bluuebunny/crossref_metadata_2025 huggingface dataset:
The stratification of ISM properties in the edge-on galaxy NGC 891 revealed by NIKA2
Authors: Katsioli S. , Xilouris E. M. , Kramer C. , Adam R. , Ade P. , Ajeddig H. , André P. , Artis E. , Aussel H. , Baes M. , Beelen A. , Benoît A. , Berta S. , Bing L. , Bourrion O. , Calvo M. , Catalano A. , Clark C. J. R. , De Looze I. , De Petris M. , Désert F.-X. , Doyle S. , Driessen E. F. C. , Ejlali G. , Galametz M. , Galliano F. , Gomez A. , Goupy J. , Hanser C. , Hughes A. , Jones A. P. , Kéruzoré F. , Ladjelate B. , Lagache G. , Leclercq S. , Lestrade J.-F. , Macías-Pérez J.-F. , Madden S. C. , Maury A. , Mauskopf P. , Mayet F. , Monfardini A. , Muñoz-Echeverría M. , Nersesian A. , Pantoni L. , Paradis D. , Perotto L. , Pisano G. , Ponthieu N. , Revéret V. , Rigby A. J. , Ritacco A. , Romero C. , Roussel H. , Ruppin F. , Schuster K. , Sievers A. , Smith M. W. L. , Tedros J. , Tabatabaei F. , Tucker C. , Ysard N. , Zylka R.
Published: September 2023

Context. As the millimeter wavelength range remains a largely unexplored spectral region for galaxies, the IMEGIN large program aims to map the millimeter continuum emission of 22 nearby galaxies at 1.15 and 2 mm.

Aims. Using the high-resolution maps produced by the NIKA2 camera, we explore the existence of very cold dust and take possible contamination by free–free and synchrotron emission into account. We study the IR-to-radio emission coming from different regions along the galactic plane and at large vertical distances.

Methods. New observations of NGC 891, using the NIKA2 camera on the IRAM 30 m telescope, along with a suite of observations at other wavelengths were used to perform a multiwavelength study of the spectral energy distribution in the interstellar medium in this galaxy. This analysis was performed globally and locally, using the advanced hierarchical Bayesian fitting code, HerBIE, coupled with the THEMIS dust model.

Results. Our dust modeling is able to reproduce the near-IR to millimeter emission of NGC 891, with the exception of an excess at a level of 25% obtained by the NIKA2 observations in the outermost parts of the disk. The radio continuum and thermal dust emission are distributed differently in the disk and galaxy halo. Different dusty environments are also revealed by a multiwavelength investigation of the emission features. Our detailed decomposition at millimeter and centimeter wavelengths shows that emission at 1 mm is purely originated by dust. Radio components become progressively important with increasing wavelengths. Finally, we find that emission arising from small dust grains accounts for ∼9.5% of the total dust mass, reaching up to 20% at large galactic latitudes. Shock waves in the outflows that shatter the dust grains might explain this higher fraction of small grains in the halo.

Conclusions. NIKA2 observations have proven essential for a complete characterization of the interstellar medium in NGC 891. They have been critical to separate the dust, free–free, and synchrotron emission in the various emitting regions within the galaxy.
Self-consistent dust and non-LTE line radiative transfer with SKIRT
Authors: Matsumoto Kosei , Camps Peter , Baes Maarten , De Ceuster Frederik , Wada Keiichi , Nakagawa Takao , Nagamine Kentaro
Published: September 2023

We introduce Monte-Carlo-based non-local thermodynamic equilibrium (non-LTE) line radiative transfer calculations in the three-dimensional (3D) dust radiative transfer code SKIRT, which was originally set up as a dust radiative transfer code. By doing so, we developed a generic and powerful 3D radiative transfer code that can self-consistently generate spectra with molecular and atomic lines against the underlying continuum. We tested the accuracy of the non-LTE line radiative transfer module in the extended SKIRT code using standard benchmarks. We find excellent agreement between the S KIRT results, the published benchmark results, and the results obtained using the ray-tracing non-LTE line radiative transfer code MAGRITTE, which validates our implementation. We applied the extended SKIRT code on a 3D hydrodynamic simulation of a dusty active galactic nucleus (AGN) torus model and generated multiwavelength images with CO rotational-line spectra against the underlying dust continuum. We find that the low-J CO emission traces the geometrically thick molecular torus, whereas the higher-J CO lines originate from the gas with high kinetic temperature located in the innermost regions of the torus. Comparing the calculations with and without dust radiative transfer, we find that higher-J CO lines are slightly attenuated by the surrounding cold dust when seen edge-on. This shows that atomic and molecular lines can experience attenuation, an effect that is particularly important for transitions at mid- and near-infrared wavelengths. Therefore, our self-consistent dust and non-LTE line radiative transfer calculations can help the observational data from Herschel, ALMA, and JWST be interpreted.
JWST’s PEARLS: Mothra, a new kaiju star at z = 2.091 extremely magnified by MACS0416, and implications for dark matter models
Authors: Diego Jose M. , Sun Bangzheng , Yan Haojing , Furtak Lukas J. , Zackrisson Erik , Dai Liang , Kelly Patrick , Nonino Mario , Adams Nathan , Meena Ashish K. , Willner Steven P. , Zitrin Adi , Cohen Seth H. , D’Silva Jordan C. J. , Jansen Rolf A. , Summers Jake , Windhorst Rogier A. , Coe Dan , Conselice Christopher J. , Driver Simon P. , Frye Brenda , Grogin Norman A. , Koekemoer Anton M. , Marshall Madeline A. , Pirzkal Nor , Robotham Aaron , Rutkowski Michael J. , Ryan Russell E. , Tompkins Scott , Willmer Christopher N. A. , Bhatawdekar Rachana
Published: September 2023

