bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on temperature distribution characteristics of oil‐immersed power transformers based on fluid network decoupling
Authors: Xu Yongming , Xu Ziyi , Ren Congrui , Wang Yaodong
Published: September 2024

Due to the complex structure and large size of large‐capacity oil‐immersed power transformers, it is difficult to predict the winding temperature distribution directly by numerical analysis. A 180 MVA, 220 kV oil‐immersed self‐cooling power transformer is used as the research object. The authors decouple the internal fluid domain of the power transformer into four regions: high voltage windings, medium voltage windings, low voltage windings, and radiators through fluid networks and establish the 3D fluid‐temperature field numerical analysis model of the four regions, respectively. The results of the fluid network model are used as the inlet boundary conditions for the 3D fluid‐temperature numerical analysis model. In turn, the fluid resistance of the fluid network model is corrected according to the results of the 3D fluid‐temperature field numerical analysis model. The prediction of the temperature distribution of windings is realised by the coupling calculation between the fluid network model and the 3D fluid‐temperature field numerical analysis model. Based on this, the effect of the loading method of the heat source is also investigated using the proposed method. The hotspot temperatures of the high‐voltage, medium‐voltage, and low‐voltage windings are 89.43, 86.33, and 80.96°C, respectively. Finally, an experimental platform is built to verify the results. The maximum relative error between calculated and measured values is 4.42%, which meets the engineering accuracy requirement.
Design and analysis of parallel quantum transfer fractal priority replay with dynamic memory algorithm in quantum reinforcement learning for robotics
Authors: Palanivel R. , Muthulakshmi P.
Published: September 2024

This paper introduces the parallel quantum transfer fractal priority reply with dynamic memory (P‐QTFPR‐DM) algorithm, an innovative approach that combines quantum computing and reinforcement learning (RL) to enhance decision‐making in autonomous vehicles. Leveraging quantum principles such as superposition and entanglement, P‐QTFPR‐DM optimises Q‐value approximation through a custom quantum circuit (UQC), facilitating efficient exploration and exploitation in high‐dimensional state‐action spaces. This algorithm utilises a quantum neural network (QNN) with 4 qubits to encode and process Q‐values. The autonomous vehicle, equipped with GPS for real‐time navigation, uses P‐QTFPR‐DM to reach a predefined destination with coordinates 12.82,514,234,148 latitude and 80.0,451,311,962,242 longitude. Through extensive numerical simulations, P‐QTFPR‐DM demonstrates a 30% reduction in decision‐making time and a 25% improvement in navigation accuracy compared to classical RL methods. The QNN‐based approach achieves a 95% success rate in reaching the destination within a 5‐m accuracy threshold, whereas traditional RL methods achieve only an 85% success rate. Dynamic memory management in P‐QTFPR‐DM optimises computational resources, enhancing the vehicle's adaptability to environmental changes. These results highlight the potential of quantum computing to significantly advance autonomous vehicle technology by improving both efficiency and effectiveness in complex navigation tasks. Future research will focus on refining the algorithm and exploring its real‐world applications to enhance autonomous vehicle performance.
Targeted detuning aiming for sensory pleasantness – A case study of Pipe Organs and Accordions
Authors: Hergert Frank
Published: September 2024

Two simultaneously sounding tones differing in frequency by a few Hertz generate a waveform, whose amplitude modulation is related to the psychoacoustic quantity “fluctuation strength”. In accordance with the widely accepted definitions of consonance, any deviation from a pure interval (a dyad, whose tone frequencies yield a frequency ratio of small integers) generates dissonance. Nevertheless, imperfect intonation is a common occurrence in musical performance. Recent publications have demonstrated that slightly detuned dyads are perceived as more pleasant than their corresponding pure intervals. Some instruments even contain a separate set of tone generators that are intentionally detuned to a slight degree. Examples of instruments that exhibit this feature include various flat and sharp Celeste ranks in the Pipe Organ or the Accordion. The resulting undulating sounds are pictured as pleasant, shimmering, or “celestial”. This work demonstrates that the tonal timbre of two harmonic complex tones, whose fundamental frequencies slightly deviate from ratios of small integers, can undergo notable periodic changes within a beat cycle while maintaining sensory pleasantness. The acceptable limit of detuning unison intervals is related to the frequency difference limen, as evidenced by data on CELESTE ranks in Pipe Organs and Accordions tuned by instrument builders. This allows for the derivation of general tuning progression rules for Celeste ranks in Pipe Organs and Accordions, which can be used to increase the auditory pleasantness of dyads despite their slight detuning.
Bibliometric analysis of food waste in economics for Sustainable Development Goals 2030
Authors: Wulandari Wida , Rafsanjani Mohamad Arief , Dewi Retno Mustika , Zain Rahmi Ramadhianti , Irawan Nico
Published: September 2024

