bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysing the effects of heating and gas puffing in Proto-MPEX helicon and auxiliary heated plasmas
*
Authors: Islam M S , Lore J D , Lau C , Rapp J 
Published: July 2023

Abstract
The Material Plasma Exposure Experiment (MPEX) is being constructed at Oak Ridge National Laboratory to investigate critical fusion reactor issues, such as plasma–material interactions (PMIs) under reactor-relevant conditions and time scales. The linear device Proto-MPEX was used as a test bed to address anticipated research and development issues associated with heating scenarios and establish the physics basis for MPEX. The SOLPS-ITER code suite has been applied to understand plasma and neutral transport in Proto-MPEX and to increase confidence in predictive simulations for MPEX. Coupling between COMSOL and SOLPS is performed to implement a 2D electron heating profile of the helicon source. The simulations show reasonable agreement with the experimental data for plasma with helicon and auxiliary electron cyclotron heating (ECH). Both Bohm and constant diffusion (D

⊥

: 0.5 m2 s−1 and

χ
⊥

: 1 m2 s−1) simulations show similar levels of agreement with respect to the sparse experimental data available, assuming a few per cent impurity concentration. ECH significantly increases the target electron temperature, however, the target electron density is reduced compared to helicon-only heated plasmas due to an increase in flow velocity and radial losses. The simulations show that further increasing the ECH power results in an increase in the target electron density due to increased recycling flux and ionization. The results indicate that ECH significantly enhances the target heat flux, with ECH power of 50 kW increasing the target heat flux from 0.4 to 17 MW m−2. It is found that a small amount of gas puffing (GP) near the target plate can further increase the target heat fluxes at the higher ECH power cases, but the target heat flux is reduced at higher GP conditions due to a significant reduction in electron temperature via radiation. ECH and GP scenarios can generate a higher target flux, facilitating improved PMI studies with more reactor-relevant plasma conditions.
Validity of Brink-Axel Hypothesis for calculations of allowed stellar weak rates of heavy nuclei
Authors: Farooq Fakeha , Nabi Jameel-Un , Shehzadi Ramoona 
Published: July 2023

Abstract
The knowledge of beta-decay transitional probabilities and Gamow-Teller (GT) strength functions from highly excited states of nuclides is of particular importance for applications to astrophysical network calculations of nucleosynthesis in explosive stellar events. These quantities are challenging to achieve from measurements or computations using various nuclear models. Due to unavailability of feasible alternatives, many theoretical studies often rely on the Brink-Axel (BA) hypothesis, that is, the response of strength functions depends merely on the transition energy of the parent nuclear ground state and is independent of the underlying details of the parent state, for the calculation of stellar rates. BA hypothesis has been used in many applications from nuclear structure determination to nucleosynthesis yield in the astrophysical matter. We explore here the the validity of BA hypothesis in the calculation of stellar beta-decay (BD) and electron capture (EC) weak rates of fp- and fpg-shell nuclides for GT transitions. Strength functions have been computed employing the fully microscopic proton-neutron QRPA (quasi-particle random-phase approximation) within a broad density, ρY
e
= (10-1011) [g cm−3], and temperature, T = (1−30) [GK], grid relevant to the pre-collapse astrophysical environment. Our work provides evidence that the use of the approximation based on the BA hypothesis does not lead to reliable calculations of excited states strength functions under extreme temperature-density conditions characteristic of presupernova and supernova evolution of massive stars. Weak rates obtained by incorporating the BA hypothesis in the calculation of strength functions substantially deviate from the rates based on the state-by-state microscopically calculated strength functions. Deviation in the two calculations becomes significant as early as neon burning phases of massive stars. The deviation in the calculation of BD rates is even more pronounced, reaching up to three orders of magnitude.
Switching motion analysis and synchronization control of a locally active memristive neuron model
Authors: Ren Yanlan , Zhang Li , An Xinlei , Zhang Jiangang 
Published: July 2023

Abstract
In this paper, a new four-dimensional HR neuron model is developed by means of injecting external alternating current and introducing a locally active memristor to simulate the induced current in the synapse. Firstly, the stableness of the equilibrium points under alternating current injection is analyzed by using Matlab software, and it is found that the addition of alternating current makes the stableness distribution of equilibrium points vary between time intervals. Secondly, with the help of bifurcation diagrams and corresponding time response diagrams, the effect of induced current on the boundary dynamic behavior is investigated in detail, meanwhile, the conditions for switching motions on separated boundaries are revealed. Finally, the multi-neuron coupling synchronization is explored by setting the corresponding coupling model. The results are beneficial to understand the boundary dynamic mechanism of neurons.
Signatures of quantized magnetic field on the nonlinear Landau damping of transverse electromagnetic waves
Authors: Rozina Ch , Asma A , Poedts S , Ali S , Shah H A 
Published: July 2023

