bluuebunny/crossref_metadata_2025 huggingface dataset:
Systematic investigation and correction of the magnetic hysteresis obtained by vibrating sample magnetometry
Authors: Santikulthani S , Eknapakul T , Pinitsoontorn S , Songsiriritthigul P
Published: February 2023

This work focused on a systematic study of data corrections for the vibrating sample magnetometry (VSM) to obtain reliable magnetic properties of strong ferromagnets. We designed the systematic experiments by varying the length-to-radius ratio of VSM samples between 1-5 and provided the step-by-step corrections of two commercial NdFeB powder magnets with reported energy product ((BH)max
) of 6.0±0.5 and 12.7±0.5 MGOe. Without data corrections, the measured hysteresis loops yield the (BH)max
between 47.3% and 62.6% of their reported values with improper values of saturation magnetization (Ms
), remnant magnetization (Mr
), and Mr/Ms
ratio. To correct the measured VSM hysteresis loop, firstly, the paramagnetic-like slope of 0.0500–0.0735 G/Oe was subtracted until the flat at high fields was obtained. Then, up to 6% of magnetization value and demagnetizing factor (N) of 0.30-0.53 was applied to achieve similar hysteresis loops for all samples. The corrected (BH)max
after all processes is around 86-95% of the reported value. Moreover, by examining the samples with different packing densities, it was found that the loose-packed samples exhibit hysteresis distortion, which could be caused by an unwanted magnetostatic interaction and degree of particle rotation of the powder.
Effect of Mn grinding time on structural, chemical, and magnetic properties of the Manganese Bismuth prepared by sintering in vacuum
Authors: Ngamsomrit S , Eknapakul T , Pinitsoontorn S , Songsiriritthigul P
Published: February 2023

This work reports the changes in structural, chemical, and magnetic properties of the low-temperature phase manganese bismuth (LTP-MnBi) sintered from mixtures of Bi and Mn ball-milled for different times. The milling time was varied from 1 to 15 hr to produce Mn powder with different particle sizes. The average particle size reduced from ~400 µm (original size) to 35 ± 5 µm and 6 ± 2 µm after 1 and 15 hr milling times, respectively. The LTP-MnBi powder was sintered at 275 °C at vacuum pressure below 5 × 10−7 mbar for 12 hours. By increasing the Mn grinding time, the maximum energy product ((BH)max) of LTP-MnBi decreased from 1.98 ± 0.05 to 1.59 ± 0.07 MGOe, and the saturation magnetization (M
s) decreased from 53.42 ± 0.90 to 44.32 ± 0.72 emu/g. The x-ray diffraction patterns indicated the reduction of LTP-MnBi content as a function of the milling time, which is agreed with the decrease in the M
s value. This is supported by the x-ray photoelectron results, which also showed the increment of Mn oxides on the surface as a function of Mn milling time. The unexpected decrease in M
s, which results in a significant reduction of magnetic performance, might be due to the presence of the oxides preventing diffusion during sintering.
Theoretical study of electrical transport across 1D ferromagnet-insulator-ferromagnet junction in small applied field
Authors: Butraburi Adithep , Nakhonthong Natthagrittha , Pairor Puangratana
Published: February 2023

We theoretically investigated how the insulating band gap, the thickness of the insulating layer, and the external field affect the electric transport through a ferromagnetic metal-insulator-ferromagnetic metal junction. Applying the Slonczewski model with the inclusion of a small external field, we calculated the magnetoresistance ratio (MR) and found that the increase in both the insulating band gap and the thickness boost MR. MR is also increased with the magnetic field. Our model indicates that MR reaches a maximum value at a particular strength of the applied field that depends on the thickness of insulating layer.
Design and simulation of a low-energy single ion irradiation system for micro/nano-biosample investigation
Authors: Thopan P , Atyotha V , Prakrajang K , Tippawan U , Yu L D
Published: February 2023

A low-energy single ion irradiation system is developed in its initiation in Thailand to follow one of the trends in novel ion beam technology exploitation. Single ion irradiation of materials is a highly technological development of ion beam technology. The developed single ion irradiation systems worldwide are primarily in the MeV-energy range and for single cell studies, and recently the trend has been extended to the low-energy range (< 100 keV) but focused on microelectronic applications. Based on our previous research on low-energy ion beam irradiation of biological cells and DNA, we design and simulate a low-energy single ion implantation system, aiming at eventual construction of such a novel ion beam apparatus for applications to the biological studies. In the system, the ion energy is decreased to orders < 1 keV by the existing deceleration lens, then the low-energy ion beam passes through µm slits, and finally, low-energy single ions are obtained by beam scanning with appropriate frequencies from scanner plates and detected by a single ion detection device. Conceptual design, calculation and simulation of this single ion system are presented.
Optimization for fuel loading and reactivity initiated accident analysis for TRR-1/M1
Authors: Tiyapun K , Wetchagarun S
Published: February 2023

