bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of nozzle contamination on microwave discharge cathode performance
Authors: Morishita Takato , Tsukizaki Ryudo , Nishiyama Kazutaka 
Published: June 2024

An understanding of the degradation mechanism of a microwave discharge cathode is the key to extending the lifetime of microwave ion thruster systems. This study investigates the effect of nozzle contamination by sputtered Ag-polytetrafluoroethylene (PTFE) on microwave discharge cathode performance. The current–voltage characteristics were measured for nominal and contaminated (by PTFE spray with 0.2 µm thick or tape with 0.15 mm thick) cathodes. The contamination thickness and area on the nozzle were varied to investigate the characteristic differences. It was confirmed that the anode voltage increased by 20 V or more in the case of the contaminated cathode. The anode voltage was measured for the sputter-contaminated cathode to evaluate the effect of contamination under more realistic conditions. After 630 h of sputter-contamination operation, it is estimated that sputtered particles were deposited to a thickness of 77 µm at most, and the anode voltage increased by 8 V. The results show that the downstream surface of the nozzle is critical for maintaining cathode performance. The insulating coating formed by the sputtered PTFE may interfere with ion absorption and degrade electron emission capability. A theoretical model based on the extended Brophy model supports these results. This study provides important information for the use of PTFE-based materials around ion thrusters.
Improved weighted nuclear norm with total variation for removing multiplicative noise
Authors: Kong Jiyu , Liu Xujiao , Liu Suyu , Sun Weigang 
Published: June 2024

This paper introduces an improved weighted nuclear norm with a total variation model tailored for removing multiplicative noise. The model incorporates a weight matrix to regularize the residual matrix, effectively leveraging image redundancy to differentiate various statistical properties of the noise. Since there is no guarantee of a unique solution, the model is reformulated as a linear equality constraint problem and decomposed into two subproblems. These are addressed by using the alternating direction method of multipliers and the split Bregman method, respectively. In addition, each alternative update step has a closed-form and convergent solution. After obtaining the denoised image in the log-domain, the recovered image is given by using the exponential function and bias correction. Experimental evaluations demonstrate the efficacy of our algorithms in enhancing image restoration quality.
Numerical study of flow past two square cylinders with horizontal detached control rod through passive control method
Authors: Kalsoom Shazia , Abbasi Waqas Sarwar , Manzoor Raheela 
Published: June 2024

A two dimensional (2-D) numerical study is conducted through the lattice Boltzmann method for flow past two square cylinders with a detached control rod placed in the horizontal position of the channel. The range of Reynolds number (Re) is fixed at Re = 150, with the length (l) of the control rod varying from l = 0.1d–21d. First, we check the accuracy of grid points and the validity of the code for present problems by comparing the results with already available data in the literature. After that, we discussed the obtained results in terms of vorticity contour, drag and lift coefficients, and force statistics. In our study of flow structure mechanisms, we examined four types of flow regimes: a small length control rod, a small and moderate length control rod, a moderate length control rod, and a larger length control rod according to flow behavior. In force statistics, we calculated the values of CDmean, CDrms, CLrms, CDamp, CLamp, and St, respectively. The mean drag coefficient contains the smallest values at the largest length, i.e., l = 19 and 21d. The maximum value of CDmean is examined at the first cylinder (C1) as compared to the second cylinder (C2) at l = 2.25d, and it is 1.2789. The values of CDmean for C2 at the length of the control rod, l = 0.1d–1.25d, and at l = 21d are negative due to the effect of thrust. The value of the Strouhal number is the same for both cylinders C1 and C2, and its highest value is 0.1036. The pressure amplitude of the drag coefficient is maximum for C1, while the pressure amplitude of the lift coefficient is maximum for C2, and its value is 2.1569.
Rovibrational analysis of AlCO3, OAlO2, and HOAlO2 for possible atmospheric detection
Authors: Firth Rebecca A. , Palmer C. Zachary , Francisco Joseph S. , Fortenberry Ryan C. 
Published: June 2024