Abstract
A quantum kinetic approach alongwith the Landau theory of quantization (LQ) is utilized to study the impact of the magnetic field on the nonlinear Landau damping (NLD) of transverse electromagnetic (EM) waves in a degenerate electron-ion plasma. The gyratory motion of fermions around the magnetic field (H) lines gets quantized into the Landau levels and consequently the associated Fermi–Dirac distribution function becomes modified with the fermion cyclotron frequency under the limit l
ℏ
ω

ce
− ε

Fe
≫ k

B

T

e
, where l is the orbital quantum number with all other standard notations. In this context, the density oscillations due to electrons are calculated in the presence of the LQ parameter η( = ℏ
ω

ce
/ε

Fe
< 1) and ion density perturbations are computed using the framework of Maxwell distribution. A new type of kinetic nonlinear Shrödinger equation is derived in the presence of η, which involves nonlocal nonlinear term responsible for the NLD of EM waves. Furthermore, longitudinal wave modes are investigated to account for quantization parameter η. The LQ is also shown to absorb oscillation spectra of the linear ion-acoustic mode. The present findings might be helpful to understand the impact of the H field on the nonlinear interaction of EM waves with astrophysical plasmas, e.g., in the atmosphere of neutron star the presence of quantized magnetic field is more common.
Optimal performance of the stochastic thermodynamic engine with a periodic heat bath
Authors: Fu Rui , Wang Qingyun 
Published: July 2023

Abstract
Stochastic thermodynamics provides a conceptual framework for describing the fluctuating behavior of small systems like colloids or biomolecules far from thermodynamic equilibriums but still contacted with a heat bath. In contrast to most literature focusing on the classical paradigm of Carnot engines, we herein study the optimal performance of the thermodynamic heat engine with a heat bath that periodically changes temperature, which is outside controllable by a time-dependent harmonic potential. Under reasonable assumptions on the control actuation, we derive the achievable upper bound for the maximal power and also the optimal control protocol. In addition, we also obtain the corresponding efficiency at maximal power, which only depends on the ratio of the minimal and maximal value of the temperature profile.
Magnetic field optimization of hall thruster with large height-radius ratio for high specific impulse operation
Authors: Fan Haotian , Wang Shangmin , Li Pei , Wei Liqiu , Li Hong , Guo Ning , Ding Yongjie 
Published: July 2023

Abstract
Hall thrusters with large height-radius ratio not only have incalculable application values in reducing the volume and weight of thrusters, but also have the potential advantages of higher discharge performance and longer service life. However, the lower propellant density in the main ionization zone and the higher electron temperature in the channel aggravate the loss of propellant and current under high voltage, and significantly reduce the discharge efficiency under high specific impulse mode. To improve the discharge performance of Hall thrusters with large height-radius ratio under high voltage, an optimization scheme of internally loaded magnetic field was proposed in this work. The simulation results show that under the internally loaded magnetic field, both the ionization zone and the acceleration zone move toward the inside of the channel. Although the ion loss on the walls increases, the higher propellant density at the channel upstream greatly promotes the increase of ionization rate and significantly improves the propellant utilization efficiency. The second zone crossed by magnetic field lines in the channel can be established by the internally loaded magnetic field, which enhances the magnetic field intensity on the inner and outer walls, and reduces the electron temperature near the channel outlet significantly. So that the axial conduction of electrons is effectively restrained and the current utilization efficiency is greatly improved. With the introduction of internally loaded magnetic field, the total efficiency of HEP-1350PM can be increased by 7.2% at 400 V. Moreover, the performance optimization effect brought by the internally loaded magnetic field will be gradually amplified with the increase of discharge voltage, which makes the Hall thruster with large height-radius ratio expected to achieve high-efficiency discharge under higher specific impulse.
The impact of anisotropic redshift distributions on angular clustering
Authors: Baleato Lizancos Antón , White Martin 
Published: July 2023

Abstract
A leading way to constrain physical theories from cosmological observations is to test their predictions for the angular clustering statistics of matter tracers, a technique that is set to become ever more central with the next generation of large imaging surveys. Interpretation of this clustering requires knowledge of the projection kernel, or the redshift distribution of the sources, and the typical assumption is an isotropic redshift distribution for the objects. However, variations in the kernel are expected across the survey footprint due to photometric variations and residual observational systematic effects. We develop the formalism for anisotropic projection and present several limiting cases that elucidate the key aspects. We quantify the impact of anisotropies in the redshift distribution on a general class of angular two-point statistics. In particular, we identify a mode-coupling effect that can add power to auto-correlations, including galaxy clustering and cosmic shear, and remove it from certain cross-correlations. If the projection anisotropy is primarily at large scales, the mode-coupling depends upon its variance as a function of redshift; furthermore, it is often of similar shape to the signal. In contrast, the cross-correlation of a field whose selection function is anisotropic with another one featuring no such variations — such as CMB lensing — is immune to these effects. We discuss explicitly several special cases of the general formalism including galaxy clustering, galaxy-galaxy lensing, cosmic shear and cross-correlations with CMB lensing, and publicly release a code to compute the biases.
Vector method of strain estimation in OCT-elastography with adaptive choice of scale for estimating interframe phase-variation gradients
Authors: Zykov Alexey A , Matveyev Alexander L , Sovetsky Alexander A , Matveev Lev A , Zaitsev Vladimir Y 
Published: July 2023

