bluuebunny/crossref_metadata_2025 huggingface dataset:
Dual-Task Interference in the Assessment of Listening Effort: Results of Normal-Hearing Adults, Cochlear Implant Users, and Hearing Aid Users
Authors: Ceuleers Dorien , Degeest Sofie , Swinnen Freya , Baudonck Nele , Kestens Katrien , Dhooge Ingeborg , Keppler Hannah
Published: August 2024

Purpose:

The purpose of the current study was to assess dual-task interference (i.e., changes between the dual-task and baseline condition) in a listening effort dual-task paradigm in normal-hearing (NH) adults, hearing aid (HA) users, and cochlear implant (CI) users.

Method:

Three groups of 31 participants were included: (a) NH adults, (b) HA users, and (c) CI users. The dual-task paradigm consisted of a primary speech understanding task in a quiet condition, and a favorable and unfavorable noise condition, and a secondary visual memory task. Dual-task interference was calculated for both tasks, and participants were classified based on their patterns of interference. Descriptive analyses were established and differences between the three groups were examined.

Results:

The descriptive results showed varying patterns of dual-task interference between the three listening conditions. Most participants showed the pattern of visual memory interference (i.e., worse results for the secondary task in the dual-task condition and no difference for the primary task) in the quiet condition, whereas the pattern of speech understanding priority trade-off (i.e., worse results for the secondary task in the dual-task condition and better results for the primary task) was most prominent in the unfavorable noise condition. Particularly, in HA and CI users, this shift was seen. However, the patterns of dual-task interference were not statistically different between the three groups.

Conclusions:

Results of this study may provide additional insight into the interpretation of dual-task paradigms for measuring listening effort in diverse participant groups. It highlights the importance of considering both the primary and secondary tasks for accurate interpretation of results.

Supplemental Material:

https://doi.org/10.23641/asha.26409088
A stochastic and analytical model of hierarchical fragmentation
Authors: Thomasson B. , Joncour I. , Moraux E. , Motte F. , Louvet F. , González M. , Nony T.
Published: August 2024

Context. Molecular clouds are the most important incubators of young stars clustered in various stellar structures whose spatial extension can vary from a few AU to several thousand AU. Although the reality of these stellar systems has been established, the physical origin of their multiplicity remains an open question.

Aims. Our aim was to characterise these stellar groups at the onset of their formation by quantifying both the number of stars they contain and their mass using a hierarchical fragmentation model of the natal molecular cloud.

Methods. We developed a stochastic and predictive model that reconciles the continuous multi-scale structure of a fragmenting molecular cloud with the discrete nature of the stars that are the products of this fragmentation. In this model a gas structure is defined as a multi-scale object associated with a subregion of a cloud. Such a structure undergoes quasi-static subfragmentation until star formation. This model was implemented within a gravo-turbulent fragmentation framework to analytically follow the fragmentation properties along spatial scales using an isothermal and adiabatic equations of state (EOSs).

Results. We highlighted three fragmentation modes depending on the amount of fragments produced by a collapsing gas structure, namely a hierarchical mode, a monolithic mode, and a mass dispersal mode. Using an adiabatic EOS we determined a characteristic spatial scale where further fragmentation is prevented, around a few tens of AU. We show that fragmentation is a self-regulated process as fragments tend to become marginally unstable following a M ∝ R Bonnor–Ebert-like mass-size profile. Supersonic turbulent fragmentation structures the cloud down to R ≈ 0.1 pc, and gradually turns into a less productive Jeans-type fragmentation under subsonic conditions so hierarchical fragmentation is a scale dependant process.

Conclusions. Our work suggests that pre-stellar objects resulting from gas fragmentation, have to progressively increase their accretion rate in order to form stars. A hierarchical fragmentation scenario is compatible with both the multiplicity of stellar systems identified in Taurus and the multi-scale structure extracted within NGC 2264 molecular cloud. This work suggests that hierarchical fragmentation is one of the main mechanisms explaining the presence of primordial structures of stellar clusters in molecular clouds.
Effect of the Earth’s declination variation on characteristics of Jovian decametric radio emissions
Authors: Jácome H. R. P. , Zarka P. , Louis C. K. , Marques M. S. , Echer E. , Lamy L.
Published: August 2024

Context. The variation in the Jovicentric sub-latitude (declination, DE) of a radio observer of Jupiter has long been known to affect the observation of Jupiter’s decametric (DAM) radio emissions due to these emissions’ anisotropic nature (through cyclotron maser instability beaming cones centered on Jovian magnetic field lines). The effect of the DE variation, however, is still not clearly understood. For ground-based observations of Jupiter, the DE variation, from −4° to +4°, occurs concomitantly with the cyclic variation in the distance to Jupiter, R, and Jupiter’s elongation angle, γ, which also affect the emission observation. Those covariant effects must be removed, then, for an analysis of the pure effect of DE.

Aims. The aim of this study is to investigate the pure effect of the Earth’s DE variation on the maximum frequency, duration, average Io phase, and average longitude of Io-induced DAM emissions observed with the Nançay Decameter Array (NDA).

