bluuebunny/crossref_metadata_2025 huggingface dataset:
Energy coupling in intense laser solid interactions: Material properties of gold
Authors: Liu X. , Wu D. , Zhang J.
Published: June 2023

In the double-cone ignition inertial confinement fusion scheme, a high density deuterium–tritium (DT) fuel is rapidly heated with high-flux fast electrons, which are generated by short and intense laser pulses. A gold cone target is usually used to shorten the distance between the critical surface and the compressed high density DT core. The material properties of the solid gold may affect the generation and transport of fast electrons significantly, among which the effects of ionization and collision are the main concerns. In this work, the effects of ionization, collision, and blow-off plasma on the laser energy absorption rate are investigated using the LAPINS code: A three-stage model is adopted to explain the mechanism of fast electron generation and the change in the laser energy absorption rate. With the increase in the charge state of Au ions, the laser–plasma interaction transfers to the later stage, resulting in a decrease in the laser energy absorption rate. Collision has both beneficial and harmful effects. On the one hand, collision provides a thermal pressure, which makes it easier for electrons to escape into the potential well in front of the target and be accelerated in the second stage. On the other hand, collision increases stopping power and suppress electron recirculation within the target in the third stage. The vacuum sheath field behind the target enhances the electron circulation inside the target and, thus, improves the laser energy absorption; however, this effect will be suppressed when the blow-off plasma density behind the target increases or collision is considered.
Realistic geometric modeling of the dielectric constant and its effect on the discharge with a porous dielectric
Authors: Mao A. Yilong , Wang B. Hao , Yao C. Chenguo , Chen D. Kai , Wu E. Feiyu , Chen F. Yue
Published: June 2023

Porous dielectric discharge (PDD) is a critical phenomenon in plasma catalysis, biomedical tissue surface functionalization, and all-solid-state battery design. The dielectric constant of porous dielectric (PD) significantly impacts discharge characteristics and breakdown mechanisms across different applications. However, the complex spatial structure of porous media presents challenges in diagnosing and simulating PDD, limiting our understanding of its mechanism. In this study, the real geometric model of PD obtained from x-ray computed tomography (X-Ray-μ CT) and a two-dimensional fluid model were used to simulate and analyze the effect of dielectric constant on PDD-plasma characteristics, especially the generation and disappearance of charged particles. The simulation results reveal the following: (1) At the breakdown moment, PDD is a density-unbalanced discharge where the electron density is two orders of magnitude higher than the ion density; (2) The breakdown discharge follows the most accessible channel instead of filling the entire gap, which is guided by the electron temperature gradient; and (3) It was first discovered that the breakdown voltage exhibits a saturated growth curve under the control of the dielectric constant. By combining these mechanisms, a comprehensive explanation has been provided for this phenomenon. This study offers a robust simulation and theoretical basis for understanding the breakdown characteristics of PDD.
Ponderomotive force due to the intrinsic spin for electrostatic waves in a magnetized plasma
Authors: Al-Naseri Haidar , Brodin Gert
Published: June 2023

We study the contribution from the electron spin to the ponderomotive force, using a quantum kinetic model, including the spin–orbit correction. Specifically, we derive an analytical expression for the ponderomotive force, applicable for electrostatic waves propagating parallel to an external magnetic field. To evaluate the expression, we focus on the case of Langmuir waves and on the case of the spin resonance wave mode, where the classical and spin contributions to the ponderomotive force are compared. Somewhat surprisingly, depending on the parameter regime, we find that the spin contribution to the ponderomotive force may dominate for the Langmuir wave, whereas the classical contribution can dominate for the spin resonance mode.
Hyperscaling of the correlation length, interfacial tension, and specific heat in two-dimensional and quasi-two-dimensional liquids
Authors: Hernández Velázquez J. D. , Gama Goicochea A.
Published: June 2023

The line tension of two immiscible liquids under two-dimensional and quasi-two dimensional conditions is calculated as a function of temperature, using mesoscale numerical simulations, finding that it decays linearly. The liquid–liquid correlation length, defined as the thickness of their interface, is also predicted as the temperature is varied, and it diverges as the temperature becomes close to the critical temperature. These results are compared with recent experiments on lipid membranes and good agreement is obtained. The scaling exponents of the line tension (μ) and the spatial correlation length (ν) with temperature are extracted, finding that they fulfill the hyperscaling relationship, μ=d−1ν, where d is the dimension. The scaling of specific heat with temperature of the binary mixture is obtained as well. This is the first report of the successful test of the hyperscaling relation between μ and ν for d = 2 and for the non-trivial case of quasi-two dimensions. This work can help to understand experiments that test properties of nanomaterials using simple scaling laws, without needing to know specific chemical details of those materials.
Maximizing supercontinuum bandwidths in gas-filled hollow-core fibers using artificial neural networks
Authors: Shih Mulaine , Nelson-Quillin Heidi D. , Garrett Kerry E. , Coyle Eleanor J. , Secondo Ray , Keyser Christian K. , Mills Matthew S. , Harper Eric S.
Published: June 2023