TRR-1/M1 reactor core consists of two types of standard TRIGA fuel, 8.5% and 20% weight uranium. Periodically, the reactor core configuration is rearranged in order to optimize its performance. The objective of this work is to show that it is safe to operate TRR-1/M1 at 1 MW steady state condition for the new core configurations of which the 8.5% weight fuels in the B ring are replaced by high burn up 20% weight fuel elements. To ensure sufficient safety margins of the reactor operation, thermal–hydraulic computer codes, i.e., COOLOD-N2 and EUREKA-2/RR, were coupled with neutronic calculation based on Monte Carlo N-Particle Transport concept in order to analyse some crucial operating parameters, e.g., coolant and fuel temperature in the reactor core as well as Departure from Nucleate Boiling Ratio (DNBR) along the fuel axial direction of the hottest channel. From this study, it can be concluded that no significant effect on the reactor operation was found when replacing the 8.5% weight fuel elements in the B ring with the high burnup 20% weight fuels. Transient phenomena of Reactivity Initiated Accident (RIA) were also performed for the rapid removal of a sample from the reactor core with reactivity insertion rate of $1.00/s. It is found that the negative temperature coefficient of TRIGA fuel provided safety for the reactor even during the prescribed reactor transients. The calculation showed slightly increase in the fuel temperature during the short period of reactivity insertion which caused insignificant energy release to heat up the fuel during the accident. The maximum fuel temperature found during the accident in this study was well below TRR-1/M1 safety.
Period variation of an eclipsing binary system BQ Ari
Authors: Rattanamala R , Komonjinda S , Awiphan S , Wutsang S , Sappankum P , Deesuan L
Published: February 2023

This study was aimed to study the period variation of the eclipsing binary BQ Ari. The system was observed from Thai Robotic Telescope at Spring Brook Observatory (TRT-SBO) between 2019 and 2020, Regional Observatory for Public, Chachoengsao (ROP-CCO) in 2021, and Transiting Exoplanet Survey Satellite (TESS) in Sector 42 and 43. The data obtained were used to create the light curves in each wavelength and compute the times of minima. As the result, we receive 311 time of minima. We combined the time of minima from the previously published with our values to calculate the O − C diagram. The O − C diagram shown the period variation with a period about 6-8 years and amplitude about 0.0020 days. The possibility of the period variation of BQ Ari may be due to the third body component with the mass of 0.0948 M
⊙ (M dwarf) and the orbital separation (a
3sini) around 3.96 AU.
Memorization and prediction capability of the interacting phase oscillators
Authors: Kumpeerakij Chanin
Published: February 2023

Nonlinear dynamical systems, such as well-tuned recurrent neural networks, have proved a powerful tool for modeling temporal data. However, tuning such models to achieve optimal performance remains an outstanding challenge, not least because of the complex behaviors that emerge from interacting microscopic constituents. Here, we consider a minimal model of two interacting phase oscillators coupled to a thermal bath and driven by a common signal. We quantify the memory and predictive capability of the system with the mutual information between the phases of oscillators and the signals at different times. We show that the interaction between oscillators can increase the information between the system and the movement. We attribute this behavior to an increase in the effective signal-to-noise ratio, resulting from a stronger correlation between the oscillators. We also demonstrate that heterogeneity in the natural frequencies of the oscillators can further increase the mutual information though more efficient uses of oscillator states.Our work offers the first step toward a systematic approach to optimizing interacting nonlinear dynamical systems for memorizing and predicting temporal patterns.
Photometric variability of high amplitude δ Scuti stars using AAVSO international database: V2455 Cyg and GP And
Authors: Chehlaeh N , Masae N
Published: February 2023

This research aims to study photometric variability and Fourier analysis of high amplitude δ Scuti stars (HADS), which are interesting short-period variable stars with spectral types between A2V and F0V. They are located in the area of the classical cepheid instability strip, which crosses the main-sequence (MS) on the Hertzsprung-Russell (H-R) diagram. The CCD photometric V-magnitude data of the selected HADS stars were acquired based on the AAVSO international database (American Association of Variable Stars Observers), which is the most comprehensive digital variable star database. Two interesting targets V2455 Cyg and GP And were selected for the study. The discrete Fourier transformation was used to analyze time-series light curves. The pulsating properties of the selected HADS stars were analyzed using the Period04 astronomical program. We obtained each star’s times of new light maxima, magnitude changes, and pulsation frequencies. The main frequency of V2245 Cyg was determined to be 10.614995 ± 0.000002 d−1 and the main frequency of GP And is 12.709253 ± 0.000001 d−1. V2245 Cyg and GP And are high amplitude δ Scuti stars. The study of the pulsation frequencies and period change of HADS stars can estimate their pulsation modes and their evolution. Moreover, HADS stars are very important as standard candles that can be used to measure galactic distances.
Simulating AGN feedback and its evolution in galaxy mergers: case study for NGC 5252
Authors: Boonmalai M , Sawangwit U , Wannawichian S
Published: February 2023