Methods. For this purpose, we selected from the NDA/Routine digital catalog Jovian DAM emissions with an intensity (distance-corrected) above or equal to 8.8 dB and a maximum frequency above or equal to 20 MHz (25 MHz) for southern (northern) emissions. Distinct maximum frequency thresholds were adopted because of the typical discrepancy in the emissions’ frequency due to the high amplitude anomaly in the Jovian magnetic field at Jupiter’s northern hemisphere. The selected emissions comprise a new “unbiased” catalog. After analyzing the tenuous variation in the characteristics of the unbiased set of Io-DAM emissions with DE, we compared them with those of matching Io-DAM simulations obtained with the Exoplanetary and Planetary Radio Emissions Simulator (ExPRES).

Results. From both the NDA data and the ExPRES simulations, it is observed that the pure DE effect on the Io-DAM emissions characteristics is minor, yet a clear proportionality of the maximum frequency and duration of the northern Io-DAM emissions with DE is noticed.

Conclusions. The northern Io-DAM emissions seem to be more strongly affected by the DE variation than the southern emissions. Additionally, ExPRES can predict Io-DAM emissions consistently, from which we conclude that the current understanding of emission generation and propagation is reasonable. This study may be extended for broader ranges of DE, such as Juno’s.
Stochastic excitation of waves in magnetic stars
Authors: Bessila L. , Mathis S.
Published: August 2024

Context. Stellar oscillations are key to unravelling stellar properties, such as their mass, radius, and age. This in turn enables us to date and characterize their exoplanetary systems. The amplitudes of acoustic (p-) modes in solar-like stars are intrinsically linked to their convective turbulent excitation source, which in turn is influenced by magnetism. In the observations of the Sun and stars, the mode amplitudes are modulated following their magnetic activity cycles: the higher the magnetic field, the lower the mode amplitudes. When the magnetic field is strong, it can even inhibit acoustic modes, which are not detected in most of the solar-like stars that are strongly magnetically active. Magnetic fields are known to freeze convection when they stronger than a critical value: the so-called on-off approach is used in the literature.

Aims. We investigate the impact of magnetic fields on the stochastic excitation of acoustic modes.

Methods. First, we generalise the forced-wave equation formalism, including the effects of magnetic fields. Second, we assess how convection is affected by magnetic fields using results from the magnetic mixing-length theory.

Results. We provide the source terms of the stochastic excitation, including a new magnetic source term and the Reynolds stresses. We derive scaling laws for the mode amplitudes that take both the driving and the damping into account. These scalings are based on the inverse Alfvén dimensionless parameter: The damping increases with the magnetic field and reaches a saturation threshold when the magnetic field is strong. The driving of the modes diminishes when the magnetic field becomes stronger and the turbulent convection is weaker.

Conculsions. As expected from the observations, we find that a stronger magnetic field diminishes the resulting mode amplitudes. The evaluation of the inverse Alfvén number in stellar models provides a means for estimating the expected amplitudes of acoustic modes in magnetically active solar-type stars.
CIRCLEZ : Reliable photometric redshifts for active galactic nuclei computed solely using photometry from Legacy Survey Imaging for DESI
Authors: Saxena A. , Salvato M. , Roster W. , Shirley R. , Buchner J. , Wolf J. , Kohl C. , Starck H. , Dwelly T. , Comparat J. , Malyali A. , Krippendorf S. , Zenteno A. , Lang D. , Schlegel D. , Zhou R. , Dey A. , Valdes F. , Myers A. , Assef R. J. , Ricci C. , Temple M. J. , Merloni A. , Koekemoer A. , Anderson S. F. , Morrison S. , Liu X. , Nandra K.
Published: August 2024

Context. Photometric redshifts for galaxies hosting an accreting supermassive black hole in their center, known as active galactic nuclei (AGNs), are notoriously challenging. At present, they are most optimally computed via spectral energy distribution (SED) fittings, assuming that deep photometry for many wavelengths is available. However, for AGNs detected from all-sky surveys, the photometry is limited and provided by a range of instruments and studies. This makes the task of homogenizing the data challenging, presenting a dramatic drawback for the millions of AGNs that wide surveys such as SRG/eROSITA are poised to detect.

Aims. This work aims to compute reliable photometric redshifts for X-ray-detected AGNs using only one dataset that covers a large area: the tenth data release of the Imaging Legacy Survey (LS10) for DESI. LS10 provides deep grizW1-W4 forced photometry within various apertures over the footprint of the eROSITA-DE survey, which avoids issues related to the cross-calibration of surveys.

Methods. We present the results from CIRCLEZ, a machine-learning algorithm based on a fully connected neural network. CIRCLEZ is built on a training sample of 14 000 X-ray-detected AGNs and utilizes multi-aperture photometry, mapping the light distribution of the sources.

Results. The accuracy (σNMAD) and the fraction of outliers (η) reached in a test sample of 2913 AGNs are equal to 0.067 and 11.6%, respectively. The results are comparable to (or even better than) what was previously obtained for the same field, but with much less effort in this instance. We further tested the stability of the results by computing the photometric redshifts for the sources detected in CSC2 and Chandra-COSMOS Legacy, reaching a comparable accuracy as in eFEDS when limiting the magnitude of the counterparts to the depth of LS10.

