bluuebunny/crossref_metadata_2025 huggingface dataset:
Support and defense strategy-assisted social network search algorithm and its application
Authors: Wang Jie , Ren Jianji , Yuan Yongliang
Published: February 2023

A novel state-of-the-art optimization strategy, named support and defense strategy, is proposed to enhance the research ability for the social network search algorithm. In the improved social network search algorithm (ISNSA), the support and defense strategy (SDS) is used to improve the conversation and disputation efficiency. The SDS can improve the correlation between the supporters and opponents in the ISNSA. The research ability of the ISNSA is verified with three constrained engineering problems. The optimization results show that the ISNSA is a competitive algorithm, which can obtain the global optimal solution.
Glassy dynamics in bacterial growth rate temperature dependence
Authors: Pinto Carlito , Shimakawa Koichi
Published: February 2023

An empirical expression for the temperature dependence of bacterial growth rate, k=b(T−T0), where k is the intrinsic growth rate, T is the ambient temperature, T0 is the hypothetical temperature, and b is the regression coefficient, has been exemplified for practical bacterial growth. Although this relationship has been popularly used as the standard evaluation of the bacterial growth rate, its scientific foundation is not clear. We propose a new relation, k = k0 exp[−Ea/kB(T − Tc)], where k0 is a constant, Ea is the activation energy (eV), kB is the Boltzmann constant, T is the absolute temperature (K), and Tc is the characteristic (frozen-in) temperature (K). The present equation resembles that for temperature-dependent fluidity (inverse viscosity) originally found for glass-forming liquids in inorganic materials. This commonality is attributed to the glass-like properties of the bacterial cytoplasm in accordance with the recent findings of glassy dynamics in active or lived matter.
Development of novel FeCo based amorphous FeCoBPSiCr alloy with high Bs of 1.71 T and high corrosion resistance
Authors: Hasegawa A. , Kajiura Y. , Hosono M. , Yoshidome K. , Matsumoto H.
Published: February 2023

Metallic ribbons of different compositions were prepared using a single-roller melt-spinning method. The (Fe0.8Co0.2)83B11P4Si2 alloy without Cr showed both high saturation magnetic flux (Bs) of 1.78 T and high corrosion resistance, with a corrosion potential of −607 mV and a corrosion current density of 29 μA/cm2 compared to those of a conventional high-Bs Fe79B13.5Si5.5C2 amorphous alloy. The (Fe0.7Co0.3)82B11P4Si2Cr1 alloy with Cr also exhibited a high Bs of 1.71 T and high corrosion resistance at the same level as that of a conventional Fe73B11Si11C3Cr2 amorphous alloy. The (Fe0.7Co0.3)82B11P4Si2Cr1 alloy showed a corrosion potential of −509 mV and a corrosion current density of 18 μA/cm2. Furthermore, the (Fe0.7Co0.3)82B11P4Si2Cr1 alloys exhibited a high amorphous forming ability because of a single amorphous phase in the metallic ribbon at a thickness of  >60 μm. Based on these results, the (Fe0.7Co0.3)82B11P4Si2Cr1 amorphous alloy with the possibility of powderization was confirmed to be a suitable material for the magnetic core that is widely used in metallic inductive components.
Effect of spin-orbit field on magnetization reversal in GaMnAs single layers with 4-fold in-plane magnetic anisotropy
Authors: Han Kyoul , Lee Kyung Jae , Lee Sanghoon , Liu Xinyu , Dobrowolska M. , Furdyna Jacek K.
Published: February 2023

Effect of spin-orbit-induced (SOI) field on magnetization reversal in ferromagnetic semiconductor GaMnAs films with 4-fold in-plane magnetic anisotropy has been investigated by planar Hall resistance (PHR) and anisotropic magnetoresistance (AMR) with current along the <110> and <100> crystallographic directions, respectively. Field scan hysteresis of PHR and AMR measured with current of 2.5 mA were observed to be asymmetric respect to zero field, showing different transition fields between positive and negative field regions. In addition, the hysteresis asymmetry is reversed as the sign of the current is reversed from positive to negative. Such dependence of asymmetry on current polarity implies that the current-induced spin-orbit field, which is known to depend on the current direction, significantly affects magnetization reversal. The asymmetry observed for currents along [100], [010], [110], and [11̄0] crystallographic directions is fully consistent with the effects arising from the Dresselhaus-type SOI fields in GaMnAs films.
Tunnel anisotropic magnetoresistance in magnetic tunnel junctions using FeAlSi
Authors: Akamatsu S. , Nakano T. , Al-Mahdawi Muftah , Yupeng W. , Tsunoda M. , Ando Y. , Oogane M.
Published: February 2023

