bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of in-medium effects of charmonia using azimuthal anisotropy and jet fragmentation function in PbPb collisions at √SNN = 5.02 TeV with the CMS experiment
Authors: Bak Gyeonghwan
Published: March 2023

Quarkonia have been long proposed as the golden probes to study quark-gluon plasma (QGP) in heavy-ion collisions. In this presentation, we present the second- and third-order Fourier coefficients, v2 and v3, for prompt and nonprompt J/ψ mesons in PbPb collisions as functions transverse momentum (pT) and PbPb collision centrality. Also, we report the first measurements of v2 and v3 for the prompt ψ(2S) mesons in PbPb collisions. The results provide v2 and v3 values over the wide studied kinematics regions of transverse momentum and collision centrality.
Heavy-flavor jets in heavy-ion collisions
Authors: Oh Saehanseul
Published: March 2023

Heavy-flavor jets are a unique tool to study dynamical evolution of QCD systems via heavy-flavor particles, allowing one to access to the original parton kinematics and to separate out production and fragmentation effects. In these proceedings, various heavy-flavor jet results in pp, pA, and AA collisions are presented, extending the scope of heavy-flavor studies discussed at this conference series, the Strangeness in Quark Matter.
Heavy-flavor anisotropic flow at RHIC and LHC energies within a full transport approach
Authors: Oliva Lucia , Sambataro Maria Lucia , Sun Yifeng , Minissale Vincenzo , Plumari Salvatore , Greco Vincenzo
Published: March 2023

The propagation of heavy quarks (HQs) in the quark-gluon plasma (QGP) is described by means of a full Boltzmann transport approach. The nonperturbative dynamics and the interaction between HQs and the bulk is taken into account by means of a Quasi-Particle Model. Including the intense electromagnetic and vortical fields, we discuss their impact on the directed flow of neutral D mesons at RHIC energy, clarifying the role of this observable in giving information on QGP transport properties. We also show a novel study of the correlations between different flow coefficients of D mesons and soft hadrons at LHC energy within a coalescence plus fragmentation hadronization scheme and including event-by-event initial state fluctuations. This investigations can put further constraints on HQ transport coefficients towards a solid determination in comparison to the lattice QCD calculations.
Medium-modifications of g → cc splitting
Authors: Park Sohyun
Published: March 2023

We study medium-modifications of the gluon splitting into a quark and anti-quark pair. Applying the Baier-Dokshitzer-Mueller-Peigné-Schiff and Zakharov (BDMPS-Z) formalism, we derive a path-integral formula for the in-medium g → qq¯ splitting function in the close-to-eikonal limit. Our analysis shows that there are two qualitatively different medium effects: transverse momentum broadening of qq¯ pairs and enhanced production of such pairs. We note that both effects are numerically sizeable if the average momentum transfer from the medium to the parton is at the quark mass scale. In ultra-relativistic heavy-ion collisions, this condition is realized by charm quarks, therefore we focus our numerical analysis on the medium-modifications of g → cc¯ splitting.
Impact of the electromagnetic field on Z0 leptonic invariant mass in ultrarelativistic heavy ion collisions
Authors: Sun Yifeng , Greco Vincenzo , Wang Xin-Nian , Plumari Salvatore
Published: March 2023

The extraordinary strong magnetic field generated in ultrarelativistic heavy ion collisions makes it possible to investigate many novel effects in the hot QCD matter, and a direct probe of it thus becomes an urgent task in the field. Here we report a new way to probe it, where the leptonic invariant mass distribution of Z0 boson will be modified in the presence of the magnetic field due to the Lorentz force on the lepton pairs from the decay of Z0 boson. It is found that the magnetic field can decrease the mean value of Z0 leptonic invariant mass and increase its width, and both shifts approximately depend on the integral of the magnetic field over its time duration quadratically.
In-medium effects on hidden strangeness production in heavy-ion collisions
Authors: Song Taesoo , Aichelin Joerg , Bratkovskaya Elena
Published: March 2023

We study ϕ meson production in heavy-ion collisions from subthreshold energies of 1.23 A GeV up to RHIC energies within the microscopic Parton-Hadron-String Dynamics (PHSD) transport approach where novel production channels for ϕ mesons based on a coupled channel T-matrix approach are implemented along with the collisional broadening of the ϕ meson spectral width in medium. Since ϕ meson production is closely related to the production of kaons and antikaons, antikaon properties are described via the self-consistent coupled-channel unitarized scheme within a SU(3) chiral Lagrangian (G-matrix) which incorporates explicitly the s− and p− waves of the kaon-nucleon interaction, while the in-medium modifications of kaons are accounted for via a kaon-nuclear potential, which is assumed to be proportional to the local baryon density.
Baryon Number Transport, Strangeness Conservation and Ω-hadron Correlations
Authors: Wu Xiatong , Dong Weijie , Yu Xiaozhou , Li Hui , Wang Gang , Zhong Huang Huan , Lin Zi-Wei
Published: March 2023

Although strange quarks are produced in ss¯ pairs, the ratio of Ω− to Ω¯+ is greater than one in heavy-ion collisions at lower RHIC energies. Thus the produced Ω hyperons must carry net baryon quantum numbers from the colliding nuclei. We present results of K-Ω correlations from AMPT model simulations of Au+Au collisions at √SNN = 14.6 GeV, to probe dynamics for baryon number transport to mid-rapidities at this beam energy. We use both the default and string-melting versions to illustrate how hadronization schemes of quark coalescence and string fragmentations could leave imprints on such correlations. Implications on the measurements of these correlations with the STAR experiment at RHIC will also be discussed.
Results of femtoscopic correlations at CMS
Authors: Pradhan Raghunath
Published: March 2023