Conclusions. The method can be applied to fainter samples of AGNs using deeper optical data from future surveys (for example, LSST, Euclid), granting LS10-like information on the light distribution beyond the morphological type. Along with this paper, we have released an updated version of the photometric redshifts (including errors and probability distribution functions) for eROSITA/eFEDS.
FAUST
Authors: Maureira M. J. , Pineda J. E. , Liu H. B. , Testi L. , Segura-Cox D. , Chandler C. , Johnstone D. , Caselli P. , Sabatini G. , Aikawa Y. , Bianchi E. , Codella C. , Cuello N. , Fedele D. , Friesen R. , Loinard L. , Podio L. , Ceccarelli C. , Sakai N. , Yamamoto S.
Published: August 2024

Context. Planets form in the disks surrounding young stars. The time at which the planet formation process begins is still an open question. Annular substructures such as rings and gaps in disks are intertwined with planet formation, and thus their presence or absence is commonly used to investigate the onset of this process.

Aims. Current observations show that a limited number of disks surrounding protostars exhibit annular substructures, all of them in the Class I stage. The lack of observed features in most of these sources may indicate a late emergence of substructures, but it could also be an artifact of these disks being optically thick. To mitigate the problem of optical depth, we investigated substructures within a very young Class 0 disk characterized by low inclination using observations at longer wavelengths.

Methods. We used 3 mm ALMA observations tracing dust emission at a resolution of 7 au to search for evidence of annular substructures in the disk around the deeply embedded Class 0 protostar Oph A SM1.

Results. The observations reveal a nearly face-on disk (inclination ∼ 16°) extending up to 40 au. The radial intensity profile shows a clear deviation from a smooth profile near 30 au, which we interpret as the presence of either a gap at 28 au or a ring at 34 au with Gaussian widths of σ = 1.4−1.2+2.3 au and σ = 3.9−1.9+2.0 au, respectively. Crucially, the 3 mm emission at the location of the possible gap or ring is determined to be optically thin, precluding the possibility that this feature in the intensity profile is due to the emission being optically thick.

Conclusions. Annular substructures resembling those in the more evolved Class I and II disks could indeed be present in the Class 0 stage, which is earlier than suggested by previous observations. Similar observations of embedded disks in which the high-optical-depth problem can be mitigated are clearly needed to better constrain the onset of substructures in the embedded stages.
The rich interstellar reservoir of dinitriles: Detection of malononitrile and maleonitrile in TMC-1
Authors: Agúndez M. , Bermúdez C. , Cabezas C. , Molpeceres G. , Endo Y. , Marcelino N. , Tercero B. , Guillemin J.-C. , de Vicente P. , Cernicharo J.
Published: August 2024

While the nitrile group is by far the most prevalent one among interstellar molecules, the existence of interstellar dinitriles (molecules containing two −CN groups) has recently been proven. Here we report the discovery of two new dinitriles in the cold dense cloud TMC-1. These newly identified species are malononitrile, CH2(CN)2, and maleonitrile, the Z isomer of NC−CH=CH−CN, which can be seen as the result of substituting two H atoms with two −CN groups in methane and ethylene, respectively. These two molecules were detected using data from the ongoing QUIJOTE line survey of TMC-1 that is being carried out with the Yebes 40 m telescope. We derive column densities of 1.8 × 1011 cm−2 and 5.1 × 1010 cm−2 for malononitrile and maleonitrile, respectively. This means that they are eight and three times less abundant than HCC−CH2−CN and (E)-HCC−CH=CH−CN, respectively, which are analog molecules detected in TMC-1 in which one −CN group is converted into a −CCH group. This is in line with previous findings in which −CCH derivatives are more abundant than the −CN counterparts in TMC-1. We examined the potential chemical pathways to these two dinitriles, and we find that while maleonitrile can be efficiently formed through the reaction of CN with CH2CHCN, the formation of malononitrile is not clear because the neutral-neutral reactions that could potentially form it are not feasible under the physical conditions of TMC-1.
Blue Book on China’s Scientific Journal Development (2022)
Authors:   China Association for Science and Technology
Published: August 2024

Blue Book on China’s Scientific Journal Development (2022) has the theme of “Platform for Academic Publishing and Exchange in the Era of Digital Economy”. Relying on renowned domestic and foreign databases and official data, we use scientific measurement methods, analyze existing problems, summarize the law of development, sort out and analyze the overall situation of Chinese science and technology journals and scientific papers, present the whole status of Chinese science and technology journals in the form of data. Besides, we study the changes in global digital publishing technology, discuss the domestic and foreign digital resources and academic exchange platform progress and trends, explore Chinese academic publishing fusion and high-end academic exchange platform development path and put forward suggestions about Chinese academic publishing and exchange platform development in the digital economy era.
Le mégaoesophage chez le chien et le chat :
conduite à tenir diagnostique et thérapeutique
Authors: Fabrès Virginie , Lavoué Rachel
Published: August 2024

Le mégaœsophage se caractérise par la présence d’une dilatation de l’œsophage sur toute sa longueur, secondaire à une diminution de son péristaltisme. Le mégaœsophage peut être congénital ou acquis.

Les formes acquises peuvent être d’origine immune, neuromusculaire, gastro-intestinale et toxique bien que la forme idiopathique soit la plus courante chez le chien adulte. La manifestation clinique principale est la présence de régurgitations. Un amaigrissement, du ptyalisme, de l’halitose ou de la toux sont également rapportés.

L’identification du mégaœsophage se fait la plupart du temps par des radiographies thoraciques sans préparation. Des radiographies avec produit de contraste ou d’une vidéofluoroscopie après ingestion d’un repas baryté peuvent être nécessaires pour confirmer le diagnostic.
Certaines formes de mégaœsophage secondaire sont réversibles après traitement de la cause sous-jacente.