We fabricated magnetic tunnel junctions (MTJs) with FeAlSi free layers and investigated the tunnel magnetoresistance (TMR) properties at low temperature. We observed TMR ratio increase with temperature decrease, and confirmed the TMR ratio of 179.9% at 10 K. The conductance dependence on bias voltage was measured, and a clear peak at low bias voltage similar to Fe/MgO/Fe MTJs was observed. This behavior can be explained by considering the majority band of Fe(001), and Δ5 electrons tunneling in FeAlSi/MgO/CoFeB MTJs at low bias voltage. We also investigated tunnel anisotropic magneto-resistance (TAMR) and clearly observed a TAMR peak similar to Fe/MgO/Fe MTJs, where the TAMR ratio of FeAlSi/MgO/CoFeB MTJs was 1.0% comparable to 1.1% in Fe/MgO/Fe MTJs. We concluded that electron tunneling was caused by the interfacial resonance states originating from spin orbit coupling in the FeAlSi/MgO/CoFeB MTJs.
A study on the shaft stability and prediction of electromagnetic and NVH characteristics of permanent magnet synchronous machine according to the different pole/slot combination
Authors: Lee Young-Keun , Bang Tae-Kyoung , Jo Seong-Tae , Lee Hoon-Ki , Kim Yong-Joo , Lee Sung-Ho , Kim Min-Seok , Choi Jang-Young
Published: February 2023

In this study, electromagnetic noise sources of permanent magnet synchronous motors with 8-pole 9-slot and 12-slot fractional slot concentrated windings were analyzed through finite element analysis, and the radiated noise/vibration levels were compared through structural-acoustic analysis. In addition, the stability of the rotational shaft generated vibration was analyzed. Electromagnetic noise sources are classified into cogging torque, torque ripple, and unbalanced magnetic force. The effect of electromagnetic noise sources on vibration/noise was analyzed in the frequency domain through the electromagnetic-mechanical coupling analysis. The noise level was compared to the electromagnetic noise source characteristics for each frequency using the waterfall diagram, and additional vibration due to mechanical resonance was analyzed using critical speed analysis while taking the rotor's bearing stiffness into account.
Low temperature synthesis of Sm-Fe alloy powder by reduction-diffusion process using new reductant of Li-Ca eutectic melt
Authors: Kim Jungryang , Okada Shusuke , Takagi Kenta
Published: February 2023

In this study, the low-temperature reduction-diffusion (LTRD) process using a Li-Ca reductant, which has a low eutectic point of about 230 °C, was demonstrated. The RD reaction was possible at a very low temperature of 400 °C significantly less than 850 °C, which is the lowest practicable temperature of the conventional RD process, by identifying the production of the SmFe2 phase. The LTRD process in this study also made it possible to investigate the Sm-Fe binary phases synthesized at the low temperature and the Sm-Fe phase transitions depending on the temperatures with the compositions of Sm and Fe.
Writing domains in nanowires using a spin torque oscillator
Authors: Greaves Simon John , Sonobe Yoshiaki
Published: February 2023

Magnetic nanowires can be used to store information. There are various ways to write magnetic domains in nanowires, usually involving the use of an Oersted field. In this work the use of a spin torque oscillator to write domains in magnetic nanowires is investigated using micromagnetic modelling. It is shown that domains can be written using a lower magnetic field than if an Oersted field were used. Writing of multiple domains in a nanowire is also demonstrated.
Effect of microwave instant heating on magnetic, electric and microwave absorption properties of La0.7Na0.3MnO3
Authors: Marimuthu Manikandan , Jiang Lu Wen , Chen Guo Hao , Lee Yong Heng , Mahendiran Ramanathan
Published: February 2023

The emerging method of microwave (MW) heating was adopted to synthesize a phase pure La0.7Na0.3MnO3 from their oxide precursors. The MW power (P) used for heating the sample was varied from P = 1000 W to 1600 W to examine the effect of MW power on its physical properties. A well-crystalline single phase La0.7Na0.3MnO3 was achieved in 20 min of MW irradiation with P = 1600 W. The obtained grain sizes at P = 1000 W have grown bigger and densified while increasing the P = 1600 W. Growth in the grains was reflected in the resistivity of La0.7Na0.3MnO3 prepared at high P. As the P increases from 1000 W to 1600 W, the resistivity decreases drastically and the metal–insulator transition also becomes sharp at a temperature very close to TC whereas the ferromagnetic Curie temperature (TC) is least affected. The sample prepared at low P showed larger microwave absorption than the sample prepared under high P. These findings were correlated and discussed with the structural and morphological features acquired by microwave irradiation with different powers.
Fault operation analysis of a novel dual-three-phase dual-rotor flux-switching permanent magnet machine
Authors: Zhao Guishu , Chang Zhe , Li Zhengliang , Zhou Yuheng , Jiang Xin
Published: February 2023

In this paper, based on the conventional flux-switching permanent magnet (PM) (FSPM) machine, a novel dual-three-phase dual-rotor FSPM machine with PMs of NS layout (NS-DRFSPM) is proposed. The stator of the proposed NS-DRFSPM machine is equipped with dual PMs and dual armature windings to operate in a variety of operating modes and to handle the case of PMs or armature windings failure. Firstly, the topological structure and eight fault operating states of the NS-DRFSPM machine are introduced, and the key design parameters of the NS-DRFSPM machine are optimized by genetic algorithm (GA) optimization and finite element analysis (FEA). Then, the operation principle of the NS-DRFSPM machine is analyzed in detail. Finally, the finite element method is used to analyze the performances of the NS-DRFSPM machine under eight fault operating states, which is mainly analyzed from two aspects: no-load performance and torque performance. The results show that the NS-DRFSPM machine has good electromagnetic performance under different fault conditions, including large back-electromotive force (EMF) amplitude, sinusoidal EMF waveform, high average torque, small torque ripple, and strong anti-saturation ability.
Characteristics of magnon-phonon coupling in magnetic insulator based on the Boltzmann equation
Authors: Chen Chao , Li Yuheng , Zhang Jianwei
Published: February 2023