Abstract
In this paper we present a method which significantly improves strain-estimation quality in phase-sensitive optical coherence elastography (OCE). Specifically, we consider the realization of phase-sensitive OCE termed ‘vector method’, among main advantages of which are its high computational efficiency and high robustness with respect to measurement noises. The method does not require any search operations, but the quality of local strain estimation heavily depends on the quality of numerical spatial differentiation of inter-frame phase variations. This differentiation does not require phase unwrapping even for supra-wavelength displacements of scatterers, but the differentiation results depend on the chosen scale for phase-gradient estimation. Either too small or too large scale may strongly degrade the results of elastographic visualization, especially in the presence of pronounced spatio-temporal strain inhomogeneity. The proposed adaptive automatic choice of the differentiation scale complements earlier proposed vector averaging and significantly improves strain-mapping quality in OCE. The method efficiency is demonstrated using both numerically simulated and real OCT scans.
Thermal safety considerations for implantable micro-coil design
Authors: Whalen Andrew J , Fried Shelley I 
Published: July 2023

Abstract
Micro magnetic stimulation of the brain via implantable micro-coils is a promising novel technology for neuromodulation. Careful consideration of the thermodynamic profile of such devices is necessary for effective and safe designs. Objective. We seek to quantify the thermal profile of bent wire micro-coils in order to understand and mitigate thermal impacts of micro-coil stimulation. Approach. In this study, we use fine wire thermocouples and COMSOL finite element modeling to examine the profile of the thermal gradients generated near bent wire micro-coils submerged in a water bath during stimulation. We tested a range of stimulation parameters previously reported in the literature such as voltage amplitude, stimulus frequency, stimulus repetition rate and coil wire materials. Main results. We found temperature increases ranging from <1 °C to 8.4 °C depending upon the stimulation parameters tested and coil wire materials used. Numerical modeling of the thermodynamics identified hot spots of the highest temperatures along the micro-coil contributing to the thermal gradients and demonstrated that these thermal gradients can be mitigated by the choice of wire conductor material and construction geometry. Significance. ISO standard 14708-1 designates a thermal safety limit of 2 °C temperature increase for active implantable medical devices. By switching the coil wire material from platinum/iridium to gold, our study achieved a 5–6-fold decrease in the thermal impact of coil stimulation. The thermal gradients generated from the gold wire coil were measured below the 2 °C safety limit for all stimulation parameters tested.
Suitable Cutoff Value of Aldosterone to Renin Concentration Ratio Measured by Chemiluminescence for Screening Primary Aldosteronism Among Hypertensive Population in Sichuan
Authors: Tang Jia , Chen Tao , Tan Lu , Xu Jing , Xu Chen-xiao , Huang Lu , Tian Hao-ming , Ren Yan 
Published: July 2023

Abstract

Background
To explore the suitable cutoff value of aldosterone to renin concentration ratio (ARR) detected by chemiluminescence immunoassay for primary aldosteronism (PA) screening among hypertensive population in Sichuan, China.

Methods
423 hypertensive patients screened for PA in Department of Endocrinology and Metabolism of West China Hospital of Sichuan University from October 2020 to May 2022 were included in this study. Blood samples were collected 2 hours after the patients were in an upright position. Chemiluminescence was used to measure the concentrations of aldosterone and renin. Receiver operating characteristic curve was used to determine the optimal cutoff value of ARR.

Results
The 423 patients with hypertension included 199 PA and 224 essential hypertension. Youden index was the highest when the upright ARR was 2.4 (ng/dl)/(mU/l), and the sensitivity and specificity for PA were 95.5% and 94.2%, respectively. The most suitable upright ARR cutoff values for male and female were 2.0 and 2.4 (ng/dl)/(mU/l), and the sensitivity were 96.5%, 95.6%, the specificity was 95.3%, 91.5%, respectively. The most suitable cutoff values of upright ARR in the ≤40, &gt;40 to &lt;60, and ≥60-year-old patients with hypertension were 1.4, 2.3, and 2.7 (ng/dl)/(mU/l), respectively.

