We also benchmark the QAOA by comparing the approximated solutions with the exact one obtained from a classical clustering algorithm.
Real Time Emotion Classification Based on Convolution Neural Network and Facial Feature
Authors: Nasuha A , Arifin F , Priambodo A S , Setiawan N , Ahwan N
Published: January 2021

Health problems due to emotion disorder should not be taken lightly because they have worse effects on health. Emotion disorder leads to prolonged stress and causes mental fatigue. Therefore, emotions need to be classified as early as possible. This classification result can be utilized to determine a person’s emotion and treatments required. In this paper, we proposed emotion classifier based on facial features. Here, we used Convolution Neural Network (CNN) to extract facial features from input images and classify them into 7 basic emotions: angry, sad, happy, neutral, fear, disgust, and surprise. Dept-wise separable convolution is applied, instead of the ordinary convolution in CNN, to reduce the number of trainable parameters so that the overall architecture of CNN can be made as simple as possible without compromising the accuracy. The simple architecture of the CNN allows us to make it work in real time. Our proposed method achieves an accuracy of 66% on 3.589 input images of FER2013 data set.
Evaluating an e-Learning Platform at Graduate School Based on User Experience Evaluation Technique
Authors: Abubakari M S , Nurkhamid  , Hungilo G
Published: January 2021

This study was aimed to evaluate the e-learning platform in a graduate school by using User Experience Questionnaire (UEQ). The data were collected from 65 respondents and analyzed using an excel data analysis tool. The results indicate that all six scales of the instrument are consistent except the novelty scale. Also, the calculated means of the scales are slightly positive as all values are greater than 0.8 compared to the UEQ benchmark. Although the respondents show a little positive impression with the platform, all scales means are below average category except efficiency scale which is above average as compared to the benchmark. This indicates that the platform needs more improvement in all aspects of user experience for it to be at least in a good category. The findings discussed in this paper are valuable for all academic stakeholders in various educational institutions which implement interactive e-learning systems as well as practitioners of user experience and developers of e-learning systems.
Analysis of Acceptance of Vocational High School e-Report in Temanggung District Using the UTAUT Model (Unified Theory of Acceptance and Use of Technology)
Authors: Erlita U A , Priyanto
Published: January 2021

This research examines the abuse of access rights of users of the VHS e-Report application which are not in accordance with the rules set by the Government. Therefore, this study aims to: (1) find the factors that affect the acceptance rate of the application of the e-Report of Vocational High Schools (VHS); and (2) find factors that do not affect the acceptance rate of implementing VHS e-Report. This research uses quantitative methods with an ex-post facto approach. This research was conducted at 4 Vocational High Schools in Temanggung Regency, namely Jumo State Vocational School, Dr Sutomo Temanggung Vocational School, Bhumi Phala Parakan Vocational School, and Vocational High School 17 Parakan. The population of all VHS was 432 respondents, while the sample is selected by proportional random sampling of 204 respondents. The data collection instrument used an online (google form) and offline (handout) questionnaire. The research questionnaire was compiled based on the UTAUT (Unified Theory of Acceptance and Use of Technology) model variables which have been adjusted to the conditions of the research field. The data analysis technique uses quantitative descriptive analysis with the PLS-SEM (Partial Least Square-Structural Equation Model) method which applies a bootstrap model to test the hypothesis. The results of this study concluded that there were: (1) factors that had a positive effect on the acceptance rate of VHS e-Report, namely business expectations, social influence, facilitation conditions, and behavioral intentions. The most influential factor was the intention to behave with the value of the path coefficients 0.412; and (2) factors that did not affect the acceptance level of the VHS e-Report application were performance expectations, age, and regulations. The least influential factor was the performance expectancy which was moderated by age with the path coefficients value of -0.188. The study on the acceptance of the VHS e-Report application in Temanggung Regency can be used as a recommendation in determining how to increase the use of the VHS e-Report application in accordance with access rights.
Predicting Potato Diseases Using Tensorflow in Mobile Apps Android
Authors: Artanto H , Arifin F
Published: January 2021

Detecting disease is something that can help to determine how to cure it. Potato diseases, namely early blight and late blight, are the problem in agriculture. Both diseases have almost the same characteristics so it is difficult to recognize. The technique used by farmers only utilizes their eyesight. In addition, previous studies have mostly used the biological aspect approach. In this study utilizing Machine Learning to detect an object. The development of this application uses the training configuration used is SSD Mobilenet v1. Application test results obtained an average value of 90% can detect and distinguish the types of diseases in the potato plant.
Improving Student’s Motivation in Pandemic Covid-19 Era Using an Authentic English Learning App
Authors: Putra M T M , Wardani R
Published: January 2021