Machine learning has been used to accelerate studies in the dynamics of optical pulses. In this study, we use machine learning to investigate the optimal design of supercontinuum-generating hollow-core antiresonant fibers (HC-ARFs) pressurized and filled with methane. Artificial neural networks (ANNs) are trained to replace the numerical solvers, accelerate the simulation of fibers, and provide a more rapid fiber design procedure. We first use an analytical model to approximate the dispersion and loss of the methane-filled silica HC-ARF. This approximation is used by the generalized unidirectional pulse propagation equation solver to simulate the pulse propagation and generate training data for our ANNs by varying design parameters including the pump center wavelength, fiber hollow-core radius, fiber length, cladding strut thickness, and gas pressure. We evaluate the performance of different spectral-predicting ANN architectures and use the trained ANN along with a custom fiber performance function to search the full parameter space. Subsequently, the regions with design parameters with predicted high performance are identified, and these high-performance HC-ARF designs are further optimized for supercontinuum generation at target supercontinuum bandwidths. We also extend our effort to maximizing the total spectral energy outside of the input pump wavelength by integrating the ANN with a global optimization technique for the search of an optimal HC-ARF design.
Ca2+ enhanced far-red emission performance and efficiency of SrGd2Al2O7:Mn4+ phosphor for the potential application in plant growth lighting
Authors: Yu Yi , Shao Kai , Niu Chonghui , Dan Mingjie , Wang Zhibin , Wang Yingying , Chen Jie , Luo Jiani , Liu Shiying , Xie Zhi
Published: June 2023

Mn-based phosphors with the wavelength of 700–750 nm are an important category of far-red phosphors that have promising potential in the application of plant lighting, and the higher ability of the far-red light emitting of the phosphors is beneficial to plant growth. Herein, a series of Mn4+- and Mn4+/Ca2+-doped double perovskite SrGd2Al2O7 red-emitting phosphors with wavelengths centered at about 709 nm were successfully synthesized by means of a traditional high-temperature solid-state method. First-principles calculations were conducted to explore the intrinsic electronic structure of SrGd2Al2O7 for a better understanding of the luminescence behavior in this material. Extensive analysis demonstrates that the introduction of Ca2+ ions into the SrGd2Al2O7:Mn4+ phosphor has significantly boosted the emission intensity, internal quantum efficiency, and thermal stability by 170%, 173.4%, and 113.7%, respectively, which are superior to those of most other Mn4+-based far-red phosphors. The mechanism of the concentration quench effect and the positive effect of co-doping Ca2+ ions in the phosphor were extensively explored. All studies suggest that the SrGd2Al2O7:0.1%Mn4+, 11%Ca2+ phosphor is a novel phosphor that can be used to effectively promote the growth of plants and regulate the flowering cycle. Therefore, promising applications can be anticipated from this new phosphor.
Stochastic hotspots in extreme ultraviolet exposed nano-patterns as correlated molecular sub-cluster formation probabilities
Authors: Fukuda Hiroshi
Published: June 2023

Stochastic pattern anomalies limit the shrinking of the size of nano-patterns in extreme-ultraviolet lithography at around 10 nm due to the discrete/probabilistic nature of photon–electron-reaction systems. We express the patterns and their anomalies as probability distributions and predict stochastic hotspots where the anomaly generation probabilities rise unexpectedly in arbitrary pattern features. Three-dimensional chemo-physical event distributions in pattern-exposed resist films are calculated by the fully coupled first-principles Monte Carlo simulation combined with the discrete development/etching models. The aggregates of molecular level solubility flipping (sub-cluster) well express spatial correlations in the observed anomalies. Spatial correlation in sub-cluster generation is not scaled and their impact increases with shrinking patterns. The correlation is squeezed near the pattern edge, inducing edge placement error, and it spreads in the areas between edges causing stochastic pattern defects. For materials with sub-cluster size not negligible compared to image size, the stochastic hotspots appear when the correlated area spreads in areas far from the edges adjacent to the higher probability region. Deep neural networks successfully predict the probability distributions of sub-clusters and anomaly generation in arbitrary pattern features without the Monte Carlo method.
In-air experimental achievement of high-voltage DC power supply to be installed in a tandem electrostatic accelerator system for boron neutron capture therapy application
Authors: Min Sun-Hong , Park Chawon , Kim Minho , Jung Hyunwoo , Back JongHyun , Park Seungwoo , Hong Bong Hwan
Published: June 2023

The boron neutron capture therapy (BNCT) system developed by the Korea Institute of Radiological and Medical Sciences is a compact neutron source that can be installed at medical institutes. The target energy was accelerated to a maximum of 2.4 MeV–20 mA by introducing a gas stripping device that converts negative hydrogen ions into positive ions. By using the tandem-type accelerator in this way, a high-voltage DC power supply was designed with 1.2 MV–45 mA as the maximum capability. The design was improved to reduce the number of stages of a Cockcroft–Walton voltage multiplier. Hence, the ripple risk of the DC flat top resulting from unwanted stray capacitance was lowered. The overall height and volume of the Cockcroft–Walton voltage multiplier were reduced to less than half those of the existing design method, making miniaturization possible. After such advanced design and manufacturing, performance tests were performed at 750 kV–45 mA under 23 stages of the Cockcroft–Walton voltage multiplier, which is the highest level that can perform at its maximum under in-air conditions. It demonstrated stable performance under in-air conditions without breakdown for 2 h, even at 620 kV–35 mA. To reach the final target of 1.2 MV–45 mA, the groundwork is laid for achieving experimental performance while satisfying the optimal requirements in SF6 gas.
Three robust temperature-drift compensation strategies for a MEMS gravimeter
Authors: Valenzuela Victor M. , Teran Daniel , Sandoval Alejandro , Gomez Eduardo , Franco-Villafañe John A. , Alcantar-Peña Jesus J. , Ponce-Hernandez Juan
Published: June 2023