Conclusions
The suitable upright ARR cutoff value may be 2.4 (ng/dl)/(mU/l) for PA among hypertensive population in Sichuan. In male, the suitable cutoff value of ARR is lower than female. The cutoff value of ARR is increased with age.
The Importance of the Morel Emotional Numbing Test Instructions: A Diagnosis Threat Induction Study
Authors: Williamson Emily S , Arentsen Timothy J , Roper Brad L , Pedersen Heather A , Shultz Laura A , Crouse Ellen M 
Published: July 2023

Abstract

Objective
Marketed as a validity test that detects feigning of posttraumatic stress disorder (PTSD), the Morel Emotional Numbing Test for PTSD (MENT) instructs examinees that PTSD may negatively affect performance on the measure. This study explored the potential that MENT performance depends on inclusion of “PTSD” in its instructions and the nature of the MENT as a performance validity versus a symptom validity test (PVT/SVT).

Method
358 participants completed the MENT as a part of a clinical neuropsychological evaluation. Participants were either administered the MENT with the standard instructions (SIs) that referenced “PTSD” or revised instructions (RIs) that did not. Others were administered instructions that referenced “ADHD” rather than PTSD (AI). Comparisons were conducted on those who presented with concerns for potential traumatic-stress related symptoms (SI vs. RI-1) or attention deficit (AI vs. RI-2).

Results
Participants in either the SI or AI condition produced more MENT errors than those in their respective RI conditions. The relationship between MENT errors and other S/PVTs was significantly stronger in the SI: RI-1 comparison, such that errors correlated with self-reported trauma-related symptoms in the SI but not RI-1 condition. MENT failure also predicted PVT failure at nearly four times the rate of SVT failure.

Conclusions
Findings suggest that the MENT relies on overt reference to PTSD in its instructions, which is linked to the growing body of literature on “diagnosis threat” effects. The MENT may be considered a measure of suggestibility. Ethical considerations are discussed, as are the construct(s) measured by PVTs versus SVTs.
Egg mimicry, not the sight of a common cuckoo, is the cue for parasitic egg rejection
Authors: Štětková Gabriela , Šulc Michal , Jelínek Václav , Hughes Anna , Honza Marcel 
Published: July 2023

Abstract
Many studies have found that if hosts observe a brood parasite at their nest, they use it as a cue to reject parasitic eggs. However, most previous work has simulated brood parasitic events by exposing a stuffed parasite near a host’s nest. Responses to the presence of a real parasite have not yet been adequately studied under natural conditions. We therefore investigated whether great reed warblers (Acrocephalus arundinaceus) are more likely to reject a parasitic egg if they see a parasitizing common cuckoo (Cuculus canorus) at their nest than if the parasite approaches the host nest unnoticed. Using video recordings of 70 nests, we showed that spotting a cuckoo at the nest did not increase the rejection rate of parasitic eggs, even if hosts saw the cuckoo repeatedly. Hosts instead used the level of mimicry in the background color for cuckoo egg rejection. Since not every visit by the cuckoo leads to parasitism, seeing the brood parasite may not be a reliable enough cue for the host. Therefore, our results suggest that the sight of a cuckoo at the nest may not have as severe consequences for it as previously thought.
Intracellular gene transfer and codon usage of cytoplasmic genomes in green plants
Authors: Zhang Ting-Ting , Zhang Yang-Yan , Wang Xiao-Ling , Zhang Chen-Qi , Shi Wen-Hua , Fu Ai-Gen , Fang Min-Feng , Zhang Xiao , Li Zhong-Hu 
Published: July 2023

AbstractIntracellular gene transfer is widely recognized as one of the most important driving forces for species evolution. Here we investigated transferred cytoplasmic motifs in green plants including spore-bearing plants and seed-bearing plants (hereafter termed spore plants and seed plants) . Our analyses revealed that gene transfer in spore plants was characterized by shorter motifs than that of seed plants. Several spore species did not exhibit intracellular gene transfer. Meanwhile, high frequency transferred tRNA genes were identified with average values of minimum free energy at moderate level. From the chloroplast to the mitochondrial genome, trnP was found to have transferred with high frequency in green plants. In gene transfer from the mitochondrial to the chloroplast genome, trnN was found to be a highly transferred gene. We observed that several tRNA genes including trnF, trnW, and trnN were involved in bidirectional transfer, which may be related to application strategy of functional protein-coding genes in a plant’s adaptive evolution. Codon Adaptation Index (CAI) analysis showed that codon usage was unbalanced in spore and seed plants. CAI values for seed plants were higher than those for spore plants in general, which may reveal rapid divergence adaptability of codon usage in the former. These results provide novel insights into gene transfer and codon usage within cytoplasmic genomes.