The magnon, an elementary excitation of an orderly magnetic system, is currently receiving substantial attention due to its excellent spin transmission properties. Researchers have observed a clear correlation between magnon transport properties and temperature. Existing theories do include the influence of temperature, but cannot clearly explain many phenomena, including a detected abnormal negative signal. In this article, we build a new magnon transport theory based on the Boltzmann method, which incorporates a magnetic field-induced “anti-diffusion” driving term, a magnon-phonon interaction induced thermal driving term, and diverse scattering terms, such as a scattering process which leads magnons to a special state with a collective velocity. We claim that collective velocity is the crucial factor in producing an abnormally negative signal. We formulated an equation capturing the system’s spin properties, which we solved. Our results qualitatively explain the abnormal phenomenon observed in experiments.
Optimization of two-dimensional generalized partial response target using multi-layer perceptron for bit-patterned media recording systems
Authors: Nguyen Thien An , Lee Jaejin
Published: February 2023

In magnetic storage systems, the read signal that is the output of the magnetic recording channel is passed through the equalizer to convert it into the desired partial response (PR) target signal. However, mapping between the output of the recording channel and the PR target signal is a non-linear problem. Therefore, many multilayer perceptron (MLP) equalizers have been proposed. In this paper, we propose an optimization scheme of two-dimensional generalized PR target using MLP for improving the detection performance of the bit-patterned magnetic recording (BPMR) systems. The simulation results show that the proposed scheme outperforms the previous methods.
Study of the magnetostructural transition in critical-element free Mn1−xNi1−xFe2xSi0.95Al0.05
Authors: Eggert Bruno G. F. , Wang Kun , Jafarzadeh Sina , Bahl Christian R. , Hauback Bjørn C. , Frommen Christoph
Published: February 2023

Two different heat treatments have been carried out on similar Mn1−xNi1−xFe2xSi0.95Al0.05 compositions with magnetostructural transitions between hexagonal and orthorhombic crystal structures around room temperature. The samples were analyzed concerning their structural, microstructural, magnetic, and caloric properties. The results show that the introduction of a high-temperature step, before the heat treatment (1073 K/7 days) usually used in the literature for such compounds modifies the microstructure, leading to sharper transitions with shorter transition widths, and stronger latent heat peaks. Magnetic field-assisted calorimetry and vibrating sample magnetometry provide methods to assess the effect of magnetic field on the broad transitions for the sample with x = 0.32 and the sharp transitions seen in the sample with x = 0.31.
Study on the characteristics of power transmission side of leaky magnetic field canceling coil for non-contact power transfer while in operation
Authors: Yokosawa M. , Kojima H. , Sato F. , Miyahara S. , Matsuki H. , Ito O. , Inada K. , Sasaki S.
Published: February 2023

Recently, automated guided vehicles (AGVs) have been deployed in factories to improve work efficiency and reduce labor shortages. However, current power supply systems, such as AGV shift systems and battery replacement systems, cannot fully utilize the advantages of these systems because of the time they are inactive. Therefore, to improve work efficiency, we have adopted an in-transit non-contact power supply system that can supply power while the work is in progress and while the machine is moving. There are several non-contact power supply methods; however, the most widely used electromagnetic induction method was used in this study. Compared to conventional non-contact power transfer, a stable power supply and reduction of magnetic leakage field are more important for non-contact power transfer while traveling because of its characteristic of transferring power over a long section of the track. Therefore, we investigated the characteristics of a cancellation coil with enhanced effectiveness based on an 8-shaped coil that reduces the leakage of magnetic fields using electromagnetic field analysis simulations. We then fabricated a feeding coil and verified its effectiveness using actual measurements. As a result, it was confirmed that the cancellation coil has superior magnetic field leakage reduction performance compared to the ordinary 8-shaped coil.
On the synthesis and characterization of bimagnetic CoO/NiFe2O4 heterostructured nanoparticles
Authors: Uddin Muhammad S. , Mayanovic Robert A. , Benamara Mourad
Published: February 2023