We are investigating the evolution of merging galaxies using numerical simulations. This research focuses on the AGN-driven feedback mechanism that can be responsible for the outflow gas found on kiloparsecs scales in Seyfert galaxies. The initial conditions of the galaxy were designed to replicate the observable characteristics of NGC 5252. NGC 5252 is an off-nucleus ultraluminous X-ray (ULX) source and has extended [OIII] emission up to 10 kpc scales. The optical spectrum properties of CXO J133815.6+043255 are comparable to those of Low-Luminosity AGNs (LLAGNs). Observations of high angular resolution very long baseline interferometry (VLBI) also showed that it is a suitable option for a dual radio-emitting AGN system. Moreover, the NGC 5252 off-nucleus component is thought to be a stripped leftover of a merging dwarf galaxy. The supermassive black hole (SMBH) physics module is used in smoothed-particle hydrodynamics (SPH) simulations of merging galaxies using the GIZMO code to investigate the evolutionary changes of such a system. Our major-merger test run could not produce the observed morphology contrary to a report that one would be able to produce a spiral galaxy. The minor-merger test run up to around 0.2-0.3 Gyr shows a promising early result of the final system however further works will be conducted to investigate the properties of the resulting double AGN system and its evolution.
Study of imaging system in proton computed tomography with data acquisition from a monolithic active pixel sensor
Authors: Ratsuntia N , Songmunnak A , Ritjoho N , Sanghangthum T , Kobdaj C
Published: February 2023

The first proton therapy system in Thailand has been installed at King Chulalongkorn Memorial Hospital (KCMH) since 2019. Apart from its clinical usage, Suranaree University of Technology (SUT) has initiated the collaborative research work with KCMH to explore a possibility of developing a proton computed tomography (pCT) prototype. Due to the proton’s depth-dose properties, this technique is more effective than photon treatment. Prior to proton therapy, pCT could help with the treatment planning. This technique simplifies proton treatment calculations since both processes involve the same particle interaction with matter. We simulated the experiment setup using G4beamline with the proton beam using a monolithic active pixel sensor (MAPS) as a proton tracker. The sensor’s output revealed that the ratio of data from protons interacting on the sensor was low, so we pre-processed the data with MATLAB by applying a mean filter to replace any empty pixels with the average of their nearby pixels. A 3D reconstruction was performed by stacking all the axial images reconstructed by the back projection method. The result shows that the material densities of reconstructed samples can be identified, however, it is still in the preliminary stage and not yet suitable for clinical trials. It is, however, possible to improve the quality of images and obtain a better 3D reconstruction for the pCT prototype by using a back-projection method.
Mock HI-galaxy catalogs and HI mass functions for future large-scale surveys
Authors: Thananusak N , Sawangwit U
Published: February 2023

One of the interesting modern astrophysics topics is the discrepancy in HI-galaxy number density between the standard model ΛCDM prediction and observations, e.g., ALFALFA and HIPASS. Since then, the simulation over-predicted the abundance and HI mass (MHI) of small satellite and low-mass galaxies. Both problems still require sensitive instruments for wider and deeper HI surveys to increase the number of low-mass HI-galaxy samples. Current HI-galaxy surveys can only reach down to ∼ 107 Solar mass (M⊙). The sensitivity of upcoming radio surveys such as FAST or ASKAP are expected to reach lower MHI and higher redshift(z) HI-galaxy data. Alternatively, the HI source catalogs from cosmological simulations are used to determine the expected HIMF with the upcoming HI survey specification. This work aims to compare the HIMF in various HI conversion recipes. Various HIMF were determined by using the Multidark(Planck) catalog with the box (MB) and the light-cone (ML) types, and were parameterized by the Schechter function. In comparison to the Schechter function, we discovered that the HIMF from cold gas mass (Mcold) conversion method begins to diverge on MHI ≲ 108.5 M⊙. The HIMF from halo mass (Mhalo) recipe, which was constrained by the optical counterpart galaxy clustering, provided a satisfactory relevant shape of HIMF. The best-fit parameter α of MB and ML are equal to 0.00 ± 0.010 and −0.02 ± 0.0026, respectively. The flatter α values from simulations could indicate that the number density of low-MHI is underestimated.
Sine-Gordon expansion method for the kink soliton to Oskolkov equation
Authors: Kheaomaingam Nupan , Phibanchon Sarun , Chimchinda Songvudhi
Published: February 2023

We used the sine-Gordon expansion method to find kink solutions of the Oskolkov equation. A solution can be found by matching coefficients and choosing some parameters of the series. We found two possible solutions—one is kink and the other is a hybrid of kink and pulse solitons. These solutions can be used for further studies, such as their stability or their interaction. Specific parameters from the solution could be useful for controlling the physical behavior of a system governed by the Oskolkov equation.
Effect of sintering time on phase, physical properties, microstructure and thermal conductivity of Y(Ba1-x
La
x
)2Cu3O7-δ ceramics
Authors: Yawirach S , Wannasut P , Boonsong P , Watcharapasorn A
Published: February 2023

This work investigates the effects of various sintering conditions on phase, physical properties microstructure and thermal conductivity of Y(Ba1-x
La
x
)2Cu3O7-δ where x = 0, 0.05, 0.10, 0.15, 0.20 and 0.25 mol fraction. The sintering conditions involved the sintering temperature of 920 °C and sintering time of 6, 8, 10 and 12 h. It was found that pure phase could be obtained in the samples sintered for 6 h regardless of composition. However, small amount of BaCuO2 secondary phase was obtained at other sintering time. The relatively low density and significantly reduced grain size was obtained in the samples with high La content (e.g. x = 0.20 and 0.25) regardless of the sintering time. This showed that La addition had apparent effects on sintering ability and grain growth. Phase analysis indicated that the structure changed from orthorhombic to tetragonal when the La concentration reached 0.20 and 0.25 mol fraction. SEM images of all ceramics also indicated irregular shaped grains. The effects of variation in density, microstructure and composition on the thermal conductivity of all ceramics were also discussed in details.
Enhancements of relativistic electron flux at geostationary orbit during high-intensity, long-duration, continuous AE activity (HILDCAA) from 2015 to 2017
Authors: Yeeram T
Published: February 2023