The two particle correlations as a function of relative momenta of identified hadrons involving Ks0 and Λ/Λ¯ are measured in PbPb collisions at √SNN = 5.02 TeV with the data samples collected by the CMS experiment at the LHC. Such correlations are sensitive to the quantum statistics and possible final state interactions between the particles. The source radii are extracted from KS0KS0 correlations in different centrality regions and found to decrease from central to peripheral collisions. The strong interaction scattering parameters are extracted from ΛKS0KS0⊕Λ¯KS0 and ΛΛ⊕ΛΛ¯ correlations using the Lednicky-Lyuboshits model, and compared with other experimental and theoretical results. In addition, we present results for the source radii of charged hadrons considering the Levy type source distributions in PbPb collisions at √SNN = 5.02 TeV.
The physics program of the NA60+ experiment
Authors: De Falco Alessandro
Published: March 2023

The NA60+ experiment, which has been proposed as a fixed target experiment at the CERN SPS, is designed to study the phase diagram of the strongly interacting matter at high baryochemical potential by performing precision studies of thermal dimuons, heavy quark and strangeness production in Pb-Pb collisions at center-of-mass energies ranging from 5 to 17 GeV. The progress of the R&D and the key points of the NA60+ physics program will be described.
Hadron production from heavy ion collisions
Authors: Ko Che Ming
Published: March 2023

A brief review of some topics in hadron production from heavy ion collisions is given. They include charged pion ratio as a probe of nuclear symmetry energy, in-medium effects on pion production, en- hanced Λc/D0 ratio, Λ local polarization, and X(3872) production.
A physics-based neural network reconstruction of the dense matter equation of state from neutron star observables
Authors: Soma Shriya , Wang Lingxiao , Shi Shuzhe , Stöcker Horst , Zhou Kai
Published: March 2023

We introduce a novel technique that utilizes a physics-driven deep learning method to reconstruct the dense matter equation of state from neutron star observables, particularly the masses and radii. The proposed framework involves two neural networks: one to optimize the EoS using Automatic Differentiation in the unsupervised learning scheme; and a pre-trained network to solve the Tolman–Oppenheimer–Volkoff (TOV) equations. The gradient-based optimization process incorporates a Bayesian picture into the proposed framework. The reconstructed EoS is proven to be consistent with the results from conventional methods. Furthermore, the resulting tidal deformation is in agreement with the limits obtained from the gravitational wave event, GW170817.
Was ist Selbstfürsorge? Möglichkeiten im
Praxisalltag.
Authors: Garten Daniela , Hultsch Anna
Published: March 2023

Mit diesem Artikel startet die Zeitschrift HEBAMME eine neue Serie zum Thema
„Selbstfürsorge“. Lesen Sie, warum es wichtig ist, immer
wieder innezuhalten – gerade in Berufen mit hoher Verantwortung,
Arbeitsbelastung und psychischer Beanspruchung. Lernen Sie, mit den eigenen
Ressourcen achtsam umzugehen, Stress zu bewältigen, sich
regelmäßig zu bewegen und zu entspannen sowie Momente des
Glücks ganz bewusst zu genießen. Lassen Sie sich inspirieren,
wie Sie Beruf und Privates besser in Balance bringen und neue Potenziale
entdecken können. Die Serie liefert wertvolles Hintergrundwissen und
praktische Anregungen.
Geburtsvorbereitung – brauchen wir dafür
überhaupt noch Hebammen?
Authors: Bloemeke Viresha , Klotzsch Anne-Katrin , Stamm Anja
Published: March 2023

Unter dem Begriff Geburtsvorbereitung versteht man verschiedene Kurs- und
Informationsangebote für Frauen und Paare in der Schwangerschaft. Diese
sollen sie körperlich, mental und/oder psychisch auf die Geburt
vorbereiten. Die Aufgabenstellung ist komplex und die involvierten Personen und
Berufsgruppen decken ein breites Spektrum ab. Dabei stellt sich die Frage
– brauchen wir dafür eigentlich noch Hebammen?
Fertility after Transcatheter Arterial Embolization for Obstetric Hemorrhage: An Urban Health Care System Observational Study
Authors: Mills Ariana C. , Marinelli Brett , Klein Emma D. , Garcia-Reyes Kirema , Shilo Dan , Nowakowski Scott , Patel Rahul , Patel Rajesh , Kim Edward , Fischman Aaron , Bishay Vivian , Loudon Holly , Stone Joanne , Lookstein Robert
Published: March 2023

Objective This study aimed to investigate pregnancy rate, pregnancy outcomes, and resumption of menses after transcatheter arterial embolization (TAE) for obstetric hemorrhage (OH).

Study Design Sixty-seven patients who underwent TAE for OH from 2006 to 2020 within an urban, multihospital health care system were identified retrospectively. Selected patients were interviewed by phone to complete a survey with a primary outcome of self-reported pregnancy in those seeking pregnancy. Secondary outcomes included pregnancy outcomes and resumption of menses. Univariate testing of association of pregnancy and miscarriage rate with embolic agent was performed using Fisher's exact test.

Results Thirty-three of 50 patients (66%) meeting the inclusion criteria completed the survey on fertility, a median of 47 (range, 13–123) months after TAE for OH. Of the 13 patients who attempted pregnancy, there was a pregnancy rate of 77% and miscarriage rate of 38%. Those who delivered live newborns conceived spontaneously, carried to term, and delivered a healthy newborn via cesarean section at a weight appropriate for gestational age. Thirty (91%) patients resumed menstruation, and the majority with unchanged frequency. Most patients underwent bilateral uterine artery embolization with radial artery access (54%). The most common embolic agents used were gelfoam only (30%) and glue only (24%). There was no statistically significant association between embolic agent and pregnancy or miscarriage rate.