Par conséquent, une cause primaire doit être recherchée par des examens complémentaires, car elle conditionne la prise en charge thérapeutique ainsi que le pronostic de l’affection.
L’endoscopie urinaire
Authors: Robin Elisabeth , Hahn Harriet , Gomes Eymeric , Le Boedec Kevin
Published: August 2024

L'endoscopie urinaire est un examen complémentaire de deuxième intention lors de l'exploration de troubles urinaires tels que l'incontinence, les infections urinaires chroniques, l'hématurie, la dysurie ou la pollakiurie.
Elle permet d'obtenir des informations morphologiques précises sur le trajet urinaire incluant les ostiums urétral et urétéraux, l’urètre et la vessie, ainsi que sur le carrefour des voies uro-génitales.
La diversité des instruments existants permet de réaliser cet acte sur les chiens de petit comme de grand format, et parfois sur les chats.
L'anesthésie générale reste indispensable pour garantir la sécurité de l’animal, et la qualité des informations recueillies. La présence d’une anémie, d’un trouble de la coagulation ou d’une insuffisance rénale aiguë représente une contre-indication à cette procédure.
Différentes anomalies congénitales (ectopie urétérale par exemple) ou acquises telles que des lésions inflammatoires (urétrite sténosante, bride, ...), ou tumorale (carcinome à cellules transitionnelles, sarcome de Sticker, ...) peuvent être observées. L'endoscopie peut aussi présenter un caractère thérapeutique, permettant l’exérèse de calculs à l'aide d'une pince basket, et le retrait de polypes à l'aide d'un lasso cautérisant. Elle peut enfin guider l’utilisation du laser pour traiter les uretères ectopiques.
Diagnostic et traitement des affections du sac anal chez le chien et le chat
Authors: Béguin Jérémy , Benchekroun Ghita
Published: August 2024

Contrairement aux chats, les affections du sac anal sont fréquentes chez le chien. Parmi celles-ci, les atteintes inflammatoires sont les plus courantes.
Une prise en charge médicale est en général suffisante, et le pronostic est considéré comme bon.

Une sacculectomie doit être envisagée lors de réponse insuffisante à un traitement médical, de sacculite chronique, d’impaction récidivante ou d’abcès. L’adénocarcinome des glandes apocrines des sacs anaux constitue la principale tumeur du sac anal.

Bien que rare, cette tumeur est la deuxième cause la plus fréquente d’hypercalcémie maligne. Son caractère invasif, et son potentiel métastatique en font une tumeur agressive au pronostic réservé.

L’exérèse chirurgicale du sac anal, et des nœuds lymphatiques infiltrés associée à une thérapie adjuvante (radiothérapie et/ou chimiothérapie) est recommandée.

La taille de la tumeur primaire, la présence de métastases à distance, une hypercalcémie, et l’absence de traitement constituent des facteurs pronostiques négatifs.
Complémentation minérale
et vitaminique de vaches allaitantes
Authors: Enjalbert Francis
Published: August 2024

Déterminer la nature et la quantité d’aliment minéral et vitaminé se fait en plusieurs étapes. Les premières sont basées sur le calcium et le phosphore.

Il est cependant important de s’assurer que la couverture des besoins en magnésium, oligo-éléments et vitamines est aussi assurée, si nécessaire en majorant les quantités calculées sur la base de la couverture des besoins en calcium et phosphore.

Les principes présentés dans cette étude de cas, relatifs à des vaches allaitantes, peuvent être appliqués aux autres ruminants.
Indikationen zur Cochlea-Implantat-Versorgung bei Kindern: Wohin geht die Reise?
Authors: Hirschfelder Anke , Mürbe Dirk
Published: August 2024

Die Indikationen zur Cochlea-Implantat-Versorgung (CI-Versorgung) von Kindern wurden in den letzten 30 Jahren schrittweise erweitert. Dies betrifft sowohl das Alter bei Implantation als auch die audiologischen Kriterien, die uni- oder bilaterale Versorgung, die Versorgung bei einseitiger Taubheit und von Kindern mit Mehrfachbehinderungen. Durch die Verbesserung des Hörerhalts und neue technische Entwicklungen ist zu erwarten, dass sich die Indikationsgrenzen auch in den kommenden Dekaden weiter verschieben.
1,3-Dipolar Cycloaddition Reaction of Nitrile Oxide to Thiocyanates: An Efficient and Eco-Friendly Synthesis of N-Aryl-2-((3-aryl-1,2,4-oxadiazol-5-yl)thio)acetamides
Authors: Nair Vipin A. , Radhakrishna Vamshikrishna Y. , Khatik Gopal L.
Published: August 2024

An efficient and eco-friendly procedure was developed for the synthesis of N-aryl-2-((3-aryl-1,2,4-oxadiazol-5-yl)thio)acetamides from N-aryl-2-thiocyanatoacetamides and substituted N-hydroxybenzimidoyl chlorides that were prepared easily from the commercially available anilines and aryl aldehydes, respectively. The N-aryl-2-thiocyanatoacetamide acts as a dipolarophile while the nitrile oxide formed in situ from substituted N-hydroxybenzimidoyl chloride acts as the nucleophilic partner in a 1,3-dipolar cycloaddition reaction mediated by triethylamine base in ethanol medium. The procedure affords excellent yields of desired products containing electron-withdrawing and electron-donating groups on the aromatic rings, in short reaction time with ease of operation. The procedure for the synthesis of scaffolds that are potentially valuable for their biological properties also offers the possibility of scale-up to higher quantities.
Hohes Defizit: Rechnungshof warnt vor zu hoher Kreditlinie
Authors: Rößing Sabine
Published: August 2024

