bluuebunny/crossref_metadata_2025 huggingface dataset:
Post-retirement employment behavior and older people’s expenditure: New evidence from urban China
Authors: Lu Di , Feng Xing , Ji Shujing
Published: October 2024

Using data from the China Health and Retirement Longitudinal Study, this research investigates how post-retirement employment influences older people’s expenditure in urban China. By broadening the understanding of post-retirement employment behaviour from a consumer welfare perspective, this study expands the literature on retirement consumption and provides theoretical explanations, empirical insights and policy recommendations. The findings reveal that post-retirement employment behaviour reduces urban retirees’ household expenditure and has a more significant effect on men than on women, but this effect diminishes as consumption levels rise. Increasing income, promoting social participation and improving subjective health outcomes are all potential channels through which post-retirement employment can affect consumption. Further analysis shows two main reasons why post-retirement employment reduces older people’s expenditure: first, the increase in subjective health levels resulting from post-retirement employment reduces healthcare expenditure; second, post-retirement employment does not promote social participation and self-rated health for all consumption levels and all genders of retirees – it also decreases expenditure. Preliminary evidence suggests that internet use positively moderates the negative impact of post-retirement employment on older people’s expenditure. These findings provide policy implications for retirement policies and the promotion of the silver economy.
Language teacher expertise research: A theoretical case and research agenda
Authors: Anderson Jason
Published: October 2024

Expertise exists among all communities of educational practitioners at all levels and in all national contexts. By identifying expert practitioners, learning from them and valuing their professional competence, researchers can support, promote and build upon sustainable, embodied, holistic models of quality in ways that have direct relevance for the classroom, the curriculum and wider educational goals. Yet, despite its potential as a field of research, there have been relatively few studies involving expert language teachers to date. After a brief historical background, this article makes the case for language teacher expertise research, noting its high ecological validity, its great practical utility, its ability to bridge the research–practice divide and its potentially positive impact on teaching communities. Key methodological considerations are also discussed, including defining expertise, identifying expert teachers and looking beyond the limits of subject-specific pedagogy to understand the whole practitioner in their sociocultural context. The article then proposes a framework for future teacher expertise research that spans diverse methodologies. Six example research tasks from within this framework are proposed, each justified and exemplified, incorporating suggestions for research design that are intended to encourage both experienced and novice researchers to engage with teacher expertise as a promising domain for future investigation.
New surveys reveal a population stronghold for the Hoary-throated Spinetail Synallaxis kollari and Rio Branco Antbird Cercomacra carbonaria along the Guyana–Brazil border
Authors: Melville Don , Ignacio Leroy , Millar Neal , Merritt Vanessa , Kays Roland , Cyril Samuel , David Dereck , Ignace Abraham , Johnny Angelbert , Johnny Frank , Thomas Flavian , Wilson Asaph , Wilson Nate , O’Shea Brian
Published: October 2024

The hoary-throated spinetail and Rio Branco antbird are two bird species endemic to the Rio Branco drainage of Brazil and Guyana, currently listed as Critically Endangered on the IUCN Red List. Previous assessments of both species’ global populations focused on the Brazilian state of Roraima but did not include most of its border with Guyana, where significant areas of suitable habitat remain along the Ireng (Maú) and Takutu (Tacutu) Rivers. In July and August 2021, we conducted a survey to determine the extent of each species’ geographic range along the two rivers, and to estimate population sizes. We used playback surveys along 219 km of river to ascertain each species’ distribution and intensively sampled three forest blocks to determine densities. Both species were locally abundant on both sides of the international border. Rio Branco antbird occurred over a greater geographic range than hoary-throated spinetail, particularly along the Takutu River, but was confined to a narrower zone along the river edges. Both species appear to have retreated from habitat along the Ireng River that was occupied in the past, possibly due to habitat degradation from increasingly frequent fires. Nevertheless, our minimum estimates of 1147 antbirds and 851 spinetails in the study area represent, respectively, 7.5% and 17.8 % increases over current estimates of global population sizes, and indicate that the Guyana-Brazil border region may become a critical stronghold for both species if effective conservation measures are implemented. We propose establishment of a Key Biodiversity Area encompassing the core of both species’ distributions along the border; extensive follow-up work including stakeholder engagement to explore possibilities for habitat management and protection; and further field study to increase general ecological knowledge of these two bird species.
Associations between pre-infection serum vitamin D concentrations and Omicron COVID-19 incidence, severity and reoccurrence in elderly individuals
Authors: Chen Jiangjie , Lu Fangying , Shen Bo , Xu Hongfang , Chen Yijun , Hu Qi , Xu Anpeng , Tung Tao-Hsin , Hong Dun
Published: October 2024

Objective:

Previous studies suggest a link between vitamin D status and COVID-19 susceptibility in hospitalised patients. This study aimed to investigate whether vitamin D concentrations in elderly individuals were associated with their susceptibility to Omicron COVID-19 incidence, the severity of the disease and the likelihood of reoccurrence during the era of the post-‘zero-COVID-19’ policies in China.

