bluuebunny/crossref_metadata_2025 huggingface dataset:
Smart forwarding deceptive jamming distribution optimal algorithm
Authors: Tang Chengkai , Ding Jiawei , Qi Huaiyuan , Zhang Lingling
Published: February 2024

With the frequent occurrence of drone black flying in large stadiums and airports, the requirement of precise electromagnetic interference to achieve unmanned aerial vehicle (UAV) displacement and forced landing in these protected area became urgent. Since traditional suppression jamming will affect normal communication, and forwarding deceptive jamming has coverage hole, a smart forwarding deceptive jamming distribution optimal algorithm (SFDJDO) is proposed. It gives a mapping error scale factor and the optimal distribution of multistation forwarding equivalent mapping to solve the problem of distortion on the mapping scale caused by different distribution methods and reduces the influence of the mapping errors and the differences between the virtual and real point neighborhoods of the jamming source. A comparison of the proposed SFDJDO method to the existing jamming source distribution optimisation method is conducted in the aspect of area mapping and trajectory mapping. The findings reveal that when the GNSS receiver clock bias is within the capture range, SFDJDO demonstrates significant enhancements in mapping precision and jamming success rates.
Anisotropy of plasma turbulence at ion scales: Hall and pressure–strain effects
Authors: Hellinger Petr , Verdini Andrea , Montagud-Camps Victor , Franci Luca , Papini Emanuele , Matteini Lorenzo , Landi Simone
Published: February 2024

Aims. We investigated the properties of plasma turbulence at ion scales in the solar wind context. We concentrated on the behaviour of the Hall physics and the pressure strain interaction and their anisotropy owing to the ambient magnetic field.

Methods. We studied the results of a three-dimensional hybrid simulation of decaying plasma turbulence using the Kármán–Howarth–Monin (KHM) equation, which quantifies different turbulent processes.

Results. The isotropised KHM analysis shows that kinetic plus magnetic (kinetic+magnetic) energy decays at large scales; this energy cascades from large to small scales via the magneto-hydrodynamic non-linearity that is partly continued via the Hall coupling around the ion scales. The cascading kinetic+magnetic energy is partly dissipated at small scales via resistive dissipation. This standard dissipation is complemented by the pressure–strain interaction, which plays the role of an effective dissipation mechanism and starts to act at relatively large scales. The pressure–strain interaction has two components, compressive and incompressive. Compressive interaction is connected with the velocity dilatation, which mostly reversibly exchanges kinetic+magnetic and internal energies. Incompressive interaction mostly irreversibly converts the kinetic+magnetic energy to internal energy. The compressive effects lead to important oscillations of the turbulence properties, but the compressibility is strongly reduced when averaged over a time period spanning a few periods of the oscillations. The ambient magnetic field induces a strong spectral anisotropy. The turbulent fluctuations exhibit larger scales along the magnetic field compared to the perpendicular directions. The KHM results show the corresponding anisotropy of turbulent processes: their characteristic scales shift to larger scales in the quasi-parallel direction with respect to the ambient magnetic field compared to the quasi-perpendicular direction. This anisotropy is weak at large scales owing to the initial isotropic spectrum, and becomes progressively stronger at small scales.
FARGOCPT: 2D Multiphysics code for simulating disk interactions with stars, planets, and particles
Authors: Rometsch Thomas , Jordan Lucas M. , Moldenhauer Tobias W. , Wehner Dennis , Rendon Restrepo Steven , Müller Tobias W. A. , Picogna Giovanni , Kley Wilhelm , Dullemond Cornelis P.
Published: February 2024

Context. Planet-disk interactions play a crucial role in the understanding of planet formation and disk evolution. There are multiple numerical tools available to simulate these interactions, including the commonly used FARGO code and its variants. Many of the codes have been extended over time to include additional physical processes, with a focus on their accurate modeling.

Aims. We introduce FARGOCPT, an updated version of FARGO that incorporates other previous enhancements to the code, to provide a simulation environment tailored to studies of the interactions between stars, planets, and disks. It is meant to ensure an accurate representation of planet systems, hydrodynamics, and dust dynamics, with a focus on usability.

Methods. The radiation-hydrodynamics part of FARGOCPT uses a second-order upwind scheme in 2D polar coordinates, supporting multiple equations of state, radiation transport, heating and cooling, and self-gravity. Shocks are considered using artificial viscosity. The integration of the N-body system is achieved by leveraging the REBOUND code. The dust module utilizes massless tracer particles, adapted to drag laws for the Stokes and Epstein regimes. Moreover, FARGOCPT provides mechanisms to simulate accretion onto stars and planets.

Results. The code has been tested in practice in the context of multiple studies. Additionally, it comes with an automated test suite for checking the physics modules. It is available online.

Conclusions. FARGOCPT offers a unique set of simulation capabilities within the current landscape of publicly available planet-disk interaction simulation tools. Its structured interface and underlying technical updates are intended to assist researchers in ongoing explorations of planet formation.
Eclipse-timing study of new hierarchical triple star candidates in the northern continuous viewing zone of TESS
Authors: Mitnyan T. , Borkovits T. , Czavalinga D. R. , Rappaport S. A. , Pál A. , Powell B. P. , Hajdu T.
Published: February 2024

Aims. We compiled a list of more than 3500 eclipsing binaries located in and near the northern continuous viewing zone (NCVZ) of the TESS space telescope that have sufficient TESS photometry to search for additional hidden components in these systems. In addition to discovering their hierarchical nature, we also determined their orbital parameters and analyzed their distributions.