We report the discovery of Mothra, an extremely magnified monster star, likely a binary system of two supergiant stars, in one of the strongly lensed galaxies behind the galaxy cluster MACS J0416.1−2403. Mothra is in a galaxy with spectroscopic redshift z = 2.091 in a portion of the galaxy that is parsecs away from the cluster caustic. The binary star is observed only on the side of the critical curve with negative parity but has been detectable for at least eight years, implying the presence of a small lensing perturber. Microlenses alone cannot explain the earlier observations of this object made with the Hubble Space Telescope. A larger perturber with a mass of at least 104 M⊙ offers a more satisfactory explanation. Based on the lack of perturbation on other nearby sources in the same arc, the maximum mass of the perturber is 2.5 × 106 M⊙, making this the smallest substructure constrained by lensing at z > 0.3. The existence of this millilens is fully consistent with expectations from standard cold dark matter cosmology. On the other hand, the existence of such a small substructure in a cluster environment has implications for other dark matter models. In particular, warm dark matter models with particle masses below 8.7 keV are excluded by our observations. Similarly, axion dark matter models are consistent with the observations only if the axion mass is in the range 0.5 × 10−22 eV < ma < 5 × 10−22 eV.
Medication Reconciliation during Transitions of Care Across Institutions: A Quantitative Analysis of Challenges and Opportunities
Authors: Araya Alejandro , Thornton Logan R. , Kwon Deukwoo , Ferguson Gayla M. , Highfield Linda D. , Hwang Kevin O. , Holmes Holly M. , Bernstam Elmer V.
Published: September 2023

Objective Medication discrepancies between clinical systems may pose a patient safety hazard. In this paper, we identify challenges and quantify medication discrepancies across transitions of care.

Methods We used structured clinical data and free-text hospital discharge summaries to compare active medications' lists at four time points: preadmission (outpatient), at-admission (inpatient), at-discharge (inpatient), and postdischarge (outpatient). Medication lists were normalized to RxNorm. RxNorm identifiers were further processed using the RxNav API to identify the ingredient. The specific drugs and ingredients from inpatient and outpatient medication lists were compared.

Results Using RxNorm drugs, the median percentage intersection when comparing active medication lists within the same electronic health record system ranged between 94.1 and 100% indicating substantial overlap. Similarly, when using RxNorm ingredients the median percentage intersection was 94.1 to 100%. In contrast, the median percentage intersection when comparing active medication lists across EHR systems was significantly lower (RxNorm drugs: 6.1–7.1%; RxNorm ingredients: 29.4–35.0%) indicating that the active medication lists were significantly less similar (p < 0.05).

Medication lists in the same EHR system are more similar to each other (fewer discrepancies) than medication lists in different EHR systems when comparing specific RxNorm drug and the more general RxNorm ingredients at transitions of care. Transitions of care that require interoperability between two EHR systems are associated with more discrepancies than transitions where medication changes are expected (e.g., at-admission vs. at-discharge). Challenges included lack of access to structured, standardized medication data across systems, and difficulty distinguishing medications from orderable supplies such as lancets and diabetic test strips.

Conclusion Despite the challenges to medication normalization, there are opportunities to identify and assist with medication reconciliation across transitions of care between institutions.
External Auditory Canal: Computed Tomography Analysis and Classification
Authors: El-Anwar Mohammad Waheed , Fouad Yasser Ahmed , Elgohary Ahmed Fouad , Saber Sameh , Mobasher Mohamed Adel
Published: September 2023

Introduction Computed tomography (CT) details of the external auditory canal (EAC) are not fully covered in the literature, so building up base for the CT evaluation and description is important. Preoperative details of the EAC are mandatory before any approach or procedure involving the canal.

Objective To determine the different dimensions, measurements, and grading of the EAC by CT scan that were not previously published.

Methods The CT scans of 100 temporal bones (200 sides) were included. Axial images were acquired with multiplanar reformates to obtain delicate details in coronal and sagittal planes for all subjects.

Results At the EAC entry, the mean vertical length (height) was 7.75 ± 1 mm, and its mean horizontal length (width) was 6.1 ± 0.8. At the bony cartilaginous junction of the EAC, the mean vertical length was 7.88 ± 1 mm, and its mean horizontal length was 6.22 ± 0.9. At the EAC isthmus, the mean vertical length was 6.8 ± 0.97 mm, and its mean horizontal length was 5.2 ± 0.76. At the medial end of the EAC, the mean vertical length was 7.1 ± 0.9 mm, and its mean horizontal length was 5.4 ± 0.85. There were no reported significant differences between right and left sides in all dimensions. Males showed significantly longer vertical and horizontal dimensions of the EAC entry, vertical dimension of the isthmus, and vertical dimension of the medial end of the EAC than females.