Design:

In this retrospective study, participants were categorised into three groups based on their 25(OH)D concentrations: deficiency (< 20 ng/ml), insufficiency (20 to < 30 ng/ml) and sufficiency (≥ 30 ng/ml). The demographic and clinical characteristics, comorbidities and the incidence rate, reoccurrence rate and severity of Omicron COVID-19 were retrospectively recorded and analysed by using hospital information system data and an online questionnaire survey.

Setting:

China.

Participants:

222 participants aged 60 years or older from a health management centre.

Results:

Our findings revealed significant differences in the incidence (P = 0·03) and recurrent rate (P = 0·02) of Omicron COVID-19 among the three groups. Participants with lower 25(OH)D concentrations (< 20 ng/ml) exhibited higher rates of initial incidence and reoccurrence and a greater percentage of severe and critical cases. Conversely, individuals with 25(OH)D concentrations ≥ 30 ng/ml had a higher percentage of mild cases (P = 0·003). Binary and ordinal logistic regression models indicated that vitamin D supplementation was not a significant risk factor for COVID-19 outcomes.

Conclusions:

In the elderly population, pre-infection vitamin D deficiency was associated with increased susceptibility to incidence, severity of illness and reoccurrence rates of Omicron COVID-19.
Language Hierarchies, Liminality, and Resistance in Canadian and Finnish Integration Educations for Adult Migrants
Authors: Pötzsch Tobias
Published: October 2024

This article explores the effects of language hierarchies within SFI (Swedish for Immigrants) and LINC (Language Instruction for Newcomers to Canada) national integration programmes and how discourses of civic integrationism framed around monolingualism and neoliberalism position adult migrant students in the liminal spaces between belonging and othering. Based on research findings obtained during multiple case study fieldwork in Finland and Canada, I examine the underlying norms and subtexts upon which practices of host language acquisition are founded. How students are positioned depends greatly on who serves as an arbiter over which expressions of linguistic diversity are deemed beneficial or obstructive to integration. Migrant liminality within integration educations could be debilitating while simultaneously fostering resistance in transgressing and reimagining essentialist integration policy and pedagogical goals, thus creating opportunities for transformation.
(−)-Epicatechin treatment modify the expression of genes related to atrophy in gastrocnemius muscle of male rats obese by programing
Authors: Alvarez-Chávez Ana Luisa , De los Santos Sergio , Coral-Vázquez Ramón Mauricio , Méndez Juan Pablo , Palma Flores Carlos , Zambrano Elena , Canto Patricia
Published: October 2024

The aim of this study is to determine if the offspring of mothers with obesity, present disorders in the expression of genes related to atrophy or protein synthesis in the muscle and if these disorders are modified with the (−)-epicatechin (Epi) treatment. Six male offspring per group were randomly assigned to the control groups [C and offspring of maternal obesity (MO)] or the Epi intervention groups, Epi treatment for 13 weeks (C + Epi long or MO + Epi long), or Epi administration for two weeks (C + Epi short or MO + Epi short). The effect of Epi in the gastrocnemius tissue was evaluated, analyzing mRNA and protein levels of Murf1, MAFbx, Foxo1, NFkB, and p70S6K-alpha. After the analysis by two-way ANOVA, we found an influence of the Epi long treatment over the model, by decreasing the Murf1 gene expression in both groups treated with the flavonoid (C + Epi long and MO + Epi long) (p = 0.036). Besides, Epi long treatment over the NFκB expression, by decreasing the fold increase in both groups treated with the flavonoid (C + Epi long and MO + Epi long) (p = 0.038). We not find any interaction between the variables or changes in the MAFbx, Foxo1 mRNA, neither in the phosphorylated/total protein ratio of NFκB, Foxo1, or p70S6K-alpha. In conclusions, treatment with a long protocol of Epi, reduces the mRNA of the muscle atrophy genes Murf 1 and NFkB, in the gastrocnemius muscle; however, these changes are not maintained at protein level.
Neuro-Palliative Care
Authors: Gerhard Christoph
Published: October 2024