This work characterizes the enhancements of relativistic electron flux (MeV) in the geostationary orbit (GEO) in High Intensity, Long Duration, Continuous AE Activity (HILDCAA) occurred during declining phase of solar cycle 24. We employed the relativistic electron (0.8 - 2.0 MeV) flux and low-energy electron (40 - 130 keV) flux measured by GOES-13 and POES satellites, respectively. Typically, the relativistic electron flux increases, while the low-energy electron flux decreases in the long recovery phase of moderate storms. The enhancements of E > 0.8 MeV and > 2.0 MeV occurred promptly and ∼1.0 day after the HILDCAA onset, respectively. A case study of short HILDCAA events shows that low solar wind dynamic pressure and long-lasting high amplitude Alfvén waves are efficient triggers of the relativistic electron enhancement at GEO. Large convection from magnetic reconnection in HILDCAA would induce substorms that injected more seed electrons for the acceleration. The peaks of the E > 2.0 MeV flux are more delayed than of the E > 0.8 MeV. After the onset of short- and prolonged-period HILDCAA, the peak flux of E > 0.8 MeV occurred about 2 and 4 days, respectively, and of E > 2.0 MeV occurred about 2 and 5 days, respectively.
Random-telegraph noise mitigation and qubit decoherence in solid-state experiments
Authors: Kamjam Nattawut , Pathumsoot Poramet , Chantasri Areeya
Published: February 2023

We investigate the recently proposed theoretical models and algorithms in Song et al. [1] for mitigating decoherence in solid-state qubit systems, where qubits are affected by charge (random telegraph) noises. The model includes a setup of a logical qubit (data qubit) and a spectator qubit, where the latter is used as a probe of the noise. The probe results can be used in correcting the phase error in order to improve the decoherence of the data qubit. In this work, we apply the proposed model with parameters extracted from recent solid-state qubit experiments. We extract parameters such as the noise switching rates, the qubit sensitivities to noise, and the measurement dead time. Using these parameters, we then numerically simulate the data qubit’s phase and the qubit decoherence. We also show that the proposed phase-correction technique using Bayesian estimation can improve the data qubit decoherence significantly.
Estimating unknown qubit phase under telegraph noises using recurrent neural network
Authors: Rojanasirivanit Suttavee , Pathumsoot Poramet , Chantasri Areeya
Published: February 2023

We consider a system of qubits affected by an environmental random-telegraph process (RTP) noise and investigate the recently proposed idea of using a spectator qubit (SQ) as a noise probe to remove noise effects from a data qubit (DQ). By measuring the SQ at various times with particular measurement bases, their measurement readouts can be used to extract the information of the noise effects. In this work, we propose the use of recurrent neural network (RNN), with the Long short-term memory (LSTM) layers, to process the SQ’s readouts and train the model to estimate the errors occurred in the DQ. We present numerical results of the DQ’s and SQ’s phases and show that the LSTM can estimate the unknown DQ’s phase with the estimation accuracy depending on the SQ’s noise sensitivity.
Laboratory implementation of Fourier transform infrared (FTIR) spectrograph using a super-continuum laser
Authors: Kunanta N , Artsang P , Sangtawesin S , Talataisong W , Meemon P
Published: February 2023

Fourier Transform infrared (FTIR) spectroscopy is a technique to indirectly measure the spectrum of electromagnetic wave over a broad range. The vibrational response signature will be revealed through the absorption spectrum. The super-continuum laser is the appropriate option for using as a light source of FTIR because of its broad spectral bandwidth and high spatial coherence, which could expand the observable region. In this work, a custom design of laboratory prototype of FTIR system using a super-continuum laser with a wavelength in the range of 1500 – 2 400 nm (6667 – 4167 cm−1) is presented. The system was designed to have a combination of monochromatic and broadband interferometers in a free space Michelson interferometer configuration. An interferogram of a monochromatic laser at 532 nm (18 797 cm−1) was used to correct the phase distortion in the interferogram of the broadband light source. The location of peaks and valleys of the monochromatic interferogram were used to resample the broadband interference signal. The resulting spectrum was analyzed and then compared to the theoretical spectrum for further performance improvements.
Research on Image Edge Detection Algorithm Based on CORDIC
Authors: Wang Yanlin
Published: February 2023

Image edge extraction is the foundation of high-level image processing. In view of the characteristics of large amount of square root algorithm and difficult hardware implementation in traditional Canny edge detection, the CORDIC algorithm is proposed in this paper, and the square root operation is completed by shifting, adding and subtracting, and multiplying. According to the experiment, under the premise of limited resources on FPGA, the image edge extraction can be completed in real time by this method, which opens up a new idea for real-time image processing.
Influence of Pixel Design on Charge Transfer in Pinned Photodiode CMOS Image Sensors
Authors: Liu Lu , Yang Shaohua , Yan Ming , Li Binkang , Guo Yang , Guo Mingan , Li Gang , Zhou Errui
Published: February 2023