Conclusion Spontaneous pregnancy with live birth and resumption of menses can occur in a majority of patients after TAE for OH.

Key Points
The high intensity diffractometer for residual stress analysis (HIDRA), a third generation residual stress mapping neutron diffractometer at the high flux isotope reactor
Authors: Bunn J. R. , Fancher C. M. , Payzant E. A. , Cornwell P. A. , Bailey W. B. , Gregory R.
Published: March 2023

This paper describes the hardware and software upgrades, operation, and performance of the high intensity diffractometer for residual stress analysis (HIDRA) instrument, a residual stress mapping neutron diffractometer located at the High Flux Isotope Reactor at Oak Ridge National Laboratory in Oak Ridge Tennessee, USA. Following a major upgrade in 2018, the new instrument has a single 3He multiwire 2D 30 × 30 cm2 position sensitive detector, yielding a field of view of 17° 2θ. The increase in the field of view (from 4° 2θ) from the previous model instrument has contributed to the tremendous improvement in the out of plane solid angle such that the 3D count rate could be obtained easily. Accordingly, the hardware, software, Data Acquisition System (DAS), and so on have also been updated. Finally, all these enhanced features of HIDRA have been ably demonstrated by conducting multi directional diffraction measurements in the quenched 750-T74 aluminum, and the evolved and improved strain/stress mappings are presented.
Comparative study of seasonal autoregressive integrated moving average and Holt–Winters modeling for forecasting monthly ground-level ozone
Authors: Alemu Abebaw Bizuneh , Parakash Raju U. Jaya , Seid Abdu Mohammed , Damtie Bayile
Published: March 2023

In this study, ground-level ozone is modeled using Seasonal Autoregressive Integrated Moving Average (SARIMA) and additive Holt–Winters models over the North-Western cluster of Ethiopia using four homogeneous series of more than 13 years of data from the European Center for Medium-Range Weather Forecasts. We split the dataset into training and testing sets. We used the data during the period 2007–2019 for model formulation and parameter estimation and the one year data in 2020 to test model forecasts. More than 60 SARIMA models have been generated for the time series. The goodness of fit of these models has been assessed using the Akaike information criterion and Bayesian information criterion. After rigorous assessment, the seasonal ARIMA(2,0,4)(1,1,2)[12], ARIMA(3,1,0)(2,0,0)[12], ARIMA(0,1,2)(0,0,2)[12], and ARIMA(2,0,0)(2,1,0)[12] models have been identified as best predictive models for Addis Ababa, Ras Dashen, Danakil Depression, and Bahir Dar, respectively. We applied model evaluation metrics, such as root mean square error, mean absolute error, and Mean Absolute Percentage Error (MAPE) to compare the accuracy between seasonal ARIMA and Holt–Winters models. Among the SARIMA and Holt–Winters models, our findings show that the best model for forecasting surface-level ozone is ARIMA(2,0,4)(1,1,2)[12] and ARIMA(3,1,0)(2,0,0)[12] for Addis Ababa and Ras Dashen stations, respectively. However, for Danakil Depression and Bahir Dar stations, the Holt–Winters model with α = 0.346, β = 0.023, γ = 0.36 and α = 0.302, β = 0.019, γ = 0.266, respectively, are found to be best models than the SARIMA. Moreover, the maximum MAPE were found to be less than 7.86% in the study, and hence all the forecasts are acceptable.
Density functional theory study of Zn(1−x)FexSe: Electronic structure, phonon, and magnetic properties
Authors: Habura Kunsa Haho , Afrassa Mesfin Asfaw , Hone Fekadu Gashaw
Published: March 2023

In this article, density functional theory is used to explore the electronic structure, phonon, and magnetic properties of Zn(1−x)FexSe (for x = 0%, 6.25%, 12.5%, 25%, and 50%). The electronic structure, phonon properties, and magnetic properties of the systems were examined using the generalized gradient approximation (GGA) and with Hubbard correction (GGA + U), where U is a Hubbard parameter. The calculated lattice parameter is 5.65 Å, which is quite close to the experimental lattice parameter of ZnSe, 5.66 Å. In this study, the GGA+U provides a better bandgap approximation (Eg = 1.3708 eV) than the GGA (Eg = 1.229 eV), which is consistent with experimental results and values previously reported. According to our results, the iron-doped zinc selenide exhibits antiferromagnetic coupling for a percentage of substitution greater than 12.5%. In addition, for an iron substitution of 12.5% with the distance between dopant atoms exceeding 5.6364 Å, it tends to exhibit ferromagnetic properties. Therefore, the iron-doped zinc selenide manifests the dilute magnetic semiconductor and can be considered to enhance its applications in the field of spintronics and magneto-optical devices based on further experimental results.
Design of squeezing-tube-driven pump for soft pneumatic robotics based on spiral spring winding
Authors: Zhang Wen Hai , Qin Ling , Wang Ji Yao , Xu Wei
Published: March 2023