Conclusion This study improves otologists and radiologists' awareness of EAC variations in the ear field and can be of help to residents in training.
Oral Contraceptive Pills Increase Circulating 25-Hydroxy-Vitamin D Concentrations in Women Who Are Lactating
Authors: Huff Lori L. , Schulz Elizabeth V. , Richardson Colby D. , Ebeling Myla D. , Shary Judy R. , Hollis Bruce W. , Wagner Carol L.
Published: September 2023

Objective This article aims to determine the association between maternal 25-hydroxy-vitamin D [25(OH)D] status and intake of hormonal oral contraceptive pills (OCPs) in women who are lactating.

Study Design Women who were exclusively breastfeeding participated in a randomized controlled trial assessing vitamin D supplementation at 400, 2,400, or 6,400 international unit (IU)/d from 1 month through 7 months postpartum. This observational, secondary analysis assessed whether OCPs were associated with maternal 25(OH)D concentrations in women who are lactating. Multivariate regression models were used to predict 25(OH)D concentrations and create parameter estimates for each variable.

Results In a bivariate analysis, the use of OCPs at 4 months was associated with increased serum 25(OH)D (p = 0.02). OCPs' use at 7 months was associated with a higher trend in 25(OH)D, but this finding was not statistically significant (p = 0.1). In a multivariate regression model at 4 months, independent positive predictors of 25(OH)D concentrations were the use of OCPs (p = 0.03) and treatment with vitamin D at 6,400 IU/d (p ≤ 0.0001). Negative predictors were Black (p = 0.001) and Hispanic (p = 0.0001) race and ethnicity, and body mass index (BMI) greater than 30 (p = 0.0002). The same pattern occurred at 7 months, with more southern latitude as a positive independent predictor (p = 0.04) of 25(OH)D concentration.

Conclusion The use of OCPs was associated with greater 25(OH)D in women who are lactating. Additionally, treatment with vitamin D at 6,400 IU/d and southern latitude was associated with greater 25(OH)D in women who are lactating. Black and Hispanic race and ethnicity, and BMI greater than 30, were independently associated with lower 25(OH)D in women who are lactating.

Key Points
Foetal programming meets human capital: biological plasticity, development, and the limits to the economization of life
Authors: Moll Tessa , Meloni Maurizio , Issaka Ayuba
Published: September 2023

The disciplinary integration of biology and economy is taking new forms in the postgenomic era, transforming long-standing exchanges between human biology and economics. In this article, we first describe how an emerging area of research in development and health economics has embraced, stabilized, and expanded the emerging field of the Developmental Origins of Health and Disease (DOHaD). We map the global expansion of this literature particularly in the Global South. Via an analysis of shifting models of health in human capital, we argue that as economists draw on DOHaD theories, their increasing focus on marginalized groups in postcolonial settings produces a darker model of health deficit. Based on notions of accumulated shocks, this model questions the generalizable expansion of the economization of life and speaks to a wider and more sombre range of figures. Health models in economics reflect the double nature of biological and developmental plasticity caught between agency and passivity, change, and near-permanency.
Mass-selected ion–molecule cluster beam apparatus for ultrafast photofragmentation studies
Authors: Wang Xiaojun , Hasan Mahmudul , Fan Lin , Wang Yibo , Li Hui , Slaughter Daniel S. , Centurion Martin
Published: September 2023

We describe an apparatus for investigating the excited-state dissociation dynamics of mass-selected ion–molecule clusters by mass-resolving and detecting photofragment-ions and neutrals, in coincidence, using an ultrafast laser operating at high repetition rates. The apparatus comprises a source that generates ion–molecule clusters, a time-of-flight spectrometer, and a mass filter that selects the desired anions, and a linear-plus-quadratic reflectron mass spectrometer that discriminates the fragment anions after the femtosecond laser excites the clusters. The fragment neutrals and anions are then captured by two channeltron detectors. The apparatus performance is tested by measuring the photofragments: I−, CF3I−, and neutrals from photoexcitation of the ion–molecule cluster CF3I·I− using femtosecond UV laser pulses with a wavelength of 266 nm. The experimental results are compared with our ground state and excited state electronic structure calculations as well as the existing results and calculations, with particular attention to the generation mechanism of the anion fragments and dissociation channels of the ion–molecule cluster CF3I·I− in the charge-transfer excited state.
Evaluation of the excitation spectra with diffusion Monte Carlo on an auxiliary bosonic ground state
Authors: Reboredo Fernando A. , Kent Paul R. C. , Krogel Jaron T.
Published: September 2023

We aim to improve upon the variational Monte Carlo (VMC) approach for excitations replacing the Jastrow factor by an auxiliary bosonic (AB) ground state and multiplying it by a fermionic component factor. The instantaneous change in imaginary time of an arbitrary excitation in the original interacting fermionic system is obtained by measuring observables via the ground-state distribution of walkers of an AB system that is subject to an auxiliary effective potential. The effective potential is used to (i) drive the AB system’s ground-state configuration space toward the configuration space of the excitations of the original fermionic system and (ii) subtract from a diffusion Monte Carlo (DMC) calculation contributions that can be included in conventional approximations, such as mean-field and configuration interaction (CI) methods. In this novel approach, the AB ground state is treated statistically in DMC, whereas the fermionic component of the original system is expanded in a basis. The excitation energies of the fermionic eigenstates are obtained by sampling a fermion–boson coupling term on the AB ground state. We show that this approach can take advantage of and correct for approximate eigenstates obtained via mean-field calculations or truncated interactions. We demonstrate that the AB ground-state factor incorporates the correlations missed by standard Jastrow factors, further reducing basis truncation errors. Relevant parts of the theory have been tested in soluble model systems and exhibit excellent agreement with exact analytical data and CI and VMC approaches. In particular, for limited basis set expansions and sufficient statistics, AB approaches outperform CI and VMC in terms of basis size for the same systems. The implementation of this method in current codes, despite being demanding, will be facilitated by reusing procedures already developed for calculating ground-state properties with DMC and excitations with VMC.
Nondiffusive particle transport in the stellarator experiment TJ-K
Authors: Müller N. , Manz P. , Ramisch M.
Published: September 2023

