bluuebunny/crossref_metadata_2025 huggingface dataset:
Bistability of operating modes and their switching in a three-machine power grid
Authors: Khramenkov V. A. , Dmitrichev A. S. , Nekorkin V. I.
Published: October 2023

We consider a power grid consisting of three synchronous generators supplying a common static load, in which one of the generators is located electrically much closer to the load than the others, due to a shorter transmission line with longitudinal inductance compensation. A reduced model is derived in the form of an ensemble with a star (hub) topology without parameter interdependence. We show that stable symmetric and asymmetric synchronous modes can be realized in the grid, which differ, in particular, in the ratio of currents through the second and third power supply paths. The modes of different types are not observed simultaneously, but the asymmetric modes always exist in pairs. A partition of the parameter space into regions with different dynamical regimes of the grid are obtained. Regions are highlighted where only synchronous operating modes can be established. It is shown that the grid can be highly multistable and, along with synchronous operating modes, have simultaneously various types of non-synchronous modes. We study non-local stability of the asymmetric synchronous modes and switchings between them under the influence one-time disturbances and additive noise fluctuations in the mechanical powers of the generators’ turbines. The characteristics of one-time disturbances are obtained leading to either return the grid back to the initial synchronous mode or switching the grid to another synchronous mode or some non-synchronous mode. The characteristics of noise fluctuations are obtained, which provide either a more probable finding of the grid in the desirable quasi-synchronous mode, or switching to an undesirable one.
Nonlinear gravity waves in the channel covered by broken ice
Authors: Ni Bao-Yu , Khabakhpasheva Tatyana I. , Semenov Yuriy A.
Published: October 2023

The two-dimensional nonlinear problem of a steady flow in a channel covered by broken ice with an arbitrary bottom topography including a semi-circular obstruction is considered. The mathematical model is based on the velocity potential theory accounting for nonlinear boundary conditions on the bottom of the channel and at the interface between the liquid and the layer of the broken ice, which are coupled through a numerical procedure. A mass loading model together with a viscous layer model is used to model the ice cover. The integral hodograph method is employed to derive the complex velocity potential of the flow, which contains the velocity magnitude at the interface in explicit form. The coupled problem is reduced to a system of integral equations in the unknown velocity magnitude at the interface, which is solved numerically using a collocation method. Case studies are conducted both for the subcritical and for the supercritical flow regimes in the channel. For subcritical flows, it is found that the ice cover allows for generating waves with amplitudes larger than those that may exist in the free surface case; the ice cover prevents the formation of a cusp and extends the solution to larger obstruction heights on the bottom. For supercritical flow regimes, the broken ice significantly affects the waveform of the soliton wave making it gentler. The viscosity factor of the model apparently governs the wave attenuation.
Effect of antioxidant addition on stability and emission aspects of novel biodiesel generated from the yeast Yarrowia lipolytica cultivated on dairy effluent
Authors: Manoharan Srirajarajeshwari , Jeyadharmarajan Jeyanthi
Published: October 2023

The continuous utilization of fossil fuel reserves and augmented pollution level leads to inevitable transition toward renewable fuel in transportation sector. Biodiesel is one of the most renowned biofuels across the energy sector in recent decade. Even though biodiesel has many advantages, the stability is a key concern on downside of biodiesel. The presence of oxygenated compounds in biodiesel leads to faster rancidation during prolonged storage period. This research focuses on producing biodiesel from diary waste and assesses the influence of synthetic antioxidant on its stability. The addition of antioxidant showed a significant increase in the induction period (IP) of biodiesel. Tert-butyl hydroquinone (TBHQ) showed superior Induction Period (IP) of 15.28 h at 110 °C, which is due to its radical suppression behavior during ageing. The thermal ageing results also confirmed the potential of the TBHQ blend with the least ageing rate of 0.08 cSt/h. The biodiesel samples showed signs of dehydration and polymerization after ageing, which is detected by FTIR spectra. Finally, the engine testing showed that antioxidant reduces dangerous NOx emission with minor sacrifice toward performance aspects. From the results, it can be seen that the biodiesel from yeast grown dairy wastewater can be a suitable competitor in the alternate fuel market.
Development of deflector mode for spin-resolved time-of-flight photoemission spectroscopy
Authors: Han Xue , Qu Jason , Sakamoto Shoya , Liu Dongyu , Guan Dandan , Liu Jin , Li Hui , Rotundu Costel R. , Andresen Nord , Jozwiak Chris , Hussain Zahid , Shen Zhi-Xun , Sobota Jonathan A.
Published: October 2023

Spin- and angle-resolved photoemission spectroscopy (“spin-ARPES”) is a powerful technique for probing the spin degree-of-freedom in materials with nontrivial topology, magnetism, and strong correlations. Spin-ARPES faces severe experimental challenges compared to conventional ARPES attributed to the dramatically lower efficiency of its detection mechanism, making it crucial for instrumentation developments that improve the overall performance of the technique. In this paper, we demonstrate the functionality of our spin-ARPES setup based on time-of-flight spectroscopy and introduce our recent development of an electrostatic deflector mode to map out spin-resolved band structures without sample rotation. We demonstrate the functionality by presenting the spin-resolved spectra of the topological insulator Bi2Te3 and describe in detail the spectrum calibrations based on numerical simulations. By implementing the deflector mode, we minimize the need for sample rotation during measurements, hence improving the overall efficiency of experiments on small or inhomogeneous samples.
Effect of stenotic shapes and arterial wall elasticity on the hemodynamics
Authors: Pabi Souvik , Khan Mohd. Kaleem , Jain Sachin Kumar , Sen Ashis Kumar , Raj Abhishek
Published: October 2023