Aiming at the demand for high-speed, easy-controllability, and integration of pneumatic soft robots and elastomer actuators, this study presents a squeezing-tube-driven pump (STDP) for soft pneumatic robotics based on spiral spring winding. This concept contains a customized spiral spring and a pneumatic tube with high-elasticity. The spiral spring is driven by an electric motor and coerced into winding deformation. Furthermore, the pneumatic tube is extruded by the spring and then the air in the tube is fast compressed to drive soft pneumatic grippers. The mechanical model and simulation are utilized to explain the operating principle of STDP. The air pressure and rotation angle of the spring under various rotation speeds are in a close linear correlation verified by the experimental results, which provides feasibility for easy controlling and rapid actuation. Finally, fast-gripping tests with an integrated gripper–pump system and a pneumatic muscle actuation test are presented to show the advantages of the proposed pump, respectively.
Effect of insulation material on the firing performance of TaN@(Al/Ni)
Authors: Liu Lan , Yu Ke-Xin , Ding Yue-Wei , Ren Xiao-Ming , Zhang Jing-Xin , Zhou Mi , Liu Wei , Yao Hong-Zhi , Ren Wei
Published: March 2023

In order to improve the ignition ability of reactive film, in this paper, the effects of copper oxide and silicon nitride on the flame height of the TaN@(Al/Ni) energy exchanger were investigated by using a high-speed photographic system. The insulating layer material was applied to the preparation TaN@(Al/Ni) by the MEMS process. The experimental results showed that the flame height of (Al/Ni)–TaN energy exchanger was obviously higher than that of silicon nitride when copper oxide was used as the insulation layer, which indicates that the oxygen-containing insulation layer could increase the flame height of the energy exchanger.
Parallel and perpendicular flows of a couple stress fluid past a solid cylinder in cell model: Slip condition
Authors: Sarkar Priya , Madasu Krishna Prasad
Published: March 2023

The axisymmetric steady flow of a couple stress fluid between two concentric cylinders with a slip effect is investigated with the help of the cell model technique. Here, the inner cylinder is rigid, and the outer cylinder is fictitious. The tangential slip, vanishing of normal velocity, and zero couple stress conditions are applied on the inner cylindrical surface. In addition, zero shear stress (Happel's model), continuity of normal velocity component, and zero couple stress conditions are used on the outer cylindrical surface. We consider two flow problems: the first is the parallel flow, and the second is the perpendicular flow to the cylinder in the cell model. Also, we have discussed the random case. For all the cases, the Kozeny constant is calculated. We described some special cases and compared them with well-known results. The effects of slip and couple stress parameters on the Kozeny constant with fixed value of couple stress viscosity parameter are presented graphically. The influence of the couple stress viscosity parameter on the Kozeny constant with fixed values of couple stress, and slip parameters for parallel flow are expressed graphically. The numerical values for the Kozeny constant for different values of fractional void volume are tabulated. We also obtained the results of the consistent couple stress theory as a special case.
An S-band klystron-like relativistic backward wave oscillator operating at low magnetic field with high conversion efficiency
Authors: Wu Yang
Published: March 2023

In order to overcome the problem of efficiency decrease in the relativistic backward wave oscillator (RBWO) operating at low magnetic field, an S-band klystron-like RBWO with a three-period slow-wave cavity-chain and a dual-cavity extractor is proposed and investigated in detail in this paper. In the device, several measures are taken to enhance the conversion efficiency at low magnetic field, which include increasing the beam bunching depth by a two-stage modulation structure comprised of a resonant reflector upstream and a three-period cavity-chain modulator downstream, strengthening the energy exchange process from the electron beam to the microwave by a dual-cavity extractor, and optimizing the envelope distribution of the electron beam in the interaction region by adjusting the drift length before the resonant reflector. Under the condition of the guiding magnetic field of 0.28 T, the device could generate a microwave with a power of 4.3 GW, a frequency of 3.79 GHz, and the conversion efficiency of 43.3% in the simulation.
On the collisional damping of plasma velocity space instabilities
Authors: Zhang Yanzeng , Tang Xian-Zhu
Published: March 2023

For plasma velocity space instabilities driven by particle distributions significantly deviated from a Maxwellian, weak collisions can damp the instabilities by an amount that is significantly beyond the collisional rate itself. This is attributed to the dual role of collisions that tend to relax the plasma distribution toward a Maxwellian and to suppress the linearly perturbed distribution function. The former effect can dominate in cases where the unstable non-Maxwellian distribution is driven by collisionless transport on a timescale much shorter than that of collisions, and the growth rate of the ideal instability has a sensitive dependence on the distribution function. The whistler instability driven by electrostatically trapped electrons is used as an example to elucidate such a strong collisional damping effect of plasma velocity space instabilities, which is confirmed by first-principles kinetic simulations.
GeTe ultrathin film based phase-change memory with extreme thermal stability, fast SET speed, and low RESET power energy
Authors: Meng Yingjie , Chen Yimin , Peng Kexin , Chen Bin , Gu Chenjie , Gao Yixiao , Wang Guoxiang , Shen Xiang
Published: March 2023

We designed the phase-change memory (PCM) cell based on ultrathin GeTe film (∼10 nm) and homemade nanoscale electrode filling craft to improve data retention ability and reduce programming energy, respectively. It was found that the temperature for ten years’ data retention of this ultrathin GeTe film is 160 ± 32.8 °C, which is much higher than that of conventional Ge2Sb2Te5 (GST, 83 ± 20.6 °C) film. Benefit to the nature of fragile-to-strong crossover behavior in GeTe supercooled liquids that was confined in a two-dimension structure, a fast SET speed of 6 ns is also detected in this ultrathin GeTe PCM. Moreover, the RESET power consumption of this ultrathin GeTe PCM is measured as 1.8 ± 0.5 nJ, and it is much lower than that of GST PCM (16.5 ± 1.5 nJ), which is attributed to the nanoscale electrode of the devices. The above-mentioned improvements enable the application of ultrathin GeTe PCM in neuromorphic computing.
The contact time of rebounding-coalescing droplets on rectangular-ridged superhydrophobic surfaces
Authors: Zhang Ben-Xi , Zhang Yan-Yi , Xu Jiang-Hai , Ma Qiang , Yang Yan-Ru , Wang Xiao-Dong
Published: March 2023