Bimagnetic nanoparticles show promise for applications in energy efficient magnetic storage media and magnetic device applications. The magnetic properties, including the exchange bias of nanostructured materials can be tuned by variation of the size, composition, and morphology of the core vs overlayer of the nanoparticles (NPs). The purpose of this study is to investigate the optimal synthesis routes, structure and magnetic properties of novel CoO/NiFe2O4 heterostructured nanocrystals (HNCs). In this work, we aim to examine how the size impacts the exchange bias, coercivity and other magnetic properties of the CoO/NiFe2O4 HNCs. The nanoparticles with sizes ranging from 10 nm to 24 nm were formed by synthesis of an antiferromagnetic (AFM) CoO core and deposition of a ferrimagnetic (FiM) NiFe2O4 overlayer. A highly crystalline magnetic phase is more likely to occur when the morphology of the core-overgrowth is present, which enhances the coupling at the AFM-FiM interface. The CoO core NPs are prepared using thermal decomposition of Co(OH)2 at 600 °C for 2 hours in a pure argon atmosphere, whereas the HNCs are obtained first using thermal evaporation followed by hydrothermal synthesis. The structural and morphological characterization made using X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM), and scanning electron microscopy (SEM) techniques verifies that the HNCs are comprised of a CoO core and a NiFe2O4 overgrowth phase. Rietveld refinement of the XRD data shows that the CoO core has the rocksalt (Fd3 m) crystal structure and the NiFe2O4 overgrowth has the spinel (C12/m1) crystal structure. SEM-EDS data indicates the presence and uniform distribution of Co, Ni and Fe in the HNCs. The results from PPMS magnetization measurements of the CoO/NiFe2O4 HNCs are discussed herein.
Evaluation of coplanar line type thin film magnetic field sensor with narrow slits
Authors: Sakamoto Masaya , Suzuki Ryota , Ishihara Tomoya , Honda Junichi , Yabukami Shin
Published: February 2023

We have proposed coplanar line type thin-film magnetic field sensor with narrow slits. The slit is employed to flow more carrier current on the signal line by improving the impedance matching. Several sensors having 6, 10, 26, 36, and 50 μm slit widths were fabricated and evaluated from the phase and the amplitude of the transmission coefficient (S21) and reflection coefficient (S11) measured by the network analyzer. The amplitude of S21 with slit was improved about five times larger than the sensor without one at around 2 GHz. The appropriate slit width was evaluated as around 10 μm for the coplanar line type thin film magnetic field sensor and the sensitivity will enhance more than 10 times higher than the sensor without slits.
The utility of body size as a functional trait to link the past and present in a diverse reptile clade
Authors: Parker Abigail K. , Müller Johannes , Boisserie Jean-Renaud , Head Jason J.
Published: February 2023

Understanding the relationships between functional traits and environment is increasingly important for assessing ecosystem health and forecasting biotic responses to future environmental change. Taxon-free analyses of functional traits (ecometrics) allow for testing the performance of such traits through time, utilizing both the fossil record and paleoenvironmental proxies. Here, we test the role of body size as a functional trait with respect to climate, using turtles as a model system. We examine the influence of mass-specific metabolic rate as a functional factor in the sorting of body size with environmental temperature and investigate the utility of community body size composition as an ecometric correlated to climate variables. We then apply our results to the fossil record of the Plio-Pleistocene Shungura Formation in Ethiopia. Results show that turtle body sizes scale with mass-specific metabolic rate for larger taxa, but not for the majority of species, indicating that metabolism is not a primary driver of size. Body size ecometrics have stronger predictive power at continental than at global scales, but without a single, dominant predictive functional relationship. Application of ecometrics to the Shungura fossil record suggests that turtle paleocommunity ecometrics coarsely track independent paleoclimate estimates at local scales. We hypothesize that both human disruption and biotic interactions limit the ecometric fit of size to climate in this clade. Nonetheless, examination of the consistency of trait–environment relationships through deep and shallow time provides a means for testing anthropogenic influences on ecosystems.
Influence of viscoelasticity on ultrasonic propagation in poly(ethylene oxide) aqueous solution
Authors: Wu Heng , Huang Xiaodong , Liang Xianrong , Wang Mengmeng , Jin Gang
Published: February 2023

Generally, ultrasonic propagation in ultrasonic non-destructive testing is regarded as a linear process, during which the interaction between ultrasonic and measured material is rarely considered. In this study, the mechanisms of ultrasonic propagation in viscoelastic poly(ethylene oxide) aqueous solution and the interaction between ultrasound and fluid are investigated. A theoretical model of ultrasonic propagation in a viscoelastic fluid is established, in which the body force from ultrasonic waves is added to the fluid momentum equation, and the viscoelasticity of the fluid is described by the Oldroyd-B model. The simulation results for the ultrasonic reflection coefficient at the solid–liquid boundary and the attenuation coefficient based on the multi-physics coupling method are experimentally verified. The results of this study show that the ultrasonic absorption coefficient at low frequencies from 2.25 to 7.5 MHz exhibits frequency dependence through ultrasonic relaxation spectroscopy. The simulation results of the velocity of disturbed flow during ultrasonic propagation show that the viscosity of the solution has a greater impact on the disturbance than the relaxation time, and the phase angle difference between the stress and strain also shows that the viscosity is the main factor affecting the ultrasonic propagation.
Design and construct full invisible band metamaterial-based coating with layer-by-layer structure in the microwave range from 8 to 10 GHz
Authors: Talati Saeed , Ghazali Seyed Morteza , SoltaniNia VahidReza
Published: February 2023

This paper presents the design and construction of a carpet-based anti-radar coating for frequencies from 8 to 10 GHz. The basic idea of the proposed method is to use a coating to guide microwaves around an object so that what is inside the coating becomes invisible. The proposed method uses metamaterial structures with heterogeneous properties to create coatings that provide complete bounding and prevent loss. Using the theory of light transformation and Zhukovsky mapping for the physical dimensions of the bulge to be invisible, the profile of the refractive index distribution with respect to the radiation of waves is determined. The simulation results of the refractive index profile have shown that it is possible to create an ideal invisible coating for each bulge by using the proposed unit cells and a layer-by-layer structure. Finally, after photolithography of the design on the 5880 fibers using a network analyzer and a pair of corrugated wave antennas, the accuracy of the proposed coating performance is confirmed.
Non-reversible processes: GENERIC, hypocoercivity and fluctuations
Authors: Duong M H , Ottobre M
Published: February 2023