Gravimeters fabricated with MEMS suffer from temperature-dependent drifts in their long-term stability. We analyze the thermal contributions to the signal, and we propose three mechanisms to mitigate their effects. The first one uses materials that fulfill the condition αE=−2α, where thermal expansion is canceled by the temperature variation of Young’s modulus. The second one uses the thermal expansion to introduce a compression that compensates variation in the force of the spring. In the third one, expansion compensates the displacement of the proof mass in the sensor, rather than the force. The three mechanisms are robust since they only depend on the temperature of the sensor itself.
Contact angle measurement system with liquid sodium in inert atmosphere
Authors: Faizal V. A. , Murugesan N. , Sukumaran V. , Jena Hrudananda , Remash C. , Ganesan Rajesh , Jayaraman V.
Published: June 2023

Liquid sodium is the heat transport medium in fast breeder reactors due to its favorable chemical, physical, and nuclear properties. Wetting of liquid sodium with the material of reactor components is essential for the effective functioning of the reactor. Liquid sodium wetting plays a crucial role, such as in (i) heat transfer and (ii) image reconstruction under sodium ultrasonic scanners. Contact angle is the inverse measure of the wetting of liquids over solid surfaces. A contact angle measurement system was set up in an inert atmosphere glow box to study the wetting behavior of liquid sodium on reactor materials. The contact angle of liquid sodium on nickel surface was measured as a function of temperature, and the results obtained were found to be in good agreement with the literature values. The contact angle of liquid sodium on SS316LN as a function of temperature was measured for the first time using this facility.
High-entropy enhanced microwave absorption in MAX phases
Authors: Shen Jibing , Zhang Min , Lin Shuai , Song Wenhai , Liu Huijun , Liu Qiangchun , Zhu Xuebin , Sun Yuping
Published: June 2023

The application of microwave absorption materials, which can effectively convert electromagnetic energy into thermal energy and/or other forms of energy, can effectively solve the increasingly serious electromagnetic pollution. As a type of promising microwave absorption material, ternary transition metal carbides/nitrides MAX phases possess layered structure and superior conduction loss capability. However, poor impedance matching and single polarization loss type seriously hinder their improvement of microwave absorption performance. High-entropy engineering is expected to be an effective strategy to address the above problems simultaneously. Herein, a series of low-, medium-, and high-entropy MAX phases with Ti2AlC structure were successfully synthesized and their structure, composition, and morphology were comprehensively characterized. High-entropy MAX phase (Ti1/5Zr1/5V1/5Nb1/5Ta1/5)2AlC presents excellent microwave absorption performance with the optimal minimum reflection loss (RLmin) of −47 dB at 11.92 GHz (a thickness of 2.4 mm) and optimal effective absorption bandwidth of 3.92 GHz between 8.48 and 12.4 GHz (a thickness of 2.78 mm), which are better than those of our prepared low-/medium-entropy MAX phases as well as most of the other previously reported MAX phases. Such excellent microwave absorption performance of (Ti1/5Zr1/5V1/5Nb1/5Ta1/5)2AlC is attributed to high-entropy engineering, which not only optimizes the impedance matching through regulating permittivity but also introduces more polarization loss type and amount. This work reveals that high-entropy engineering is not only a workable method to enhance the microwave absorption performance in MAX phases, but also an effective strategy to tailor the balance between impedance matching and loss capability through compositional design in single-phase systems.
Application of a semi-analytical method to the dynamic analysis of functionally graded porous conical–conical–cylindrical shell
Authors: Li Gang , Yan Zhicha
Published: June 2023

The dynamic response characteristics of a coupled, functionally graded porous conical–conical–cylindrical shell (FGP-CCCS) with arbitrary boundary conditions are investigated using a semi-analytical method in this research. The individual shells are firmly connected at the interface. It is assumed that FGP-CCCS is made of three types of FGP materials with uniform or non-uniform distribution of porosity along the thickness direction. The overall theoretical model for the dynamic response analysis of FGP-CCCS is established based on the first-order shear deformation theory. All the displacement components of individual shells, including boundary conditions, are expanded along the meridian direction into the Chebyshev polynomial and along the circumferential direction into the standard Fourier series. By applying the Rayleigh–Ritz method to the determination of the expansion coefficient, a unified solution for a FGP-CCCS with arbitrary boundary conditions is derived directly without the need to change the equation of motion or the displacement functions. The reliability and accuracy of this method is verified in comparison with the results in the literature and finite element method. New numerical examples are presented to illustrate the dynamic response characteristics of FGP-CCCS, and the effects of the geometrical, material parameters and external forces on the dynamic response of FGP-CCCS with different boundary conditions are reported.
Mesoscale computer modeling of asphaltene aggregation in liquid paraffin
Authors: Gurtovenko Andrey A. , Nazarychev Victor M. , Glova Artem D. , Larin Sergey V. , Lyulin Sergey V.
Published: June 2023