This research attempts to investigate the economic implication of food waste within the framework of sustainable goals (SDGs) for 2030, using bibliometric analysis. Further, the Scopus database is used in this research; this research analyzes 60 relevant articles covering the period of 1987 to 2024 by using Vos viewer and Publish or Perish (PoP) software to visualize and measure the data. The result of the research shows that the publication trend has fluctuated which has been significantly increasing after 2016, as the campaign of global SDGs is promoted. The key findings show that consumer behavior, economic policy, and social factors play important roles to understanding the food-wasting mechanism. The impactful publications and leading researchers are identified, demonstrating that food waste is related to the economic model; food security; and sustainable implications. This research emphasizes the need to integrate economic strategies with sustainable consumption and production to achieve 2030 SDGs.
Solar radio bursts impact on the International GNSS Service Network during Solar Cycle 24
Authors: Flores-Soriano Manuel
Published: September 2024

Solar radio bursts (SRB) are a known source of noise for Global Navigation Satellite Systems (GNSS) such as GPS or Galileo. They can degrade the carrier-to-noise ratio of satellite signals, thereby diminishing system performance and, in severe cases, causing total service outages. Although a small amount of particularly intense events have already been studied in detail, the commonness and intensity of SRBs that could potentially impair GNSS performance remain uncertain. This study broadens the scope beyond merely extreme SRBs, studying the impact of SRBs on GNSS throughout Solar Cycle 24. Solar 1.4 GHz observations from the Radio Solar Telescope Network are used to find the 20 most intense SRBs at that frequency. The impact of each SRB is then evaluated in terms of GNSS signal strength decrease, reduction in the number of available satellites, and precision degradation. The results show that at the GPS L1 frequency only one event presented extended service degradation, while at the L2 frequency, minimum operational requirements were not met by at least one station during seven of the SRBs. Only a modest correlation between performance degradation and SRB intensity is found. In particular, it is reported how some mild SRBs affected satellite signals while others almost ten times more intense went unnoticed. The fundamental role that the SRB circular polarization plays in these discrepancies is shown with new 1.4 GHz circular polarization observations from the SMOS satellite. The different responses of GNSS receivers to SRBs depending on the receiver manufacturer are also explored.
Machine-learning-derived thermal conductivity of two-dimensional TiS2/MoS2 van der Waals heterostructures
Authors: Nair A. K. , Da Silva C. M. , Amon C. H.
Published: September 2024

Predicting the thermal conductivity of two-dimensional (2D) heterostructures is challenging and cannot be adequately resolved using conventional computational approaches. To address this challenge, we propose a new and efficient approach that combines first-principles density functional theory (DFT) calculations with a machine-learning interatomic potential (MLIP) methodology to determine the thermal conductivity of a novel 2D van der Waals TiS2/MoS2 heterostructure. We leverage the proposed approach to estimate the thermal conductivities of TiS2/MoS2 heterostructures as well as bilayer-TiS2 and bilayer-MoS2. A unique aspect of this approach is the combined implementation of the moment tensor potential for short-range (intralayer) interactions and the D3-dispersion correction scheme for long-range (interlayer) van der Waals interactions. This approach employs relatively inexpensive computational DFT-based datasets generated from ab initio molecular dynamics simulations to accurately describe the interatomic interactions in the bilayers. The thermal conductivities of the bilayers exhibit the following trend: bilayer-TiS2 > bilayer-MoS2 > the TiS2/MoS2 heterostructure. In addition, this work makes the case that the 2D bilayers exhibit considerably higher thermal conductivities than bulk graphite, a common battery anode material, indicating the potential to utilize 2D heterostructures in thermal management applications and energy storage devices. Furthermore, the MLIP-based methodology provides a reliable approach for estimating the thermal conductivity of bilayers and heterostructures.
Experimental validation of a collision-radiation dataset for molecular hydrogen in plasmas
Authors: Fujii Keisuke , Sawada Keiji , Kuzmin Arseniy , Goto Motoshi , Kobayashi Masahiro , Scarlett Liam H. , Fursa Dmitry V. , Bray Igor , Zammit Mark C. , Biewer Theodore M.
Published: September 2024

Quantitative spectroscopy of molecular hydrogen has generated substantial demand, leading to the accumulation of diverse elementary process data encompassing radiative transitions, electron-impact transitions, predissociations, and quenching. However, their rates currently available are still sparse, and there are inconsistencies among those proposed by different authors. In this study, we demonstrate an experimental validation of such a molecular dataset by composing a collisional-radiative model (CRM) for molecular hydrogen and comparing experimentally obtained vibronic populations across multiple levels. From the population kinetics of molecular hydrogen, the importance of each elementary process in various parameter space is studied. In low-density plasmas (electron density ne≲1017 m−3) the excitation rates from the ground states and radiative decay rates, both of which have been reported previously, determine the excited state population. The inconsistency in the excitation rates affects the population distribution the most significantly in this parameter space. However, in higher density plasmas (ne≳1018 m−3), the excitation rates from excited states become important, which have never been reported in the literature, and may need to be approximated in some way. In order to validate these molecular datasets and approximated rates, we carried out experimental observations for two different hydrogen plasmas; a low-density radio frequency heated plasma (ne≈1016 m−3) and the Large Helical Device (LHD) divertor plasma (ne≳1018 m−3). The visible emission lines from EF1Σg+, HH¯1Σg+, D1Πu±, GK1Σg+, I1Πg±, J1Δg±, h3Σg+, e3Σu+, d3Πu±,g3Σg+, i3Πg±, and j3Δg± states were observed simultaneously and their population distributions were obtained from their intensities. We compared the observed population distributions with the CRM prediction, in particular the CRM with the rates compiled by Janev et al., Miles et al., and those calculated with the molecular convergent close-coupling (MCCC) method. The MCCC prediction gives the best agreement with the experiment, particularly for the emission from the low-density plasma. However, the population distribution in the LHD divertor shows a worse agreement with the CRM than those from low-density plasma, indicating the necessity of the precise excitation rates from excited states. We also found that the rates for the electron attachment is inconsistent with experimental results. This requires further investigation.
A practical approach to calculating magnetic Johnson noise for precision measurements
Authors: Phan N. S. , Clayton S. M. , Kim Y. J. , Ito T. M.
Published: September 2024