The present study employs an arbitrary Lagrangian–Eulerian fluid–structure interaction approach to investigate pulsatile blood flow through a deformable stenosed channel. The flow is modeled by solving the incompressible continuity and momentum equations using finite element-based commercial solver COMSOL Multiphysics®. In this work, we explore the effects of different stenotic shapes—elliptical, round, and sinusoidal, degrees of stenosis (30%, 50%, and 70%), and arterial wall stiffnesses—0.5, 1.5, and 2.5 MPa on the velocity profile, pressure and wall shear stress distribution, and wall deformation. The oscillatory shear index (OSI) is analyzed to predict further plaque formation in the stenosed artery. We find that the flow velocity, wall shear stress, and pressure difference across the stenosed region increase with an increase in the stenotic severity and artery stiffness. The velocity profiles intersect at a radial location in the stenotic region termed critical radius, where relative magnitudes get reversed. With the increase in stenotic severity, the wall displacement decreases at the throat and increases at the upstream side. With the increase in wall stiffness, the wall deformation decreases, and shear stress increases, thereby increasing the pressure drop across the stenosed region. At a lower mass flow rate and a higher degree of stenosis, the vortices are formed upstream and downstream of the stenosed region for all stenotic shapes. The vorticity magnitude is found to be more than 21% higher for sinusoidal stenotic shape than round and elliptical ones. The effect of stenotic profile on the pressure drop characteristics shows that blood experiences maximum wall shear stress for the sinusoidal stenotic geometry, whereas the pressure drop is the maximum for the elliptical stenotic shape. The elliptical stenotic shape is more prone to further plaque formation than round and sinusoidal stenotic shapes. At lower Womersley number (Wo=2.76) corresponding to 60 beats per min heart beat rate, secondary vortices are formed downstream of the channel, causing higher OSI.
Rimming flow in a rotating horizontal cylinder with phase change at the interface
Authors: Kumawat Tara Chand , Tiwari Naveen
Published: October 2023

The two-dimensional solutions and stability analysis are presented for an evaporating thin viscous liquid film flowing inside a uniformly heated rotating horizontal cylinder. A non-linear, fourth-order, partial differential evolution equation is obtained by simplifying mass, momentum, and energy conservation equations within the lubrication approximation. The effect of evaporation, gravity, viscous drag, surface tension, thermocapillary stress, and intermolecular forces has been taken into account. The numerical solutions of the model are validated against the existing experimental as well as the numerical results, along with the analytical result for the limiting cases of the present model. The film thickness model is solved to elucidate two-dimensional spatiotemporal solutions and their stability for a wide range of thermal and other parameters. The evaporative mass flux at the liquid–air interface results in unsteady solutions which are oscillatory in nature, and the amplitude of the oscillations increases with an increase in the evaporative flux. The film ruptures after some time and the rupture time is found to be inversely proportional to the evaporation number, a non-dimensional number quantifying the rate of evaporation. The linear stability analysis shows that the thermocapillary stresses as well as the long-range molecular forces destabilize the film. A negative disjoining pressure is shown to reduce the rupture time and vice versa. Evaporation (condensation) plays a destabilizing (stabilizing) role in the thin film flow. Non-linear computations are carried out for the steady profiles, validating the growth rates obtained from the linear stability analysis.
A long short-term memory neural network-based error estimator for three-dimensional dynamically adaptive mesh generation
Authors: Wu X. , Gan P. , Li J. , Fang F. , Zou X. , Pain C. C. , Tang X. , Xin J. , Wang Z. , Zhu J.
Published: October 2023

Adaptive meshes are pivotal in numerical modeling and simulation, offering a means to efficiently, precisely, and flexibly represent intricate physical phenomena, particularly when grappling with their intricacies and varying scales. However, the transition from two dimensions (2D) to three dimensions (3D) poses a substantial challenge, as the computational demands of dynamically adaptive mesh techniques increase exponentially. Addressing this challenge effectively, we turn to the cutting-edge realm of artificial intelligence and neural networks. In our study, we harness the innovative power of a long short-term memory (LSTM) neural network as an error estimator for adapting unstructured meshes in both 2D and 3D scenarios. This LSTM network predicts the evolution of the adaptive grid based on specified variables, presenting itself as an artificial intelligence-driven architecture to optimize the adaptive criterion for the target variable. This is achieved by establishing a direct correspondence between the Riemann metric and these variables. To demonstrate the practical applicability of our approach, we seamlessly integrate the LSTM error estimator into the 3D adaptive atmospheric model Fluidity-Atmosphere (Fluidity-Atmos), thereby enabling real-time mesh adaptation during numerical simulations. We assess the effectiveness of this method in terms of simulation precision and computational efficiency through a series of experiments in both 2D and 3D settings. Our results not only reveal that the mesh patterns generated by the LSTM error estimator within Fluidity-Atmos closely resemble those produced by traditional error estimators but also underscore its superior performance in enhancing simulation accuracy. Notably, as the number of nodes increases, the LSTM mesh generator substantially reduces CPU time requirements by up to 50% in 3D cases compared to the conventional mesh generator within Fluidity-Atmos, highlighting its remarkable computational efficiency.
A linear chirp fiber Bragg grating with tunable bandwidth enabled by MXene's photothermal effect
Authors: Li Xiaokang , Chong Yizhuo , Wang Jianguo , Xue Ting , Yan Jiahui , Feng Dingyi , Jiang Yajun , Zou Jie , Du Bobo , Yang Dexing
Published: October 2023