Asphaltenes represent a novel class of carbon nanofillers that are of potential interest for many applications, including polymer nanocomposites, solar cells, and domestic heat storage devices. In this work, we developed a realistic coarse-grained Martini model that was refined against the thermodynamic data extracted from atomistic simulations. This allowed us to explore the aggregation behavior of thousands of asphaltene molecules in liquid paraffin on a microsecond time scale. Our computational findings show that native asphaltenes with aliphatic side groups form small clusters that are uniformly distributed in paraffin. The chemical modification of asphaltenes via cutting off their aliphatic periphery changes their aggregation behavior: modified asphaltenes form extended stacks whose size increases with asphaltene concentration. At a certain large concentration (44 mol. %), the stacks of modified asphaltenes partly overlap, leading to the formation of large, disordered super-aggregates. Importantly, the size of such super-aggregates increases with the simulation box due to phase separation in the paraffin–asphaltene system. The mobility of native asphaltenes is systematically lower than that of their modified counterparts since the aliphatic side groups mix with paraffin chains, slowing down the diffusion of native asphaltenes. We also show that diffusion coefficients of asphaltenes are not very sensitive to the system size: enlarging the simulation box results in some increase in diffusion coefficients, with the effect being less pronounced at high asphaltene concentrations. Overall, our findings provide valuable insight into the aggregation behavior of asphaltenes on spatial and time scales that are normally beyond the scales accessible for atomistic simulations.
Low intensity saturation of an ISB transition by a mid-IR quantum cascade laser
Authors: Jeannin Mathieu , Cosentino Eduardo , Pirotta Stefano , Malerba Mario , Biasiol Giorgio , Manceau Jean-Michel , Colombelli Raffaele
Published: June 2023

We demonstrate that absorption saturation of a mid-infrared intersubband transition can be engineered to occur at moderate light intensities of the order of 10–20 kW cm−2 and at room temperature. The structure consists of an array of metal–semiconductor–metal patches hosting a judiciously designed 253 nm thick GaAs/AlGaAs semiconductor heterostructure. At low incident intensity, the structure operates in the strong light–matter coupling regime and exhibits two absorption peaks at wavelengths close to 8.9 μm. Saturation appears as a transition to the weak coupling regime—and therefore, to a single-peaked absorption—when increasing the incident intensity. Comparison with a coupled mode theory model explains the data and permits to infer the relevant system parameters. When the pump laser is tuned at the cavity frequency, the reflectivity decreases with increasing incident intensity. When instead the laser is tuned at the polariton frequencies, the reflectivity non-linearly increases with increasing incident intensity. At those wavelengths, the system, therefore, mimics the behavior of a saturable absorption mirror in the mid-IR range, a technology that is currently missing.
The electro-mechanical coupling responses of functionally graded piezoelectric nanobeams with flexoelectric effect
Authors: Liu Zhenhai , Wang Peng , Xu Jiawei
Published: June 2023

The aim of this paper is to study the electro-mechanical coupling responses of functionally graded (FG) piezoelectric cantilever nanobeam under the concentrated load, and the material properties follow an exponential distribution in the thickness direction. The constitutive equations are derived from the electric Gibbs free energy density function. The governing equations and boundary conditions of the Euler–Bernoulli FG beam can be obtained by variational principle, and then, the analytical expressions for its deflection, polarization intensity, and induced potential are obtained. The results show that the flexoelectric effect has a significant impact on the deflection, polarization intensity, and induced potential of the FG cantilever nanobeam.
Toward interpretability of machine learning methods for the classification of patients with major depressive disorder based on functional network measures
Authors: Andreev Andrey V. , Kurkin Semen A. , Stoyanov Drozdstoy , Badarin Artem A. , Paunova Rossitsa , Hramov Alexander E.
Published: June 2023

We address the interpretability of the machine learning algorithm in the context of the relevant problem of discriminating between patients with major depressive disorder (MDD) and healthy controls using functional networks derived from resting-state functional magnetic resonance imaging data. We applied linear discriminant analysis (LDA) to the data from 35 MDD patients and 50 healthy controls to discriminate between the two groups utilizing functional networks’ global measures as the features. We proposed the combined approach for feature selection based on statistical methods and the wrapper-type algorithm. This approach revealed that the groups are indistinguishable in the univariate feature space but become distinguishable in a three-dimensional feature space formed by the identified most important features: mean node strength, clustering coefficient, and the number of edges. LDA achieves the highest accuracy when considering the network with all connections or only the strongest ones. Our approach allowed us to analyze the separability of classes in the multidimensional feature space, which is critical for interpreting the results of machine learning models. We demonstrated that the parametric planes of the control and MDD groups rotate in the feature space with increasing the thresholding parameter and that their intersection increases with approaching the threshold of 0.45, for which classification accuracy is minimal. Overall, the combined approach for feature selection provides an effective and interpretable scenario for discriminating between MDD patients and healthy controls using measures of functional connectivity networks. This approach can be applied to other machine learning tasks to achieve high accuracy while ensuring the interpretability of the results.
Further refinement of helicopter capture for Australian chital deer (Axis axis)
Authors: Amos Matt , De Ridder Tom R. , Pople Anthony , Brennan Michael , Hampton Jordan O.
Published: June 2023