On a rectangular-ridged superhydrophobic surface, the contact time of the rebounding-coalescing droplet is for the first time investigated via lattice Boltzmann method simulations, where the rebounding-coalescing droplet is caused by an impinging droplet coalescing with an adhesive droplet. The simulation results show that at constant initial radii of impinging droplets, R0, and various initial radii of adhesive droplets, R1, the contact time of rebounding–coalescing droplets depends not only on the impact condition but also on the surface condition. Under various impact conditions, that is, with increased Weber numbers of We = 1–30, the contact time is gradually reduced, and then nearly constant, and eventually constant after slightly reduced at R0 = 35 and R1 = 25. However, at R0 = 35 and R1 = 10, it is gradually reduced, then increased, and eventually constant. It indicates that the contact time of rebounding-coalescing droplets is affected by the initial radii of adhesive droplets. Under different surface conditions, that is, with increased spacing distances between adhesive droplets and ridges of L = 3–17, the contact time is reduced at the low Weber number of We = 3, constant at the moderate Weber number of We = 12, and increased at the high Weber number of We = 28 at R0 = 35 and R1 = 25. However, at R0 = 35 and R1 = 10, it is reduced at both low and moderate Weber numbers of We = 3 and 12, and constant at the high Weber number of We = 28. It indicates that under different surface conditions, the contact time of rebounding-coalescing droplets is also affected by the initial radii of adhesive droplets.
Influence of dual-axial swirler configuration on hydrodynamic stability in combustor
Authors: Xing Li , Li Yifei , Zheng Mingxin , Gui Tao , Zhang Qun , Li Wu , Zeng Jun , Xu Huasheng
Published: March 2023

To improve hydrodynamic stability in a combustor, an unsteady flow analysis method is needed. Hence, the proper orthogonal decomposition (POD) method based on a large eddy simulation (LES) unsteady flow field and corresponding experimental verification were utilized to analyze and assess the influence of the precession vortex core (PVC) motion law on the pulsation downstream of different swirler configurations. The pulsation outcomes of the unsteady simulation match the experimental data quite well, with case 1 having the highest pulsation quantity. The POD analysis reveals that the majority of pulsation energy is concentrated in the first two modes. The results of the motion state, regularity of the time coefficient, and frequency characteristics also demonstrate that the combustor's PVC features are compatible with modes 1 and 2. There is an optimum value of swirl number, 0.72, for which the flow field's stability has the lowest degree of disturbance. Moreover, the airfoil vane's stability is beyond that of the straight vane. The mean flow field and the coherent flow field in the pulsation flow field of case 3 are the most beneficial factors concerning combustion stability, and the unstable aspects of the transition flow field and the turbulent flow field are the least in shape and energy ratio. The data procured from the experiment certify that there is no characteristic frequency of pulsation within 5000 Hz that exists in case 3.
Preparation and characterization of sodium dodecyl sulfate/Ag nanoparticles constituting branched microfibers
Authors: Almarashi Jamal Q. M.
Published: March 2023

Branched microfibers of sodium dodecyl sulfate/Ag nanoparticles were synthesized using a nanosecond laser at a wavelength of 532 nm. The synthesis process was investigated at three laser intensities (0.38, 0.76, and 1.53 MW/cm2) and five exposure times (5, 15, 30, 45, and 60 min). At intensities of 0.38 and 0.76 MW/cm2, with increasing the exposure time, the number of nanoparticles increases until an exposure time of 30 min. Above this, exposure saturation of the number of Ag nanoparticles takes place. A similar effect was detected for the size of nanoparticles at these laser intensities. The saturation effect begins at 5 min of exposure for a laser intensity of 1.53 MW/cm2. The estimated nanoparticle size ranges from 116 to 120 nm based on the exposure time for a laser intensity of 0.38 and 0.76 MW/cm2, respectively. Scanning electron microscopy images at low magnification show the branched microfiber structure, while at higher magnifications, nanoparticles of Ag covering these microfibers appear. Electron dispersion x-ray spectroscopy confirmed the presence of Ag. X-ray diffraction results for the particles deposited on a fluorine-doped tin oxide-coated glass substrate were discussed.
Resonator-like behavior of a wall-bounded precessing vortex core in a diffuser with wall asymmetries
Authors: Favrel Arthur , Liu Zhihao , Miyagawa Kazuyoshi
Published: March 2023