Methods. We obtained the TESS light curves of all targets in an automated way by applying convolution-aided differential photometry on the TESS full-frame images from all available sectors up to sector 60. Using a new self-developed Python GUI, we visually confirmed all of these light curves, determined the eclipsing periods of the objects, and calculated their eclipse-timing variations (ETVs). The ETV curves were used in order to search for nonlinear variations that could be attributed to a light travel-time effect (LTTE) or dynamical perturbations caused by additional components in these systems. We preselected 351 such candidates and modeled their ETVs with the analytic formulae of pure LTTE or with a combination of LTTE and dynamical perturbations.

Results. We were able to fit a model solution for the ETVs of 135 hierarchical triple candidates, 10 systems of which were known from the literature, and the remaining 125 systems are new discoveries. These systems include some more noteworthy ones, such as five tight triples that are very close to their dynamical stability limit with a period ratio lower than 20, and three newly discovered triply eclipsing triples. We point out that dynamical perturbations occur in GZ Dra, which we found to be a triple, and that the system is one of the most strongly inclined systems known in the literature, with im = 58° ±7°. We also compared the distributions of some orbital parameters from our solutions with those from a previous Kepler sample. Finally, we verified the correlations between the available parameters for systems that have Gaia non-single star orbital solutions with those from our ETV solutions.
The reaction πN → ωN in a dynamical coupled-channel approach
Authors: Wang Yu-Fei
Published: February 2024

This talk is on a refined investigation on light flavor meson-baryon scatterings, using a dynamical coupled-channel approach, i.e. the Jülich-Bonn model. The previous channel space of πN, πΔ, σN, ρN, ηN, KΛ and Kσ is extended by adding the ωN final state. The spectra of N* and Δ resonances are extracted, based on the result of a global fit to a worldwide collection of data, in the energy region from the πN threshold to center-of-mass energy z = 2.3 GeV (approximately 300 parameters against 9000 data points). A negative value of the ωN elastic spin-averaged scattering length has been extracted.
Revealing violations of macrorealism in flavor oscillations: Leggett-Garg inequalities and no-signaling-in-time conditions
Authors: Blasone Massimo , Illuminati Fabrizio , Petruzziello Luciano , Simonov Kyrylo , Smaldone Luca
Published: February 2024

Abstract. We briefly review recent developments in the study of the quantum nature of flavor mixing; in particular, the attention will be devoted to neutrino and neutral meson oscillations. We employ Leggett-Garg type inequalities and no-signaling-in-time conditions to probe the intrinsic quantumness of such a physical manifestation, showing how the analysis is not affected by the wave-packet spreading (for neutrinos) and the intrinsic particle instability (for mesons).
Observation of e+e− → χc1 at BESIII
Authors: Lellmann Max
Published: February 2024

Abstract. In electron-positron annihilation, the process of e+e− → χc1 can occur via the production of two virtual photons or through neutral current, therefore being suppressed with respect to the normal annihilation process via one virtual photon. Using a dedicated scan sample around the χc1 mass, the direct production of χc1 has been established for the first time in experiments. This provides a new approach for the study of the internal nature of hadrons.
Search for the Y(2175) in photoproduction at GlueX
Authors: Götzen Klaus , Nerling Frank
Published: February 2024

Abstract. The Y(2175), recently renamed to ϕ(2170), is one of the rare exotic candidates connected to strangeonium as compared to the heavier charmonium-like and bottomonium-like exotic states. Originally observed in initial state radiation events by the BaBar experiment in 2006, it is suggested to be a strange partner state of the charmonium-like exotic vector state Y(4230) that was one of the first of the so-called XYZ states reported in the charmonium mass region. The Y(2175) has been seen in various experiments and decay channels,but it has not yet been searched for in a photo-production experiment. In this talk we report on a measurement of the production cross section of the reaction γ + p → ϕπ+ π− + p based on data recorded by the GlueX experiment in order to search for Y(2175) → ϕπ+π−.>
Photon-photon correlations in Ag+Ag collisions at √SNN = 2.55 GeV
Authors: Grunwald Mateusz
Published: February 2024

Abstract. Photons, as penetrative probes, can deliver information about early stages of heavy-ion collisions, in contrast to hadrons, whose kinematics are determined after the freeze-out era. Given that, they provide access to quantities inaccessible for many other particle species. However, due to technical challenges of photon detection and dominance of photons from particle decays, exploiting their properties requires significant effort. Femtoscopy, a technique used to investigate the space-time characteristics of the source area, is sensitive to the emission sequence of studied particles. Hence, it can be utilized as a tool to separate photons originating from different sources. Studying femto-scopic correlations of photons can offer a new and unique perspective on source parameters before kinematic freeze-out. Using data from Ag+Ag collisions at √SNN = 2.55 GeV, collected by the HADES spectrometer, a preliminary study of photon-photon correlations was performed.
The FAIR Phase-0 Hyperon Program at HADES
Authors: Rieger Jana
Published: February 2024