Current transport modeling follows a local, diffusive paradigm to describe the dynamics in the edge of magnetically confined plasmas. In the presence of steep gradients, the applicability of local transport theory can break down. In the low-temperature plasmas of the TJ-K stellarator, the extent and characteristics of nonlocal transport contributions are investigated experimentally. In this context, the convection–diffusion equation, which obeys a conventional diffusive formalism, is chosen. However, the predicted linear flux-gradient relationship differs significantly from the behavior observed in most discharges. A second method, which requires no previous assumptions on the diffusivity of particle transport, is applied. This model confirms the presence of significant nondiffusive contributions in the turbulent particle transport of TJ-K. Furthermore, three different regimes were identified at large, intermediate, and small scales. These could be governed by conventional, superdiffusive, and subdiffusive processes, respectively. All three regions persist across discharges at different gases and pressures.
Accelerated and interpretable prediction of local properties in composites
Authors: Zhang Shengtong , Mojumder Satyajit , Liu Wing Kam , Chen Wei , Apley Daniel W.
Published: September 2023

The localized stress and strain field simulation results are critical for understanding the mechanical properties of materials, such as strength and toughness. However, applying off-the-shelf machine learning or deep learning methods to a digitized microstructure restricts the image samples to be of a fixed size and also lacks interpretability. Additionally, existing methods that utilize deep learning models to solve boundary value problems require retraining the model for each set of boundary conditions. To address these limitations, we propose a customized Pixel-Wise Convolutional Neural Network (PWCNN) to make fast predictions of stress and strain fields pixel-by-pixel under different loading conditions and for a wide range of composite microstructures of any size (e.g., much larger or smaller than the sample on which the PWCNN is trained). Through numerical experiments, we show that our PWCNN model serves as an alternative approach to numerical solution methods, such as finite element analysis, but is computationally more efficient, and the prediction errors on the test microstructure are around 5%. Moreover, we also propose an interpretable machine learning framework to facilitate the scientific discovery of why certain microstructures have better or worse performance than others, which has important implications in the design of composite microstructures in advanced manufacturing.
Significant efficiency increment of spintronic terahertz emitters by oxygen engineering
Authors: Li Weiwei , Cui Zhangzhang , Wang Yangkai , Cheng Hao , Zhu Mo , Xiong Bing , Huang Jianping , Shan Zheling , Huang Qiuping , Fu Zhengping , Lu Yalin
Published: September 2023

Spintronic terahertz (THz) emitters have been intensively explored as next-generation sources of THz waves due to their low-cost, nanometer thickness, and broadband spectra. Growing research works are focusing on how to improve the THz emission efficiency, mainly by using a larger spin-Hall angle heavy metal. Currently, the highest intensity spintronic THz emission was based on a CoFeB/Pt heterostructure. Here, we significantly improve the THz emission intensity of CoFeB/Pt by a factor up to 270% through simply incorporating oxygen atoms into the Pt layer. The oxidation of a Pt layer generates a large extrinsic spin Hall angle, which promotes the spin-to-charge conversion of PtOx. Furthermore, the oxygen incorporation also causes a finite oxidation of CoFeB near the interface. We revealed that the significantly enhanced THz emission of CoFeB/PtOx is contributed by both the bulk inverse spin Hall effect of PtOx and the interface effect. Finally, we demonstrated that the oxygen engineering procedure to improve the THz emission of spintronic THz emitters is a common phenomenon as verified in examples, including Co/PtOx, NiFe/PtOx, CoFeB/WOx, and CoFeB/TaOx heterostructures. These findings show that an oxidized heavy metal is a simple, low-cost, and effective route to enhance the spin-to-charge conversion and achieve intense THz pulses, which is promising especially for on-chip THz devices.
A computational study of particle dynamics in synthetic jet flow field
Authors: Stewart Merrylin , Panda Samarendra , Arumuru Venugopal
Published: September 2023