The lack of observational data for the AlO molecule in the mesosphere/lower thermosphere may be due to ablated aluminum reacting quickly to form other species. Previously proposed reaction pathways show that aluminum could be ablated in the atmosphere from meteoritic activity, but there currently exist very limited spectroscopic data on the intermediates in these reactions, limiting the possible detection of said molecules. As such, rovibrational spectroscopic data are computed herein using quartic force field methodology at four different levels of theory for the neutral intermediates AlCO3, OAlO2, and HOAlO2. Each molecule exhibits multiple vibrational modes with large vibrational transition intensities. For instance, the C–O stretch (ν1) in AlCO3 has a harmonic intensity of 536 km mol−1, the Al–O stretch (ν2) in OAlO2 has an intensity of 678 km mol−1, and the out-of-plane torsion (ν9) in HOAlO2 has an intensity of 158 km mol−1. All three molecules have exceptionally large dipole moments of 6.27, 4.21, and 5.04 D, respectively. These properties indicate that all three molecules are good candidates for potential atmospheric observation utilizing vibrational and/or rotational spectroscopic techniques.
English in the internationalization of higher education and international student mobility
Authors: Kurusu Kenichiro , Oda Chisato , Go Mikhail Alic C. , Wu Di , Saure Kevin Brandon , Narang Sakshi 
Published: June 2024

Abstract
In this article, we discuss the significance of English in the internationalization of higher education and
international student mobility, using Kachru’s (1985) Three Circles Model of World
English. As education is one of the major forms of migration (Liu-Farrer, 2022; Borlongan, 2023) in the so-called ‘age of migration’ (cf. de Haas, Castles, & Miller, 2020), more and more students are motivated to study abroad to complete
their tertiary education. First, we discuss motivating factors both for the internationalization of higher education and
international student mobility. Second, we point out how English has been playing a very central role in the internationalization
of higher education institutions and international student mobility (Philipson, 2010;
Jenkins, 2017) among these factors. Then, we present the dynamics of international
student mobility by looking at their global flow, English-medium programs, and English language proficiency requirements. While
Inner Circle countries are still the most attractive destinations for most international students, Expanding Circle countries,
where English is not an institutionalized medium of instruction in higher education, also value English by expanding
English-medium degree programs and requiring English proficiency test scores to admission. Finally, we end the article by
reiterating the dominance and utility of English in the internationalization of higher education and international student
mobility and its stable position as the language of educational migration.
Navigating through Transnational Experiences of Chinese Working Holiday Makers in New Zealand
Authors: Zhu Hongrui 
Published: June 2024

Summary
In 2008, New Zealand took the lead globally in offering a working holiday scheme to Chinese youth following the Free Trade Agreement between the two countries. This scheme allows Chinese participants to live, work, and/or travel for 12 months in New Zealand, which attracted huge attention and sparked enormous interest among young Chinese. Against this backdrop, the primary focus of this case study is to examine the transnational experiences of Chinese working holiday makers (WHMs) in New Zealand through a cultural lens, highlighting the distinctive characteristics of this cohort. In particular, this case study explores the factors that motivated young Chinese to become WHMs in New Zealand. Moreover, this case sheds light on their dual-layered working experience; namely how they adapted to the positive working dynamics in New Zealand compared to the working experience back in China while still navigating through perceived precarious situations. This case further discusses how Chinese individuals have transformed their understanding of sociocultural norms and parental expectations through working holidays. Furthermore, the case study examines the broader economic impact of this growing cohort on New Zealand, providing insights into the implications of the working holiday scheme.