Abstract. Hyperons are a unique probe to study the non-perturbative aspects of the strong interaction. At HADES, they are produced in proton or pion induced reactions at kinetic energies up to 4.5 GeV. Already in the past, HADES has shown its potential for hyperon physics, including λ polarization, λ-N interaction and measurements of the λ(1405) and λ(1520) line-shapes. The HADES detector has recently been extended with a forward detector, partly developed for the PANDA experiment, extending the acceptance for hyperon channels at forward angles. The PANDA@HADES initiative gives the opportunity for an even richer hyperon program. The current main objectives are the production of hyperon resonances, electromagnetic decays of hyperons with special focus on hyperon Dalitz decays and double strangeness production, including a λ – λ interaction study and ξ− production. First results from the ongoing studies promise a successful execution of the program. In the future, there is the possibility for a pion beam experiment with HADES, enabling further hyperon studies.
Analysis of 𝚵(1620) resonance with chiral unitary approach
Authors: Nishibuchi Takuma , Hyodo Tetsuo
Published: February 2024

Abstract. Recently, the ξ(1620) resonance has attracted much attention, thanks to detailed experimental data by the Belle and ALICE collaborations. This experimental progress has prepared us to conduct theoretical analyses based on experimental data. In this study, we analyze the ξ(1620) resonance using the chiral unitary model and discuss the properties of the ξ(1620) resonance and the K−Λ scattering length.
Conservation en mouvement : savoirs, pratiques et politiques. Retour sur un colloque interdisciplinaire
Authors: Wittersheim Lucile
Published: February 2024

Cet article vise à restituer les échanges qui ont eu lieu lors du colloque « Conservation en mouvement » les 14 et 15 juin 2022 à l’École normale supérieure de Paris et au nouveau Campus Condorcet. Conserver la nature est un travail complexe en termes de savoirs, de techniques, de décisions éthiques, de logiques affectives. Ce colloque souhaitait engager des réflexions épistémologiques sur la conservation à différentes échelles spatiales et temporelles. Les communications avaient pour objets des réserves naturelles, des coalitions d’acteurs, des pratiques muséales, les liens entre conservation et capitalisme. Elles étaient présentées par des anthropologues, sociologues, écologues, des étudiants en littérature, en biologie et en géographie. La discussion de cet article portera sur les enjeux de sensibilité des données, sur la violence de la conservation, sur ses frontières et limites ainsi que sur ses instabilités.
Roles of heat shock proteins in tumor immune microenvironment
Authors: Zhou Qin , Guan Xin-Yuan , Li Yan
Published: February 2024

Heat shock proteins (HSPs) are the most abundant molecular chaperones in cells, categorized based on function and molecular weight into HSP families, namely, HSP40, HSP70, HSP90, HSP110, and HSPB (heat shock protein B), et al. HSPs are involved in protein homeostasis by assisting in the correct folding of proteins or incorrectly folded proteins, refolding partially denatured proteins, and degrading damaged proteins. High levels of HSPs have been shown to participate in oncogenesis, progression, and chemotherapy resistance in many cancers. Recently a new range of functions besides chaperons, mostly in modulation of immune responses, have been shown for these extracellular HSPs. Here, we review the interactions between the HSPs and different immune cells, such as T lymphocytes, B cells, dendritic cells, macrophages, NK cells, and myeloid suppressor cells in the tumor microenvironment, as well as tumor vasculature and angiogenesis in tumor formation. The underlying mechanisms of HSPs’ regulation on immune response in tumor microenvironments are also discussed. The understanding of new functions of HSPs in tumor microenvironment may provide critical insights for the development of effective immunotherapies.
Green Endoscopy – Strategien für mehr Nachhaltigkeit in der Endoskopie
Authors: Eickhoff Axel , Goetz Martin
Published: February 2024

Das Thema Klimaschutz, Ökologie und CO2-Neutralität wird seit Jahren in der Gesellschaft intensiv und zunehmend diskutiert. Auch in Krankenhäusern und anderen medizinischen Einrichtungen nimmt dies einen immer höheren Stellenwert ein. Der Gesundheitssektor ist für 5,6% aller deutschlandweiten CO2-Emissionen verantwortlich, insbesondere durch den hohen Energieverbrauch und den anfallenden Müll von 6kg pro Patient und Tag. Der folgende Beitrag fasst die Möglichkeiten zusammen, die die Endoskopie als Beitrag zur ökologischen Nachhaltigkeit zu leisten vermag. Ein besonderer Focus liegt auf den heute schon einfach umzusetzenden Maßnahmen.
Suppressing galloping-induced vibrations by integrating bluff body with surface protrusions
Authors: Xing Juntong , Rezaei Masoud , Dai Huliang , Liao Wei-Hsin
Published: February 2024