This computational study aims to investigate the transport and dispersion of solid particles in a synthetic jet flow field. Solid spherical particles were injected into the jet at a single point, and their behavior was observed until they left the domain. The interaction between the particles and the vortex rings in the jet was compared for synthetic jets, with different Strouhal numbers (0.05, 0.1, and 0.2). The Reynolds number (Re = 150), the mass of injected particles, particle diameter distribution, and particle Stokes number at injection were kept constant. The results showed that the jet's momentum mainly transported the particles, while the vorticity of the vortex rings caused them to spread. The particle Stokes number affected the distribution of particles within the jet, with a higher Stokes number particle concentrating at the jet's center and lower Stokes number particles being carried within the vortex ring. For the low Strouhal number jet, the combined effect of the fast decline in the particle Stokes number, low vorticity of vortex ring, significant distance between successive vortices, and high jet momentum resulted in a higher spread of particles and rapid transport across the domain. As the Strouhal number increased, the particle Stokes number decreased slowly downstream; moreover, the vorticity of the vortex ring increased, the distance between vortices decreased, and low momentum imparted by the jet led to less particle spread and slower transport. Overall, the spread and transport of particles were most effective in the synthetic jet, with the low Strouhal number.
Large-incidence-angle multiple-beam two-plasmon decay instability in inertial confinement fusion
Authors: Zhou F. X. , Cao S. H. , Lian C. W. , Ji Y. , Yan R. , Li J. , Yang D. , Hao L. , Ren C. , Zheng J.
Published: September 2023

A multi-dimensional code FLAME-MD solving fluid-like laser-plasma instabilities' (LPIs) equations has been developed and is used to study multiple-beam two-plasmon decay (TPD) instability relevant to a laser-entrance-hole window burn-off scenario in inertial confinement fusion (ICF) experiments. It is found that TPD can be collectively driven by multiple beams incident at large incidence angles with respect to the electron density gradient at a very low threshold. The polarization configuration of the laser beams is a key factor determining the way of sharing common daughter electron plasma waves (EPWs). The p-polarized beams arranged on the same incidence cone can collectively drive common EPWs along the cone axis. The common-wave sharing mechanisms among the s-polarized beams are largely dependent on the geometry of the beams and are less robust. The simulation results also show that the p-polarized beams are dominating the multiple-beam TPD processes. The common EPWs along the cone axis can accelerate energetic electrons toward the capsule inside the hohlraum and, therefore, pose a fuel-preheat risk to ICF implosions.
Prediction of wave-induced ship motions based on integrated neural network system and spatiotemporal wave-field data
Authors: Lee Jae-Hoon , Lee Jaehak , Kim Yonghwan , Ahn Yangjun
Published: September 2023

This study introduces an artificial neural network system for ship motion prediction in seaways. To consider the physical characteristics of wave-induced ship motions, neural networks based on a Long Short-Term Memory (LSTM) encoder and decoder, and a convolutional neural network (CNN) are integrated. The LSTM encoder computes the state vector representing the memory effects of motion-induced radiated waves based on past motion records, that is, a sequence-to-one model. In the LSTM decoder, the motion time series is predicted using the encoded initial state vector and foreseen information on the ocean wave field around a vessel, that is, a sequence-to-sequence model. In addition, a CNN is adopted to compress the wave data into a vector sequence. Particularly, the present CNN uses spatiotemporal wave-field data, not a wave signal at single location. To validate the proposed system, a database for training the integrated system was constructed using a physics-based seakeeping program for various sea states. By applying the trained model, deterministic predictions were performed for a new ocean environment, and the accuracy and reliability of the testing results are investigated according to the input data and neural network structures. From the simulation results, it was confirmed that the present encoder–decoder system can conduct ship motion forecasting by effectively considering the motion memory effects and wave excitations as in the ship hydrodynamic model. In addition, excitations and resulting motion responses by short-crested waves can be considered through CNN-based wave-field data processing. Finally, the present machine-learning model also showed the capability of extracting ship operation information (maneuvering quantities) from the given wave-field data.
Gain-loss-induced non-Abelian Bloch braids
Authors: Midya Bikashkali
Published: September 2023

Onsite gain-loss-induced topological braiding principle of non-Hermitian energy bands is theoretically formulated in multiband lattice models with Hermitian hopping amplitudes. Braid phase transition occurs when the gain-loss parameter is tuned across exceptional point degeneracy. Laboratory realizable effective-Hamiltonians are proposed to realize braid groups B2 and B3 of two and three bands, respectively. While B2 is trivially Abelian, the group B3 features non-Abelian braiding and energy permutation originating from the collective behavior of multiple exceptional points. Phase diagrams with respect to lattice parameters to realize braid group generators and their non-commutativity are shown. The proposed theory is conducive to synthesizing exceptional materials for applications in topological computation and information processing.
Compositional dependence of spintronic properties in Pt/GdCo films
Authors: Suzuki Daniel H. , Lee Byung Hun , Beach Geoffrey S. D.
Published: September 2023

GdCo films have been widely used in spintronic applications, owing largely to their tunable degree of ferrimagnetic compensation. However, all key properties likewise depend on the alloy composition, and a systematic study of the interdependent spintronic properties with composition has not been reported. Here, we report the compositional dependence of key spintronic properties, including anisotropy, symmetric, and antisymmetric (Dzyaloshinskii–Moriya, DMI) exchange interactions, effective spin Hall angle, and domain wall mobility in a 3 nm Pt/GdCo composition series. We measure the magnetic anisotropy and determine an interfacial Pt/Co and bulk GdCo pair-ordering contribution to total anisotropy. Additionally, we estimate the exchange stiffness of all three interactions in GdCo as a function of composition. We conduct two types of domain wall motion experiments on patterned racetracks to determine the effective spin Hall angle and current-driven domain wall mobility. We find a 5× increase in effective spin Hall angle with increasing Gd concentration, suggesting an improvement in spin transfer efficiency in rare earth materials. Finally, we observe a monotonic decrease in the DMI strength with increasing Gd content, suggesting that DMI arises from the Pt/Co interfacial interaction.
Numerical study of bubble rise in a three-dimensional sinusoidal channel
Authors: Agnihotry Akshat , Prasad Niraj Kr , Dalal Amaresh
Published: September 2023