This study improves a technique to capture wild chital deer (Axis axis) in northern Australia by darting from a helicopter. We quantified several metrics, including the frequency of adverse animal welfare events. Mortality at the time of capture was 15%, but no animals died post-release, and the frequencies of hyperthermia and hypoxaemia were lower than in previous operations. This study can be used as a template for iterative refinement of high-risk capture methodologies.
Metaphorical polysemy of the Chinese color termhēi黑 “black”
Authors: Liu Meichun , Dou Jinmeng
Published: June 2023

This paper reports a corpus-based, cognitive semantic study on profiling the varied uses of the Chinese color termhēi黑“black” with regard to its metaphorical polysemy. We hypothesize that the semantic (dis)similarities among the eight metaphorical meanings ofhēi“black” can be captured by clustering their contextual features, including collocational patterns, morphosyntactic and semantic properties, and discourse information. The Behavioral Profiles approach is adopted for the analyses with the annotations of 800 instances for 46 contextual features and a hierarchical agglomerative cluster analysis conducted on the annotated data. The results show that the eight metaphorical senses ofhēi“black” fall into three clusters. This clustering can be explained by the conceptual bases pertaining to color perceptions and color changes, in line with Conceptual Metaphor Theory. This study demonstrates the effectiveness of the corpus-based Behavioral Profiles approach in exploring the underlying cognitive mechanisms of metaphorical extensions and meaning differentiations.
Investigation of Faraday cage materials with low eddy current and high RF shielding effectiveness for PET/MRI applications
Authors: Dong Qian , Adams Zander , Watkins Ronald D , Chang Chen-Ming , Lee Brian J , Levin Craig S
Published: June 2023

Objective. This study aims to evaluate radiofrequency (RF) shielding effectiveness (SE), gradient-induced eddy current, magnetic resonance (MR) susceptibility, and positron emission tomography (PET) photon attenuation of six shielding materials: copper plate, copper tape, carbon fiber fabric, stainless steel mesh, phosphor bronze mesh, and a spray-on conductive coating. Approach. We evaluated the six shielding materials by implementing them on identical clear plastic enclosures. We measured the RF SE and eddy current in benchtop experiments (outside of the MR environment) and in a 3T MR scanner. The magnetic susceptibility performance was evaluated in the same MR scanner. Additionally, we measured their effects on PET detectors, including global coincidence time resolution, global energy resolution, and coincidence count rate. Main results. The RF SEs for copper plate, copper tape, carbon fiber fabric, stainless steel mesh, phosphor bronze mesh, and conductive coating enclosures were 56.8 ± 5.8, 63.9 ± 4.3, 33.1 ± 11.7, 43.6 ± 4.5, 52.7 ± 4.6, and 47.8 ±7.1 dB, respectively, in the benchtop experiment. Copper plate and copper tape experienced the most eddy current at 10 kHz in the benchtop experiment and also generated the largest ghosting artifacts in the MR scanner. Stainless steel mesh had the highest mean absolute difference (7.6 ±0.2 Hz) compared to the reference in the MR susceptibility evaluation. The carbon fiber fabric and phosphor bronze mesh enclosures caused the largest photon attenuation, reducing the coincidence count rate by 3.3%, while the rest caused less than 2.6%. Significance. The conductive coating proposed in this study is shown to be a high-performance Faraday cage material for PET/MRI applications based on its overall performance in all the experiments conducted in this study, as well as its ease and flexibility of manufacturing. As a result, it will be selected as the Faraday cage material for our second-generation MR-compatible PET insert.
The Aharonov Casher phase of a bipartite entanglement pair traversing a quantum square ring
Authors: Huang Che-Chun , Tan Seng Ghee , Chang Ching-Ray
Published: June 2023

We propose in this article a quantum square ring that conveniently generates, annihilates and distills the Aharonov Casher phase with the aid of entanglement. The non-Abelian phase is carried by a pair of spin-entangled particles traversing the square ring. At maximal entanglement, dynamic phases are eliminated from the ring and geometric phases are generated in discrete values. By contrast, at partial to no entanglement, both geometric and dynamic phases take on discrete or locally continuous values depending only on the wavelength and the ring size. We have shown that entanglement in a non-Abelian system could greatly simplify future experimental efforts revolving around the studies of geometric phases.
An image encryption scheme based on elementary and life-liked cellular automatons
Authors: Lv Wenrui , Fu Chong , Chai Xiuli , Zhang Leo Yu , Chen Junxin
Published: June 2023

Among the encryption technologies with chaos theory, cellular automatons with feature of discrete dynamical system and easy implementation, have unique advantages. Based on the Elementary and Life-liked cellular automaton, a new image encryption scheme is proposed in this paper. In this scheme, encryption equations are space distributed according to a chaotic map, and pixels in different areas might be encrypted with distinct encryption kernels. This fashion can provide additional security for the whole system. The simulation results and security analysis demonstrate the effectiveness and advantages of the proposed cryptosystem.
Causal structure and the geodesics in the hairy extension of the Bertotti-Robinson spacetime
Authors: Memari Vahideh , Mazharimousavi S Habib
Published: June 2023