Das Uniklinikum Schleswig-Holstein (UKSH) schreibt tiefrote Zahlen, investiert aber gleichzeitig massiv in den modernen Ausbau des Maximalversorgers. Finanziert wird das über Kredite. Landesrechnungshof und Teile der Opposition warnen, dass das UKSH sich verheben könnte.
Artemed SE: Auf Expansionskurs
Authors: Schmidt Hartmut
Published: August 2024

Börsenexperte Hartmut Schmidt analysiert für kma die Jahresabschlüsse ausgewählter Kliniken. kma Online Ausführliche Berichte lesen Sie jeden Monat auf kma Online unter www.kma-online.de/kassensturz
Bilderbuchkarriere: Helios pragmatische Powerfrau
Authors: Hohnstein Aileen
Published: August 2024

Seit Mai leitet Carmen Bier das Helios Klinikum Berlin-Buch. Die Gesundheitsökonomin hat innerhalb von zehn Jahren eine Biltzstart beim privaten Gesundheitsversorger hingelegt: Von der Marketingpraktikantin zur Geschäftsführerin der größten Klinik der Helios Region Ost. Ein Blick auf ihren Werdegang.
Wegweisende Strategien: Steuerungsmechanismen im Gesundheitswesen
Authors: Schmid Andreas
Published: August 2024

Trotz der aktuellen Herausforderungen in der Gesundheitspolitik, ist es entscheidend, den Blick jetzt schon nach vorne zu richten und die drängenden Themen für 2025 zu identifizieren.
How vulnerable are people to victimisation of County Lines drug dealing?
Authors: Fawell Lilly , Davies Joseph L. , Stubbings Daniel , Payne Libby
Published: August 2024

The current study examined how willing a non-probability sample of adults were to engage in hypothetical activities typical of County Lines, and whether involvement could be predicted by perceived risk factors. Of the 101 participants; 48% were willing to engage in activities that could lead to cuckooing, 63% to a coffee meet up, 50% to transferring money, 32% would accept free drugs, 56% would pay off a friend’s debt, whereas only 1% were willing to engage in the control scenario (a phone scam). Actual occurrences of these scenarios were also documented and occurred in approximately 1% of the sample. Males and people with greater drug use scores were more likely to endorse engagement in a County Lines scenario involving drugs, whilst greater drug use scores were only associated with a lower risk of a County Lines scenario involving lending money to a friend. Our findings suggest that drug use may predict endorsement to engage in some County Lines scenarios. However, given a small non-probability sample was used in the current study, further development of methodologies to capture the likelihood to engage in County Lines activities are needed.
Hydrogen in superconductors (Review article)
Authors: Bondarenko S. I. , Timofeev V. P. , Koverya V. P. , Krevsun A. V.
Published: August 2024

Information on the state of research on the effect of hydrogen on the superconducting properties of various compounds is presented. The review consists of an introduction, one appendix and four sections: methods for the synthesis of modern hydrogen-containing superconductors, experimental studies of the properties of hydrogen-containing superconductors, mechanisms of the influence of hydrogen on superconductivity, problems and prospects of hydrogen-containing superconductors.
Superconductivity in TiZrNb and TiZrNbHf bulk equimolar alloys
Authors: Košuth Filip , Cedervall Johan , Ek Gustav , Gabáni Slavomír , Pristáš Gabriel , Orendáč Matúš , Bačkai Július , Onufriienko Oleksandr , Szabó Pavol , Flachbart Karol
Published: August 2024

We have prepared and investigated superconducting equimolar medium-entropy alloys of TiZrNb and TiZrNbHf. Their basic superconducting parameters, as the values of the critical temperature Tc, upper critical magnetic field Bc2 and the superconducting energy gap Δ have been studied with the use of magnetic susceptibility and point-contact Andreev reflection (PCAR) spectroscopy measurements. Although our samples have different critical temperatures, namely Tc ∼ 8.2 K for TiZrNb and Tc ∼ 6.3 K for TiZrNbHf, their zero-temperature critical magnetic field has the same value Bc2(0) = 12 T, from the vicinity of the Clogston limit. We have observed the presence of degraded phases on the surfaces of all the investigated samples using PCAR measurements. Still, we were able to show that the bulk phase in both systems exhibits BCS weakly coupled superconductivity with 2Δ(0)/kBTc ∼ 3.5.
Smartphone offers on-site soil microbiome profiling
Authors: Patrick Chris
Published: August 2024

A low-cost, portable platform based on autofluorescence detection and machine learning can quickly identify bacterial species to assess soil health.
Classical solvability to the free boundary problem for a foam drainage equation. I. From the top to the interface
Authors: Tani Atusi , Tani Marie
Published: August 2024

We study a nonlinear partial differential equation describing the evolution of a foam drainage in one dimensional case which was proposed by Goldfarb et al. [Izv. Akad. Nauk SSSR Mekh. Ghidk. Gaza 2, 103–108 (1988)] in order to investigate the flow of liquid through channels (Plateau borders) and nodes (intersections of four channels) between the bubbles, driven by gravity and capillarity. Its mathematical studies so far are mainly restricted within numerical and particular solutions; as for mathematical analysis of it there are only a few. We prove that the free boundary problem for the foam drainage equation in the region from the top to the interface in a foam column admits a unique global-in-time classical solution by the standard classical mathematical method, the maximum principle and the comparison theorem. Moreover, the existence of its steady solution and its stability are discussed.
Classical solvability to the free boundary problem for a foam drainage equation. II. From the interface to the bottom
Authors: Tani Atusi , Tani Marie
Published: August 2024