Magnetic Johnson noise is an important consideration for many applications involving precision magnetometry, and its significance will only increase in the future with improvements in measurement sensitivity. The fluctuation–dissipation theorem can be utilized to derive analytic expressions for magnetic Johnson noise in certain situations, but when used in conjunction with finite element analysis tools, the combined approach is particularly powerful as it provides a practical means to calculate the magnetic Johnson noise arising from conductors of arbitrary geometry and permeability. In this paper, we demonstrate this method to be one of the most comprehensive approaches presently available to calculate thermal magnetic noise. In particular, its applicability is shown to not be limited to cases where the noise is evaluated at a point in space but also can be expanded to include cases where the magnetic field detector has a more general shape, such as a finite-size loop, a gradiometer, or a detector that consists of a polarized atomic species trapped in a volume. Furthermore, some physics insights gained through studies made using this method are discussed.
Large eddy simulation of a swirling kerosene spray flame: A proper orthogonal decomposition and wavelet transform analysis on the flow structure and hydroxyl species field
Authors: Wan Kaidi , Huang Yunzhe , Liu Rongtang , He Yong , Lu Maoqi , Jiang Chongwen
Published: September 2024

The combustion performance can be promoted by the shear layer, recirculation zones, and precessing vortex cores in the swirling flow field. The swirling flow promotes the mixing between air and fuel, but may also jeopardize the combustion stability. In order to study the interaction between the swirling flow structure and the combustion reaction, large eddy simulation (LES) is employed to simulate the turbulent combustion process of a typical swirling kerosene spray burner. A flamelet generated manifold (FGM) chemistry table built with three-component surrogate kerosene skeletal mechanism is coupled with LES to describe the combustion reaction. The FGM-LES approach is validated by comparing the velocity and temperature statistics against the experimental data. The obtained instantaneous LES snapshots of the kerosene flame are then analyzed using proper orthogonal decomposition (POD) and wavelet transform to investigate the time–frequency characteristics. The influence of swirling flow structures on the combustion reaction field is discussed. The results show that the first POD mode with the highest energy contribution is characterized by a low-frequency signal at 2.46 Hz. The second and third modes correspond to the double helix structure in the flow field, while the fourth and fifth modes correspond to the large vortex core structure in the central recirculation zone. The signals of combustion intermediate product hydroxyl species show higher amplitudes near the 78.62 Hz associated with the second and third modes, suggesting the two modes have a significant influence on the turbulent combustion characteristics of the swirling kerosene spray flame.
Dynamics of economic growth and environment: Governance strategies and sustainability
Authors: Li Jiaorui , Li Kaiyuan , Lin Zi-Fei
Published: September 2024

In recent years, the environmental problem caused by economic development has been an important issue all over the world. The traditional analysis of environmental pollution often relies on the endogenous growth model, where environmental pollution is treated as a factor that influences capital and population. In this paper, we develop a nonlinear model that integrates economic growth, technological progress, resource consumption, and environmental pollution to explore the dynamic mechanisms of economic growth under environmental constraints. We first prove the non-negativity of the model’s solutions, followed by establishing their boundedness using a Lyapunov function. Additionally, we investigate, for the first time, the tipping point of a key parameter within the model related to environmental pollution, demonstrating that neglecting environmental pollution renders economic growth unsustainable and can lead to collapse. The study also examines two distinct types of environmental governance aimed at controlling pollution, computing the tipping points associated with economic growth under each governance strategy. Our findings highlight the critical role of green production methods in sustaining economic growth. Finally, we analyze how initial conditions and random disturbances affect the steady-state of economic growth, revealing that initial levels of capital and technological skill can determine the system’s steady-state, while stochastic shocks can alter tipping points and push the system away from stability.
Comparative study of blast loading on solid and porous structures
Authors: Li Jiarui , Xue Kun , Tian Baolin , Xiang Meizhen , Miao Lvlan , Chen Jun
Published: September 2024