Das interdisziplinär angelegte Praxishandbuch zur palliativen Versorgung von Menschen mit neurologischen Erkrankungen

bietet eine personzentrierte und ressourcenorientierte Perspektive auf die Patient*innen und zielt darauf, deren Lebensqualität und -sinn am Ende des Lebens zu fördern und zu erhalten
erläutert das Grundverständnis der Palliative Care im Kontext der Versorgung neurologischer Patient*innen
beschreibt, wie Symptome neurologisch beeinträchtigter Menschen systematisch erfasst und spezifisch behandelt werden können
zeigt, wie die Teammitglieder mit kommunikationsbeeinträchtigten, verwirrten und bewusstseinsgestörten Menschen kommunizieren können
stellt konkrete Behandlungsmöglichkeiten bei Agitation, Delir, Fatigue, Muskeltonuserhöhung, gastrointestinalen und pulmonalen Symptomen sowie Schmerzen und Schlafstörungen vor
zeigt neuro-palliative Besonderheiten von Erkrankungen der Muskulatur und des peripheren Nervensystems sowie von ALS, Demenz, MS, Muskelerkrankungen, Parkinson, Schlaganfall und (wach-)komatösen Zuständen auf
beschreibt ethisch schwierige Entscheidungssituationen und zeigt Möglichkeiten, um diese zu analysieren und einvernehmlich zu lösen
stellt mit zahlreichen Fallbeispielen enge Bezüge zur Praxis her.

Die 2. Auflage berücksichtigt aktuelle AWMF-Leitlinien aus der Palliativmedizin und Neurologie. Der Autor bietet neue Beiträge zu Advance Care Planning (ACP), Todeswunsch, Suizidbeihilfe und Sterbefasten sowie Multisystematrophien. Im Anhang finden sich zusätzliche ACP-Dokumentationsbögen und ein Modell zur ethischen Fallbesprechung (KRISE).

Rezensionen

Geniales Lehrbuch zu Palliativmedizin insbesondere zu den Bedürfnissen neurologischer Patienten. Matthias Thöns, Amazon
Nicht-medikamentöse Maßnahmen im Schmerzmanagement
Authors: Nestler Nadja , Berger Stefanie
Published: October 2024

Schmerzexpertise in den Feldern der Gesundheitsversorgung

Schmerz ist ein multidimensionales Phänomen und betrifft Menschen aller Altersstufen und Erkrankungen in jedem Stadium ihres Lebenslaufs. Neben den körperbezogenen Faktoren rücken zunehmend psycho-soziale Faktoren in den Fokus der Schmerzexpert*innen. Sie koordinieren den therapeutischen Prozess, beraten die Patient*innen und ihre Zu- und Angehörigen, fördern ihre Lebensqualität und gestalten maßgeblich ihre gesundheitliche Versorgung. In ihrer spezifischen Nähe zu Menschen mit Schmerz sind sie die professionellen Fachkräfte für Assessment, Diagnostik, Intervention und Evaluation in einem multiprofessionellen Kontext. Die insgesamt vier Bände zum Thema orientieren sich am Curriculum der European Pain Federation (EFIC) und verknüpfen u.a. mit Case Reports die interdisziplinären Perspektiven mit den praxisorientierten Erkenntnissen der Herausgeber*innen und Autor*innen aus den verschiedenen Feldern der Schmerztherapie.

Nicht-medikamentöse Maßnahmen bilden in jedem Kontext eine bedeutende Therapieoption für alle Schmerzexpert*innen. Die Autor*innen beschreiben und analysieren in diesem Band die Interventionen der nicht-medikamentösen Therapie im Kontext unterschiedlicher Versorgungssettings, für spezielle Personengruppen und im interprofessionellen Team, inklusive der aktuellen Entwicklung durch digitale Medien.
Chemoselective seleno-click amidation in kinetic target-guided synthesis
Authors: Huang Lili , Parvatkar Prakash T. , Wagner Alicia , Kulkarni Sameer S. , Manetsch Roman
Published: October 2024

We used seleno-click amidation in KTGS at 37 °C and 4 °C to form an amide-linked Mcl-1 inhibitor, demonstrating potential as a bioorthogonal reaction.
Real-time monitoring of a 3D blood–brain barrier model maturation and integrity with a sensorized microfluidic device
Authors: Ceccarelli Maria Cristina , Lefevre Marie Celine , Marino Attilio , Pignatelli Francesca , Krukiewicz Katarzyna , Battaglini Matteo , Ciofani Gianni
Published: October 2024