As a kind of self-excited large amplitude vibration, galloping is detrimental to engineering structures. Therefore, how to effectively suppress it has been a crucial issue for both industry and academia. In this Letter, a passive method based on integrating rectangular prismatic bluff bodies with different surface protrusions is proposed to mitigate galloping-induced vibrations. Both wind tunnel experiments and numerical simulations prove the validity of this method. Moreover, computational fluid dynamics simulations are also performed to investigate the underlying aerodynamic phenomena. Results reveal that the maximum amplitude and energy suppression ratios can reach 100%, especially for wind speeds higher than 3 m/s. As opposed to previous methods that delay galloping vibrations to higher wind speeds, this technique can directly change the vibration type from conjoint vortex-induced vibration (VIV)-galloping to VIV, which fundamentally eliminates galloping oscillations. Therefore, this method is promising in suppressing galloping vibrations.
Logistic regression analysis of mRNA expression changes and prognosis after cervical surgery
Authors: Song Yinghui , Zhang Min , Zhang Cui , Du Shiyu , Zhai Furui
Published: February 2024

Objective: The aim of this study was to investigate the diagnostic value of HPV (human papillomavirus) E6/E7 mRNA combined with thin-layer liquid-based cytology test (TCT) detection in patients with cervical intraepithelial neoplasia (CIN) in the residual and recurrence of lesions after cervical conization. Methods: A total of 154 patients who had undergone cervical conization and were diagnosed with high-grade cervical intraepithelial neoplasia (CIN 1 and CIN 3) by histopathology and had complete follow-up data were enrolled. TCT, HPV-DNA detection, and HPV E6/E7 mRNA detection combined with TCT detection in 12 months can be used to detect abnormal cytology (>atypical squamous epithelium of undetermined significance). Patients with atypical squamous cell of undetermined significance or high-risk HPV-DNA (+) or HPV E6/E7 mRNA combined with TCT (+) underwent colposcopy and cervical biopsy again for pathological diagnosis. Results: There were 9 cases of residual lesions and 22 cases of recurrence. Thirty of the 57 cases with positive HPV-DNA after surgery were still there or came back. Of the 26 cases with positive HPV E6/E7 mRNA combined with TCT, 24 were still there or came back. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy rate of HPV-DNA detection were 96.8%, 78.0%, 52.6%, 99.0%, and 81.8%, respectively; the sensitivity and specificity of HPV E6/E7 mRNA were combined with TCT detection of sex. Conclusion: HPV E6/E7 mRNA combined with TCT detection can be included in follow-up examinations, which can timely and effectively predict the risk of CIN residual or recurrence after cervical conization and reduce excessive examination and treatment.
Study on the pyrolysis characteristics of styrene-grafted polypropylene cable insulation material
Authors: Peng Chao , Chu Fanwu , Xu Mingzhong , Hou Junping , Zhang Wei , Deng Kai , Gong Jian , Qin Zihang
Published: February 2024

Polypropylene (PP) has garnered significant attention as a cable insulation material due to its exceptional electrical performance and recyclability. Styrene-grafted polypropylene (PP-g) emerges as a promising alternative in this context. This study employs thermogravimetric-gas chromatography experiments and reactive molecular dynamics simulations to compare the pyrolysis process and decomposition products of pure PP and PP-g as cable insulation materials. Results indicate that while both materials produce similar pyrolysis products, PP-g exhibits greater resistance to decomposition than PP. The predominant hydrocarbons in the decomposition products include methane (CH4), ethylene (C2H4), propylene (C3H6), and ethane (C2H6). The relative proportion of hydrocarbons decreases with increasing temperature, with a shift toward increased C2H6 production. The ratio of C2H6 to (CH4 + C2H4) molecular weights in thermal decomposition products rises with temperature, suggesting enhanced stability. Graft modification alters the decomposition pathway, specifically increasing the generation of C2H6. This study lays a theoretical foundation for cable aging monitoring and life assessment.
Results on partial approximate controllability of fractional control systems in Hilbert spaces with conformable derivatives
Authors: Jneid Maher
Published: February 2024

This paper investigates partial approximate controllability of fractional linear and semi-linear control systems involving the conformable derivative. First, we derive sufficient and necessary conditions for partial approximate controllability of fractional linear systems over a small interval. Then, we apply a new approach, different from typical methods involving complexity inequalities and fixed point theorems, to obtain sufficient conditions for partial approximate controllability of semi-linear fractional control systems, assuming that the linear part is partially approximately controllable. The effectiveness of these results is demonstrated through an illustrative example.
Electromagnetic analysis of permanent magnet-assisted synchronous reluctance motor based on magnetic equivalent circuit
Authors: Kim Su-Min , Kim Tae-Seong , Jung Woo-Sung , Nguyen Manh-Dung , Kim Yong-Joo , Shin Kyung-Hun , Choi Jang-Young
Published: February 2024