An efficient method for tunable spectra of the fiber Bragg grating (FBG) using a gradient temperature field is proposed theoretically and experimentally. The temperature field modulation in the core region of the FBG is achieved by utilizing the photothermal conversion properties of MXene Ti3C2Tx, which guarantees a flexible adjustment of temperature gradients in the FBG axis. The spectra of FBG under different gradients of temperature fields are simulated by the transfer matrix method. The simulation results show that the gradient temperature distribution in the FBG axis can induce spectral chirps of FBG. The increase in the bandwidth of the spectrum and the decrease in the reflection intensity are caused by the rise of the temperature gradient. In the experiments, Ti3C2Tx films are coated onto the sidewall of FBG, and the non-uniform temperature gradient field in the FBG axis is formed and tuned by varying the intensity and spatial distribution of the pump laser on the Ti3C2Tx film. The spectral bandwidth measured at 10 dB can be broadened by 4.6 times from 0.57 to 2.63 nm with excellent linear tunability as a function of the pump power. This method provides an effective scheme for the spectral tuning of linear chirp FBGs in all-optical control.
Using a multilingual parallel corpus for Journalistic Translation Research
Authors: Li Biwei
Published: October 2023

By introducing the New York Times Multilingual Parallel Corpus (NYTMPC), this contribution illustrates how multilingual parallel corpora can be designed, constructed, and used for Journalistic Translation Research (JTR). Also, by drawing on a theoretical framework interconnecting imagology and journalistic translation, I conduct a pilot study to demonstrate the exploitation of the NYTMPC for studying national image construction in news translation. The results indicate that stereotyped images of China in English news are reconstructed differently in their Chinese and Spanish translations, and the translational factors that underlie this process are uncovered more clearly with the aid of multilingual parallel corpora.
Host factor TIMP1 sustains long-lasting myeloid-biased hematopoiesis after severe infection
Authors: Song Tengfei , Yao Yonghong , Papoin Julien , Sherry Barbara , Diamond Betty , Gu Hua , Blanc Lionel , Zou Yong-Rui
Published: October 2023

Infection is able to promote innate immunity by enhancing a long-term myeloid output even after the inciting infectious agent has been cleared. However, the mechanisms underlying such a regulation are not fully understood. Using a mouse polymicrobial peritonitis (sepsis) model, we show that severe infection leads to increased, sustained myelopoiesis after the infection is resolved. In post-infection mice, the tissue inhibitor of metalloproteinases 1 (TIMP1) is constitutively upregulated. TIMP1 antagonizes the function of ADAM10, an essential cleavage enzyme for the activation of the Notch signaling pathway, which suppresses myelopoiesis. While TIMP1 is dispensable for myelopoiesis under the steady state, increased TIMP1 enhances myelopoiesis after infection. Thus, our data establish TIMP1 as a molecular reporter of past infection in the host, sustaining hyper myelopoiesis and serving as a potential therapeutic target for modulating HSPC cell fate.
Black-bounces with multiple throats and anti-throats
Authors: Rodrigues Manuel E , Silva Marcos V de S
Published: October 2023

In this article, we test the possibility of building new black-bounce spacetimes with changes in the area in the context of general relativity in four dimensions. These new metrics can present extra structures, such as anti-throats. We see two regions where the area goes to infinity, and, depending on the model, one of these regions presents curvature singularities. Regular metrics can be extended to negative values of the radial coordinate and have a symmetrical structure, whereas some singular cases cannot be extended and have no symmetrical structure. The energy conditions are analyzed, and, for some cases, at least one of the inequalities in the null energy condition is not respected. We also presented models that satisfied the null energy condition outside the event horizon. The event horizon hides the throats of these models.
In horizon penetrating coordinates: Kerr black hole metric perturbation, construction and completion
Authors: Aly Fawzi , Stojkovic Dejan
Published: October 2023

We investigate the Teukolsky equation in horizon-penetrating coordinates to study the behavior of perturbation waves crossing the outer horizon. For this purpose, we use the null ingoing/outgoing Eddington–Finkelstein coordinates. The first derivative of the radial equation is a Fuchsian differential equation with an additional regular singularity to the ones the radial one has. The radial functions satisfy the physical boundary conditions without imposing any regularity conditions. We also observe that the Hertz-Weyl scalar equations preserve their angular and radial signatures in these coordinates. Using the angular equation, we construct the metric perturbation for a circularly orbiting perturber around a black hole in Kerr spacetime in a horizon-penetrating setting. Furthermore, we completed the missing metric pieces due to the mass M and angular momentum J perturbations. We also provide an explicit formula for the metric perturbation as a function of the radial part, its derivative, and the angular part of the solution to the Teukolsky equation. Finally, we discuss the importance of the extra singularity in the radial derivative for the convergence of the metric expansion.
Local momentum space: scalar field and gravity
Authors: Panda Sukanta , Tinwala Abbas , Vidyarthi Archit
Published: October 2023