The influence of pixel design on charge transfer, mainly on potential barrier and potential pocket, is investigated in this paper. By simplifying the interface region between the pinned photodiode (PPD) and the transfer gate (TG), an intuitive and simple method for analyzing the potential barrier and pocket is presented. Through TCAD simulations, the validity of the analysis method is verified, and the influence of some key dimension and process parameters in PPD pixel design on the potential barrier and pocket is clarified. The whole study help improve the understanding of the charge transfer limitation mechanism, and can achieve high charge transfer efficiency and low image lag noise in the PPD pixel design of CMOS image sensors (CISs).
Shape Dependence of Silver Nanowires on Synthesis Conditions and it’s Effect on the Optical and Electrical Properties
Authors: Zhao Zhenzhen
Published: February 2023

As the market share of optoelectronic devices grows yearly, the transparent conductive electrodes that guarantee device performance subsequently gain attention. In order to solve the cost issue of the most commonly commercialised transparent conductive electrodes (indium tin oxide) and the problem that they cannot be used in portable wearable devices, flexible carbon-based hybrid nanomaterials are considered as an alternative. But, it still suffers the complicated synthesis process. Thus, silver nanowire (AgNW) is regarded as the most promising material with advantages of the facile synthesis process, high conductivity and transparency. The synthesis conditions and AgNW morphology are believed to be vital for their optical and electrical properties. This research investigated the effect of synthesis conditions (capping agent molecular weight and compositions, reaction temperature and the stirring rate) and discussed the connection between the optical transmission and electrical resistance of coated films fabricated by AgNW with various morphology. Results show that heavier capping agents with more viscous solutions are more favourable for long wire growth, and mixed capping agent solutions can achieve higher aspect ratios. Both relatively low reaction temperature and no stirring could prevent silver particles nucleation and agglomeration, achieving longer nanowires. The AgNW-coated film by nanowires with longer lengths could have more advantages in the trade-off between conductivity and transparency for better performance. This article illustrates and explains the influence of factors in the synthesis process on its morphology and functionality, creating more possibilities for the development and application of flexible transparent conductive electrodes.
Design of Experimental Circuit Board of Spectrometer Amplifier in Nuclear Electronics
Authors: Liu Guanhua , Lai Wanchang , Jiang Yunrui , Shi Jie
Published: February 2023

The signal output by a nuclear radiation detector is small in amplitude and irregular in waveform, which needs to be amplified and shaped to measure accurately. Spectrometer amplifiers assume the role of signal amplification and shaping in nuclear radiation measurement instruments, strictly maintaining useful information from the detector output (such as energy information and time information of the rays) and minimizing their distortion during signal processing. According to the needs of undergraduate experimental teaching and nuclear instrument development and application of nuclear electronics courses in nuclear science and technology, this paper designs a flexibly switchable pole zero phase extinction circuit, linear pulse amplification circuit, integral filter forming circuit, and baseline restoration circuit in the experimental circuit board of spectrometer amplifier. The total magnification is about 0 ~ 2040 times adjustable, and the forming time is 0~20μs adjustable. It has the functions of limiting voltage amplitude and optional input and output polarity, which can be adapted to scintillator detectors, proportional counters, Si-PIN, SDD, HpGe and other semiconductor detectors.
Application of Ultrasonic Testing Method in Particle Detection of GIS Handover Test
Authors: Man Yuyan , Zhang Chi , Tang Qinghua , He Jin , Cao Meng , Zhao Qi
Published: February 2023

Ultrasonic partial discharge detection is a necessary test in GIS handover test, which is very significant to detect the internal defects of GIS. This article introduces in detail how the ultrasonic partial discharge detection method is applied to the GIS handover test through a case in which the internal particles are found through the ultrasonic partial discharge detection method in the GIS handover test. It also fully proves that the ultrasonic partial discharge detection method is very effective for discovering the internal particles of GIS through this case. The experience of this case can provide a very meaningful experience for the subsequent GIS handover, operation and maintenance tests.
A Case Analysis of Particle Defects Found in 220kV GIS by Ultrasonic Partial Discharge and SF6 Gas Decomposition Products Joint Detection
Authors: He Jin , Li Songyuan , Zhang Chi , Cao Meng , Chen Rong , Zhu Xuliang
Published: February 2023

The particles inside GIS have become the biggest factor affecting the safe and stable operation of GIS. How to effectively and timely find the particle defects is very important to ensure the reliable operation of GIS. This article describes in detail how to find particles in GIS through ultrasonic partial discharge method and comprehensive diagnosis of SF6 gas decomposition products, and gives specific solutions, which will provide very useful experience for subsequent GIS operation and maintenance.
Reconstruction algorithm for a novel Cherenkov scintillation detector
Authors: Luo Wentai , Liu Qian , Zheng Yangheng , Wang Zhe , Chen Shaomin
Published: February 2023