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Isolated single-photon emitters with low Huang–Rhys factor in hexagonal boron nitride at room temperature
Authors: Bhunia Amit , Joshi Pragya , Singh Nitesh , Chakraborty Biswanath , Nair Rajesh V 
Published: June 2024

Abstract
The development of stable room-temperature bright single-photon emitters using atomic defects in hexagonal boron nitride flakes (h-BN) provides significant promise for quantum technologies. However, an outstanding challenge in h-BN is the creation and detection of isolated, stable single-photon emitters with high emission rates and with very low Huang–Rhys (HR) factor. Here, we discuss the quantum photonic properties of a single, isolated, stable quantum emitter that emits single photons with a high emission rate and a low HR value of 0.6 ± 0.2 at room temperature. A scanning confocal image confirms the presence of a deserted, single-quantum emitter with a prominent zero-phonon line at ∼578 nm with a well-separated phonon sideband at 626 nm. The second-order intensity-intensity correlation measurement shows an anti-bunching dip of ∼0.25 with an emission lifetime of 2.46 ± 0.1 ns, reinforcing distinct features of the single-photon emitter. The importance of low-energy electron beam irradiation and subsequent annealing is emphasized to achieve stable, reproducible single-photon emitters.
Dual-luminophore fast-responding pressure-sensitive paint for the simultaneous elimination of motion- and temperature-induced errors
Authors: Gu Feng , Wei Chunhua , Jiao Lingrui , Liu Yingzheng , Peng Di 
Published: June 2024

Abstract
Motion- and temperature-induced errors are the major sources of error in pressure-sensitive paint (PSP) measurement. In this study, we developed a novel dual-luminophore fast-responding PSP with reference and pressure-sensitive channels that have similar temperature sensitivities, enabling motion- and temperature-induced errors to be simultaneously eliminated by taking the intensity ratio of the two channels. Rhodamine B (RhB), which was loaded on the Mobil Composition of Matter No. 41 (MCM-41) molecular sieve, and platinum tetrakis (pentafluorophenyl) porphyrin (PtTFPP) were chosen as the reference and pressure-sensitive luminophores, respectively. These luminophores were mixed with mesoporous SiO2 particles and a small amount of polymer to form a sprayable motion–temperature cancellation (MTC) PSP. By controlling the concentration of RhB, the temperature sensitivity of the reference channel was adjusted to match that of PtTFPP. To minimize temperature-induced errors, the effect of spectral ranges was also investigated. The lowest temperature sensitivity achieved for the MTC-PSP was 0.025%/°C, yielding an extremely low temperature-induced error of 55 Pa °C−1. Its pressure sensitivity and response time were 0.46%/kPa and 145 μs, respectively. In addition, a theoretical model for the MTC-PSP that considers the effect of spectral overlap was proposed. The model accurately predicted the nonlinear relationship between the intensity ratio and pressure. The capability of the MTC-PSP was confirmed in a fast-rotating-disk experiment, and the pressure results agreed well with the theoretical pressure distribution on the disk.
The potential mechanisms and treatment effects of stem cell-derived exosomes in cardiac reengineering
Authors: Wang Yibin , Shi Xiulian 
Published: June 2024

Abstract
Exosomes are extracellular vesicles of diverse compositions that are secreted by numerous cell types. Exosomes contain significant bioactive components, including lipids, proteins, mRNA, and miRNA. Exosomes play an important role in regulating cellular signaling and trafficking under both normal physiological and pathological circumstances. A multitude of factors, including thermal stress, ribosomal stress, endoplasmic reticulum stress, and oxidative stress influence the concentrations of exosomal mRNA, miRNA, proteins, and lipids. It has been stated that exosomes derived from stem cells (SCs) modulate a range of stresses by preventing or fostering cell balance. Exosomes derived from SCs facilitate recovery by facilitating cross-cellular communication via the transmission of information in the form of proteins, lipids, and other components. For this reason, exosomes are used as biomarkers to diagnose a wide variety of diseases. The focus of this review is the bioengineering of artificial exosomal cargoes. This process encompasses the control and transportation of particular exosomal cargoes, including but not limited to small molecules, recombinant proteins, immune modulators, and therapeutic medications. Therapeutic approaches of this nature have the potential to deliver therapeutic medications precisely to the intended site for the cure of a variety of disorders. Notably, our attention has been directed towards the therapeutic implementations of exosomes derived from SCs in the cure of cardiovascular ailments, including but not limited to ischemic heart disease, myocardial infarction, sepsis, heart failure, cardiomyopathy, and cardiac fibrosis. In general, researchers employ two methodologies when it comes to exosomal bioengineering. This review aims to explain the function of exosomes derived from SCs in the regulation of stress and present a novel therapeutic approach for cardiovascular disorders.
Consistent spectral approximation of Koopman operators using resolvent compactification
Authors: Giannakis Dimitrios , Valva Claire 
Published: June 2024