We use the local momentum space technique to obtain an expansion of the Feynman propagators for scalar field and graviton up to first order in the background curvature. The expressions for the propagators are cross-checked with the past literature as well as with the expressions for the traced heat kernel coefficients. The propagators so obtained are used to compute one-loop divergences in the Vilkovisky-Dewitt’s (VD’s) effective action for a scalar field non-minimally coupled with gravity for an arbitrary spacetime metric background. The VD effective action is then compared with the standard effective action in the limit κ = 0, where

κ
=
2

/

M
P

in terms of the Planck mass. The comparison yields the important result that taking the limit κ = 0 after computing the VD effective action is not equivalent to computing the VD effective action for the same theory in the absence of gravity.
Plasmon-induced hot-electron injection effect: mechanism of performance enhancement for ZnO MSM hybrid photodetector by introducing Ag NWs and MXene
Authors: Chu Lingling , Xu Chao , Liu Duanwangde , Nie Chao , Deng Liting
Published: October 2023

In this paper, a performance-enhanced hybrid ultraviolet metal–semiconductor–metal photodetector (UVPD) has been produced. This device incorporates a mixed photosensitive layer consisting of MXene nanoflakes that are covered on a thin film formed by Ag nanowires (NWs) wrapped in ZnO nanoparticles. This configuration, referred to as ZnO@Ag NWs/Mxene, capitalizes on the hot electrons generated by the localized surface plasmon resonance phenomenon occurring in the Ag NWs and MXene. These hot electrons possess sufficient energy to traverse the interface depletion layer and reach the ZnO layer. Therefore, the injected hot electrons serve as additional photo carriers in the ZnO layer, thereby increasing the number of photo-generated carriers and improving the carrier concentration in ZnO. The improved UVPD device exhibits an amplified photocurrent of ∼2499.35 nA at 5 V, under a light intensity of 6.52 mW cm−2 and a wavelength of 365 nm. Simultaneously, it achieves enhanced performance indices, including an On/Off ratio of ∼984.19, a responsivity (R
p) of ∼66.87 mA W−1, and a detectivity (D
*) of ∼1.82 × 1011 jones. These values represent a significant improvement compared to devices based solely on the ZnO configuration, with enhancements of ∼24.90, 3.93, 23.38, and 9.33 times, respectively. Based on the obtained results, it can be inferred that employing the hot electron injection effect to design and enhance the performance of optoelectronic devices based on wide band gap semiconductors is a reasonable and effective strategy.
Resistive switching modulation by incorporating thermally enhanced layer in HfO2-based memristor
Authors: Li Xing , Feng Zhe , Zou Jianxun , Wu Zuheng , Xu Zuyu , Yang Fei , Zhu Yunlai , Dai Yuehua
Published: October 2023

Oxide-based memristors by incorporating thermally enhanced layer (TEL) have showed great potential in electronic devices for high-efficient and high-density neuromorphic computing owing to the improvement of multilevel resistive switching. However, research on the mechanism of resistive switching regulation is still lacking. In this work, based on the method of finite element numerical simulation analysis, a bilayer oxide-based memristor Pt/HfO2 (5 nm)/Ta2O5 (5 nm)/Pt with the Ta2O5 TEL was proposed. The oxygen vacancy concentrates distribution shows that the fracture of conductive filaments (CF) is at the interface where the local temperature is the highest during the reset process. The multilevel resistive switching properties were also obtained by applying different stop voltages. The fracture gap of CF can be enlarged with the increase of the stopping voltage, which is attributed to the heat-gathering ability of the TEL. Moreover, it was found that the fracture position of oxygen CF is dependent on the thickness of TEL, which exhibits a modulation of device RS performance. These results provide a theoretical guidance on the suitability of memristor devices for use in high-density memory and brain-actuated computer systems.
Transition in radio frequency gas breakdown with a transverse magnetic field
Authors: Yang Dong , Wang Huihui , Zheng Bocong , Liu Zhigang , Fu Yangyang
Published: October 2023

This paper presents the quantification of gas breakdown voltages in low-pressure argon capacitive radio frequency (rf) discharges in the presence of an external transverse magnetic field via fully kinetic particle-in-cell/Monte Carlo collision simulations. It is found that as the magnetic field increases, the left branch of the breakdown curve, a double-valued rf breakdown voltage regime, shifts toward a lower-pressure region. A split of the breakdown curve into lower and upper branches occurs when the external magnetic field rises to a critical value. The observed abrupt transition of rf breakdown behaviors can be understood based on the electron kinetics behaviors, with the consideration of the enhanced ionization and electron confinement induced by