The bubble formation phenomenon and its movement have numerous applications in the shipbuilding, nuclear, mechanical, and ocean industries. Thus, a complete understanding of bubble rise is of immense importance in the fields mentioned above. Although, even after a plethora of research, a significant understanding of bubble wobbling and path instability still needs to be achieved. Furthermore, the complexity increases when a bubble rises in complex channels. Although various two-dimensional studies have attempted to report the bubble wobbling in the complex channels, a three-dimensional study on it still needs to be explored. Thus, in the present study, we attempted to report the bubble rise tendency in a three-dimensional sinusoidal channel. As bubble rise velocity plays a significant role in bubble wobbling, we attempted to study the bubble's path instability and rising velocity at different Reynolds numbers (Re) and Bond numbers (Bo). The maximum bubble rise velocity was observed to increase with Reynolds number (Re) while it decreases with an increase in Bond number (Bo). Furthermore, the wobbling tendency was also less in three-dimensional cases compared to previously reported two-dimensional studies. The bubble wobbling was reported to increase with the Reynolds number with a more periodic nature of the velocity profile. Bubble wobbling increased with an increase in a Bond number less than 9. The multi-phase simulation was performed on the open-source solver Gerris. The present study unveiled various aspects of bubble rise in three-dimensional sinusoidal channels and highlighted the role of rising velocity in the path instability of bubble rise.
Impact of bileaflet mechanical heart valve leaflet dysfunction on left ventricular blood flow: An experimental study
Authors: Qiang Yan , Duan Tianci , Zhang Minzu , Qi Liang , Wei Liejiang , Zhong Wenqi
Published: September 2023

Artificial heart valve replacement is recognized as the most effective method for treating valvular heart disease. Presently, the bileaflet mechanical heart valve is the predominant type utilized. Nonetheless, complications are known to arise following valve replacement surgery, mostly attributable to deviations in the left ventricular blood flow pattern instigated by the dysfunction of the bileaflet mechanical valve. However, the impact of mitral valve leaflet dysfunction on left ventricular hemodynamics has not been studied in depth. Hence, to approximate the physiological conditions of the left ventricular flow and pressure, a left heart circulation pulsatile flow system was devised. The time-resolved particle image velocimetry method was employed to evaluate the left ventricular blood flow under standard working conditions of the bileaflet mechanical valve and in the case where one of the valve leaflets is determined to be functionally impaired. The experimental results reveal that the normally functioning bileaflet valve manifests a tri-jet flow pattern, with intense jets on both sides generating two expansive vortices. Conversely, when one of the valve leaflets is impaired, the tri-jet flow metamorphoses into a bi-jet flow, coupled with augmented velocity. In both instances, the jets traverse along the ventricular model wall and alter their direction subsequent to passing the apex. Consequently, the employment of bileaflet valves culminates in a multifaceted left ventricular blood flow pattern. Furthermore, the valve leaflet dysfunction escalates shear stress, a condition that could potentially instigate damage to blood cells. The insights gained from this study can potentially guide the improved design of the mechanical bivalve.
Investigating airborne transmission risks: A mathematical model of evaporating droplets with solid residue
Authors: Pan Lun-Sheng , Leong Fong Yew , Klaseboer Evert , Kang Chang-Wei , Wang Yun Ching , Lim Keng Hui , Xu George , Zhao Cunlu , Che Zhizhao , Ooi Chinchun , Ge Zhengwei , Yap Yit Fatt , Li Hongying
Published: September 2023

The COVID-19 pandemic has spotlit the scientific field of fluid dynamics governing airborne transmission through virus-laden mucosal-salivary droplets. In this work, a mathematical model for airborne droplet dispersion and viral transmission centered on evaporating droplets containing solid residue was proposed. Droplet dynamics are influenced by factors such as initial velocity, relative humidity (RH), and solid residue, in agreement with analytical and experimental results. Interestingly, the maximum droplet dispersion distance depends strongly on initial droplet size and RH, such as 0.8-mm-diameter droplet at 0.3 RH, 1.0 mm at 0.6 RH, and 1.75 mm at 0.9 RH, but only weakly on initial projected velocity. Under realistic conditions, an evaporating sputum droplet can cover a dispersion distance at least three times than that of a pure water droplet. Based on Wells falling curves, the critical droplet size, the largest droplet that can remain suspended in air without settling due to gravity, ranges from 120 μm at 0.3 RH to 75 μm at 0.9 RH. Together, our results highlight the role of evaporation on droplet lifetime, dispersion distance, and transmission risks.
Laboratory investigation on gas slippage phenomenon in coal sample and its research significance
Authors: Meng Ya , Li Zhiping
Published: September 2023