The characteristics and parameter dependences of blast loading on solid and porous structures subject to explosions in a confined space are numerically investigated based on a shock tube configuration wherein the explosive source is approximated by a section at the closed end of the tube filled with high pressure gases. Using a four-way coupling compressible gas–solid numerical method, this work reveals the explicit correlations between the wave dynamics and the characteristic features of blast loading during the shock impinging transient state and the long-time steady state. Upon the shock impingement, the blast loading on the solid and porous structures both exhibits impulsive features caused by the reciprocating shock and rarefaction waves with moderate and considerable amplitude declines, respectively. The imprints of first several impulses manifest the complex wave propagations between the closed end of the tube and the surfaces of solid or porous structures. The pressure profile on the solid structure soon transitions into a shape consisting of periodic triangular waves with sharp jump fronts and unvaried amplitudes. In contrast, the peak overpressure and amplitude of impulses experienced by the porous structure undergo a significant decay so that a gradual declining loading defines the long-term blast loading. The differences of blast loading between the solid and porous structure can be attributed to the substantial energy loss due to the gas filtration inside the porous structure which becomes more intensive as the porosity is increased. Compaction of the porous structure also plays a significant role since the receding porous surface contributes to the marked dissipation of reflected waves. We further investigate the parameter dependences of the defining features of the blast loading on the solid and porous structure, including the explosion energy, the space between explosion source and the structure, and the porosity as well.
Interfacial local field and surface response coefficients
Authors: Wei Yuxuan , Shen Y. R.
Published: September 2024

The interfacial local field is of critical importance in data analysis to deduce intrinsic surface responses from optical measurements of interfaces of condensed media but has not yet been well interrogated. We present here a simple approach to find local fields approximately at various interfaces of isotropic or nearly isotropic media. We divide a medium into atomic planes or molecular layers. It is found that the dipolar field contribution to the local field in a plane or layer from induced dipoles residing in planes beyond the nearest neighbor planes or layers is negligible; in many cases, the contribution is dominated by in-plane dipoles and the local field has a simple expression very much like that for an isotropic bulk. This finding allows us to calculate approximate local field variation at various interfaces. With the interfacial local field known, intrinsic surface response coefficients can be extracted from the optically measured surface responses.
Effect of ions anisotropy pressure on the ion-acoustic cnoidal waves in electron–positron–ion magnetoplasmas
Authors: Alrowaily Albandari W. , Khalid Muhammad , Kabir Abdul , Shah Rasool , Tiofack C. G. L. , Alhejaili Weaam , El-Tantawy S. A.
Published: September 2024

The main objective of this work is to investigate the characteristics and behavior of the ion-acoustic cnoidal waves (IACWs) in an electron–positron–ion magnetoplasma having inertial positive ions with anisotropic thermal pressure and inertialess Maxwellian positrons and electrons. We utilize the reductive perturbation technique to reduce the fluid governing equations of the present model into the Korteweg–de Vries (KdV) equation in order to achieve this objective. We calculate the periodic solution of the KdV equation, also referred to as the cnoidal wave. We investigate the impact of various related parameters, including ion pressure anisotropy, positron concentrations, and temperature ratio, on the properties of IACWs. This study, particularly in the near-Earth magnetosheath and magnetosphere, may offer an insightful analysis of space and astrophysical plasma systems displaying ion pressure anisotropy.
Analytical solutions to the cylindrically symmetric compressible isothermal Euler–Poisson equations of galaxies
Authors: Zhang Qiao , Dong Jianwei
Published: September 2024

In this paper, we study the cylindrically symmetric compressible isothermal Euler–Poisson equations of galaxies with a negative cosmological constant. By using some ansatzes, we construct a family of analytical periodic solutions to the system, which partially complements the result in Yuen (2009 Class. Quantum Grav.
26 235011), where a family of analytical periodic solutions to the system with spherical symmetry were given for the adiabatic exponent

γ
=

4
3

. Our result may provide an explanation about the dynamical evolution of the cylindrically symmetric galaxies or interstellar clouds.
Accurate determination of matrix composition in

Cd

x

Zn

1
−
x

O

semiconductor material using MS-SIMS and ToF-SIMS methods
Authors: Khosravizadeh Z , Trzyna-Sowa M , Lysak A , Przeździecka E , Jakiela R
Published: September 2024

This study focuses on the method for determining the exact composition for

Cd

x

Zn

1
−
x

O

semiconducting material using secondary ion mass spectrometry. The calibration curve method is employed to establish a quantitative relationship between the intensity of secondary ions and the concentrations of elements in

Cd

x

Zn

1
−
x

O

thin films. Additionally, the study compares the relative sensitivity factors with the calibration curve method for determining the value of x in

Cd

x

Zn

1
−
x

O

. A comparison between the performances of Time of Flight and Magnetic Sector SIMS in analyzing

Cd

x

Zn

1
−
x

O

thin films is also presented. This approach aims to enhance the accuracy and reliability of quantitative analysis in SIMS for

Cd

x

Zn

1
−
x

O

thin films.
Pressure tuning of HgCdTe epitaxial layers—the role of the highly disordered buffer layer
Authors: Yavorskiy D , Ivonyak Y , But D , Karpierz K , Krajewska A , Haras M , Sai P , Dub M , Kazakov A , Cywiński G , Knap W , Łusakowski J
Published: September 2024

Hg

1
−
x

Cd
x
Te alloys are unique because by increasing the Cd content x, one modifies the band structure from inverted to normal, which fundamentally modifies the dispersion of bulk, surface or edge (in the case of quantum wells) energy states. Using alloys with x close to the concentration xc
at which the band inversion transition is observed and with additional application of hydrostatic pressure (p), one creates a favorable playground for studying the evolution of Dirac matter and its topological properties. In this work, cryogenic magnetospectroscopy in quantizing magnetic fields (B) in the far-infrared is used to study inter-Landau-level transitions in high-quality Hg