E

×

B

drift motions. An improved analytical model is developed, which can estimate the critical magnetic field required for the occurrence of the transition.
Performance test of REBCO CICC sub-cables with 10 kA current under 20 T background field
Authors: Jin Huan , Zhou Chao , Fang Zhen , Xiao Guanyu , Wu Yongsheng , Chen Wenge , Ma Hongjun , Liu Fang , Liu Huajun , Kanazawa Shintetsu , Ma Tao , Tan Yunfei , Wu Zuojiafeng , Qin Jinggang
Published: October 2023

While commercially manufactured rare earth barium copper oxide (REBCO) tapes show significant promise in facilitating the operation of fusion magnets with magnetic fields above 15 T, the design and development of highly stable cable in conduit conductor (CICC) technology is very important to achieve their practical application. To find a good solution for this demand, the Institute of Plasma Physics, Chinese Academy of Sciences, proposed two kinds of CICC design concepts, which are both manufactured from a sub-cable formed by winding REBCO tape around a stainless steel spiral tube. As part of the ongoing activities to develop an REBCO CICC, two sections of sub-cable specimens were manufactured and bent into a U-shape for testing under magnetic fields up to 20 T. A sub-cable specimen with 30 commercial 4 mm wide REBCO tapes displayed around 10 kA at 4.2 K and a background magnetic field of up to 20 T. It also showed stable operation under an electromagnetic (EM) load of around 200 kN m−1, which is above the 150 kN m−1 required by the designed CICC sub-cable. However, the calculated I
c of the other specimen degraded from 8.8 kA to 8.5 kA when cycling with an EM load of around 160 kN m−1. The lower calculated n-value at 77 K and self-field as well as the observed imprints on the disassembled tape edges suggested that defects were generated in the cable during cabling, bending to the sample holder or operation with high EM and thermal loads. These results exhibit the potential and feasibility of using high flexible REBCO cable (HFRC) sub-cables for high-field fusion magnets. However, the winding parameters need to be optimized to ensure safe operation in more complex conditions, such as in tokamaks, especially if using tapes similar to those used in sample-B in this study. Moreover, it is imperative to establish much more rigorous requirements for coil manufacturing processes in order to avoid the occurrence of defects in the tapes.
Unraveling quench dynamics and real-time continuous detection in HTS tapes through distributed fiber optic sensing
Authors: Yang Taolue , Wang Xingzhe
Published: October 2023

High-temperature superconducting (HTS) tapes, coils, and magnets often experiences intricate quench instabilities and failures during high current-carrying operations, posing challenges to their practical applications. This study addresses the need for a measurement approach capable of monitoring multi-field signals in superconducting structures within cryogenic and extreme electromagnetic environments. We explore the application of distributed fiber optic sensing (DFOS) technology, specifically employing the optical frequency domain reflectometry scheme, which offers distinct advantages over traditional point-type electrical testing methods, particularly for superconducting materials and magnets. In this experimental study, we continuously track the quench evolution process in superconducting tapes using both bonded and stress-free fibers for real-time monitoring. A comprehensive analysis of the acquired temperature and thermoelastic strain profiles provides essential insights into the dynamic behavior of quench events. The findings demonstrate the effectiveness of DFOS in identifying and characterizing the onset and propagation of quenches. By arranging bonded and stress-free fibers in parallel on the HTS tape’s surface, we successfully decouple the effects of strain-temperature cross-sensitivity, enabling the extraction of temperature and train profiles. The bonded fiber optic sensor demonstrates rapid sensitivity to the thermally quenched events. Temporal derivatives of voltage and thermal strain exhibit characteristic plateaus and slope changes during quenches, respectively. The voltage rate displays two plateaus corresponding to superconducting-to-normal transitions, while strain rates exhibit potential as criteria for identifying quench events in HTS materials. Moreover, DFOS outperforms traditional terminal average voltage measurement, capturing quench evolution tails from the initial point of quench until the complete transition of the segment into the normal state. This experiment provides a solid foundation for further exploration of the underlying quench mechanism.
Success-rate-driven strategy updating enhances cooperation in social dilemmas
Authors: Lu Shounan , Dai Jianhua
Published: October 2023

Strategy updates play an important role in the evolution of cooperation. In traditional imitation rules, it is assumed that strategic learning is driven by payoff bias. In this study, a modified Fermi rule was proposed, in which payoff and success-rate are synthetically considered to determine players’ strategy updates. It is assumed that individuals have an immediate memory length M, and that success can be measured by using an identical aspiration level a as a benchmark. Success-rate is defined in the frequency that an individual’s payoff equals or exceeds the benchmark a within the memory length M. Numerical simulations conducted by considering the two factors in the strategy update show that cooperation can be facilitated compared to the traditional version. Using the identical aspiration level a as benchmark, the results show that there is a clear phase shift phenomenon in enhancing cooperation. This implies that different b will have an appropriate aspiration interval to achieve optimal cooperation. Moreover, only a moderate immediate memory length can facilitate cooperation. The proposed mechanism is highly robust and can provide valuable insights into the emergence and maintenance of cooperation.
Quantum steering in two-forked tree-shaped networks
Authors: Yang Shuyuan , He Kan , Qi Xiaofei , Hou Jinchuan
Published: October 2023