As rare-earth permanent magnet prices continue to fluctuate, interest in non-rare-earth permanent magnet-assisted synchronous reluctance motors (PMa-SynRMs) is increasing. However, non-rare-earth PMa-SynRMs have a multi-layer structure with interior permanent magnets to compensate for the low magnetic fields. Therefore, the rotor has several design parameters, and electromagnetic analysis is time-consuming. To overcome these challenges, magnetic equivalent circuit analysis was used to perform fast electromagnetic analysis of non-rare-earth PMa-SynRMs. In addition, the validity of the proposed method was confirmed through a comparison of the obtained results with those of finite element analysis.
Revisiting the universality law in magnetically detected residual stresses in steels
Authors: Mangiorou Eleni , Damatopoulou Tatiana V. , Angelopoulos Spyridon , Kalkanis Konstantinos , Vourna Polyxeni , Ktena Aphrodite , Hristoforou Evangelos
Published: February 2024

The dependence of residual stresses on differential permeability, determining the so called Magnetic Stress Calibration (MASC) curve, results in the Universal MASC curve after normalizing the stress and permeability axes with the yield stress and the maximum differential permeability of the steel under test, respectively. The motivation of this paper is to illustrate the ability of obtaining the MASC curve of an unknown steel just by measuring its yield stress and maximum differential permeability. The calculated MASC curve of an unknown type of steel, obtained by multiplying the stress and permeability axes of the Universal MASC curve with the yield stress and maximum differential permeability obtained by the stress-strain curve under simultaneous measurement of the permeability, was compared with the actual MASC curve of the same unknown type of steel determined by the classical method, with an agreement better than ±5%. The conclusion is that the actual MASC curve of an unknown type of steel can be determined just by a stress-strain measurement, with simultaneous determination of the maximum amplitude of the differential permeability.
A revisit of three hypotheses about second language development of English relative clauses
Authors: Ng Chi Wui
Published: February 2024

Cantonese-English learners in Hong Kong confront with substantial difficulty in development of English relative
clauses. This study aims at verifying predictions of hypotheses about second language learners’ development of English relative
clauses with data of written Hong Kong English. wh relatives and that relatives in the Hong Kong
component of the International Corpus of English were identified. Frequencies of occurrence of distinct types of relative clauses
in the Hong Kong component were compared to evaluate whether predictions of Keenan and
Comrie’s (1977) Noun Phrase Accessibility Hierarchy, Kuno’s (1974)
Perceptual Difficulty Hypothesis, and Hamilton’s (1994) Subject-Object Hierarchy
Hypothesis are supported by the corpus data respectively. Results indicate that the Perceptual Difficulty Hypothesis is supported
by data of written Hong Kong English whilst the other two hypotheses are partially supported only. Hypotheses supported by corpus
data of written Hong Kong English are suggested to inform English language education in Hong Kong by illuminating the
instructional order of different types of English relative clauses.
Dealing with a Multi-Rabbit Household When Breeding is Uncontrolled
Authors: Tyson Jane
Published: February 2024

The Royal Society for the Prevention of Cruelty to Animals (RSPCA) was called to help an owner with a large number of rabbits living on a domestic property. As often happens in these situations, the owner initially acquired a pair of rabbits which quickly bred, and because the owner had no knowledge of their reproductive systems, the numbers quickly spiralled. At first, the owner was reluctant to engage but over time realised that help was needed, not just for the rabbits but for themselves too. It became clear that they were not intentionally causing suffering to their animals, but had become overwhelmed and did not know how to get support. Over a period of time, the RSPCA built a trusting relationship with the owner and was able to reduce the number of rabbits in their home by removing them into the care of the charity where they were triaged and the majority were rehabilitated and rehomed. While the overall living conditions were poor, the rabbits were fed a hay-based diet and had access to conspecifics, so these needs were met in terms of diet and social opportunities. The rabbits were free-roaming and had space to meet the need to be able to move with different gaits and stretch. However, evidence of aggressive encounters indicates social and space needs were only partially met as there was no opportunity for individuals to move right away to set up separate compatible social groups. The owner was supported in their desire to keep a small group of four rabbits; the property was thoroughly cleaned and disinfected and became a suitable place for the remaining rabbits to live. These rabbits were provided with veterinary treatment including neutering to ensure this situation was prevented from happening again. Additionally, the RSPCA signposted the owner to other organisations for ongoing support with their own health and wellbeing.

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Exploring strategies for pet owners experiencing homelessness: A rapid scoping review
Authors: Kurkowski Michelle , Springer Andrew
Published: February 2024

Approximately 10% of homeless individuals keep pets, but little information exists on specific interventions for this population. The aim of this rapid review is to describe what is currently known about intervention strategies for improving the health of homeless pet owners and their companion animals to identify knowledge gaps and inform future research and interventions. A database search of PubMed and Embase was conducted, and relevant articles were divided into primary research studies and “white papers” reporting proposed or attempted interventions, with each group analyzed separately. Common intervention strategies found across the literature were then summarized in narrative form. Nineteen articles fit the inclusion criteria, including 6 original research studies, 9 case reports and 4 narrative reviews. From analysis of these articles, 5 common intervention strategies emerged, including: (1) Free veterinary clinics, (2) Joint human/animal clinics, (3) Stigma reduction, (4) Interdisciplinary relationships and (5) Pet-friendly lodging. Studies on this population exhibited significant heterogeneity, and further program evaluation is needed to recommend intervention best practices. Joint human/animal clinics and interdisciplinary partnerships are promising avenues for evaluating interventions and improving health outcomes.
Analysis and implementation of shorting pins in microstrip patch antenna for SAR reduction
Authors: Kurup Hrudya B , Antony Divya , Rajan Vivek , Rodrigues Stephen
Published: February 2024