The gas slippage effect (GSE) of coal is associated with the coalbed methane (CBM) wells' productivity. Through the helium permeability experiment of five coal samples with different vitrinite reflectance, characteristics of gas permeability variations in coal samples with different coalification degrees are analyzed, the influence of coalification degrees, coal pore structures, and different gases on GSE is revealed, and the impact of GSE on the CBM wells productivity is discussed. It indicatess that the gas permeability of coal varies with the pore pressure in a negative power function and a gas slippage coefficient of coals declines with the rise of Klinkenberg permeability by a negative power function. With the ascend of vitrinite reflectance of coal, there is an asymmetric “U-shaped” change trend in GSE. The GSE in coal with different vitrinite reflectance is mostly govern by the pore diameter distribution of coal. The slippage parameter of gas is consistent with the evolution law of coal pore structures during coal metamorphism. The slippage coefficient of different gases is obtained. On this basis, the prediction model of CBM well production considering GSE is established, and the impact degree of GSE on CBM well productivity is revealed.
What keeps nanopores boiling
Authors: Giacomello Alberto
Published: September 2023

The liquid-to-vapor transition can occur under unexpected conditions in nanopores, opening the door to fundamental questions and new technologies. The physics of boiling in confinement is progressively introduced, starting from classical nucleation theory, passing through nanoscale effects, and terminating with the material and external parameters that affect the boiling conditions. The relevance of boiling in specific nanoconfined systems is discussed, focusing on heterogeneous lyophobic systems, chromatographic columns, and ion channels. The current level of control of boiling in nanopores enabled by microporous materials such as metal organic frameworks and biological nanopores paves the way to thrilling theoretical challenges and to new technological opportunities in the fields of energy, neuromorphic computing, and sensing.
Front propagation in ultrastable glasses is dynamically heterogeneous
Authors: Herrero Cecilia , Ediger Mark D. , Berthier Ludovic
Published: September 2023

Upon heating, ultrastable glassy films transform into liquids via a propagating equilibration front, resembling the heterogeneous melting of crystals. A microscopic understanding of this robust phenomenology is, however, lacking because experimental resolution is limited. We simulate the heterogeneous transformation kinetics of ultrastable configurations prepared using the swap Monte Carlo algorithm, thus allowing a direct comparison with experiments. We resolve the liquid–glass interface both in space and in time as well as the underlying particle motion responsible for its propagation. We perform a detailed statistical analysis of the interface geometry and kinetics over a broad range of temperatures. We show that the dynamic heterogeneity of the bulk liquid is passed on to the front that propagates heterogeneously in space and intermittently in time. This observation allows us to relate the averaged front velocity to the equilibrium diffusion coefficient of the liquid. We suggest that an experimental characterization of the interface geometry during the heterogeneous devitrification of ultrastable glassy films could provide direct experimental access to the long-sought characteristic length scale of dynamic heterogeneity in bulk supercooled liquids.
Neutral gas pressure dependence of ion–ion mutual neutralization rate constants using Landau–Zener theory coupled with trajectory simulations
Authors: Liu Zhibo , Roy Mrittika , DeYonker Nathan J. , Gopalakrishnan Ranganathan
Published: September 2023

In this computational study, we describe a self-consistent trajectory simulation approach to capture the effect of neutral gas pressure on ion–ion mutual neutralization (MN) reactions. The electron transfer probability estimated using Landau–Zener (LZ) transition state theory is incorporated into classical trajectory simulations to elicit predictions of MN cross sections in vacuum and rate constants at finite neutral gas pressures. Electronic structure calculations with multireference configuration interaction and large correlation consistent basis sets are used to derive inputs to the LZ theory. The key advance of our trajectory simulation approach is the inclusion of the effect of ion-neutral interactions on MN using a Langevin representation of the effect of background gas on ion transport. For H+ − H− and Li+ − H(D)−, our approach quantitatively agrees with measured speed-dependent cross sections for up to ∼105 m/s. For the ion pair Ne+ − Cl−, our predictions of the MN rate constant at ∼1 Torr are a factor of ∼2 to 3 higher than the experimentally measured value. Similarly, for Xe+ − F− in the pressure range of ∼20 000–80 000 Pa, our predictions of the MN rate constant are ∼20% lower but are in excellent qualitative agreement with experimental data. The paradigm of using trajectory simulations to self-consistently capture the effect of gas pressure on MN reactions advanced here provides avenues for the inclusion of additional nonclassical effects in future work.
Adaptive multi-modes absorption with enhanced electromagnetic environment compatibility
Authors: Ye Yongzhi , He Bo , Liu Run , Sima Boyu , Sun Zhiwei
Published: September 2023

Absorption of electromagnetic (EM) wave has been widely studied and applied in EM, optics, and material research. By constructing an adaptive multi-mode absorption, an EM absorber approach that can be used in a variety of EM environments is provided in this research. This property demonstrates the absorber has an improved environment compatibility. It is used as an application example to address the issue that has recently come up in phased array research on the need to reduce the coupling between antenna elements in varied beam-scanning cases. After analyzing the electric and magnetic characteristics of a patch antenna array in different beam-scanning states, an absorber structure is constructed, with electric absorption in the sum beam case, magnetic absorption in the difference beam case, and combined electric-magnetic absorption in other beam scanning cases. The proposed method is systematically investigated and, finally validated by simulation and measurement evidently. In arbitrary beam-scanning states, the absorber exhibits good absorption and coupling reduction performance, while the radiation performance of the array is well maintained after introducing the absorber. This research can be used in absorber and coupling reduction studies, as well as, potentially in metamaterial and electromagnetic compatibility (EMC).
Large eddy simulations of pilot-stage equivalence ratio effects on combustion instabilities in a coaxial staged model combustor
Authors: Lv Guangpu , Liu Xiao , Zhang Zhihao , Li Shengnan , Liu Enhui , Zheng Hongtao
Published: September 2023