Network quantum steering (NQS) arises from network models required with classification of trusted and untrusted parties. The network local hidden state (NLHS) models have first been proposed to define the NQS in a linear network with end points being trusted. In the paper, we devote to establishing the NLHS model to define the NQS in a kind of more complex and applied-extensively networks, namely, the two-forked tree-shaped network. Here we assume that the parties at the last layer are trusted while the remaining parties are untrusted in this network. According to the NLHS model, we observe that network nonlocality implies network steerability. Furthermore, we pay more attentions to discovering the relationship between the network quantum unsteerability and separability/unsteerability of bipartite sources in this two-forked tree-shaped network. Moreover, we generalize two kinds of bipartite steering inequality criteria as the NQS criteria. They are built based on statistical quantities, which can be directly evaluated in experiments.
A new highly fractal 1D- chaotic map-based novel encryption on HVS-based watermarked Fundus images for 2-level security in teleophthalmology applications
Authors: Amrutha M , Kannammal A
Published: October 2023

In recent years the combination of medical image watermarking and encryption is becoming popular due to a better trade-off between authenticity and security, since, each of these methods alone is insufficient to offer complete security. In the proposed work, the watermark is embedded into the Fundus image using the Singular Value Decomposition (SVD) of the La*b* space image of the Fundus image. The scaling factor is selected based on the HVS property of the human eye. The proposed embedding algorithm is semi-blind because the system requires the singular values (s) of the La*b* image at the receiver side in order to extract the watermark. To improve security, the authenticated image then undergoes 2-levels of confusion process followed by diffusion for encryption. For diffusion, the key is generated from the newly developed Modified Sine-Logistic Chaotic System (MSLCS), which is constructed by the combination of logistic map and sine map. The performance evaluation of the new chaotic system has been done in terms of the Bifurcation diagram, Lyapunov exponent, Phase portrait and Entropy. Also, Different tests such as Blood vessel segmentation and Retinal object identification were carried out on the original image, watermarked image, decrypted image and recovered image. The results show that the embedding of watermarks followed by encryption, on Fundus images does not affect the diagnosis and identification of retinal objects. Correct decryption, secured recovery of Fundus image and guaranteed extraction of the watermark at the receiver side make the proposed system secure for Fundus images in tele-ophthalmology applications.
Study of quantum well mixing induced by impurity-free vacancy in the primary epitaxial wafers of a 915 nm semiconductor laser
Authors: He Tianjiang , Liu Suping , Li Wei , Zhong Li , Ma Xiaoyu , Xiong Cong , Lin Nan , Wang Zhennuo
Published: October 2023

Output power and reliability are the most important characteristic parameters of semiconductor lasers. However, catastrophic optical damage (COD), which usually occurs on the cavity surface, will seriously damage the further improvement of the output power and affect the reliability. To improve the anti-optical disaster ability of the cavity surface, a non-absorption window (NAW) is adopted for the 915 nm InGaAsP/GaAsP single-quantum well semiconductor laser using quantum well mixing (QWI) induced by impurity-free vacancy. Both the principle and the process of point defect diffusion are described in detail in this paper. We also studied the effects of annealing temperature, annealing time, and the thickness of SiO2 film on the quantum well mixing in a semiconductor laser with a primary epitaxial structure, which is distinct from the previous structures. We found that when compared with the complete epitaxial structure, the blue shift of the semiconductor laser with the primary epitaxial structure is larger under the same conditions. To obtain the appropriate blue shift window, the primary epitaxial structure can use a lower annealing temperature and shorter annealing time. In addition, the process is less expensive. We also provide references for upcoming device fabrication.
Commissioning the digital mass-filter/ion-trap module for the MS SPIDOC prototype
Authors: Simke Florian , Fischer Paul , Damjanović Tomislav , Kádek Alan , Kierspel Thomas , Lorenzen Kristina , Uetrecht Charlotte , Schweikhard Lutz
Published: October 2023

The combination of a linear quadrupole ion-filter and linear Paul trap operated with a
rectangular guiding field for the filtering and accumulation of ions within the Mass
 Spectrometry for Single Particle Imaging of Dipole
 Oriented protein Complexes (MS SPIDOC) prototype [T. Kierspel et al.,
 Anal. Bioanal. Chem., published online] is characterized. Using cationic caesium-iodide
clusters, the ion-separation performance, ion accumulation, cooling, and ejection via in-trap pin
electrodes is evaluated. Furthermore, proof-of-principle measurements are performed with
64 kDa multiply-charged non-covalent protein complexes of human hemoglobin and
804 kDa non-covalent complex of GroEL, to demonstrate that the module meets the
criteria to handle high-mass ions which are the main objective of the MS SPIDOC project. The
setup's performance is found to be in line with previous results from ion-trajectory
simulations [F. Simke et al., Int. J. Mass Spectrom.
473 (2022) 116779].
Design of a mobile neutron spectrometer for the Laboratori Nazionali del Gran Sasso (LNGS)
Authors: Solmaz M. , Balzer M. , Eitel K. , Ferella A. , Oberlack U. , Pirling U. , Pompa F. , Tcherniakhovski D. , Valerius K. , Wüstling S.
Published: October 2023