We study a nonlinear partial differential equation describing the evolution of a foam drainage in one dimensional case which was proposed by Goldfarb et al. in 1988 in order to investigate the flow of liquid through channels (Plateau borders) and nodes (intersections of four channels) between the bubbles, driven by gravity and capillarity. Its mathematical studies so far are mainly restricted within numerical and particular solutions; as for mathematical analysis of it there are only a few. We prove that the free boundary problem for the foam drainage equation in the region below an interface to the bottom in a foam column admits a unique global-in-time classical solution by the standard classical mathematical method, the maximum principle. Moreover, the existence of its steady solution and its stability are shown.
Location preference of boron and nitrogen dopants at graphene/copper interface
Authors: Zhong Boan , Ni Jiamiao , Zhang Qi , Song Jian , Liu Yue , Gong Mingyu , Fan Tongxiang
Published: August 2024

Controlling the placement of dopants can significantly tailor graphene's properties, but this process is influenced by copper substrates during vapor deposition. Understanding the influence of interfacial atomic structures on the preference for dopant locations is crucial. In this work, we conducted a systematic first-principles study of boron- and nitrogen-doped graphene on copper {111}, considering both sublattice and superlattice configurations. Our calculations revealed that the formation energy is minimized at the top-fccb site (−0.60 eV) for boron and the hcp-fcca site (1.94 eV) for nitrogen, suggesting a possible selective distribution of dopants in both sublattice and superlattice arrangements at the graphene/copper interface. Furthermore, a lower formation energy indicates a higher release of energy during doping, resulting in a stronger interfacial binding. Since formation energy is closely associated with out-of-plane interactions, while in-plane interactions remain relatively stable, these differences offer potential avenues for modifying dopant distribution at graphene/copper interfaces.
Kinetomagnetism of chirality and its applications
Authors: Cheong Sang-Wook , Huang Fei-Ting
Published: August 2024

Chiral functionalities exhibited by systems lacking any mirror symmetry encompass natural optical activity, magnetochiral effect, diagonal current-induced magnetization, chirality-selective spin-polarized current of charged electrons or neutral neutrons, self-inductance, and chiral phonons. These phenomena are unified under the hypothesis of “kinetomagnetism of chirality,” which posits that any moving (charged or neutral) object in chiral systems induces magnetization in its direction of motion, consequently imparting chirality to the object due to this induced magnetization. We also found conjugate relationships among the kinetomagnetism of chirality, “linear magnetoelectricity,” and “electric field-induced directional nonreciprocity,” highlighting their interconnections with magnetic, electric, and toroidal orders. The concept of the kinetomagnetism of chirality will be an essential basis for the theoretical understanding of known chiral phenomena, such as natural optical activity or chiral phonons, and also the discovery of unexplored chiral functionalities.
Modal and non-modal stability for Hagen–Poiseuille flow with non-ideal fluid
Authors: Zheng Congren , Chen Yong , Ding Zijing
Published: August 2024

Modal and non-modal stability analyses are applied to Hagen–Poiseuille flow with a non-ideal fluid. The non-ideal fluid is defined as a fluid close to its vapor–liquid critical point. In this region, properties of the fluid deviate significantly from the assumptions of the ideal gas model. In this paper, the specific example of CO2 near the critical point is taken as a non-ideal fluid. We studied fluids at supercritical pressure and different wall temperatures so that the centerline temperatures can be lower, equal, and higher than the pseudo-critical temperature. Flow instability is characterized by the Reynolds number, and the product of the Prandtl and Eckert numbers. In modal stability analysis, we observe that there is no unstable mode in Hagen–Poiseuille flow with a non-ideal fluid. Regarding the growth rate, as the axial wavenumber increases, another mode becomes the least stable. The non-modal theory is employed to investigate the optimal response to harmonic external force and transient energy growth. The influence of axial and azimuthal wave numbers, Prandtl and Eckert numbers, and thermodynamic states are also taken into account. In this study, we identify an generalized inflection point in the transcritical base profile, causing the transcritical state to be the most unstable. In non-modal instability, we observe that the optimal response mainly occurs at time invariant axisymmetric disturbance. This suggests that the axisymmetric disturbance could potentially initiate the transition to turbulence.
Assessing the domain-based local pair natural orbital (DLPNO) approximation for non-covalent interactions in sizable supramolecular complexes
Authors: Gray Montgomery , Herbert John M.
Published: August 2024