For future MeV-scale neutrino experiments, a Cherenkov
scintillation detector, CSD, is of particular interest for its
capability to reconstruct both energy and direction for charged
particles. A type of new target material, slow liquid scintillator,
SlowLS, which can be used to separate Cherenkov and scintillation
lights, is one of the options for the neutrino detectors. A
multi-hundred ton spherical CSD is simulated using a Geant4-based
Monte Carlo software, which handles the detailed the micro processes
of MeV particles and optical photons and the functions for
photomultiplier, PMT, and readout electronics. Twelve SlowLS
samples are simulated and studied to cover a wide range of
scintillation light yields and scintillation emission time
constants. Based on the detailed knowledge of the signal processes,
simplified functions are constructed to predict the charge and time
signals on the PMTs to fulfill an efficient reconstruction for the
energy, direction, and position of charged particles. The
performance of the SlowLS reconstruction, including the resulting
energy, angular, and position resolution, and particle
identification capability, is presented for these samples. The
dependence of the performance on the scintillation light yield and
emission time constants is understood. This study will be a
guideline for future MeV-scale neutrino CSD design and SlowLS
development for the interested physics goals.
GPU-accelerated CZT detector simulation with charge build-up effects
Authors: Delcourt A. , Montémont G.
Published: February 2023

The simulation of semiconductor detectors is a key tool for
developping and studying their behavior. In general, simulations of
CZT detectors assume the crystal to be perfect, meaning that its
properties are uniform. However, structural defects appearing in the
crystal during growth modify these properties. Moreover, dynamic
phenomena like polarization can appear. In particular, the electric
field inside the detector can be disturbed by bulk charges, which
creates uncertainties on measurement of incident photon energy and
on interaction position estimated by sub-pixel positioning.

One of the main issues of a simulation considering these
non-uniformities is its complexity, especially if multiple or
evolving electric field distributions have to be considered. Hence,
we have developed a model accepting electric field modifications and
allowing to observe quickly the detector's response modifications
with the electric field. We leveraged GPU to address such
computational burden. Indeed, we can afford to consider more complex
simulations as the computation time is reduced.

In this study, we introduced different types of spatial defects
which may be found in real CZT crystals (point-like, planar, etc.)
to observe quickly and easily their impact on the detector's
measurement, on both spatial and spectral response.
Egg white improves the biological properties of an alginate-methylcellulose bioink for 3D bioprinting of volumetric bone constructs
Authors: Liu Suihong , Kilian David , Ahlfeld Tilman , Hu Qingxi , Gelinsky Michael
Published: February 2023

Three-dimensional microextrusion bioprinting has attracted great interest for fabrication of hierarchically structured, functional tissue substitutes with spatially defined cell distribution. Despite considerable progress, several significant limitations remain such as a lack of suitable bioinks which combine favorable cell response with high shape fidelity. Therefore, in this work a novel bioink of alginate-methylcellulose (AlgMC) blend functionalized with egg white (EW) was developed with the aim of solving this limitation. In this regard, a stepwise strategy was proposed to improve and examine the cell response in low-viscosity alginate inks (3%, w/v) with different EW concentrations, and in high-viscosity inks after gradual methylcellulose addition for enhancing printability. The rheological properties and printability of these cell-responsive bioinks were characterized to obtain an optimized formulation eliciting balanced physicochemical and biological properties for fabrication of volumetric scaffolds. The bioprinted AlgMC + EW constructs exhibited excellent shape fidelity while encapsulated human mesenchymal stem cells showed high post-printing viability as well as adhesion and spreading within the matrix. In a proof-of-concept experiment, the impact of these EW-mediated effects on osteogenesis of bioprinted primary human pre-osteoblasts (hOB) was evaluated. Results confirmed a high viability of hOB (93.7 ± 0.15%) post-fabrication in an EW-supported AlgMC bioink allowing cell adhesion, proliferation and migration. EW even promoted the expression of osteogenic genes, coding for bone sialoprotein (integrin binding sialoprotein/bone sialoprotein precursor (IBSP)) and osteocalcin (BGLAP) on mRNA level. To demonstrate the suitability of the novel ink for future fabrication of multi-zonal bone substitutes, AlgMC + EW was successfully co-printed together with a pasty calcium phosphate bone cement biomaterial ink to achieve a partly mineralized 3D volumetric environment with good cell viability and spreading. Along with the EW-mediated positive effects within bioprinted AlgMC-based scaffolds, this highlighted the promising potential of this novel ink for biofabrication of bone tissue substitutes in clinically relevant dimensions.
Effect of process parameters on the strength of ABS based FDM prototypes: novel machine learning based hybrid optimization technique
Authors: Ramiah Karthikeyan , Pandian Pitchipoo
Published: February 2023