We consider two approaches to study non-reversible Markov processes, namely the hypocoercivity theory and general equations for non-equilibrium reversible–irreversible coupling; the basic idea behind both of them is to split the process into a reversible component and a non-reversible one, and then quantify the way in which they interact. We compare such theories and provide explicit formulas to pass from one formulation to the other; as a bi-product we give a simple proof of the link between reversibility of the dynamics and gradient flow structure of the associated Fokker–Planck equation. We do this both for linear Markov processes and for a class of nonlinear Markov process as well. We then characterise the structure of the large deviation functional of generalised-reversible processes; this is a class of non-reversible processes of large relevance in applications. Finally, we show how our results apply to two classes of Markov processes, namely non-reversible diffusion processes and a class of piecewise deterministic Markov processes (PDMPs), which have recently attracted the attention of the statistical sampling community. In particular, for the PDMPs we consider we prove entropy decay.
The impact of charges at the dielectric/channel interface on performance degradation in negative capacitance ferroelectric FETs
Authors: Li Ming-Hao , Li Qiang , Hsu Hsiao-Hsuan , Ying Lei-Ying , Zhang Bao-Ping , Zheng Zhi-Wei
Published: February 2023

In this study, the impact of interfacial charges including fixed charges and acceptor-type traps between the dielectric and the channel in negative capacitance ferroelectric FETs (FeFETs) is investigated by simulation based on the Landau–Khalatnikov model. The results reveal the separate impact of the fixed charges and acceptor-type traps on device performance degradation, respectively, including the subthreshold swing (SS), switching current (I
on and I
off) and threshold voltage (V
T). On this basis, the combined impact of interfacial charges with the fixed charges and acceptor-type traps co-existing equally is further explored. Our findings indicate that the fixed charges play a key role in the V
T and I
off, while the acceptor-type traps predominate in the SS and I
on. This study helps to understand the degradation mechanism of FeFETs and extend the device end-of-lifetime.
Impacts of pulse conditions on endurance behavior of ferroelectric thin-film transistor non-volatile memory
Authors: Ma William Cheng-Yu , Su Chun-Jung , Kao Kuo-Hsing , Lee Yao-Jen , Wu Pin-Hua , Tseng Hsin-Chun , Liao Hsu-Tang , Chou Yu-Wen , Chiu Min-Yu , Chen Yan-Qing
Published: February 2023

In this work, the ferroelectric thin-film transistor (Fe-TFT) with polycrystalline-silicon (poly-Si) channel and HfZrO
x
gate dielectric is fabricated to study the characteristics of non-volatile memory (NVM). Significant threshold voltage (V
TH) modulation can be achieved with low pulse voltages less than ±3.5 V and pulse widths within 1 μs. In order to achieve the NVM characteristics of low voltage and high speed operation, the impact of the program/erase (PRG/ERS) pulse voltage (V
PRG/V
ERS) and pulse width on endurance is a critical consideration. In the study of the pulse width effect on endurance, it can be observed that the V
TH in PRG-state exhibits the wake-up effect at both short and long pulse widths. In addition, with the increase of pulse width, the V
TH in the PRG-state exhibits significant fatigue effect and subthreshold swing (SS) degradation effect. For V
TH in the ERS-state, the increase of the pulse width also exhibits the fatigue effect and the SS degradation effect, which is dominated by the SS degradation effect at long pulse widths. In the study of the pulse voltage effect on endurance, the increase of V
PRG shows the imprint effect that the V
TH in either PRG- or ERS-state reveals a decreasing trend. When the V
ERS increases, the SS of the PRG- and ERS-states is degraded, and the fatigue effect of the PRG-state is enhanced. Moreover, the retention characteristics of poly-Si Fe-TFTs exhibit stable characteristics at both room temperature and 50 °C.
Physical design guidelines to minimize area-specific ON-resistance for rated ON-current and breakdown voltage of GaN power HEMTs
Authors: Khan Md Arif , Muralidharan Rangarajan , Chandrasekar Hareesh
Published: February 2023

In this article, we report on the development of an analytical model to estimate area-specific ON-state resistance (R
ds,on) of GaN-based power high electron mobility transistor (HEMT) using rated device specifications—ON-state drain current (I
ON) and maximum operating drain-to-source voltage (V
DSO)—as input parameters. The rated I
ON and V
DSO are considered as fractions k and S, of the maximum possible drain current (I
DS,max) and breakdown voltage (V
BR), respectively, deliverable by the power device. The developed model is utilized to obtain the optimal physical design space parameters for a comb-like power HEMT design. Due consideration has been given to the trade-off between R
ds,on and area-specific R
ds,on of the transistor, device processing limitations for all the physical device parameters. The developed model has been validated with experimental results of prior literature. Our calculations impose a lower-bound for the best possible R
ds,on as well as the area-specific on-resistance product (R
ds,on