This paper reports a detailed investigation of the interaction between a wall-bounded precessing vortex core (PVC) occurring in swirling flows after vortex breakdown and a wall asymmetry. Experiments are carried out in an axisymmetric diffuser downstream of an axial swirl generator inducing a swirling flow with a swirl number of S = 1.1. Wall pressure measurements and two-component particle image velocimetry (PIV) are conducted for Reynolds numbers (Re) ranging from 20 000 to 76 000 in the initial axisymmetric configuration and several asymmetric configurations, with an additional cylindrical protrusion placed on the diffuser wall at different streamwise and circumferential positions. It is first confirmed that synchronous pressure fluctuations at the PVC frequency are only produced in asymmetric configurations. Furthermore, the analysis of the pressure data in several asymmetric configurations revealed for the first time a resonator-like behavior of a wall-bounded PVC. While a change of the protrusion circumferential position in a given cross section of the diffuser only affects the phase of the synchronous pressure fluctuations, the amplitude of the latter features successive minima (pressure node) and maxima (pressure anti-node) as the protrusion is moved along the diffuser in the streamwise direction. In addition, as the protrusion is moved closer to a pressure node, the phase of the synchronous pressure fluctuations exhibits a sudden variation of ±π. Similar results are observed for all tested values of Reynolds number, whereas the PVC frequency linearly increases with Re. A reconstruction of the PVC helical structure based on PIV measurements showed that these consecutive pressure nodes are spaced by a distance equal to approximately one third of the PVC helical pitch. Finally, it also revealed that two different states are observed, depending on the position of the protrusion along the diffuser: the synchronous pressure component reaches its maximum value as the PVC center is approaching either its closest or farthest angular position with respect to the protrusion. The transition from one state to another one depends on the streamwise position of the protrusion with respect to the pressure nodes. These unprecedented experimental observations pave the way to novel theoretical developments for a better understanding and modeling of synchronous pressure fluctuations induced by wall-bounded PVC in asymmetric geometries.
Underwater oscillations of rigid plates with H-shaped cross sections: An experimental study to explore their flow physics
Authors: Gulsacan Burak , Aureli Matteo
Published: March 2023

In this work, we present a comprehensive experimental study on the problem of harmonic oscillations of rigid plates with H-shaped cross sections submerged in a quiescent, Newtonian, incompressible, viscous fluid environment. Motivated by recent results on the minimization of hydrodynamic damping for transversely oscillating flat plates, we conduct a detailed qualitative and quantitative experimental investigation of the flow physics created by the presence of the flanges, that is, the vertical segments in the plate cross section. Specifically, the main goal is to elucidate the effect of flange size on various aspects of fluid–structure interaction, by primarily investigating the dynamics of vortex shedding and convection. We perform particle image velocimetry experiments over a broad range of oscillation amplitudes, frequencies, and flange size-to-width ratios by leveraging the identification of pathlines, vortex shedding and dynamics, distinctive hydrodynamic regimes, and steady streaming. The fundamental contributions of this work include novel hydrodynamic regime phase diagrams demonstrating the effect of flange ratio on regime transitions, and in the investigation of their relation to qualitatively distinct patterns of vortex–vortex and vortex–structure interactions. Finally, we discuss steady streaming, identifying primary, and secondary structures as a function of the governing parameters.
Straightforward synthesis of monodisperse Co/Zn-based nanoparticles and their antifungal activities on Botrytis cinerea
Authors: Freire Rafael M. , Silva-Moreno Evelyn , Robles-Kelly Christian , Infante Claudia D. , Denardin Juliano C. , Michea Sebastian
Published: March 2023

Herein, we have displayed an easy way to produce monodisperse spinel nanoparticles (NPs) and the antifungal activity of CoFe2O4, Co0.5Zn0.5Fe2O4 and ZnFe2O4 nanostructures. Firstly, the structural, morphological and magnetic properties of each NP were investigated through x-ray diffraction (XRD), Transmission Electron Microscopy (TEM) and Vibrating Sample Magnetometer (VSM). The XRD data showed diffraction peaks related to the crystalline spinel phase. The TEM micrographs displayed monodisperse NPs with spherical morphology. The average sizes of CoFe2O4, Co0.5Zn0.5Fe2O4 and ZnFe2O4 NPs were 6.87 ± 0.05 nm, 5.18 ± 0.01 nm and 11.52 ± 0.09 nm, respectively. The VSM data indicated that the nanostructures are superparamagnetic at room temperature. Afterward, the antifungal properties of the Co/Zn-based ferrite NPs against Botrytis cinerea were tested. So, the inhibition of mycelial growth by different concentrations (45 – 360 ppm) of NPs was measured. The most effective nanostructure was CoFe2O4, with an EC50 value of 265 ppm. Further, to elucidate how the NPs are affecting B. cinerea, reactive oxygen species (ROS) production was measured. The results indicated that the CoFe2O4 monodisperse NPs could induce a burst of ROS in B. cinerea, promoting cellular damage.
NIF success gives laser fusion energy a shot in the arm
Authors: Kramer David
Published: March 2023

Startup companies are betting on different approaches and laser technologies for fusion to become a commercially viable energy source.
An 8-year long retrospective analysis identifies the major causes of morbidity and mortality in rescued koala joeys
Authors: Pahuja Harsh Pramila , Narayan Edward Jitik
Published: March 2023