The titular domain-based local pair natural orbital (DLPNO) approximation is the most widely used method for extending correlated wave function models to large molecular systems, yet its fidelity for intermolecular interaction energies in large supramolecular complexes has not been thoroughly vetted. Non-covalent interactions are sensitive to tails of the electron density and involve nonlocal dispersion that is discarded or approximated if the screening of pair natural orbitals (PNOs) is too aggressive. Meanwhile, the accuracy of the DLPNO approximation is known to deteriorate as molecular size increases. Here, we test the DLPNO approximation at the level of second-order Møller–Plesset perturbation theory (MP2) and coupled-cluster theory with singles, doubles, and perturbative triples [CCSD(T)] for a variety of large supramolecular complexes. DLPNO-MP2 interaction energies are within 3% of canonical values for small dimers with ≲10 heavy atoms, but for larger systems, the DLPNO approximation is often quite poor unless the results are extrapolated to the canonical limit where the threshold for discarding PNOs is taken to zero. Counterpoise correction proves to be essential in reducing errors with respect to canonical results. For a sequence of nanoscale graphene dimers up to (C96H24)2, extrapolated DLPNO-MP2 interaction energies agree with canonical values to within 1%, independent of system size, provided that the basis set does not contain diffuse functions; these cause the DLPNO approximation to behave erratically, such that results cannot be extrapolated in a meaningful way. DLPNO-CCSD(T) calculations are typically performed using looser PNO thresholds as compared to DLPNO-MP2, but this significantly impacts accuracy for large supramolecular complexes. Standard DLPNO-CCSD(T) settings afford errors of 2–6 kcal/mol for dimers involving coronene (C24H12) and circumcoronene (C54H18), even at the DLPNO-CCSD(T1) level.
IP2 optimization in frequency mixers using ferroelectric field-effect transistors
Authors: Mitchell Cody , Ho Fat D.
Published: August 2024

Ferroelectric devices have traditionally been utilized in memory circuits due to their ability to retain a polarization charge and potentially act as a nonvolatile storage device. Their usage in applications unrelated to memory has also previously expanded into other digital and analog circuits, and now, it is being investigated in radio frequency circuits. This work explores the implementation of a frequency mixer using ferroelectric field-effect transistors in order to demonstrate stability against voltage offsets in a single-balanced mixer, making use of the polarization in the switching transistors to improve the performance of the second-order intermodulation product.
An improved delayed detached-eddy study on the aerodynamic braking technique based on blunting the streamlined section of the high-speed train
Authors: Wang Jiabin , Zhang Puyang , Shang Wenfei , Liu Cao , Su Xinchao , Zhang Jie , Gao Guangjun
Published: August 2024

This paper utilizes the improved delayed detached-eddy simulation method to investigate an aerodynamic braking technique involving blunting the streamlined portion of a high-speed train (HST) at Re = 5.0 × 105. The accuracy of the numerical simulation method was validated through reduced-scale wind tunnel experiments at the same Reynolds number level. The study compares aerodynamic drag, pressure distribution, boundary layer, and wake flow characteristics between the original configuration and the braking configuration of the HST. Additionally, the impact of aerodynamic braking plates on the flow characteristics around the key components of the HST has also been discussed. The results indicate a significant increase in the pressure drag experienced by the HST with the application of aerodynamic braking plates to its streamlined sections, while there is a slight decrease in viscous drag. This leads to a remarkable 235.4% rise in the overall aerodynamic drag of the entire HST. The aerodynamic braking plates also have a substantial impact on the turbulent wake flow topology, significantly increasing turbulence levels in the near-wake region. Furthermore, the implementation of aerodynamic braking plates may affect pantograph current collection by significantly altering stream-wise and vertical velocity components, notably increasing velocity fluctuation around the contact position between the pantograph and power supply lines.
Repetitive shock waves generated by a single long pulse underwater arc discharge
Authors: Li Xian-Dong , Lan Ming-Yan , Zheng Peng , Zheng Wei-Yang , Song Yong , Zhao Zi-Xiang , Li Jian
Published: August 2024

The electrohydraulic effect induced by underwater arc discharge is an efficient way to generate controllable, high-intensity shock waves. However, the development process of underwater arc discharge involves the complex coupling of plasma arc, gas bubble, and liquid medium, of which the evolution mechanism is not well understood. In this paper, the underwater arc discharge process at a millisecond pulse (>50 ms) was investigated by high-speed shadow imaging and colorimetric temperature measurement, and a simulation model of bubble pulsation was proposed to quantitatively estimate the state variation and energy transfer of the gas bubble. The results indicate that the whole arc discharge process can be categorized into three successive stages: short-period oscillation, long-period oscillation, and quasi-steady state. The vapor inside the bubble can reach a supercritical state (827 K and 140 MPa) at the minimum bubble radius. The simulation shows that the light radiation absorption and the heat conduct loss through metal electrodes are the two dominant factors influencing the pulsation of the bubble, and further analysis indicates that the dynamic evolution of the arc determines the bubble pulsation mode. Our findings demonstrate why and how repetitive electrohydraulic shock waves can be generated by a single long pulse underwater arc discharge, providing a low-cost way of shock wave generator based on an AC/DC high-voltage power source.
Topology optimization with vortex-intensity-based objective function enables novel film cooling hole with superior performance
Authors: Tang Huidong , Zhu Jianqin , Tao Zhi , Qiu Lu
Published: August 2024

Film cooling is widely adopted in the thermal protection of modern aerospace engines. The optimization of the film hole is an important issue in thermal designs. In this work, a density-based topology optimization is conducted to obtain a high-performance film cooling hole geometry. Unlike the traditional wall-temperature-based optimization objectives, a novel objective function based on the Q-criteria is proposed by taking the vorticity dynamics and flow mixing into account. Finally, a unique high-performance film hole is obtained, which shows superior performance compared to the standard cylindrical hole, particularly at high blowing ratios. The film cooling effectiveness can be elevated by 51 folds in the case of a high blowing ratio (M = 1.5). Analyses of the vortices and velocity fields suggest that the presence of the additional secondary vortex pair enhances the attachment of cooling air to the wall.
Effect of self-excited oscillation of three-dimensional rectangular shock-induced thrust vector nozzle jet
Authors: Wu Kexin , Fan Xinyi , Fu Song , S Ajith Kumar , Petha Sethuraman Vignesh Ram
Published: August 2024