Environmental neutrons are a source of background for rare event searches (e.g., dark
matter direct detection and neutrinoless double beta decay experiments) taking place in deep
underground laboratories. The overwhelming majority of these neutrons are produced in the cavern
walls by means of intrinsic radioactivity of the rock and concrete. Their flux and spectrum
depend on time and location. Precise knowledge of this background is necessary to devise
sufficient shielding and veto mechanisms, improving the sensitivity of the neutron-susceptible
underground experiments. In this report, we present the design and the expected performance of a
mobile neutron detector for the LNGS underground laboratory. The detector is based on
capture-gated spectroscopy technique and comprises essentially a stack of plastic scintillator
bars wrapped with gadolinium foils. The extensive simulation studies demonstrate that the detector
will be capable of measuring ambient neutrons at low flux levels
(∼10-6 n/cm2/s) at LNGS, where the ambient gamma flux is by about 5 orders of
magnitude larger.
An HA/PEEK scaffold with modified crystallinity via 3D-bioprinting for multiple applications in hard tissue engineering
Authors: Chen Jiahao , Xiao Jingyi , Han Xue , Sima Xiutian , Guo Weihua
Published: October 2023

Hard tissues, especially teeth and bones, are highly mineralized and the large-scale defect or total loss of them is irreversible. There is still no ideal strategy for the reconstruction of various hard tissue defects that can achieve the balance between biological and mechanical properties. Polyether ether ketone (PEEK) has the potential to substitute for natural hard tissue in defect areas but is limited by its biological inertness. The addition of hydroxyapatite (HA) can significantly improve the osteogenic properties and osteointegration of PEEK materials. But the mechanical properties of HA/PEEK scaffolds are far from satisfaction making scaffolds easy to fracture. We put forward a strategy to balance the mechanical and biological properties of HA/PEEK scaffolds via the regulation of the inner crystallinity and HA mixing ratio and we systematically evaluated the modified HA/PEEK scaffolds through material characterization, in vitro and in vivo experiments. And we found that the 20%HA/PEEK scaffolds with low crystallinity achieved the required strength and elasticity, and exhibited the characteristics of promoting the proliferation, migration and osteogenic differentiation of bone marrow mesenchymal stem cells. The results of the implantation of beagles’ teeth, mandible and rib showed that the 20%HA/PEEK scaffold with low crystallinity could well withstand the local complex force in the defect area and combine well with natural bone tissue, which made it a candidate for a practical versatile hard tissue engineering scaffold.
Cell sheet-based in vitro bone defect model for long term evaluation of bone repair materials
Authors: Gao Jing , Li Yuqi , Wu Tingting , Zhou Xinting , Feng Jie , Cai Yixuan , Guan Shuwen , Dai Zhengning , Han Jianmin , Gao Botao
Published: October 2023

Development of tissue-engineered in vitro human bone defect models for evaluation of bone repair materials (BRMs) is a promising approach for addressing both translational and ethical concerns regarding animal models. In this study, human bone marrow mesenchymal stem cell sheets were stacked to form a periosteum like tissue. HE staining showed a cell-dense, multilayered structure. BRMs were implanted in the defect area of the three-dimensional (3D) model. The CCK-8 test demonstrated that the 3D model was stronger in resisting the cytotoxicity of three kinds of commercial BRMs than the 2D culture model, which was consistent with in vivo results. After 28 d implantation in the 3D model, western blot and RT-qPCR showed that three materials induced increased expressions of RUNX2, OSX, OCN, OPN, while Materials B and C seemed to have stronger osteoinductivity than A. In vivo experiments also confirmed the osteoinductivity of the BRMs after 28 and 182 d implantation. Alizarin red staining proved that the mineralized nodules of Materials B and C were more than that of A. The differences of osteogenic properties among three BMRs might be attributed to calcium ion release. This cell sheet-based bone tissue model can resist cytotoxicity of BRMs, demonstrating the priority of long-term evaluation of osteoinductivity of BRMs. Further, the osteoinduction results of the 3D model corresponded to that of in vivo experiments, suggesting this model may have a potential to be used as a novel tool for rapid, accurate evaluation of BRMs, and thus shorten their research and development process.
Noncommutative geometry and deformation quantization in the quantum Hall fluids with inhomogeneous magnetic fields
Authors: Palumbo Giandomenico
Published: October 2023

It is well known that noncommutative geometry naturally emerges in the quantum Hall states due to the presence of strong and constant magnetic fields. Here, we discuss the underlying noncommutative geometry of quantum Hall fluids in which the magnetic fields are spatially inhomogenoeus. We analyze these cases by employing symplectic geometry and Fedosov’s deformation quantization, which rely on symplectic connections and Fedosov’s star-product. Through this formalism, we unveil some new features concerning the static limit of the Haldane’s unimodular metric and the Girvin–MacDonald–Platzman algebra of the density operators, which plays a central role in the fractional quantum Hall effect.
Revisiting weak values through non-normality
Authors: Ballesteros Ferraz Lorena , Muolo Riccardo , Caudano Yves , Carletti Timoteo
Published: October 2023