A newin vitrosensorized model of the blood–brain barrier has been developed and characterized.
Enhancement of electrocatalytic CO2 performance by different components of Cu-based bimetallic MOFs
Authors: Liu Jvwei , Zhang Qiang , Wang Jianlin , Chen Conglin , Zhang Shenjie , Guo Fang , Xu Junqiang
Published: October 2024

Cu-based catalysts have been promising materials for electrocatalytic reduction of carbon dioxide into C2+ products.
Bi- and tricyclic diterpenoids: landmarks from a decade (2013–2023) in search of leads against infectious diseases
Authors: Antoniuk Olha , Maranha Ana , Salvador Jorge A. R. , Empadinhas Nuno , Moreira Vânia M.
Published: October 2024

Relevant biological activities of both naturally occurring and semi-synthetic bi- and tricyclic diterpenoids, in the context of infection, are highlighted in this review alongside significant structure–activity relationships.
Synthesis and properties of thienonaphtho[bc]pyridines and thienonaphtho[bc]quinolines
Authors: Vardanyan Arpine , Polkaehn Jonas , Bauder Marie-Louis , Villinger Alexander , Ehlers Peter , Langer Peter
Published: October 2024

Thienonaphtho[bc]pyridines and -quinolines were prepared and their photophysical and electrochemical properties studied.
Retraction: The extract from the roots of Rose odorata sweet var. gigantean (Coll. et Hemsl.) Rehd. et Wils attenuates DSS-induced ulcerative colitis by regulating the Nrf2/NF-κB signaling pathways
Authors: Li Xinyu , Liu Rui , Zhao Yanmin , Gao Naying , Jin Xin , Gao Xiaoxia , Li Tan , Liu Dailin
Published: October 2024

Retraction of ‘The extract from the roots of Rose odorata sweet var. gigantean (Coll. et Hemsl.) Rehd. et Wils attenuates DSS-induced ulcerative colitis by regulating the Nrf2/NF-κB signaling pathways’ by Xinyu Li et al., RSC Adv., 2020, 10, 9450–9461, https://doi.org/10.1039/C9RA10747A.
Exploring the dynamics and interactions of the N-myc transactivation domain through solution nuclear magnetic resonance spectroscopy
Authors: Rejnowicz Ewa , Batchelor Matthew , Leen Eoin , Ahangar Mohd Syed , Burgess Selena G. , Richards Mark W. , Kalverda Arnout P. , Bayliss Richard
Published: October 2024

Myc proteins are transcription factors crucial for cell proliferation. They have a C-terminal domain that mediates Max and DNA binding, and an N-terminal disordered region culminating in the transactivation domain (TAD). The TAD participates in many protein–protein interactions, notably with kinases that promote stability (Aurora-A) or degradation (ERK1, GSK3) via the ubiquitin-proteasome system. We probed the structure, dynamics and interactions of N-myc TAD using nuclear magnetic resonance (NMR) spectroscopy following its complete backbone assignment. Chemical shift analysis revealed that N-myc has two regions with clear helical propensity: Trp77–Glu86 and Ala122–Glu132. These regions also have more restricted ps–ns motions than the rest of the TAD, and, along with the phosphodegron, have comparatively high transverse (R2) 15N relaxation rates, indicative of slower timescale dynamics and/or chemical exchange. Collectively these features suggest differential propensities for structure and interaction, either internal or with binding partners, across the TAD. Solution studies on the interaction between N-myc and Aurora-A revealed a previously uncharacterised binding site. The specificity and kinetics of sequential phosphorylation of N-myc by ERK1 and GSK3 were characterised using NMR and resulted in no significant structural changes outside the phosphodegron. When the phosphodegron was doubly phosphorylated, N-myc formed a robust interaction with the Fbxw7–Skp1 complex, but mapping the interaction by NMR suggests a more extensive interface. Our study provides foundational insights into N-myc TAD dynamics and a backbone assignment that will underpin future work on the structure, dynamics, interactions and regulatory post-translational modifications of this key oncoprotein.
Novel scaling laws to derive spatially resolved flare and CME parameters from sun-as-a-star observables
Authors: Mohan Atul , Gopalswamy Natchimuthuk , Raju Hemapriya , Akiyama Sachiko
Published: October 2024