The fluidic thrust vector nozzles including the shock-induced thrust vector nozzles stand out from traditional mechanical thrust vector nozzles used in aeronautics and astronautics due to their simplicity and potential for higher efficiency. However, a significant challenge in the transition from theoretical studies to practical applications is the phenomenon of self-excited oscillation of the nozzle jet, particularly in ramjet and scramjet engines. This oscillation can notably impact the jet control stability, which is critical for the operational reliability, accuracy, and safety of these engines. To investigate the effects of self-excited oscillation of the jet in the three-dimensional rectangular shock-induced thrust vector nozzles, a large eddy simulation approach has been utilized to examine various nozzle pressure ratios and secondary pressure ratios. The simulation data are in good agreement with the experimental data of National Aeronautics and Space Administration Langley Research Center, lending credibility to the simulation results. The research sheds light on the formation and evolution of self-excited oscillation. It does so by examining the interactions between shock waves and boundary layers, as well as bubble dynamics, offering a comprehensive view of the oscillation mechanism in a three-dimensional context. The results demonstrate that the self-excited oscillation of jet mainly belongs to low-frequency oscillation. With the increase in nozzle pressure ratio, the self-excited oscillation of the jet is suppressed because the shock system is pushed out of the shock-induced thrust vector nozzle exit. The variation of secondary pressure ratio only affects the amplitude of jet self-excited oscillation and does not transform the motion pattern.
On the unsteady aerodynamics of flapping wings under dynamic hovering kinematics
Authors: Poletti Romain , Calado Andre , Koloszar Lilla K. , Degroote Joris , Mendez Miguel A.
Published: August 2024

Hummingbirds and insects achieve outstanding flight performance by adapting their flapping motion to the flight requirements. Their wing kinematics can change from smooth flapping to highly dynamic waveforms, generating unsteady aerodynamic phenomena such as leading-edge vortices (LEV), rotational circulation, wing wake capture, and added mass. This article uncovers the interactions of these mechanisms in the case of a rigid semi-elliptical wing undergoing aggressive kinematics in the hovering regime at Re∼O(103). The flapping kinematics were parametrized using smoothed steps and triangular functions and the flow dynamics were simulated by combining the overset method with large eddy simulations. The analysis of the results identifies an initial acceleration phase and a cruising phase. During the former, the flow is mostly irrotational and governed by the added mass effect. The added mass was shown to be responsible for a lift first peak due to the strong flapping acceleration. The dynamic pitching and the wing wake interaction generate a second lift peak due to a downwash flow and a vortex system on the proximal and distal parts of the wing's pressure side. Conversely, aerodynamic forces in the cruising phase are mainly governed by the growth and the establishment of the LEV. Finally, the leading flow structures in each phase and their impact on the aerodynamic forces were isolated using the extended proper orthogonal decomposition.
Numerical study of granulation in anelastic thermal convection in spherical shells
Authors: Khan Hamid Hassan , Jagad Pankaj , Parsani Matteo
Published: August 2024

The present work investigates granulation or convective flow patterns in density-stratified (or anelastic) convection in spherical shells. The density-stratified thermal convection is typically present in astrophysical systems (such as solar convection); motivated by this, we performed a series of three-dimensional anelastic convection simulations in a spherical shell geometry using an in-house developed hybrid solver. We explored the effect of Rayleigh number and density scale height on the convective flow patterns. The granulation (or cell-like structures) are more prominent at higher density scale height and Rayleigh number. The granulation is further characterized by kinetic energy and helicity spectra. Our results support the argument that the convective flow patterns (or granulation) emerge due to inverse cascade owing to the presence of density stratification. Convective patterns (or granulation) are identified based on length scales, time scales, and flow velocity. The length scale of granules is further verified using a solar granulation model. Our analysis suggests the existence of inverse cascade and supergranulation on the spherical surface due to density-stratified thermal convection in spherical shells.
Three-dimensional particle-scale investigation of transient gas–solid flow characteristics in the propulsion system with a complex charge structure
Authors: Chen An , Yu Yonggang
Published: August 2024

This work is focused on researching the particle behavior of the transient gas–solid flow in the propulsion system with the modular charge structure, which has a great effect on the temporal-spatial distribution of energy release. Based on the coupling method of computational fluid dynamics and the discrete element method, an efficient three-dimensional unsteady gas–solid model is developed to provide a detailed means of capturing particle behavior in the propulsion system with a complex structure. Comparisons of the particle distribution of simulation results are done with experimental research, and a reasonable match has been obtained. Furthermore, the particle behavior characteristics can be divided into three stages. In the first stage, the particle behavior is dominated by the high-pressure, high-speed gas from the igniter. In the other two stages, the particle behavior is dominated by the complex gas flow generated by the opening of the module and the groove structure of the vehicle. The results show that the distribution of particles consists of slope accumulation and horizontal accumulation. The slope accumulation with a large gradient contains 84% of the total particles, and the height of the slope accumulation is increased exponentially along the axis.