1
−
x

Cd
x
Te MBE-grown epitaxial layers with

x
≈

x
c

as a function of p up to 4.2 kbar. Special attention is paid to elucidate the role of the substrate and buffer layers, which usually modify the pressure coefficients of epitaxial layers. For this purpose, comparative measurements were carried out on as-grown epilayers with a GaAs substrate and on free-standing layers obtained by etching off the substrate. Spectra registered as a function of B (at given p) were analyzed with the help of the Kane model modified to include magnetic field. The pressure coefficient as well as the difference between conduction and valence band deformation potentials of the free-standing layer were determined at 2 K. Surprisingly, the deformation potentials and pressure coefficients of the epitaxial layer and those of the free-standing layer differed by no more than 10% in the pressure range up to 4.2 kbar. This finding questions the common belief of a dominant influence of the substrate on the pressure coefficients of epitaxial layers. We attribute the smallness of this difference to the presence of a highly disordered CdTe buffer separating the substrate from the epitaxial layer, which relaxes the transmission of strain from the substrate to the layer. Our results contribute to a better understanding of pressure experiments carried out on epitaxial layers on a substrate.
Unveiling the boson peaks in amorphous phase-change materials
Authors: Moesgaard Jens , Fujita Tomoki , Wei Shuai
Published: September 2024

The boson peak is a universal phenomenon in amorphous solids. It can be observed as an anomalous contribution to the low-temperature heat capacity over the Debye model. Amorphous phase-change materials (PCMs) such as Ge–Sb–Te are a family of poor glass formers with fast crystallization kinetics, being of interest for phase-change memory applications. So far, whether boson peaks exist in PCMs is unknown and, if they do, their relevance to PCM properties is unclear. Here, we investigate the thermodynamic properties of the pseudo-binary compositions on the tie-line between Ge15Te85 and Ge15Sb85 from a few Kelvins to the liquidus temperatures. Our results demonstrate the evidence of the pronounced boson peaks in heat capacity below 10 K in the amorphous phase of all compositions. By fitting the data using the Debye model combined with a modification of the Einstein model, we can extract the characteristic parameters of the boson peaks and attribute their origin to the excess vibrational modes of dynamic defects in the amorphous solids. We find that these parameters correlate almost linearly with the Sb-content of the alloys, despite the nonmonotonic behaviors in glass forming abilities and thermal stabilities. In a broader context, we show that the correlations of the characteristic parameters of the boson peaks with T
g and kinetic fragility, vary according to the type of bonding. Specifically, metallic glasses and conventional covalent glasses exhibit distinct patterns of dependence, whereas PCMs manifest characteristics that lie in between. A deeper understanding of the boson peaks in PCMs holds the promise to enable predictions of material properties at higher temperatures based on features observed in low-temperature heat capacity.
A coupled plasma-thermal model for hollow cathode power decomposition and parametric analysis
Authors: Luo Zihao , Ren Junxue , Cao Lehui , Zhang Guangchuan , Wang Yibai , Zhang Zun , Wang Weizong , Tang Haibin
Published: September 2024

A 2D axisymmetric transient coupled plasma-thermal model is developed to simulate the plasma behavior during the self-sustained discharge of hollow cathodes, which presents a complete hollow cathode structure and energy transfer processes in multiphysics fields. The model has been validated by quantitative agreement between the simulation results and experimental data on the plasma and emitter temperature at the NSTAR cathode. The effects of thermal protection design, operating conditions, and geometric design on the cathode performance are analysed through electric and thermal power decomposition. The parametric analysis shows that the optimal thermal protection design is to use a 1/3 thickness cathode tube with 4 layers of radiation shielding close to the tube, which reduces 43.7% conductive and 61.1% radiative heat dissipation, respectively. Increasing the inlet flow rate counter-intuitively reduces the emitter temperature due to the potential reversal in the diffusion electric field dominated region, revealing that the flow rate can be traded for the dual optimisation of lifetime and power consumption. Under high current conditions, the IAT effect dominates the plume resistance to increase the discharge voltage after an inflexion point, which is the main factor limiting the cathode performance. A large internal radius gives a uniform low emission and helps to prolong life, while the orifice length should be avoided to be longer than 4 times the orifice radius due to the significantly enhanced Joule heating in the narrow orifice. The orifice radius determines the power deposition due to electron and ion bombardment through potential penetration. For high-current discharger cathodes dominated by electron bombardment, large or through-orifice designs are preferred, while for low-current neutralizer cathodes dominated by electron bombardment, small-orifice designs are recommended.
Berezinsky hidden sources: an emergent tension in the high-energy neutrino sky?
Authors: Ambrosone Antonio
Published: September 2024