Quantum measurement is one of the most fascinating and discussed phenomena in quantum physics, due to the impact on the system of the measurement action and the resulting interpretation issues. Scholars proposed weak measurements to amplify measured signals by exploiting a quantity called a weak value, but also to overcome philosophical difficulties related to the system perturbation induced by the measurement process. The method finds many applications and raises many philosophical questions as well, especially about the proper interpretation of the observations. In this paper, we show that any weak value can be expressed as the expectation value of a suitable non-normal operator. We propose a preliminary explanation of their anomalous and amplification behavior based on the theory of non-normal matrices and their link with non-normality: the weak value is different from an eigenvalue when the operator involved in the expectation value is non-normal. Our study paves the way for a deeper understanding of the measurement phenomenon, helps the design of experiments, and it is a call for collaboration to researchers in both fields to unravel new quantum phenomena induced by non-normality.
Hankel determinants for a Gaussian weight with Fisher–Hartwig singularities and generalized Painlevé IV equation
Authors: Mu Xinyu , Lyu Shulin
Published: October 2023

We study the Hankel determinant generated by a Gaussian weight with Fisher–Hartwig singularities of root type at tj
,

j
=
1
,
⋯
,
N

. It characterizes a type of average characteristic polynomial of matrices from Gaussian unitary ensembles. We derive the ladder operators satisfied by the associated monic orthogonal polynomials and three compatibility conditions. By using them and introducing 2N auxiliary quantities

{

R

n
,
j

,

r

n
,
j

,
j
=
1
,
⋯
,
N
}

, we build a series of difference equations. Furthermore, we prove that

{

R

n
,
j

,

r

n
,
j

}

satisfy Riccati equations. From them we deduce a system of second order PDEs satisfied by

{

R

n
,
j

,
j
=
1
,
⋯
,
N
}

, which reduces to a Painlevé IV equation for N = 1. We also show that the logarithmic derivative of the Hankel determinant satisfies the generalized σ-form of a Painlevé IV equation.
Green synthesis of recyclable reduced graphene oxide-gold nanocatalyst using Alstonia scholaris: Applications in waste water purification and microbial field
Authors: Das Piu , Bairy Bapan , Ghosh Sanjukta , Ghosh Raktim , Dam Somasri , Ghorai Avijit , Baskey Sen Moni
Published: October 2023

The green synthetic approaches are the alternative methods for the preparation of various types of nanoparticles to keep sustainable evolution. A novel green synthesis of gold- reduced graphene oxide nanocomposites was conducted through simple heating method using Alstonia scholaris (A. scholaris) bark extract. There are several techniques that confirm the formation of the nanocomposites for synthesis of gold nanoparticles on reduced graphene oxide (RGO), such as X-ray diffraction (XRD), UV–visible spectroscopy (UV–vis) and Fourier transformed infrared spectroscopy (FT-IR). The size distributions of the gold nanoparticles (Au NPs) grown on RGO surface was measured using two different methods: particle distribution study and transmission electron microscopy (TEM) image. These two methods provided similar size distribution which is around 5–8 nm. Subsequently, the catalytic performance was evaluated by 4-nitro aniline (4-NA). The photocatalytic activities were investigated using different organic hazardous dyes, such as methylene blue (MB), methyl orange (MO) and the change of photocatalytic behaviour was shown by varying the catalyst amount and pH. The chemical oxygen demand (COD) analyses for complete removal of organic dye were carried out using the two nanocomposite samples. To perceive the effect on different bacterial strains, antibacterial and antiprotozoal studies have been carried out with this nanocomposite.
Characterization and medicinal applications of Karakoram shilajit; angiogenesis activity, antibacterial properties and cytotoxicity
Authors: Yaqoob Zahida , Batool Syeda Ammara , Khan Ahmad , Hussain Rabia , Raza Mohsin Ali , Alqahtani Mohammed S , Abbas Mohamed , Almubarak Hassan Ali , Alqahtani Fawaz F , Ur Rehman Muhammad Atiq
Published: October 2023

Shilajit is a natural substance found in the Himalayan region from Nepal to Pakistan. It is a decomposition product of Royle’s spurge, white clover, and different species of molds. The decomposition takes place over a time span of centuries by the action of microorganism. In the present study, shilajit samples from four different origins including siachen khaplu shilajit (SKS), kharmang pari saspolo shilajit (KPSS), kharmang ghandus shilajit (KGS), and kharmang shilajit center (KSC) of district Skardu, Pakistan were investigated. These samples were characterized using scanning electron microscopy (SEM), Energy-dispersive x-ray spectroscopy (EDS), x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and UV-visible spectroscopy (UV/vis). SEM revealed a notable difference in the shape and size of collected samples. All samples were found to possess crystalline nature, which is confirmed from XRD. The presence of multi-components and complex silicates confirmed the presence of humic substances (HS) in shilajit. A slight disparity in physiological properties of four samples were revealed due to geographical variations and ecological conditions, which determine the natural synthesis of shilajit. All samples exhibited antibacterial effects against Gram negative bacteria; Escherichia coli (E.coli). About 76%, 98%, and 100% of bacteria were killed by SKS, both KPSS and KGS, and KSC samples, respectively. The cell viability analysis revealed that the KPSS (66%) and KGS (53%) were cyto-compatible as compared to the SKS (23%) and KSC (25%) samples. The Chick Chorionic Allantoic Membrane (CAM) assay was used to observe the angiogenic potential for SKS, KSC, and KGS samples. Hence, shilajit sample could be a potential candidate for the medicinal applications and offer a new approach to biomedical applications.