×

AA) that can be obtained for a given starting channel sheet resistance in the comb architecture for a desired I
ON − V
DSO rating.
Precision redshift-space galaxy power spectra using Zel'dovich control variates
Authors: DeRose Joseph , Chen Shi-Fan , Kokron Nickolas , White Martin
Published: February 2023

Numerical simulations in cosmology require trade-offs between volume, resolution and run-time that limit the volume of the Universe that can be simulated, leading to sample variance in predictions of ensemble-average quantities such as the power spectrum or correlation function(s). Sample variance is particularly acute at large scales, which is also where analytic techniques can be highly reliable. This provides an opportunity to combine analytic and numerical techniques in a principled way to improve the dynamic range and reliability of predictions for clustering statistics.
In this paper we extend the technique of Zel'dovich control variates, previously demonstrated for 2-point functions in real space, to reduce the sample variance in measurements of 2-point statistics of biased tracers in redshift space. We demonstrate that with this technique, we can reduce the sample variance of these statistics down to their shot-noise limit out to k ∼ 0.2 h Mpc-1. This allows a better matching with perturbative models and improved predictions for the clustering of e.g. quasars, galaxies and neutral Hydrogen measured in spectroscopic redshift surveys at very modest computational expense. We discuss the implementation of ZCV, give some examples and provide forecasts for the efficacy of the method under various conditions.
Two-dimensional electromagnetically induced grating via phase regulation in a closed-loop four-level atomic system
Authors: Li Ya-Qian , Zhang Duo , Xia Hong-Ming , Sun Zhao-Yu , Wang Mei
Published: February 2023

We proposed a theoretical scheme for two-dimensional (2D) electromagnetically induced grating (EIG) in a closed-loop four-level atomic system driven by a weak probe field, a traveling-wave control field, two orthogonal standing-wave fields and a microwave field. Due to low amplitude modulation accompanied with large phase modulation, EIG can be obtained and the probe energy can be diffracted into first-order and even high-order directions with high efficiency. The results show that the diffraction pattern and efficiency of the EIG could be adjusted effectively by the probe field detuning, the coherent field intensity, the interaction length. Meanwhile, the quantum interference between the amplitude modulation and phase modulation can be manipulated by the relative phase, which can be used to regulate the diffraction pattern and efficiency of the 2D EIG. Our scheme of 2D EIG may be useful in beam splitting and all-optical switching.
Optical properties of freeze-dried partial delignified balsa wood
Authors: Tapsanit Piyawath , Maitip Jakkrawut
Published: February 2023

Radiative cooling (RC) is natural phenomenon in which an object passively cools itself by highly radiating mid-infrared waves to the cold outer space. The delignified wood (DW), in which lignin molecules are removed from natural wood, shows promising performance of daytime radiative cooling (DRC). However, the DW is usually hot-pressed during oven drying process which results in the collapse of wood cell walls. This problem hinders the application of DW as a scaffold for polymer-wood composite. In this study, we have fabricated a partial delignified wood (PDW) with the combination of the delignification and freeze-drying processes. The delignification process has been performed with boiling hydrogen peroxide (H2O2) solution in renewable system. It is found that the PDW turns to white colour after 30 hours of boiling time. The ATR-FTIR spectroscopy confirms that lignin molecules are removed and altered after the delignification process, and the strong emission peaks due to the molecular vibrations of cellulose in the PDW appear in the atmospheric windows. The averaged solar absorptivity of the PDW, measured by diffuse reflectance UV-Vis-NIR spectroscopy, is equal to 11% which is about three times lower than that of the natural wood. The relative drop of solar radiation absorption has maximum value at the wavelength 529 nm and the full-width-at-half-maximum equal to.
A model for the estimation of global spectral solar irradiance under all-sky conditions for Nakhon Pathom station, Thailand
Authors: Khakhu S , Masiri I , Wattan R , Janjai S
Published: February 2023

In this work, a model was developed to estimate global spectral solar irradiance under all-sky conditions using data from the Nakhon Pathom station, Thailand. This model expresses the global spectral solar irradiance under all-sky conditions as the multiplication of two functions. The global spectral irradiance under clear sky conditions from the calculation and the cloud correction factor are considered in the model. The cloud correction factor is a function of the cloud index from Himawari satellite data and the ratio of global spectral irradiance under all sky conditions and clear sky conditions. The global spectral irradiance was measured at Nakhon Pathom station using a spectroradiometer (EKO, MS-710) from 2017 to 2019. Model validation was computed using the 2020 dataset. The global solar spectral irradiance from measurements and calculated from the model were found to be in reasonable agreement, with discrepancies in mean bias difference and root mean squared difference of 4.85% and 14.21%, respectively.
A model for estimating solar ultraviolet radiation for vitamin D photosynthesis
Authors: Laiwarin P , Buntoung S , Wattan R , Janjai S
Published: February 2023