Context Wildlife rescue and rehabilitation centres aid millions of species worldwide. The clinical databases from these wildlife rehabilitation centres are increasingly being recognised as valuable scientific resources that have the potential to yield information on animal biology and inform conservation efforts. Although orphaned koala joeys constitute a substantial proportion of wildlife rescues in Australia, the causes of morbidity and mortality, specifically in rescued young koalas, remain largely unexplored. Aims The primary aim of this study is to analyse the trends in causes and outcomes of koala joeys admitted for rehabilitation at the Adelaide Koala Wildlife Centre (AKWC). Methods We analysed the hospital records of koala joeys admitted to the AKWC over an 8-year period (2014–2021) to identify the major causes of morbidity and mortality, and analysed the trends in arrivals in terms of season, sex and release rate. Key results Our examination indicates that the top five major reasons for admission and mortality in koala joeys are as follows – renal disease, heat stress, chlamydiosis, animal attack and vehicle collision. A significant increase in the proportion of heat stress, renal disease and chlamydiosis cases can be observed over the study period. Of the major causes of mortality, the most distinctive feature is the exceptionally high mortality rate of koala joeys with renal disease. Over the study period, the overall positive outcome for all joeys increased up to two-fold, and the mortality rate also declined slightly. Conclusion Despite the significant increase in positive outcome, it is evident that renal disease, chlamydiosis and heat stress are increasing at a rapid rate. Renal disease poses a major threat to rehabilitating koala joeys due to its severely high mortality rate. Implication This is the first study identifying the key drivers of morbidity and mortality of rescued koala joeys, and the rapid increase of renal disease, chlamydiosis and heat stress warrant the attention of future conservation policy developers. Furthermore, the severely high mortality rate of koala joeys due to renal disease warrants improving treatment protocols and any measures that can help reduce the mortality rate of this disease in koala joeys.
An antisense intragenic lncRNA SEAIRa mediates transcriptional and epigenetic repression of
SERRATE
in
Arabidopsis
Authors: Chen Wei , Zhu Tao , Shi Yining , Chen Ying , Li Wei Jian , Chan Ru Jing , Chen Dijun , Zhang Wenli , Yuan Yuren Adam , Xu Jian , Wang Xiue , Sun Bo
Published: March 2023

SERRATE (SE) is a core protein for microRNA (miRNA) biogenesis as well as for mRNA alternative splicing. Investigating the regulatory mechanism of
SE
expression is hence critical to understanding its detailed function in diverse biological processes. However, little about the control of
SE
expression has been clarified, especially through long noncoding RNA (lncRNA). Here, we identified an antisense intragenic lncRNA transcribed from the 3′ end of
SE
, named SEAIRa. SEAIRa repressed
SE
expression, which in turn led to serrated leaves. SEAIRa recruited plant U-box proteins PUB25/26 with unreported RNA binding ability and a ubiquitin-like protein related to ubiquitin 1 (RUB1) for H2A monoubiquitination (H2Aub) at exon 11 of
SE
. In addition, PUB25/26 helped cleave SEAIRa and release the 5′ domain fragment, which recruited the PRC2 complex for H3 lysine 27 trimethylation (H3K27me3) deposition at the first exon of
SE
. The distinct modifications of H2Aub and H3K27me3 at different sites of the
SE
locus cooperatively suppressed
SE
expression. Collectively, our results uncover an epigenetic mechanism mediated by the lncRNA SEAIRa that modulates
SE
expression, which is indispensable for plant growth and development.
Effect of Co/P micro-alloying on stress relaxation behaviour of Cu-15Ni-8Sn alloy
Authors: Yahui Gong , Chengjun Guo , Jian Huang , Yufan Shi , Xiangpeng Xiao , Guihuan An , Bin Yang
Published: March 2023

To improve the stress relaxation resistance of the Cu-5Ni-S8n alloy, the effects of Co or P addition on its stress relaxation resistance were investigated by scanning electron microscopy, transmission electron microscopy, electron backscatter diffraction), X-ray diffraction, and high-temperature creep durability tester. The results revealed that the relaxation rate increased dramatically as the temperature rose. The thermal stress relaxation resistance of Cu-15Ni-8Sn alloy was significantly improved with Co addition; After 100 h of stress relaxation tests at 200°C or 250°C, the residual stress value of the Cu-15Ni-8Sn alloy increased by 23 MPa or 22 MPa with Co addition, which was associated with the consumption of vacancies by Co atoms and the pinning effect of Co atoms on dislocation. However, at 250°C, the stress relaxation resistance of the Cu-15Ni-8Sn-0.2P alloy was lower than that of the Cu-15Ni-8Sn alloy. This difference was due to the inclusion of P, which promoted the recrystallization reaction.

Article highlights Recrystallization and the decrease of dislocation density are the major reasons for the stress relaxation of the samples. The stress relaxation resistance of Cu-15Ni-8Sn alloy was significantly improved with Co addition. The addition of the P element is not conducive to the improvement of thermal stress relaxation resistance.
Surface current engineering enabled broadband monopole patch antenna with low profile
Authors: Qu Bingyue , Pang Yongqiang , Wang Jiafu , Fu Xinmin , Shi Hongyu , Wang Luyi , Zhang Anxue , Xu Zhuo
Published: March 2023

Antennas with broadband radiation and small-size are highly required in wireless communication system. The trade-off relation between bandwidth and size became a difficulty when it comes to miniaturized antenna design. A method of realizing antenna miniaturization and bandwidth enhancement at the same time is needed. Monopole antennas are the most common used one in the devices of Internet of Things, Internet of Vehicles, and wireless access points et al. In this paper, a wideband low-profile top-loaded patch monopole antenna based on surface current engineering is proposed. The topology combines a center-fed circular patch with inductive vias. The patch is designed with patterns, which consists of four concentric annular rings and some strips in radial direction. In this way, three resonances are generated, and the pattern is optimized to bring three resonances close to each other. The number of the strips is specially designed to bring three resonances close to each other. By loading the inductive vias on the outermost rings, connecting to the ground, the resonance at low frequencies can be enhanced, as a consequence of the optimized impedance matching. The field distribution is analyzed to verify the operation principle. A prototype is fabricated, and the measured results agree well with the simulated ones. The relative −10 dB bandwidth is 69% and the omnidirectional radiation pattern is stable in the operating band. The antenna achieves a rather wideband radiation while maintaining a low profile. The method of antenna miniaturization and bandwidth enhancement based on surface current engineering paves the way for antenna design in low-profile ultra-wideband applications.
A compact LWIR borescope sensor for 2D engine component surface temperature measurement
Authors: Hsu Paul S , Chen Trevor , Roy Awnik , Zhang Andy , Oleksandr Bibik , Adhikari Subodh , Emerson Benjamin , Lieuwen Timothy
Published: March 2023