A hairy extension of the Bertotti-Robinson regular spacetime has been recently introduced in the context of the Einstein-Maxwell-Scaler theory that surprisingly is a singular black hole formed in the S
3 background spatial topology [CQG39(2022)167001]. In this research, we first clarify the topology of the spacetime based on the coordinate transformations as well as the energy-momentum configuration and the causal structure of the black hole. Furthermore, we investigate the geodesics of the null and timelike particles in this spacetime. It is shown that in the radial motion on the equatorial plane, while photons may collapse to the singularity or escape to the edge of the Universe, a massive particle always collapses to the singularity. The general geodesics of null and massive particles reveal that all particles except the outgoing light ray, eventually fall into the black hole.
The effect of the plasma response on peeling–ballooning modes during edge localized modes mitigated by resonant magnetic perturbations
Authors: Dong L.K. , Chen S.Y. , Mou M.L. , Luo Y. , Qin C.C. , Tang C.J.
Published: June 2023

The effects of resonant magnetic perturbation (RMP) fields on peeling–ballooning (P–B) modes are studied with the experimental equilibria of EAST based on the four-field model in BOUT++ code. As the two basic types of plasma responses, the magnetic and the transport response to RMP are considered in our simulation to reveal the roles of the plasma response during edge localized mode mitigation. On the one hand, the results show that RMP can reduce the linear growth rates of the P–B modes and the pedestal energy loss in the nonlinear process by directly coupling with the P–B modes. The magnetic response can weaken the impacts of RMPs on the P–B modes by partially screening the applied RMP fields more precisely the resonant components. On the other hand, RMP can further reduce the linear growth rates of the P–B modes and the pedestal energy loss by changing the equilibrium pressure profiles through the transport response. More detailed analysis suggests that, compared with other resonant components of RMPs, the components whose corresponding rational surfaces are located at the top of the pedestal can lead to stronger reductions in the linear growth rates of the P–B modes, and can reduce pedestal energy loss more significantly by enhancing multi-mode coupling in the nonlinear process. Finally, the multi-mode coupling increases with the strength of the resonant components, so one can change the RMP poloidal spectrum by adjusting the phase difference

Δ

ϕ

between the upper and low RMP coils from

0

to

360
∘

, and hence obtain the optimal coil phase difference that leads to the strongest reductions in the linear growth rates of the P–B modes and the pedestal energy loss through maximizing the strength of resonant components, especially the resonant components whose corresponding rational surfaces are located at the top of the pedestal.
Pellet-fueled I-mode plasmas in ASDEX Upgrade
Authors: Silvagni D. , Lang P.T. , Happel T. , Bock A. , Fischer R. , Gil L. , Kardaun O.J.W.F. , McDermott R.M. , Plank U. , Plöckl B. , Stieglitz D. , Tardini G.
Published: June 2023

This letter reports on the efforts carried out at the ASDEX Upgrade tokamak to integrate I-mode plasmas with pellet fueling and to increase the I-mode Greenwald fraction

f

G
W

, two important requirements for any DEMO operational scenario. For the first time, stationary I-mode plasmas have been achieved with pellet fueling and the core Greenwald fraction has been increased up to 0.8. Larger

f

G
W

were not achieved due to technical constraints rather than to a physics-based limit. Pellet-fueled I-mode plasmas exhibit enhanced core and edge density, while core and edge temperature are reduced. Nonetheless, edge normalized gradients remain I-mode-like, namely shallow for the density and steep for the temperature. The I-mode energy confinement time is found to obey two distinct density dependencies: for

f

G
W

<
0.4

it rises with increasing

f

G
W

, while for

f

G
W

>
0.4

the energy confinement time plateaus with increasing

f

G
W

, or even decreases with

f

G
W

for the pellet-fueled plasmas. Similarities with Ohmic and L-mode energy confinement time dependency on density are discussed.
Reoperative surgery after magnetic sphincter augmentation
Authors: Poola Ashwini S , Gatta Prakash
Published: June 2023

Reoperative surgery following magnetic sphincter augmentation (MSA) is rare. The clinical indications include the removal of MSA for dysphagia, the recurrence of reflux, or the issues of erosion. Diagnostic evaluation follows that of patients with recurrent reflux and dysphagia following surgical fundoplication. Procedures following the complications of MSA can be performed in a minimally invasive fashion, either endoscopically or robotic/laparoscopically, with good clinical outcomes.
Methyl salicylate improves the effectiveness of the odor-baited trap tree approach for adult plum curculio, Conotrachelus nenuphar (Coleoptera: Curculionidae), monitoring and attract-and-kill
Authors: Regmi Prabina , Leskey Tracy C , Piñero Jaime C
Published: June 2023