Solar ultraviolet radiation has impacts on human health both beneficial and drawback. Excessive exposure to high energy of solar ultraviolet radiation is hazardous for human. For instant, it can create cataracts, skin cancer and immune system suppression. On the contrary, solar ultraviolet radiation helps in the vitamin D photosynthesis in the human skin. It is required in the operation of synthesize previtamin D in the epidermis to 25 hydroxyvitamin D via the kidneys and liver. The solar ultraviolet radiation for vitamin D photosynthesis (DUV) can be obtained from a Bentham spectrophotometer together with the CIE action spectral response of vitamin D. However, such ground-based spectrophotometer instrument in Thailand is very scarce. Therefore, this research focuses on developing an empirical model for calculating hourly DUV under all sky conditions using several atmospheric parameters at a solar monitoring site in the central region of Thailand. The input parameters of the model include total ozone column from OMI/AURA satellite, aerosol optical depth from an AERONET sunphotometer, cloud index from geostationary satellite, and air mass from a well-known equation. The data used in this research are totally three years (2016-2018). The analysis result indicates that the solar DUV obtained from the model calculation and that from the ground-based measurement are consistent with the root mean square error (RMSE) of 17.1% and mean bias error (MBE) of –9.2%.
Study of plasma activated water and secondary effects on water using gamma radiation with FTIR in seeds germinations
Authors: Somjaimak A , Prakrajang K , Sarapirom S , Rimjaem S , Janpong K
Published: February 2023

Plasma activated water (PAW) and gamma radiation have been arduously used in many horticultural implementations; especially in increasing plant germination rates and general growth advancements. Attention has to be paid to both the effect of PAW and gamma radiation. The detailed chemical composition and appearance of tap water and distilled water that has been stimulated by plasma and gamma radiation on seed germination using Fourier transform infrared spectroscopy (FTIR) technique and optical emission spectroscopy (OES) are to be analysed. The result found that one important property of air plasma treatment on water is the creation of reactive atom species such as oxygen (O), Nitrogen (N) also known as RONS, as well as other ion molecules radical to water. Whilst gamma radiation can directly induce and generate water molecules radicals by its strong electromagnetic fields.
Optical properties of carbon dots derived from table sugar via gamma irradiation
Authors: Wechakorn Kanokorn , Utapong Teerawat , Chutimasakul Threeraphat , Sirisit Natee , Kwamman Tanagorn
Published: February 2023

Gamma irradiation is the only approach for green environmental synthesis that does not require further waste treatment. Therefore, gamma irradiation was employed for carbon dot production at room temperature in this study. The table sugar was utilized as a raw material without the addition of any hazardous additives. Using sugar concentrations of 4, 20, and 40% by weight, carbon dots were produced using gamma irradiation at 25 kGy. The as-synthesized carbon dots were characterized using Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy. Utilizing UV-Visible absorption and fluorescence spectroscopy, the optical characteristics of carbon dots were investigated. The carbon dots as synthesized had a high UV absorption peak at 271 nm and adjustable fluorescence emission.
Experimental study of tap water activated by commercial fruit and vegetable purifier
Authors: Nupangtha W , Masae S , Suwanchatree J , Nilgumhang K
Published: February 2023

Green and clean diets are on focus for consumers with healthy and safety concerns. Good sources of safe and clean vegetables and fruits are vital. Vegetables and fruits are often found on market shelves below the standard of good agricultural practices. Pesticides and other chemical residues are found in those fruits and vegetables which may connect to many late complication issues in health. Various methods are utilized as common wisdom to fight the problem. Some methods are more practical and handier. This contribution has studied the properties of tap water after activation by a commercial fruit and vegetable purifier. Chlorine, which is present in tap water, is bound with hydroxyl radical from electrohydrolysis by an apparatus to form hypochlorous acid. The activated water peaks at 291 nm in its absorbance with a UV-Vis spectrophotometer. Properties of water were studied under various experimental settings such as comparing with activation of de-ionized water, as a function of (i) operating time, (ii) storing time of input tap water, (iii) storage time of activated water, and (iv) water volume. The concentration of hypochlorous acid is calibrated against commercial ready-to-use acid.
An approach to the development of Raman spectroscopy system for field usage
Authors: Saeyee Thiti , Plaipichit Suwan , Wicharn Surawut
Published: February 2023

A spectroscopic technique that uses the scattering of photons for analysis of the chemical structure is called Raman spectroscopy. Raman spectrometers used in labs are typically large, so they are not applicable for use in fieldwork, and commercially portable Raman spectrometers are expensive. So, we developed a compact Raman spectrometer for field usage that consists of only the necessary optical components to make the compact system affordable for carrying in the field. Reduce fluorescence noise in the system by using the Vancouver Raman algorithm, which is based on polynomial fitting to achieve a quality Raman spectrum and can correctly identify the chemical structure in the sample. There are four samples: paracetamol, naphthalene, acetone, and toluene. The Raman spectra of the measured samples were compared with the database. The results are close to the commercial Raman spectrometer, which indicates our proposed compact Raman spectrometer is reliable.
Analyzing pre-instruction math knowledge and its correlation with introductory physics exam results
Authors: Popanao M , Smith M F , Pairor P
Published: February 2023