Even though the prototypes built using Fused Deposition Modelling (FDM) process are found to exhibit good mechanical properties, there are ample scopes to improve them by means of selecting suitable process parameters. Since the FDM process involves more number of process parameters, the selection of optimized values becomes more complex and time consuming. Further, the complex correlation among the process parameters makes the selection process more tedious and involves more numerical steps. Hence it has been intended to perform a physical experiment with the known parameters to determine the performance measures of the built prototypes. With this moto, in this work the effect of the 3D printing parameters is studied and the optimal combination of these parameters are determined. The Taguchi L18 orthogonal array based values are assigned for process parameters and the physical prototypes are fabricated. These specimens are tested in the laboratory and the observations are analyzed. It has been found that the process parameters under consideration have a good effect on the strength of the built models. Out of the 18 experiments, better experiments are selected by using a Machine Learning (ML) approach namely decision tree (DT). Finally, the best combination of parameters has been determined by using a novel hybrid multi objective technique which is formulated by integrating Fuzzy Analytical Hierarchy Process (FAHP) and Complex Proportional Assessment of alternatives (COPRAS) techniques. Then a confirmation experiment has also been done to confirm the optimal combination of parameters. The influence of the parameters is also found by using ANOVA (Analysis of Variance) method. The final results show that the raster angle influences the outputs more while the raster to raster gap has the least influence.
Unexpected high contribution of in-cloud wet scavenging to nitrogen deposition induced by pumping effect of typhoon landfall in China
Authors: Tan Qixin , Ge Baozhu , Itahashi Syuichi , Gan Lu , Zhang Ying , Xie Shuyan , Liu Ying , Xu Danhui , Chen Xueshun , Wu Lin , Pan Xiaole , Wang Wei , Wu Jianbin , Li Jie , Wang Junhua , Xu Xiaobin , Fu Joshua S , Wang Zifa
Published: February 2023

Atmospheric nitrogen deposition has large eco-environmental effects such as ocean acidification, eutrophication in coastal areas. However, knowledge of the source and the pathway of N deposition in coastal areas is limited, especially during tropical storms, hindering the accurate quantification of how anthropogenic activities influence the ocean ecosystem. In this study, the Nested Air Quality Prediction Modeling System was used to investigate the wet deposition of N induced by typhoon Hagupit over eastern coastal China from an in- and below-cloud process perspective. Our results reveal for the first time an enhancement mechanism of N deposition related to the ‘pumping effect’ of the typhoon. Different from the non-typhoon conditions, air pollutants in the typhoon-affected regions were pumped into the higher altitudes and deposited via the in-cloud scavenging process in the moving path of the typhoon-affected regions. This study updates our understanding of the source–receptor relationship on atmospheric wet deposition caused by tropical cyclones.
Impact on air quality from increasing cruise ship activity in Copenhagen port
Authors: Lansø Anne Sofie , Winther Morten , Jensen Steen Solvang , Løfstrøm Per
Published: February 2023

The impact of the growing cruise ship industry on air quality levels was investigated at the port of Copenhagen, Denmark. In 2018, 345 cruise ships visited Copenhagen, emitting 291 tons of NOx near the city centre. A spatiotemporal cruise ship emission inventory was developed for 2018 based on port list information, engine data, main and auxiliary engine power functions, and NOx emission factors, and was implemented in the OML-Multi atmospheric dispersion model. Evident plume effects from the cruise ships, which were traced by introducing the concept of likely concentration contribution, were obtained in the modelled and measured concentrations at Langelinie Quay, which is the busiest cruise ship terminal in Copenhagen port. Hourly peak values of NOx well above 200 μg m−3 were obtained at the top of a residential building at Langelinie Quay. The emissions from cruise ships were increasing the annual concentration of NO2 in the port area by up to 31% at ground level, and 86% 50 m above the ground in comparison to the urban background level. No exceedance of the European annual limit value of NO2 was obtained. The short-term impact of cruise ships was more pronounced with local exceedances of the hourly European limit value for NO2. Increasing cruise ship activity in Copenhagen port leads to air quality deterioration on short time scales with implications for human health.
An equilibrium finite element method for electrical impedance tomography
Authors: Ma Erfang
Published: February 2023

We present a new numerical method for the forward problem of electrical impedance tomography with the shunt model. The new method builds on a discretization of the total Joule heat consumed over the region, in terms of the current density. It gives an approximation of the distribution of current density before using it to reconstruct the potential distribution. Simulations on a 2D and a 3D EIT model indicate the new method can produce more accurate approximations than the traditional FEM, based on the same mesh. The new method has the potential to be a competitive alternative of the traditional FEMs and incoporated into some reconstruction algorithms of EIT.
Quenched-in liquid in glass
Authors: Wang Qing , Shang Ying-Hui , Yang Yong
Published: February 2023

Glasses have long been considered as frozen liquids because of the similarity between their static amorphous structures. While the modern theories about glass transition suggest that glass transition may result from supercooling of a heterogeneous liquid that contains fast and slow regions, it remains unclear whether such a physical picture applies to metallic glasses, which are a densely packed solid glass that was once believed to be a vitrified homogeneous metallic liquid. However, in the recent work published in Nature Materials, Chang et al provide compelling evidence to show that metallic glasses contain liquid-like atoms that behave as a high-temperature liquid in stress relaxation. Being activated under cyclic loading, this quenched-in liquid results in a fast relaxation process, which is discovered in a variety of metallic glasses. Their results are important and deliver a strong message that metallic glasses have a dynamic microstructure containing liquid- and solid-like atoms. Most importantly, the outcome of their research provides physical insight into the nature of glass-transition in metallic glasses, and also helps unravel their structure-property relations.
FOXO nuclear shuttling dynamics are stimulus-dependent and correspond with cell fate
Authors: Lasick Kathleen A. , Jose Elizabeth , Samayoa Allison M. , Shanks Lisa , Pond Kelvin W. , Thorne Curtis A. , Paek Andrew L.
Published: February 2023