In commercial apple orchards, the odor-baited trap tree approach involving the synergistic lure composed of benzaldehyde (BEN) and the PC aggregation pheromone grandisoic acid (GA) serves as an effective monitoring tool as well as an attract-and-kill strategy for plum curculio (PC), Conotrachelus nenuphar Herbst. (Coleoptera: Curculionidae), management. However, the relatively high cost of the lure and the degradation of commercial BEN lures by UV light and heat discourage its adoption by growers. Over a 3-yr period, we compared the attractiveness of methyl salicylate (MeSA), either alone or in combination with GA, to plum curculio (PC) with that of the standard combination of BEN + GA. Our main goal was to identify a potential replacement for BEN. Treatment performance was quantified using 2 approaches: (i) unbaited black pyramid traps (2020, 2021) to capture PC adults and (ii) PC oviposition injury (2021, 2022) on apple fruitlets of trap trees and of neighboring trees to assess potential spillover effects. Traps baited with MeSA captured significantly more PCs than unbaited traps. Trap trees baited with a single MeSA lure and 1 GA dispenser attracted a similar number of PCs as trap trees baited with the standard lure composed of 4 BEN lures and 1 GA dispenser based on PC injury. Trap trees baited with MeSA + GA received significantly more PC fruit injury than neighboring trees suggesting no or limited spill-over effects. Our collective findings suggest that MeSA is a replacement for BEN thereby cutting costs of lures by ca. 50% while maintaining trap tree effectiveness.
Constraining the LyC escape fraction from LEGUS star clusters with SIGNALS H ii region observations: a pilot study of NGC 628
Authors: Teh Jia Wei , Grasha Kathryn , Krumholz Mark R , Battisti Andrew J , Calzetti Daniela , Rousseau-Nepton Laurie , Rhea Carter , Adamo Angela , Kennicutt Robert C , Grebel Eva K , Cook David O , Combes Francoise , Messa Matteo , Linden Sean T , Klessen Ralf S , Vilchez José M , Fumagalli Michele , McLeod Anna , Smith Linda J , Chemin Laurent , Wang Junfeng , Sabbi Elena , Sacchi Elena , Petric Andreea , Bruna Lorenza Della , Boselli Alessandro
Published: June 2023

The ionizing radiation of young and massive stars is a crucial form of stellar feedback. Most ionizing (Lyman-continuum; LyC, λ < 912Å) photons are absorbed close to the stars that produce them, forming compact H ii regions, but some escape into the wider galaxy. Quantifying the fraction of LyC photons that escape is an open problem. In this work, we present a seminovel method to estimate the escape fraction by combining broadband photometry of star clusters from the Legacy ExtraGalactic UV Survey (LEGUS) with H ii regions observed by the Star formation, Ionized gas, and Nebular Abundances Legacy Survey (SIGNALS) in the nearby spiral galaxy NGC 628. We first assess the completeness of the combined catalogue, and find that 49  per cent of H ii regions lack corresponding star clusters as a result of a difference in the sensitivities of the LEGUS and SIGNALS surveys. For H ii regions that do have matching clusters, we infer the escape fraction from the difference between the ionizing power required to produce the observed H ii luminosity and the predicted ionizing photon output of their host star clusters; the latter is computed using a combination of LEGUS photometric observations and a stochastic stellar population synthesis code slug (Stochastically Lighting Up Galaxies). Overall, we find an escape fraction of ${f}_{\textrm {esc}}= 0.09^{+0.06}_{-0.06}$ across our sample of 42 H ii regions; in particular, we find H ii regions with high fesc are predominantly regions with low $\operatorname{H\alpha }$-luminosity. We also report possible correlation between fesc and the emission lines $\rm [O\, \rm {\small II}]/[N\, \rm {\small II}]$ and $\rm [O\, \rm {\small II}]/H\beta$.
Magnetically activated accretion outbursts of pre-main-sequence discs
Authors: Cleaver Jacob , Hartmann Lee , Bae Jaehan
Published: June 2023

We investigate whether triggering of the magnetorotational instability (MRI) in protoplanetary discs can account for the wide diversity of observed accretion outbursts. We show that short-lived, relatively low accretion rate events probably result from triggering in the inner disc and can occur at low surface densities, comparable to or smaller than the minimum mass solar nebula, and thus are very unlikely to result from MRI triggering by gravitational instability. We develop time-dependent accretion disc models using an α-viscosity approach and calculate light curves to compare with observations. Our modelling indicates that the lag time between infrared and optical bursts seen in Gaia 17bpi can be explained with an outside-in propagation with an α ∼ 0.1 in the MRI-active region, consistent with other estimates. While outbursts in inner discs can show time delays of a few yr between infrared and optical light curves, our models indicate that large, FU Ori-like bursts can exhibit infrared precursors decades before optical bursts. Detecting such precursors could enable analysis of the central star before it is overwhelmed by the rapid accreting material, as well as constraining outburst physics. Our results emphasize the importance of near-infrared monitoring of young stellar objects in addition to optical surveys. In addition, our findings emphasize the need for more sophisticated, three-dimensional, non-ideal magnetohydrodynamic simulations to fully exploit observational results.
Tax competition and state aid
Authors: Mason Ruth
Published: June 2023

At the inception of a new and potentially transformative type of tax enforcement, this article reviews the goals underlying the prohibition on state aid, and, in particular, whether those goals properly encompass limitations on tax competition. To explore this question, this article examines treaty text and structure, doctrine, and policy arguments for and against using state aid to curb tax competition. It concludes that the European Commission’s expansion of state-aid doctrine to limit tax competition improperly constrains Member State tax autonomy, arrogates tax policy power to the unelected Commission, and increases legal uncertainty. This article urges the Court of Justice of the European Union to clarify that preventing tax competition is not an independent goal of state-aid enforcement, although limits on tax competition may arise instrumentally via a free-trade interpretation of the prohibition of state aid.
Decision-making Algorithm for the Surgical Treatment of Degenerative Lumbar Spondylolisthesis of L4/L5
Authors: Schönnagel Lukas , Caffard Thomas , Zhu Jiaqi , Tani Soji , Camino-Willhuber Gaston , Amini Dominik A. , Haffer Henryk , Muellner Maximilian , Guven Ali E. , Chiapparelli Erika , Arzani Artine , Amoroso Krizia , Shue Jennifer , Duculan Roland , Zippelius Timo , Sama Andrew A. , Cammisa Frank P. , Girardi Federico P. , Mancuso Carol A. , Hughes Alexander P.
Published: June 2023

Study Design.