Abstract
Koopman operators and transfer operators represent dynamical systems through their induced linear action on vector spaces of observables, enabling the use of operator-theoretic techniques to analyze nonlinear dynamics in state space. The extraction of approximate Koopman or transfer operator eigenfunctions (and the associated eigenvalues) from an unknown system is nontrivial, particularly if the system has mixed or continuous spectrum. In this paper, we describe a spectrally accurate approach to approximate the Koopman operator on L
2 for measure-preserving, continuous-time systems via a ‘compactification’ of the resolvent of the generator. This approach employs kernel integral operators to approximate the skew-adjoint Koopman generator by a family of skew-adjoint operators with compact resolvent, whose spectral measures converge in a suitable asymptotic limit, and whose eigenfunctions are approximately periodic. Moreover, we develop a data-driven formulation of our approach, utilizing data sampled on dynamical trajectories and associated dictionaries of kernel eigenfunctions for operator approximation. The data-driven scheme is shown to converge in the limit of large training data under natural assumptions on the dynamical system and observation modality. We explore applications of this technique to dynamical systems on tori with pure point spectra and the Lorenz 63 system as an example with mixing dynamics.
Oblique streaming waves observed in multipactor-induced plasma discharge above a dielectric surface
Authors: Jin Biemeng , Chen Jian , Sun Guangyu , Wang Zhibin , Sun Haomin 
Published: June 2024

Abstract
In a recent discovery (Wen et al 2022 Phys. Rev. Lett.
129 045001), streaming waves were found in multipactor-induced plasma discharges. However, due to the limitations of a 1D simulation setup, these waves displayed only transverse dynamics. In this letter, an extended 2D particle-in-cell/Monte Carlo model is used to simulate multipactor-induced plasma discharge above a dielectric surface. The results reveal that the streaming waves are not solely transverse but oblique, featuring both transverse and longitudinal components of the wave vector. Furthermore, it is identified that the sheath-accelerated field-emission electrons, rather than the previously reported secondary emission electrons, predominantly cause the excitation of streaming waves. The simulated wave spectrum achieves an excellent agreement with the theoretical dispersion relation. The identification of oblique streaming waves provides new insights into multipactor physics and is anticipated to inspire novel mitigation strategies for multipactor-induced breakdown processes.
Analyzing election trends incorporating memory effect through a fractional-order mathematical modeling
Authors: Santra P K , R Induchoodan , Mahapatra G S 
Published: June 2024

Abstract
This study proposes a new mathematical model to analyze and predict the results of a political election. In general, we predict or analyze the results using statistical methods; however, to minimize the effort of the study, we propose a fractional-order modeling approach. This study proposes a model to analyze and predict general election result trends in India, focusing on the state of West Bengal. To incorporate memory into the model, we consider the Caputo fractional derivative. The model solution’s positivity, boundedness, existence, and uniqueness were tested analytically. Numerical simulations were carried out to investigate the impact of the parameters and evaluate the model’s performance by incorporating the implications of the previous election for realistic situations. Following this, a qualitative analysis of the performance of political parties is discussed, and a prediction of the electoral victory is obtained.
New signature of low mass Z′ in J/ψ decays*
Authors: Geng 耿 Chao-Qiang 朝强 , Liu 劉 Chia-Wei 佳韋 , Zhang 张 Jiabao 嘉宝 
Published: June 2024