Specific absorption rate (SAR), is the safety measure to quantify human exposure to electromagnetic radiation from mobile phones and other wireless devices, which must be kept within the permissible levels to avoid various health concerns. This paper provides an experimental study on the effectiveness of SAR reduction, using shorting pins, and its corresponding effects on antenna performance. A compact, single-element, microstrip patch antenna design, using shorting pins, with reduced SAR value, is also presented. The surface current distribution on the patch can be modified by the strategic positioning of shorting pins to produce a mushroom shaped radiation pattern having nearly omnidirectional nature in the +Z direction with a near-field null in the vicinity of the user’s direction. This completely minimizes the back lobes in the E-plane, with minor back lobes in the H-Plane creating a deep null, which reduces the SAR value without compromising the signal coverage. The antenna is fabricated and cross-verified by experimental evaluation in an anechoic chamber for return loss, gain, and radiation pattern.
A new synchronization result for fractional-order discrete-time chaotic systems via bandlimited channels
Authors: Hamiche Hamid , Megherbi Ouerdia , Kemih Karim , Kara Redouane , Ouslimani Achour
Published: February 2024

Recently, digital chaotic communication with limited bandwidth has seized the attention of several researchers. This interest stems from the fact that all physical communication channels are limited in bandwidth for data transmission. In furtherance of this, researchers and investigators in this area have put forward various new communication strategies based on synchronizing and controlling coupled chaotic systems evolving in discrete time. In this article, we present a new robust communication scheme based on the synchronization of two fractional-order discrete-time chaotic systems connected by bandlimited channels. The major contribution is to give a sufficient condition in term of the existing and updated parameters of the incorporated fractional-order system on one hand and the inserted filter coefficients, on the other hand. Once applied for data communications, the currently drawn up synchronization scheme pledges to enhance the transmission robustness. Indeed, the new considered parameters act like novel secret keys which widen the cipher key space. Primary and pertinent simulation curves and results performed on Matlab software portray and illustrate the effectiveness of our approach.
High-frequency suppression of inductive coupling between flux qubit and transmission line resonator
Authors: Ashhab Sahel , Ao Ziqiao , Yoshihara Fumiki , Lupascu Adrian , Semba Kouichi
Published: February 2024

We perform theoretical calculations to investigate the naturally occurring high-frequency cutoff in a circuit comprising a flux qubit coupled inductively to a transmission line resonator (TLR). Specifically, a decoupling occurs between the qubit and the high-frequency modes. The coupling strength between the qubit and resonator modes increases with mode frequency ω as

ω

at low frequencies and decreases as

1

/

ω

at high frequencies. This result is similar to those of past studies that considered somewhat similar circuit designs. By avoiding the approximation of ignoring the qubit-TLR coupling in certain steps in the analysis, we obtain effects not captured in previous studies. In particular, we obtain a resonance effect that shifts the TLR mode frequencies close to qubit oscillation frequencies. We derive expressions for the TLR mode frequencies, qubit-TLR coupling strengths and qubit Lamb shift. We identify features in the spectrum of the system that can be used in future experiments to test and validate the theoretical model.
Mechanistic insights of COVID-19 dynamics by considering the influence of neurodegeneration and memory trace
Authors: Joshi Hardik
Published: February 2024

COVID-19 has been declared a global pandemic as it disturbs education, society, agriculture, the economy, poverty, death rate, social development, mental psychology, and many more. Neurodegenerative disease is a brain disorder associated with several pathological factors along with mental psychology. This paper introduces a mathematical model to inspect mechanistic insights into COVID-19 dynamics by considering the influence of neurodegeneration and memory trace. The analysis of the proposed model and the existence and uniqueness of the model are derived using the fixed-point criteria. A numerical experiment is presented to validate the theoretical results and examine the impact of various biological parameters, the influence of neurodegeneration, and memory trace on the transmission dynamics of COVID-19.
An adaptive dynamic window approach for UUV obstacle avoidance planning in 3D environments
Authors: Lin Changjian , Liu Yuhao , Lin Shibo
Published: February 2024

Unmanned Underwater Vehicles (UUVs) are essential equipment for Marine development, widely used in Marine scientific research, Marine resource survey, and Marine security. The autonomous navigation planning ability in unknown environments is a critical indicator for UUV intelligence. This paper focuses on the particularity of UUV motion and the complexity of the underwater environment and proposes an adaptive Dynamic Window Approach (DWA) for UUV obstacle avoidance planning. The adaptive DWA introduces novel heading angle evaluation and adaptive dynamic strategies to solve the problems of poor adaptability of traditional DWA to complex environments and unreasonable path selection in encountering dynamic obstacles and approaching targets. Simulations verify the effectiveness and superiority of the proposed method.
Research on the linear driving characteristics of endoscopic continuous robot
Authors: Niu Yibo , Jin Xiaoyi , He Zhikun , Meng Panpan
Published: February 2024