In this paper, the effects of pilot-stage equivalence ratio on combustion instabilities in a coaxial staged model combustor are investigated using the Wall-Modeled Large Eddy Simulation. The global equivalence ratio is maintained constant, and the Stratification Ratio of the first main-stage and the second main-stage is set to 1; the dynamic mode decomposition and system identification methods are employed to analyze the flame dynamics, velocity, heat release rate modes, and flame transfer function (FTF) of the model combustor under different pilot-stage equivalence ratios. The results show that when the pilot-stage equivalence ratio is 0.6, the oscillation amplitude of heat release rate (HRR) exceeds 7.5% of the global average HRR, and the velocity oscillation and the global HRR oscillation in the combustor are coupled. As the pilot-stage equivalence ratio increases to 0.8, the oscillation amplitude of HRR decreases to 2.5%, and the oscillation of velocity and global HRR in the combustor are decoupled. Furthermore, the maximum value of FTF decreases from 3.5 to below 1 with the increase in the pilot-stage equivalence ratio.
Inverse power Ramos–Louzada distribution with various classical estimation methods and modeling to engineering data
Authors: Al Mutairi Aned , Hassan Amal S. , Alshqaq Shokrya S. , Alsultan Rehab , Gemeay Ahmed M. , Nassr Said G. , Elgarhy Mohammed
Published: September 2023

This work uses the inverse-power transformation to create the inverse power Ramos–Louzada distribution (IPRLD), a novel two-parameter version of the Ramos–Louzada distribution. The failure rate of the new distribution can be represented by a reverse bathtub shape, a rising shape, or a decreasing shape, making it appropriate for a range of real data. Asymmetrical and unimodal densities can be produced via the IPRLD. Its mathematical characteristics are computed in some cases. The novel proposed model’s structural characteristics are derived. To estimate the model parameters, several estimating strategies are explored, including ten classical methods. Simulation results with their partial and total ranks are used to evaluate the ranking and behavior of various approaches. Finally, two real-world datasets are used to experimentally show the suggested distribution’s adaptability. The analysis of the data reveals that the introduced distribution offers a better fit than some significant rival distributions, including the inverse Ramos–Louzada, inverse power Burr Hatke, inverse Nakagami-M, inverse log-logistic, inverse weighted Lindley, inverse Lindley, and Ramos–Louzada.
Accurate identification of cross-sectional bending stiffness in large-scale wind turbine blades through static loading test
Authors: Ma Yi , Zhou Aiguo , Shi Jinlei , Zhu Yutian , Ren Lili
Published: September 2023

To ensure the safe and stable operation of wind turbines, it is essential that the blades have sufficient bending stiffness to prevent excessive deflection and tower impact. A method combining static loading test and numerical analysis is proposed to solve the problem of identifying the cross-sectional bending stiffness of actual blades. Two working conditions, namely multi-point static test and single-point static calibration, are considered. A mathematical model of a cantilever beam with an initial small curvature and variable cross section is established. By fitting the deflection measurement data obtained from the static loading test, the deflection differential equation is solved by the finite difference method to obtain expressions for the cross-sectional bending stiffness under large and small deflection. The analysis results of several blade models show that the bending stiffness identification error for most blade sections is less than 10%, confirming the effectiveness of this method. This provides a practical and theoretical basis for the design, analysis, and refinement of test parameters for large-scale blades.
Environmentally robust
cis
-regulatory changes underlie rapid climatic adaptation
Authors: Ballinger Mallory A. , Mack Katya L. , Durkin Sylvia M. , Riddell Eric A. , Nachman Michael W.
Published: September 2023

Changes in gene expression are thought to play a major role in adaptive evolution. While it is known that gene expression is highly sensitive to the environment, very few studies have determined the influence of genetic and environmental effects on adaptive gene expression differences in natural populations. Here, we utilize allele-specific expression to characterize
cis
and
trans
gene regulatory divergence in temperate and tropical house mice in two metabolic tissues under two thermal conditions. First, we show that gene expression divergence is pervasive between populations and across thermal conditions, with roughly 5 to 10% of genes exhibiting genotype-by-environment interactions. Second, we found that most expression divergence was due to
cis
-regulatory changes that were stable across temperatures. In contrast, patterns of expression plasticity were largely attributable to
trans
-effects, which showed greater sensitivity to temperature. Nonetheless, we found a small subset of temperature-dependent
cis
-regulatory changes, thereby identifying loci underlying expression plasticity. Finally, we performed scans for selection in wild house mice to identify genomic signatures of rapid adaptation. Genomic outliers were enriched in genes with evidence for
cis
-regulatory divergence. Notably, these genes were associated with phenotypes that affected body weight and metabolism, suggesting that
cis-
regulatory changes are a possible mechanism for adaptive body size evolution between populations. Our results show that gene expression plasticity, largely controlled in
trans
, may facilitate the colonization of new environments, but that evolved changes in gene expression are largely controlled in
cis
, illustrating the genetic and nongenetic mechanisms underlying the establishment of populations in new environments.