Both H2O2 and serum starvation activate FOXO transcription factors, but they lead to different FOXO-induced cell outcomes. Here we find a link between the dynamics of FOXO activation and cell fate. H2O2 induces sustained nuclear FOXO, which is linked to cell death, while serum starvation causes pulses of nuclear FOXO and cell-cycle arrest.
Motivation, Physical Activity, and Affect in Community-Dwelling Stroke Survivors: An Ambulatory Assessment Approach
Authors: Lau Stephen C L , Tabor Connor Lisa , Baum Carolyn M
Published: February 2023

Background

Motivation is a frequently reported but far less studied driver for post-stroke physical activity participation. Motivation and physical activity may be important contributors to the prevention management and alleviation of affective symptoms among stroke survivors.

Purpose

To investigate the real-time associations between motivation, physical activity, and affect in the daily lives of community-dwelling stroke survivors using ecological momentary assessment (EMA) and accelerometry.

Methods

Forty community-dwelling stroke survivors wore an accelerometer on the thigh and completed EMA surveys assessing motivation (autonomous motivation, controlled motivation) and affect (negative affect, positive affect) eight times daily for 7 days. Multivariate regression analysis and multilevel modeling investigated the associations between motivation, physical activity, and affect.

Results

Greater autonomous motivation for physical activity was associated with less sedentary behavior (β = −0.40, p = .049) and more moderate-to-vigorous physical activity (β = 0.45, p = .020) participation in daily life. Greater autonomous motivation was momentarily associated with less depressed affect (β = −0.05, p < .001) and greater positive affect (β = 0.13, p < .001). Moreover, greater controlled motivation was momentarily associated with greater depressed affect (β = 0.06, p < .001). More intense physical activity was momentarily associated with greater positive affect (β = 0.13, p = .016). No moderating effect of motivation on the association between physical activity and affect was found.

Conclusions

Motivation and physical activity are momentarily associated with affect among stroke survivors. Assessing and fostering autonomous motivation may be beneficial for promoting physical activity and managing positive and depressed affect as stroke survivors return to the community.
Inflammaging as a target for healthy ageing
Authors: Dugan Ben , Conway Jessica , Duggal Niharika A
Published: February 2023

Life expectancy has been on the rise for the past few decades, but healthy life expectancy has not kept pace, leading to a global burden of age-associated disorders. Advancing age is accompanied by a chronic increase in basal systemic inflammation, termed inflammaging, contributing towards an increased risk of developing chronic diseases in old age. This article reviews the recent literature to formulate hypotheses regarding how age-associated inflammaging plays a crucial role in driving chronic diseases and ill health in older adults. Here, we discuss how non-pharmacological intervention strategies (diet, nutraceutical supplements, phytochemicals, physical activity, microbiome-based therapies) targeting inflammaging restore health in older adults. We also consider alternative existing pharmacological interventions (Caloric restriction mimetics, p38 mitogen-activated protein kinase inhibitors) and explore novel targets (senolytics) aimed at combating inflammaging and optimising the ageing process to increase healthy lifespan.
The ‘Bermuda Triangle’ of orthostatic hypotension, cognitive impairment and reduced mobility: prospective associations with falls and fractures in The Irish Longitudinal Study on Ageing
Authors: Donnell Desmond O , Romero-Ortuno Roman , Kennelly Sean P , O’Neill Desmond , Donoghue Patrick O , Lavan Amanda , Cunningham Conal , McElwaine Paul , Kenny Rose Anne , Briggs Robert
Published: February 2023

Background

Orthostatic hypotension (OH), cognitive impairment (Cog) and mobility impairment (MI) frequently co-occur in older adults who fall. This study examines clustering of these three geriatric syndromes and ascertains their relationship with future falls/fractures in a large cohort of community-dwelling people ≥ 65 years during 8-year follow-up.

Methods

OH was defined as an orthostatic drop ≥ 20 mmHg in systolic blood pressure (from seated to standing) and/or reporting orthostatic unsteadiness. CI was defined as Mini Mental State Examination ≤ 24 and/or self-reporting memory as fair/poor. MI was defined as Timed Up and Go ≥12 s. Logistic regression models, including three-way interactions, assessed the longitudinal association with future falls (explained and unexplained) and fractures.

Results

Almost 10% (88/2,108) of participants had all three Bermuda syndromes. One-fifth of participants had an unexplained fall during follow-up, whereas 1/10 had a fracture. There was a graded relationship with incident unexplained falls and fracture as the number of Bermuda syndromes accumulated. In fully adjusted models, the cluster of OH, CI and MI was most strongly associated with unexplained falls (odds ratios (OR) 4.33 (2.59–7.24); P < 0.001) and incident fracture (OR 2.51 (1.26–4.98); P = 0.045). Other clusters significantly associated with unexplained falls included OH; CI and MI; MI and OH; CI and OH. No other clusters were associated with fracture.

Discussion

The ‘Bermuda Triangle’ of OH, CI and MI was independently associated with future unexplained falls and fractures amongst community-dwelling older people. This simple risk identification scheme may represent an ideal target for multifaceted falls prevention strategies in community-dwelling older adults.