We examined the pre-instruction math knowledge of two similar groups of first-year engineering students at Suranaree University of Technology. The result showed the students’ math knowledge was increased after taking mandatory courses in the first trimester. We also looked into the correlation between pre-instruction math knowledge and the introductory physics exam result and found it to be positive. However, the group with the higher pre-instruction math score had a less positive correlation. This suggests that once the math knowledge is not the issue, there are other factors that can help students be more successful in studying physics.
A modification of Newton’s cooling law with correlation to fractional derivative
Authors: Keeratisiwakul Kumkup , Anantachaisophon Supphanat , Vatiwutipong Pat
Published: February 2023

Newton’s cooling law (NCL) provides a linear differential equation governing the rate of heat loss of a heated body using the temperature difference of the body with the environment. However, the prediction of NCL still did not fit with the data under the laboratory framework. Previous works have modified NCL by incorporating fractional derivative as a basis of their models, and in particular cases of convective fluid, higher correlations with the experimental data can be observed. In this study, to model the empirical value obtained from the experiment, the conventional model is enhanced by appending a new parameter as the exponent of time in the differential equation. The comparison is shown between the conventional NCL and the modified model, along with its adjusted R-Squared value from the regression of the experimental data, which results in a significant enhancement from the conventional model. In a numerical relationship between the two parameters, correlation of this newly proposed model is found with an established model of NCL using Caputo type fractional derivative, thereby providing some support to the theoretical basis of the model. Moreover, the performance of this modified model is to a certain degree higher than the fractional derivative model.
Utilization of DBD plasma in shelf-life extension for Namwa banana
Authors: Udtachee K , Yatongchai C , Sarapirom S
Published: February 2023

This work proposed the utilization of dielectric barrier discharge (DBD) plasma to lengthen the shelf life of Namwa bananas. The samples of fresh Namwa bananas were packaged by different technique to carry out the study into the effect of DBD plasma on the ripeness of Namwa bananas. It was found that Namwa banana ripening could be delayed by DBD plasma treatment, suggesting that DBD plasma is a potential technique for shelf life extension of climatic fruits.
Online physics experiment creation on resonance in the LC circuit with a simple metal detector circuit
Authors: Hongsith N , Wongrat E , Ketsuwan P , Kritpetch C , Rangdee P , Chunlen S , Tongmee T , Lianghiranthaworn T , Chanchaimongkol K , Kruaboon N , Boonpeaw R , Prasongcharoen S , Tohkeng N I
Published: February 2023

Online learning is necessary and challenging to develop effective teaching strategies to support student learning during the COVID-19 period. This course has seven students. Some essential equipment is sent to students by post. We demonstrate a simple experiment on the resonance frequency in the LC circuit with a simple metal detector circuit based on an IC555-timer transistor. In principle, Metal objects within the magnetic field of inductance affect the resonance frequency resulting in oscillator frequency changes. So, we could study the resonance frequency of the LC circuit from frequency changes by changing the inductance of the inductor. The sound frequency has been generated from the metal detector circuit and is altered depending on the coil’s inductance. The frequency change is measured by a sound detector application on the smartphone. From the results, we discuss the equation of the resonance frequency and the oscillator frequency changes and calculate the relationship between the frequency of sound and the inductance value of the coil. As a result, it is possible to adapt the simple metal detector to use the study of the resonance formula and calculate the inductance of any coil with accuracy.
How does student skill on interpreting circular motion situation change in an online physics classroom?
Authors: Eambaipreuk A , Emarat N , Arayathanitkul K
Published: February 2023

High-school physics has become challenging to many teachers after their classrooms were moved to an online platform. How to teach effectively is concerned when students struggled to grasp the concept learning in the online classroom. Circular motion is the topic that the students could not understand the content well while concentrating on the screen. This work aims to investigate the achievement of using peer instruction to teach the first three steps of circular motion problem solving strategy. These are (i) identify the path of motion and its radius, (ii) draw a free-body diagram, and (iii) find the force components acting on the object. The approach was implemented to an online physics classroom with 12 high-school students. The result was analyzed from pre- and post-test data, and student practices during the teaching. The finding showed that there were more students who could interpret the circular motion situation correctly than at the beginning of the class. The path of motion and the forces acting on the object could be identified, and some students could find the centripetal force correctly. Moreover, their interaction in the class related to the of their understanding of the topic.
Monte Carlo study of uncertainty propagation in Euler rotational kinematic equation
Authors: Nutsathaporn C , Chomkokard S , Wongkokua W , Ruengittinun S , Jinuntuya N
Published: February 2023

We perform a Monte Carlo simulation to study the propagation of uncertainty in Euler rotational kinematic equation. The rate gyro data from an IMU sensor are inserted into the Euler rotational kinematic differential equation to calculate the sensor orientation, which is specified by its Euler angles. The uncertainty of sensor orientation is determined by simulating the variation of rate gyro input due to its uncertainty obtained from the calibration process. We find that the uncertainties of the Euler angles grow with time. Their values are proportional to the square root of time elapse. We find also that the uncertainties are linearly proportional to the uncertainties of rate gyro data and the square root of sampling time. These results interestingly resemble the behaviour of the Wiener process, with the step size of random walk depends on the time step. We can use these results as a criterion to choose a suitable IMU due to the characteristic of the integrated rate gyro sensor, especially in the application like the vehicle tracking or posture warning for elderly/disable people, where the precise sensor orientation is needed for a long period of operation.