A habit of the learning process in the classroom where students only receive lessons from the teacher makes students passive in the learning process. Therefore, students learning motivation decreases when it comes to distance learning. The development of Authentic English Learning App aims to motivate and facilitate students during the distance learning process. This system is designed for students to learn English in an authentic context in their surrounding at home. Moreover, students can collaborate with their peers and give feedback to their peers’ work. The App was tested using black box testing before it used by students. Black Box testing show a Very Good performance of the App. Furthermore, The result of this study shows that in the post-motivation, there is a significant difference of learning motivation between students who use Authentic English Learning App (EG) and students who only read a book (CG) (F = 4.664, p < 0.05). Therefore, Authentic English Learning App can motivate students to learn English effectively. Moreover, Technology Acceptance Model (TAM) questionnaire shows a high level of trust in each dimension (M > 4.5), It shows that Authentic English Learning App can facilitate students during Covid-19 in distance learning.
Development of Inverse Kinematics Learning Media Using Hexapod Robot for Robotics Course
Authors: Suprihono H , Mashoedah
Published: January 2021

This study aims to (1) get an inverse kinematic learning media design, (2) find out inverse kinematic learning media performance, (3) find out feasibility level of inverse kinematic learning media using hexapod robot. This type of research is research and development using ADDIE model, with stages: (1) Analysis, (2) Design, (3) Develop, (4) Implement, and (5) Evaluate. The object of research is hexapod robot. The subjects of research are students of Electronic Engineering Education Study Program who took the concentration of Industrial Electronics. Methods of data collection using classroom observation and questionnaires. The data analysis technique is descriptive qualitative analysis. The result of this research and development shows: (1) inverse kinematic learning media design using hexapod robot, (2) the performance through black box testing get result 100%. Each robot’s feet can move with an average axis error percentage x of 7,4%, y of 11,67% and z of 7,87% and produces 14 types of movement, (3) feasibility level of learning media based on the assessment of material expert obtained 94,46% (very feasible), media expert obtained 96,2% (very feasible), and users obtained 80,99% (feasible).
Developing UNYSA Chatbot as Information Services about Yogyakarta State University
Authors: Muhyidin Andri , Setiawan Muhammad Adi Febri , Nurkhamid
Published: January 2021

This study aims to (1) develop chatbot-based public relations communication media that are able to overcome the limitations of service in interacting and providing information about UNY to the public, (2) ensure the quality of software developed with the ISO/IEC 25010 model. The research method used is Research and Development (R&D) with the Agile: Scrum software development model. The results of this study are (1) a chatbot-based PR communication media named UNYSA as an information service about UNY, (2) UNYSA meets ISO/IEC 25010 quality standards on functional suitability characteristics with software developer experts at 0.86 (most features successfully implemented), material experts of 98.82% (Very Eligible), UAT of 83.95% (Very Good); performance efficiency has a latency response of 15 ms (faster than standard speed: 2 seconds); 100% portability (supports all planned frontend apps); usability of 83.81% (Very Eligible); reliability of 92% (Very Feasible), and maintainability with a maintainability index of 83.21 (very easy to maintain).
Development of WeShare As a Knowledge Sharing Platform to Realize the Freedom in Learning
Authors: Setialana Pradana , Fitria Anissa , Atika Riza , Hestiana  , Fadilla Risma Nor , Nurkhamid
Published: January 2021

Education builds a society quality to be creative, innovative. The Ministry of Education and Culture of Indonesia (Kemdikbud) program, “Freedom in Learning”, is expected to be able to create a happy learning atmosphere for the community. It also deals with the innovative Community 5.0 where the community is human-centred and based on technology to improve the human ability to open opportunities for humanity, on the other side to break the sense of stagnation, mutual respect and be able to lead a life active and fun. Therefore, an educational platform “WeShare” was built to promote culture of sharing knowledge to society with the mission of “Together Empowerment”. The research method used Research & Development (RnD) with Waterfall Models such as planning, analysis & design, development, testing, and maintenance programs. The aim of this program is to develop WeShare as a Knowledge Sharing Platform, and to understand the effects and benefits of WeShare program.
Eligibility of Certification Schemes for the Electrical Installation Competency of Electrical Engineering Education Study Program Students
Authors: Hartoyo  , Laras D , Zamtinah  , Sukisno Toto
Published: January 2021