Due to the way line drive, the continuous endoscope robot will have a certain lag in the process of movement, which will affect the accuracy and flexibility of the operation. In addition, the hysteresis and return difference caused by wire rope transmission will also increase the hysteresis effect of continuous robots. In this paper, the motion characteristics of the continuous endoscopic robot are analyzed, the hysteresis of the robot is modeled theoretically based on the Preisach model, and the effectiveness of the model is verified. Preisach hysteretic nonlinear hyperbola model predicts the bending changes under different positive and negative drives. The experimental results show that the maximum error between the model and the theoretical prediction is 3.18 degrees. The hysteresis model can predict the hysteresis characteristics of the continuous endoscope robot well.
Calculation Model and Accuracy Study of Transformer Standard Oil Preparation
Authors: Li Yanping , Fang Jianjun , Xu Yingjie , Cui Xinyi
Published: February 2024

This article introduces a treatment method, component concentration calculation model, and device for preparing standard oil using transformer oil. The base oil is prepared by deeply purifying the transformer oil and measuring its background value. Based on the target component concentration, the appropriate volume of standard gas is determined, and the background value of the combined oil is used in the component concentration calculation model to determine the theoretical value of the standard oil. The standard oil value that has been prepared is in good agreement with the anticipated target value, thereby simplifying the purification process and cutting down on the processing cost of used transformer oil. Simultaneously, a fully automatic integrated device has been developed for the advanced purification of transformer oil and the production of standard oil. This device comprises a vacuum pump, an oil storage tank, an electromagnetic valve, an oil cylinder, and various sensors, all managed by sophisticated software. The standard oil for transformers can be prepared and stored stably for an extended period. The standard oil output is processed under sealed and unchanging pressure conditions to ensure a consistent concentration of components in the standard oil.
Limiting Factors of Simultaneous Measurement Method for Turbidity and Total Suspended Solids Based on Image Processing Approaches
Authors: Hakiki Rijal , Purnama Irwan , Zevi Yuniati , Muntalif Barti Setiani
Published: February 2024

Image processing is one of the computational approaches that can be applied to measure fluctuations in surface water pollutant concentrations. Identifying factors that can affect and become a limitation in the development of image processing-based simultaneous measurement methods is the focus of the discussion in this article. Nineteen variables have been identified from the three-factor categories of hardware configuration, software settings, and the measured suspension characteristics. Measurements were made on thirty images extracted from video captured with a USB Mechanic-DX-230 camera with a 23-megapixel resolution Panasonic CMOS sensor equipped with a macro lens in 130X magnification on the S-EYE-1.6.0.11 interface. Image frame extraction was performed with VirtualDub2 build 4428/release, followed by digital image processing and analysis with ImageJ 1.46r. The lens’s focal length to the sample cell is 5 cm, setting the brightness parameter minimum of 90 and maximum of 255 and minimum threshold settings of 209 and maximum of 255, which is a controlled factor to achieve the best repeatability rate. It is indicated by a relative standard deviation of up to 6% in the measurement chamber with a dark background. Complying with the stated factors is essential to ensure measurement results’ reliability and validity.
Coordinated control strategy for microgrid based on improved virtual DC motor
Authors: Cheng Xiaoman , Yue Youjun , Zhao Hui , Wang Hongjun
Published: February 2024

The coordinated control strategy based on the improved virtual DC motor (VDCM) is proposed to address the bus voltage fluctuation of an isolated DC microgrid and the power distribution problem of multiple energy storage units. Firstly, the memory converter control process unit is enhanced by adding the VDCM link and low-pass filtering link. Secondly, considering factors such as photovoltaic power, constant-power loads, and battery charging state, six working modes are defined to ensure stable DC bus voltage in each mode. Finally, a simulation model of the isolated DC microgrid is found by using simulation software to verify the validity of this method.
Predefined time backstepping control of photovoltaic grid connected inverter
Authors: Xu Zhao , Ji Yuehui , Chen Jiaqi , Liu Junjie
Published: February 2024

The large-scale grid connection of photovoltaic (PV) systems creates great hazards to the operation of power equipment and has a great impact on the stability and reliability of power systems. To achieve stable control and flexible management of PV grid connection, a predefined time adaptive backstepping control method based on the predefined boundary is proposed. Based on the predefined boundary time-varying function, the user’s predefined boundary design of the control signal is accomplished to ensure the boundedness of the global signal, which is independent of the initial state of the system. The controller with predefined boundaries is designed based on backstepping control, and the estimation and compensation of perturbations are attained based on adaptive control. The global predefined time stability of the predefined boundary of the closed-loop system is certified using the Lyapunov function. Simulation studies attest to the performance of the predefined time control strategy.
The interelectrode breakdown mechanism and discharge characteristics of the electrospray thruster
Authors: Han Xiao , Ye Jifei , Cui Haichao , Yu Chenghao , Song Hang
Published: February 2024