A retrospective analysis of prospectively collected data.

Objective.

To report the decision-making process for DA and DF at a tertiary orthopedic center and compare the operative outcomes between both groups.

Background.

Controversy exists around the optimal operative treatment for DLS, either with decompression and fusion (DF) or decompression alone (DA). Although previous studies tried to establish specific indications, clinical decision-making algorithms are needed.

Methods.

Patients undergoing spinal surgery for DLS at L4/5 were retrospectively analyzed. A survey of spine surgeons was performed to identify factors influencing surgical decision-making, and their association with the surgical procedure was tested in the clinical dataset. We then developed a clinical score based on the statistical analysis and survey results. The predictive capability of the score was tested in the clinical dataset with a ROC analysis. To evaluate the clinical outcome, two years follow-up postoperative Oswestry Disability Index (ODI), postoperative low back pain (LBP) (NAS), and patient satisfaction were compared between the DF and DA groups.

Results.

124 patients were included in the analysis; 66 received DF (53.2%) and 58 DA (46.8%). Both groups showed no significant differences in postoperative ODI, LBP, or satisfaction. The degree of spondylolisthesis, facet joint diastasis and effusion, sagittal disbalance, and severity of LBP were identified as the most important factors for deciding on DA or DF. The AUC of the decision-making score was 0.84. At a cut-off of 3 points indicating DF, the accuracy was 80.6%.

Conclusion.

The 2-year follow-up data showed that both groups showed similar improvement in ODI after both procedures, validating the respective decision. The developed score shows excellent predictive capabilities for the decision processes of different spine surgeons at a single tertiary center and highlights relevant clinical and radiographic parameters. Further studies are needed to assess the external applicability of these findings.
Open vs Robotic Radical Cystectomy Outcomes at a Single Institution: A Retrospective Review of 152 Patients
Authors: Gonzalez Ashley N. , Zhao Lee C. , Steinberg Gary D. , Corcoran Anthony , Wysock James S. , Huang William C.
Published: June 2023

Introduction:

Robotic radical cystectomy is becoming increasingly used over the traditional open approach; however, the potential advantages remain an area of active investigation, with several studies to date finding overall comparable outcomes. We sought to add to the existing body of work by performing a retrospective review of open vs robotic radical cystectomies performed at our institution.

Methods:

All patients who underwent radical cystectomy for urothelial cancer with curative intent at New York University (Manhattan and Long Island sites) were included. Surgical dates spanned between October 2017 and March 2022. Individual patient charts were reviewed in Epic for data extraction.

Results:

A total of 152 patients were included in the final analysis including 71 robotic and 81 open radical cystectomies. Estimated blood loss and the number of perioperative blood transfusions were significantly lower in the robotic cohort, whereas operative times were significantly longer. The median length of stay was 5 days in the robotic cohort vs 6 days in the open cohort; this only reached statistical significance for the ileal conduit subgroup. However, 90-day mortality, return to emergency department, readmissions, and complication rates were not significantly different. Oncologic outcomes were also similar, aside from an increase in lymph node count among the robotic cohort.

Conclusions:

In the hands of experienced surgeons, a robotic surgical approach did not confer major benefits in perioperative morbidity and mortality, although it did achieve similar oncologic efficacy, led to fewer blood transfusions, and led to a shorter length of stay in patients who underwent ileal conduits diversions.
Protective Effects of Infliximab Against Kanamycin-Induced Ototoxicity in Rats
Authors: Koçdor Pelin , Özkan Esra , Akpunar Fatmanur , Hızal Evren , Özdemir Yasemin Gürsoy
Published: June 2023

Hypothesis

To examine the protective effects of infliximab (INF) against kanamycin (KM)-induced hearing loss.

Background

Tumor necrosis factor α blockers can reduce cellular inflammatory reactions and decrease cell death.

Methods

Thirty-six rats with normal hearing were randomly divided into six groups. The first group was injected with 400 mg/kg KM intramuscularly (IM), the second group with 7 mg/kg INF intraperitoneally (IP) and 400 mg/kg KM IM, the third group with 7 mg/kg INF IP and 200 mg/kg KM IM, and the fourth group with 1 mg/kg 6-methylprednisolone (MP) IP and 400 mg/kg KM IM. Group 5 was injected with 1 mg/kg MP IP and 200 mg/kg KM IM, and group 6 with saline IP once. Auditory brain-stem response (ABR) for hearing thresholds was performed on days 7 and 14. From the frozen sections of the cochlea, the area of the stria vascularis, the number of neurons in the spiral ganglion, the fluorescence intensity of hair cells (FIHC), postsynaptic density (PSD), and presynaptic ribbons (PSRs) were calculated.

Results

The KM-induced increase in hearing thresholds was detected on the 14th day. Hearing was only preserved in the group treated with INF after low-dose KM exposure but not in the groups that received high-dose KM. The FIHC, excitatory PSD, and PSR were preserved only in the INF-treated group after half-dose KM exposure. In MP groups, FIHC, excitatory PSD, and PSR were significantly lower than in the control group.

Conclusions

Our results support that tumor necrosis factor–based inflammation may play a role in the ototoxicity mechanism.