The IceCube Collaboration has recently reported compelling evidence of high-energy neutrino emission from NGC 1068, and also mild excesses for NGC 4151 and CGCG420-015, local Seyfert galaxies. This has increased the interest along neutrino emission from hot-corona surrounding the super massive black holes of Seyfert Galaxies. In this paper, we revisit phenomenological constraints on the neutrino emission from hot-coronae of Seyfert galaxies, using an assumption of sub-equipartition between cosmic-rays and magnetic energy densities. We show that not only these sources are consistent with such an assumption but also that the data point towards low values for the ratio between thermal and magnetic pressure, the so called beta plasma parameters inside Seyfert galaxies. We exploit this finding to constrain the Seyfert diffuse neutrino flux and we obtain that, in order not to overproduce neutrinos, not all the sources can be efficient neutrino emitters. In our approach (along with previous findings), Seyfert galaxies provide a negligible contribution to the diffuse neutrino spectrum above ∼ 100 TeV, allowing space for other astrophysical sources. However, future data from high-energy neutrino telescopes will be crucial to shed more light onto the contribution of this source class to the cosmic neutrino background.
Interacting ultralight dark matter and dark energy and fits to cosmological data in a field theory approach
Authors: Aboubrahim Amin , Nath Pran
Published: September 2024

The description of dark matter as a pressure-less fluid and of dark energy as a cosmological constant, both minimally coupled to gravity, constitutes the basis of the concordance
ΛCDM model. However, the concordance model is based on using equations of motion directly for the fluids with constraints placed on their sources, and
lacks an underlying Lagrangian. In this work, we propose a Lagrangian model of two spin zero fields describing dark energy and dark matter with an interaction term between the two along with self-interactions. We study the background evolution of the fields as well as their linear perturbations, suggesting an alternative to ΛCDM with dark matter and dark energy being fundamental dynamical fields. The parameters of the model are extracted using a Bayesian inference tool based on multiple cosmological data sets which include those of Planck (with lensing), BAO, Pantheon, SH0ES, and WiggleZ. Using these data, we set constraints on the dark matter mass and the interaction strengths. Furthermore, we find that the model is able to alleviate the Hubble tension for some data sets while also resolving the S
8 tension.
A GPU Algorithm for Solving the Positions of New Pulsars
Authors: Fang 方 Ziyao 子瑶 , Zhu 朱 Weiwei 炜玮 , Miao 缪 Chenchen 晨晨 , Zhou 周 Yukai 宇凯 , Zhou 周 Dejiang 德江 , Chen 陈 Tianlu 天禄 , Fu 付 Qiuyang 秋阳 , Meng 孟 Lingqi 令祺 , Miao 缪 Xueli 雪丽 , Niu 牛 Jiarui 佳瑞 , Xue 薛 Mengyao 梦瑶
Published: September 2024

Timing newly discovered pulsars requires gradually building up a timing model that connects observations taken days to months apart. This sometimes can be challenging when our initial knowledge of the pulsar’s position is arcminutes off from its true position. Such a position error leads to significant arrival time shifts as a result of the Earth’s orbital motion. Traditional down-hill fitting timing algorithms become ineffective when our model predicts the wrong pulse rotations for our next observation. For some pulsars whose model prediction is not too far off, the correct rotation number could be found by trial-and-error methods. For the remaining challenging pulsars, a more generalized method is called for. This paper proposes a GPU-based algorithm that could exhaustively search a large area of trail positions for probable timing solutions. This could help find phase-connected timing solutions for new pulsars using brute force.
I-mode plasma confinement improvement by real-time lithium injection and its classification on EAST tokamak
Authors: Zhong X.M. , Zou X.L. , Liu A.D. , Song Y.T. , Zhuang G. , Liu H.Q. , Xu L.Q. , Li E.Z. , Zhang B. , Zuo G.Z. , Wang Z. , Zhou C. , Zhang J. , Shi W.X. , Gao L.T. , Wang S.F. , Gao W. , Jia T.Q. , Zang Q. , Zhao H.L. , Wang M. , Xu H.D. , Wang X.J. , Gao X. , Lin X.D. , Li J.G. ,   EAST I-mode Working Group,   the EAST Team
Published: September 2024

I-mode is a promising regime for future fusion reactors due to the high energy confinement and the moderate particle confinement. However, the effect of lithium, which has been widely applied for particle recycling and impurity control, on I-mode plasma is still unclear. Recently, experiments of real-time lithium powder injection on I-mode plasma have been carried out in EAST Tokamak. It was found that the confinement performance of the I-mode can be improved by the lithium powder injection, which can strongly reduce electron turbulence (ET) and then trigger ion turbulence (IT). And it was observed that the ET intensity is inversely proportional to the velocity shear, which suggests that the injection of lithium powder leads to a gradual enhancement of the shear flow, whereby the turbulence is reduced and consequently the confinement is improved. Four different regimes of I-mode have been identified in EAST. The Type I I-mode plasma is characterized by the weakly coherent mode (WCM) and the geodesic-acoustic mode (GAM). The Type II I-mode is featured as the WCM and the edge temperature ring oscillation (ETRO). The Type III I-mode corresponds to the plasma with the co-existence of ETRO, GAM, and WCM. The Type IV I-mode denotes the plasma with only WCM but without ETRO and GAM. It was observed that the WCM intensity is increased with lithium powder injection by the confinement improvement/pedestal temperature increase. EAST experiments demonstrate that lithium powder injection is an effective tool for real-time control and confinement improvement of I-mode plasma.
Clinical study of matrix vascular component gel combined with vacuum sealing drainage technique in chronic wounds
Authors: Wu Zeyong , Huang Haiyan , Shi Yucang , Li Jin , Liao Simu , Xu Shuhao , Xian Jiajie , Cai Xiaofen , Zhang Peihua , Wu Zhiyuan
Published: September 2024