In the actual working process of electric thrusters based on high-voltage electric fields, the discharge breakdown phenomenon is universal and complex, and such phenomena will have a significant impact on the thruster structure, working state and spacecraft system. In order to study the interpolar discharge breakdown characteristics of ionic liquid electrospray thrusters, a basic electrospray model and test system were constructed, and the change curves of discharge characteristic parameters such as breakdown voltage, threshold current, breakdown voltage frequency and so on in the range of 7×10−3~105 Pa with air pressure and transmitter inner diameter were obtained, and the air pressure range that the electrospray model could work in normally was calibrated. The results show that the breakdown voltage characteristic curve of the electrospray model has typical minimum characteristics, and the minimum values all appear around 80 Pa. Lowering the air pressure below 10−2 Pa can effectively increase the breakdown threshold between the poles and the emission current, thereby obtaining a larger voltage regulation range, and when the air pressure is reduced to 7×10−3 Pa, the breakdown can reach more than 3200 V. The 60-μm inner diameter emitter performed better in the discharge experiment, and the breakdown threshold, emission current and operating area range were better than the slightly larger inner diameter emitter under the same working conditions.
Numerical simulation analysis of wind load on an integral bridge with steel-concrete composite girder based on cloud platform
Authors: Liu Hongwei
Published: February 2024

The integral bridge with steel-concrete composite girder will be affected by wind load in the natural environment, so the buffeting effect of wind on the integral bridge with steel-concrete composite girder cannot be ignored. In order to solve the above problems, the numerical simulation analysis on the wind load on integral bridge with steel-concrete composite girder based on cloud platform is carried out. Before the buffeting analysis of the bridge, the wind environment condition should be calculated. Taking the integral bridge with steel-concrete composite girder as an example, based on empirical formula, the influence of girder size change on static wind load and static wind load under different wind speeds are calculated and analyzed. With the help of Davenport fluctuating wind’s power spectrum, the fluctuating wind field of integral bridge with steel-concrete composite girder under certain wind speed is simulated by harmonic synthesis method, the wind load value of integral bridge with steel-concrete composite girder is simulated, and the structural design of bridge is carried out, in order to ensure the scientificity and safety of bridge design. The numerical simulation can correctly react the test law, and can predict the wind resistance of the structure with the existing model.
Numerical study on aerodynamic performance during the process of entering the formation flight
Authors: Wang Xiaobing , Li Yuping , Ma Shang , Liu Guangyuan , Tao Yang
Published: February 2024

. Two or more planes can fly in close formation similar to migratory birds, making use of the wing-tip vortex of the leader plane to increase lift and reduce drag, thereby effectively improving the flying range. By conducting wind tunnel tests and numerical simulations, the aerodynamic performance of formation flight at different relative positions can be obtained, the optimal formation position can thereby be solved. However, significant nonlinear and unsteady aerodynamic characteristics, induced by the interference between the follower plane and the wing-tip vortices of the leader plane, will affect the flight safety of the whole formation. At present, there is no effective prediction methods. Numerical simulations adopting adaptive grid refinement and dynamic overset grid were conducted for the dynamic entering process of the formation flight containing two Ty-154 planes. The aerodynamic characteristics and vortex interferences were analysed considering the effects of approaching direction and speed. The results indicate that there is deterioration of stability at the position where maximum lift gain is reached; Compared to the entering speed, the impact of directions on dynamic aerodynamic characteristics is more significant.
Investigation of the inhibiting effect of environmentally friendly cerium-containing conversion films on the corrosion of zinc coatings
Authors: Peshova M , Bachvarov V
Published: February 2024

In the present work, the inhibiting effect of environmentally friendly cerium and phosphorus-based conversion films on zinc corrosion in 5% NaCl and 1 N Na2SO4 test media was investigated. The films were prepared by immersion and stirring in the passivating/converting solution for time periods of 3,5,7, 10 min., respectively. The chemical composition of the films was determined by EDX analysis. The results of the electrochemical studies showed that in 5% NaCl medium, cerium- and phosphorus-based films exhibited high inhibition effect only during the first days of polarization resistance (Rp) measurement. In 1 N Na2SO4 medium, the Rp of the conversion films was up to 2.5 times higher than that of pure zinc coatings throughout the test period.
Effect of deposition conditions on the structural and mechanical properties of oxynitride TaON coatings for biomedical applications
Authors: Donkov N , Zykova A , Safonov V , Dudin S , Yakovin S , Georgieva B
Published: February 2024

A thorough evaluation was conducted of the structural and nano-mechanical characteristics of oxynitride coatings with TaOxNy structures formed by reactive magnetron sputtering at different flows of the reactive oxygen/nitrogen gasses. Tantalum oxynitrides exhibit a broad range of modifications in their structure and elemental content depending on the conditions of deposition. The TaON structures combine the characteristics exhibited by tantalum nitride, used as a hard material for tribological and mechanical applications, with the excellent dielectric properties of the tantalum oxide. The results discussed point to the deposited tantalum oxynitrides being promising candidates for biomedical applications.
New diffraction-limited laser systems with variable output parameters operating in visible spectral range on copper atomic transitions for advanced material micromachining
Authors: Kostadinov I K , Temelkov K A , Shehadi M , Slaveeva S I , Yankov G P
Published: February 2024

New considerably improved laser systems (LS) featuring beam propagation factor equal to unit, two different laser pulse durations and an average output power from several tens of Watts up to 50 W are reported. Micron-sized machining is also demonstrated.