A compact long-wavelength infrared (LWIR) borescope imaging sensor operating in the wavelength range of 8–14 μm is designed and developed for non-contact two-dimensional (2D) surface temperature measurements in gas-turbine engines. The LWIR detection minimizes optical interferences from hot combustion gases and soot (emission within UV–mid IR region). Using simulations, the system is optimized for improving the signal collection efficiency and minimize image aberrations. The LWIR borescope probe is shielded by the custom-build compact water-cooled probe housing (outer diamter (OD) 19 mm, inner diameter (ID) 10 mm), which can sustain flame temperature up to 2400 K at a pressure of 50 bar. It facilitates long-term optical diagnostics inside the actual high-pressure combustion facilities where extreme thermal acoustic perturbation and intense heat fluxes are encountered. The design, construction, and characterization of the LWIR borescope sensor are discussed in detail. We present the 2D surface temperature measurements of a V-gutter bluff-body with simple nitrogen gas cooling in a laboratory testbed. The results indicate the sensor’s ability to accurately measure surface temperature with low background noise and to track transient cooling effect. The water-cooled probe housing was tested to verify the effectiveness of fast heat dissipation in high-temperature combustion environment to avoid unwanted thermal signals from the LWIR probe window. The developed LWIR sensor suite has promising applications in surface temperature measurements of engine components. The findings of this study may aid propulsion system engineers and researchers in designing thermal management systems and optimizing operation.
Enhanced electrocatalytic performance for oxygen evolution reaction via active interfaces of Co3O4 arrays@FeO
x
/Carbon cloth heterostructure by plasma-enhanced atomic layer deposition
Authors: Zhu Qingying , Yang Guoyong , Tang Limin , Mi Hongwei , Sun Lingna , Zhang Qianling , Deng Libo , Zhang Peixin , Ren Xiangzhong , Li Yongliang
Published: March 2023

Oxygen evolution reaction (OER) is a necessary procedure in various devices including water splitting and rechargeable metal-air batteries but required a higher potential to improve oxygen evolution efficiency due to its slow reaction kinetics. In order to solve this problem, a heterostructured electrocatalyst (Co3O4@FeO
x
/CC) is synthesized by deposition of iron oxides (FeO
x
) on carbon cloth (CC) via plasma-enhanced atomic layer deposition, then growth of the cobalt oxide (Co3O4) nanosheet arrays. The deposition cycle of FeO
x
on the CC strongly influences the in situ growth and distribution of Co3O4 nanosheets and electronic conductivity of the electrocatalyst. Owing to the high accessible and electroactive areas and improved electrical conductivity, the free-standing electrode of Co3O4@FeO
x
/CC with 100 deposition cycles of FeO
x
exhibits excellent electrocatalytic performance for OER with a low overpotential of 314.0 mV at 10 mA cm−2 and a small Tafel slope of 29.2 mV dec−1 in alkaline solution, which is much better than that of Co3O4/CC (448 mV), and even commercial RuO2 (380 mV). This design and optimization strategy shows a promising way to synthesize ideally designed catalytic architectures for application in energy storage and conversion.
p-n Homojunction perovskite solar cells: effects of ionic density and thickness of the doped layers
Authors: Ranpariya Spandan , Sinha Dhirendra Kumar
Published: March 2023

The p-n homojunction perovskite solar cells are promising in comparison to planar heterojunction perovskite solar cells. It is observed that the p-n homojunction provides an efficient built-in electric field for the photo-generated electron-hole pairs to dissociate into free charge-carriers and orient them to transport to the respective electrodes, thereby reducing the overall losses due to recombination processes. However, the existence of p-n homojunction, while in operation, is currently undergoing experimental tests. In this study, we simulated the current-voltage characteristics of both planar heterojunction and p-n homojunction perovskite solar cells. For simulation, we utilised a one-dimensional drift-diffusion equation. The current-voltage characteristics show a high fill factor for the p-n homojunction devices indicating better power conversion efficiency as compared to that of planar heterojunction devices. In addition, we report the spatial distribution of electron- and hole-density with variations in (i) the mobile ionic density, inherently present in the perovskite material and (ii) the thickness of p- and n-type perovskite layers. It is observed that the role of p-n homojunction ceases when the ionic density is higher than 1017 cm−3 or when one of the doped layers is substantially thicker as compared to the other. We correlate the cease of p-n homojunction to (i) the ionic effect which screens the built-in field, and (ii) the predominance of the effect of one doped layer over the other. The study provides impetus to the development of the p-n homojunction perovskite solar cells.
A' view of the sunrise: boosting helioscopes with angular information
Authors: Frerick Jonas , Kahlhoefer Felix , Schmidt-Hoberg Kai
Published: March 2023

The Sun may copiously produce hypothetical light particles such as axions or dark photons,
a scenario which can be experimentally probed with so-called helioscopes. Here we investigate the
impact of the angular and spectral distribution of solar dark photons on the sensitivity of such
instruments. For the first time we evaluate this spectral and angular dependence of the dark
photon flux over the whole mass range and apply this information to existing data from the Hinode
Solar X-Ray Telescope. Specifically we use calibration images for a classical helioscope analysis
as well as data from a solar eclipse providing sensitivity to exceptionally large oscillation
lengths. We demonstrate that exploiting the signal features can boost the constraints by more than
one order of magnitude in terms of the mixing parameter compared to a naive counting experiment.