This study investigates the efficacy of the combination of extracellular matrix/stromal
vascular fraction gel (ECM/SVF-gel) and vacuum sealing drainage (VSD) on chronic wounds. From February 2021 to February 2022, 20 patients with chronic wounds were recruited and were divided into experimental and control groups, with 10 patients in each group. Following debridement, we applied various treatments to all cases for 2 weeks. Subsequently, we
observed the changes in the wound area and calculated the rate of wound healing. Simultaneously, the wound margin tissues were collected for histological analysis, and the inflammatory cell infiltration within the wound was assessed using HE staining. Masson staining was used to observe the collagen deposition on the wound surface, and CD31 immunohistochemistry was used to count the number of microvessels to evaluate the angiogenesis (Clinical trial registration number: ChiCTR-INR-17 013 540). The therapeutic outcomes for all cases included in this study were favorable after a two-week treatment period, and the wound area was smaller than before. The experimental group exhibited a significantly higher rate of wound healing compared to the control group. As revealed by HE staining in the experimental group, there was a marked reduction in the infiltration of
inflammatory cells in the dermis. Masson staining demonstrated that the deposition of collagen fibers in the experimental group was more than the control group. CD31 immunohistochemistry showed an increased number of new blood vessels in the experimental group compared to the control group. Additionally, ECM/SVF-gel extract significantly enhanced the fibroblast proliferation and migration in vitro. The application of ECM/SVF gel combined with VSD in chronic wounds can accelerate wound healing by reducing inflammatory reaction, increasing collagen fiber deposition, and promoting angiogenesis. Therefore, the combination of ECM/SVF gel and VSD can be used as a simple, safe, and effective therapeutic method for chronic wounds.
Role of North Atlantic warming in the extremely hot summer of 2023 in North China
Authors: Feng Juan , Chen Yan , Chen Wen , Chen Shangfeng , Ding Shuoyi
Published: September 2024

A deadly heatwave hit North China in the summer of 2023, causing severe damage to human health and public infrastructure. However, the underlying physical mechanism is still unknown completely. In this study, we explore the causative role of anomalous sea surface temperatures in three oceans using observation and reanalysis data, as well as partial regression and correlation methods. This heatwave exhibited the longest maximum duration of the past 50 years. According to the probability density function, the maximum temperature also reached an unprecedented high. A long-lived anticyclone dominated North China, causing persistent downward motion and adiabatic heating, enabling the heatwave to form and continue for more than 20 d. The Indian, Pacific, and North Atlantic oceans all experienced extreme warming. However, our results indicate that North Atlantic warming played a decisive role in the occurrence of this heatwave by exciting a Rossby wave train that propagated eastward, generating the long-lived anomalous anticyclone and inducing heatwaves. In comparison, the other two oceans exhibited weak or negative contributions to the heatwave. As the North Atlantic shows an obvious warming trend with increasing global warming, more attention should be paid to its relationship with heatwaves in North China.
Radiative-conductive heat transfer dynamics in dissipative dispersive anisotropic media
Authors: Mariji Hodjat , Maslovski Stanislav
Published: September 2024

We develop a self-consistent theoretical formalism to model the dynamics of heat transfer in dissipative, dispersive, anisotropic nanoscale media, such as metamaterials. We employ our envelope dyadic Green’s function method to solve Maxwell’s macroscopic equations for the propagation of fluctuating electromagnetic fields in these media. We assume that the photonic radiative heat transfer mechanism in these media is complemented by dynamic phononic mechanisms of heat storage and conduction, accounting for effects of local heat generation. By employing the Poynting theorem and the fluctuation-dissipation theorem, we derive novel closed-form expressions for the radiative heat flux and the coupling term of photonic and phononic subsystems, which contains the heating rate and the radiative heat power contributions. We apply our formalism to the paraxial heat transfer in uniaxial media and present relevant closed-form expressions. By considering a Gaussian transverse temperature profile, we also obtain and solve a system of integro-differential heat diffusion equations to model the paraxial heat transfer in uniaxial reciprocal media. By applying the developed analytical model to radiative-conductive heat tranfer in nanolayered media constructed by layers of silica and germanium, we compute the temperature profiles for the three first orders of expansion and the total temperature profile as well. The results of this research can be of interest in areas of science and technology related to thermophotovoltaics, energy harvesting, radiative cooling, and thermal management at micro- and nanoscale.
Z22-graded supersymmetry via superfield on minimalZ22-superspace
Authors: Aizawa N , Ito Ren , Tanaka Toshiya
Published: September 2024