Abstract
We explored a new approach to search for a low-mass

particle through

decays by identifying its existence through parity-violating phenomena in the isospin-violating final states of

and the corresponding charge conjugated states of

. Our investigation centered on a generation-independent and leptophobic

with mass below 10 GeV. Given the present experimental conditions at Beijing Spectrometer III (BESIII) and the anticipated opportunities at the Super Tau Charm Factory (STCF), we conducted Monte-Carlo simulations to predict possible events at both facilities. Notably, we foresee a substantial enhancement in the precision of the lower limit estimation of

as well as a reduction in statistical uncertainty with upcoming STCF experiments. Furthermore, it is essential to highlight that a null result in the measurement of

would impose stringent constraints, requiring the

couplings to be in the order of

.
0– – hidden-heavy tetraquark states via QCD sum rules*
Authors: Wan 万 Bing-Dong 秉东 , Xu 徐 Hong-Tai 鸿泰 
Published: June 2024

Abstract
In this study, we evaluated the mass spectra of the prospective

hidden-charm and hidden-bottom tetraquark states in molecular configuration via QCD sum rules. In our calculation, the nonperturbative condensate contributions are considered up to dimension eight in operator product expansion. It is found that there could exist 4 possible

hidden-charm tetraquark states with masses

,

,

, and

GeV. Their corresponding hidden-bottom partners are found lying at

,

,

, and

GeV, respectively. The possible tetraquark decay modes were analyzed, which are expected to be measured in BESIII, BELLEII, and LHCb experiments.
Top-quark rare decays with flavor violation*
Authors: Liu 刘 Ming-Yue 明月 , Zhao 赵 Shu-Min 树民 , Gao 高 Song 松 , Han 韩 Xing-Yu 星宇 , Feng 冯 Tai-Fu 太傅 
Published: June 2024

Abstract
In the present study, we investigated the decays of the top quark:

,

,

, and

. They are extremely rare processes in the standard model (SM). As the

extension of the minimal supersymmetric standard model (MSSM), the

SSM features new superfields such as the right-handed neutrinos and three Higgs singlets. We analyzed the effects of different sensitive parameters on the results and made reasonable theoretical predictions, thereby providing a useful reference for future experimental development. Considering the constraint set by the updated experimental data, the numerical results show that the branching ratios of the four processes, i.e.,

, can reach the same order of magnitude as their experimental upper limits. Among them,

has the most evident effect on these processes and is the main parameter;

,

,

,

,

,

, and

are also important parameters for the processes, and have effects on the numerical results.
Robust adaptive deep brain stimulation control of in-silico non-stationary Parkinsonian neural oscillatory dynamics
Authors: Fang Hao , Berman Stephen A , Wang Yueming , Yang Yuxiao 
Published: June 2024

Abstract

Objective. Closed-loop deep brain stimulation (DBS) is a promising therapy for Parkinson’s disease (PD) that works by adjusting DBS patterns in real time from the guidance of feedback neural activity. Current closed-loop DBS mainly uses threshold-crossing on-off controllers or linear time-invariant (LTI) controllers to regulate the basal ganglia (BG) Parkinsonian beta band oscillation power. However, the critical cortex-BG-thalamus network dynamics underlying PD are nonlinear, non-stationary, and noisy, hindering accurate and robust control of Parkinsonian neural oscillatory dynamics. Approach. Here, we develop a new robust adaptive closed-loop DBS method for regulating the Parkinsonian beta oscillatory dynamics of the cortex-BG-thalamus network. We first build an adaptive state-space model to quantify the dynamic, nonlinear, and non-stationary neural activity. We then construct an adaptive estimator to track the nonlinearity and non-stationarity in real time. We next design a robust controller to automatically determine the DBS frequency based on the estimated Parkinsonian neural state while reducing the system’s sensitivity to high-frequency noise. We adopt and tune a biophysical cortex-BG-thalamus network model as an in-silico simulation testbed to generate nonlinear and non-stationary Parkinsonian neural dynamics for evaluating DBS methods. Main results. We find that under different nonlinear and non-stationary neural dynamics, our robust adaptive DBS method achieved accurate regulation of the BG Parkinsonian beta band oscillation power with small control error, bias, and deviation. Moreover, the accurate regulation generalizes across different therapeutic targets and consistently outperforms current on-off and LTI DBS methods. Significance. These results have implications for future designs of closed-loop DBS systems to treat PD.