The objectives of this study were to: (1) know the weaknesses of current certification model, (2) describe a Certification Scheme of Electrical Installation Competency for the Electrical Engineering Education Study Program (EEESP) Students’, Faculty of Engineering, Yogyakarta State University, and (3) know the eligibility of the Certification Scheme for Electrical Installation Competency of Electrical engineering Education Study program Students’. This research was conducted in the Department of Electrical Engineering Education, Faculty of Engineering, Yogyakarta State University from February to September 2020. This research is survey. The data collection used a questionnaire and an assessment of the feasibility of the certification scheme. The research respondents were lecturers, students, assessors, and practitioners in the field of Electrical Installation Competency. The validation of the research instrument was based on expert judgment by calculating the Aiken’s V index. The reliabilities of instrument were measured by Alpha Cronbach and Inter rater using interclass correlation coefficient (ICC). The data analysis technique used quantitative descriptive analysis, namely mean and percentage. The results of the research were as follows: (1) The weaknesses of current certification model were: (a) expensive competency test costs (77%), (b) there is no special certification scheme for the Electrical Engineering Education Study Program students as a prospective teacher (68%), (c) unclear competency test mechanism (52%), (d) inadequate competency test material (51%), and (f) the competency level tested was not suitable (32%); (2) The developed certification scheme is Low Voltage Electrical Installation Engineering Competency for EEESP Students’; (3) The Eligibility of the Electrical Installation Competency Certification Scheme for EEESP Students’ is very eligible with an average score of 3.66 out of 4.00.
Effects of flight altitude on the lift generation of monarch butterflies: from sea level to overwintering mountain
Authors: Sridhar Madhu K , Kang Chang-Kwon , Landrum D Brian , Aono Hikaru , Mathis Shannon L , Lee Taeyoung
Published: January 2021

Aerodynamic efficiency behind the annual migration of monarch butterflies, the longest among insects, is an unsolved mystery. Monarchs migrate 4000 km at high-altitudes to their overwintering mountains in Central Mexico. The air is thinner at higher altitudes, yielding reduced aerodynamic drag and enhanced range. However, the lift is also expected to reduce in lower density conditions. To investigate the ability of monarchs to produce sufficient lift to fly in thinner air, we measured the climbing motion of freely flying monarchs in high-altitude conditions. An optical method was used to track the flapping wing and body motions inside a large pressure chamber. The air density inside the chamber was reduced to recreate the higher altitude densities. The lift coefficient generated by monarchs increased from 1.7 at the sea-level to 9.4 at 3000 m. The correlation between this increase and the flapping amplitude and frequency was insignificant. However, it strongly correlated to the effective angle of attack, which measures the wing to body velocity ratio. These results support the hypothesis that monarchs produce sufficiently high lift coefficients at high altitudes despite a lower dynamic pressure.
Partitioning uncertainty in projections of Arctic sea ice
Authors: Bonan David B , Lehner Flavio , Holland Marika M
Published: January 2021

Improved knowledge of the contributing sources of uncertainty in projections of Arctic sea ice over the 21st century is essential for evaluating impacts of a changing Arctic environment. Here, we consider the role of internal variability, model structure and emissions scenario in projections of Arctic sea-ice area (SIA) by using six single model initial-condition large ensembles and a suite of models participating in Phase 5 of the Coupled Model Intercomparison Project. For projections of September Arctic SIA change, internal variability accounts for as much as 40%–60% of the total uncertainty in the next decade, while emissions scenario dominates uncertainty toward the end of the century. Model structure accounts for 60%–70% of the total uncertainty by mid-century and declines to 30% at the end of the 21st century in the summer months. For projections of wintertime Arctic SIA change, internal variability contributes as much as 50%–60% of the total uncertainty in the next decade and impacts total uncertainty at longer lead times when compared to the summertime. In winter, there exists a considerable scenario dependence of model uncertainty with relatively larger model uncertainty under strong forcing compared to weak forcing. At regional scales, the contribution of internal variability can vary widely and strongly depends on the calendar month and region. For wintertime SIA change in the Greenland-Iceland-Norwegian and Barents Seas, internal variability contributes 60%–70% to the total uncertainty over the coming decades and remains important much longer than in other regions. We further find that the relative contribution of internal variability to total uncertainty is state-dependent and increases as sea ice volume declines. These results demonstrate that internal variability is a significant source of uncertainty in projections of Arctic sea ice.
Friction: from Leonardo da Vinci to modern nanotechnologies
Authors: Makarov A V
Published: January 2021

The review paper presents an outstanding contribution of Leonardo da Vinci to the science of friction, which is the heart of modern nanotechnologies. It demonstrates a significant role of nanocrystalline friction structures (NCFS) in the formation of the tribological properties of metal alloys and in the implementation of deformation-induced nanostructuring techniques for metal alloy surface processing. Inherent in the very nature of friction, the ability to obtain an NCFS can be effectively used for targeted nanostructuring of product surface layers in order to increase their resistance to wear, corrosion, mechanical loads, and high temperatures. This can be achieved by using simple frictional and ultrasonic impact-frictional surface treatments, as well as combined methods based on the chemical modification of the formed NCFS. It is proposed to use nanostructuring frictional pretreatment and the industrial technology of nanostructuring burnishing in combined methods for surface preparation of structural stainless steels, including those produced by additive laser technology, for applying high-strength nanocomposite thin-film coatings.