A superfield formalism for the minimalZ22-graded version of supersymmetry is developed. This is done by using the recently introduced definition of integration on the minimalZ22-superspace. It is shown that one may constructZ22-supersymmetric action by the procedure similar to the standard supersymmetry. However, the Lagrangian obtained has very general interaction terms, which give rise to aZ22-graded extension of many known theories defined in two-dimensional spacetime. As an illustration, we will give aZ22-extension of the sine-Gordon model different from the one already discussed in the literature.
A compartmentalized microfluidic platform to investigate immune cells cross-talk in rheumatoid arthritis
Authors: Palma Cecilia , Aterini Bianca , Ferrari Erika , Mangione Marta , Romeo Martina , Nezi Luigi , Lopa Silvia , Manzo Teresa , Occhetta Paola , Rasponi Marco
Published: September 2024

The dysregulation of the immune system plays a crucial role in the pathogenesis of manyfold diseases, among which we find rheumatoid arthritis (RA), an autoimmune disease characterized by chronic inflammation in synovial joints, leading to pain and disability. Immune cells such as pro-inflammatory macrophages and T helper 1 (Th1) cells drive the inflammatory cascade. Thus, including immune system in in vitro models is pivotal to recapitulate and better understand the complex interactions between these immune cell subsets and their secreted mediators. Here, a compartmentalized microfluidic platform is presented, for precise confinement of circulating immune cells in organs-on-chip. The integration of innovative normally-closed sieving valves allows, through minimal waste of biological material, to co-culture different immune cell types (e.g. macrophages and Th1). Moreover, the platform allows to stimulate cell subsets separately, and to assess their cross-talk at desired time points. Functional validation of the platform demonstrates its ability to create stable chemotactic gradients, allowing for induction and evaluation of Th1 cells migration. In a proof-of-concept study, the platform allowed to assess Th1 T cells migration towards pro-inflammatory macrophages, thus replicating a characteristic interaction among immune cells triggered during RA onset. These results thus support the suitability of the platform to study immune cells cross-talk and migration phenomena, being potentially applicable to a manyfold immune cell mechanisms, both involved in RA progression and in different immune-mediated pathologies.
Effective reduction of iron impurities in recycled aluminium-silicon alloy type LM-6 through sedimentation and filtration with synthesized Mn, Cr and Zr transition metal powders
Authors: P Srinath , C Bhagyanathan
Published: September 2024

In secondary aluminium recycling, impurity reduction, especially of iron, is a significant challenge as it deteriorates the material quality in the aluminium melt. Recycled aluminium alloys are widely used in various industries, including automotive, marine, and structural engineering. Specifically, LM-6 aluminium alloy is commonly used in automotive engine parts and transmission cases. This research focused on reducing the excessive iron content in LM-6 alloy scrap. Elements like manganese (Mn), chromium (Cr) and zirconium (Zr) were added to the melt in form of synthesized powders to form intermetallic compounds. These powders will also act as grain refiners, neutralizers and reducing the detrimental effects on the alloys. The powders were synthesized using the ball milling method with a ball to powder ratio of (5:1) to enhance mixing and amalgamation with the melt. The melt was held at an optimized temperature of 640 ± 10 °C to promote the formation of intermetallic sludge, encouraging the sedimentation of aluminium-iron (Al-Fe) intermetallic phases. XRD confirmed the formation of AlMn, AlCr, AlZr with other phases. After sedimentation, a glass fabric mesh with a pore size of 200 μm was used to effectively filter out β-iron during the filtration process. This technique reduced iron impurity in the melt by 50%–60%. As a result, the mechanical properties of the recycled aluminium improved significantly: hardness increased by 14%, and tensile strength increased by 36%. The wear and corrosion resistance of the material also improved due to the incorporation of the synthesized powders. SEM analysis revealed the plate-like formation of iron structures and confirmed the presence of the manganese, chromium, and zirconium powders in the metallographic analysis.
Impacts of T6 heat treatment on the microstructural, mechanical, and corrosion properties of thixoformed AA7075 alloy produced by cooling slope casting
Authors: Acar Serhat , Guler Kerem Altug
Published: September 2024

Research into semi-solid metal forming techniques has been ongoing for an extended period with the aim of producing near-net shape products from aluminum alloys. The primary focus has traditionally been on casting alloys seeking to offer an alternative to the other processes such as high pressure die casting. Over the past twenty years, wrought aluminum alloys have also been explored for thixoforming operations as an alternative to traditional plastic deformation techniques. This research investigated the impacts of T6 heat treatment on the microstructural, mechanical, and corrosion properties of AA7075 alloy samples produced through cooling slope casting and subsequent thixoforming with different reheating durations. The selected alloy was chosen due to its widespread use in various industries, attributed to its excellent strength-to-density ratio achieved after T6 heat treatment. Building on optimized cooling slope casting parameters from a prior study, the standard solution treatment procedure following thixoforming with extended reheating times was found to be inadequate. Hardness and tensile tests revealed that specimens reheated for 120 min exhibited significantly reduced response to T6 treatment. Despite achieving the targeted hardness value of 154 HB with samples reheated for 20 min prior to thixoforming and T6 heat treatment, especially the elongation at break values were unsatisfactory. Potentiodynamic polarization tests indicated that corrosion primarily involved grain dissolution, with longer reheating times decreasing corrosion resistance due to increased amount of secondary phases and grain isolation. These findings highlight that while AA7075 alloy can be processed into semi-solid formable materials via cooling slope casting, issues such as hot tearing, micro-shrinkage, and physical defects post-thixoforming hinder the achievement of desired tensile properties.