Coronal mass ejections (CMEs) are often associated with X-ray (SXR) flares powered by magnetic reconnection in the low corona, while the CME shocks in the upper corona and interplanetary (IP) space accelerate electrons often producing the type II radio bursts. The CME and the reconnection event are part of the same energy release process as highlighted by the correlation between reconnection flux (ϕrec) that quantifies the strength of the released magnetic free energy during the SXR flare, and the CME kinetic energy that drives the IP shocks leading to type II bursts. Unlike the Sun, these physical parameters cannot be directly inferred in stellar observations. Hence, scaling laws between unresolved sun-as-a-star observables, namely SXR luminosity (LX) and type II luminosity (LR), and the physical properties of the associated dynamical events are crucial. Such scaling laws also provide insights into the interconnections between the particle acceleration processes across low-corona to IP space during solar-stellar “flare-CME-type II” events. Using long-term solar data in the SXR to radio waveband, we derived a scaling law between two novel power metrics for the flare and CME-associated processes. The metrics of “flare power” (Pflare = √(LXϕrec)) and “CME power” (PCME = √(LRVCME2)), where VCME is the CME speed, scale as Pflare ∝ PCME0.76 ± 0.04. In addition, LX and ϕrec show power-law trends with PCME with indices of 1.12 ± 0.05 and 0.61 ± 0.05, respectively. These power laws help infer the spatially resolved physical parameters, VCME and ϕrec, from disk-averaged observables, LX and LR during solar-stellar flare-CME-type II events.
Die Zukunft wird „algig“-Lebensmittel aus dem Wasser, ihr Potenzial
für eine pflanzenbasierte Ernährung
Authors: Kopp Lena , Janentzky Annalena , Bischoff Stephan C.
Published: October 2024

Algen, unterteilt in Makroalgen und Mikroalgen, stellen eine vielversprechende
Ressource dar. Die kommerzielle Nutzung von Algen steht jedoch vor
Herausforderungen wie regulatorischen Hürden und Verbraucherakzeptanz, die die
Zulassung neuer Algenarten oder -produkte zeitaufwändig machen können. Trotz der
überwindbaren Hindernisse für eine groß angelegte Algenproduktion erfordert der
kommerzielle Erfolg ein koordiniertes Vorgehen. Algen dienen als biologische
Fabriken mit einem großen Potenzial an wertvollen Nährstoffen, darunter
Fettsäuren, Carotinoide und Proteine. Diese bieten nicht nur Möglichkeiten zur
Nahrungsversorgung, sondern tragen auch zu gesundheitlichen Vorteilen bei, u. a.
als bioäquivalente Primärquelle für langkettige Omega-3-Fettsäuren,
Antioxidantien und Polysaccharide zur Förderung der Darmgesundheit. Die Qualität
und Sicherheit von Algen als Lebensmittel hängt in hohem Maße von den
Anbaubedingungen ab und kann von diesen beeinflusst werden. Eine geschmackvolle
Verarbeitung von Algen zu Produkten könnte die Akzeptanz erhöhen und
ernährungsphysiologisch vollwertige Lebensmittel ermöglichen.
Einnässen im Kindesalter
Authors: Löser Julia , Henn Michael
Published: October 2024

Ab einem Alter von fünf Jahren spricht man von Harninkontinenz, wenn Kinder tagsüber und von Enuresis nocturna, wenn Kinder nachts einnässen. Liegt eine Mischform vor, werden die Nomenklatur und die sich daraus ergebende Diagnostik und Therapie schon etwas komplizierter.

Das Einnässen im Kindesalter ist oft funktioneller Natur. Mittels non-invasiver Diagnostik lassen sich organische Ursachen ausschließen und eine genaue Diagnose stellen. Als Behandlung schließt sich die sogenannte Urotherapie an, die vordergründig dazu dient, das schambehaftete Krankheitsbild zu entmystifizieren und enttabuisieren. Unsere Hauptaufgabe ist es, bei Eltern und Kindern Verständnis füreinander und für das vorliegende Problem zu schaffen. Wir ernennen das Kind zum Chef seiner Blase und begleiten die Familie mit viel Geduld auf ihrem individuellen Weg zur Kontinenz.
Interventionen bei sich zuspitzenden Krisensituationen in der
stationären akutpsychiatrischen Behandlung – Ergebnisse einer
inhaltsanalytischen Auswertung von Behandlungsvereinbarungen
Authors: Rixe Jacqueline , Neumann Eva , Bosch Marnie Melissa , Schulz Michael , Juckel Georg , Driessen Martin
Published: October 2024

Ziel der Studie Identifikation von Interventionen bei sich zuspitzenden
Krisensituationen im stationären akutpsychiatrischen Behandlungskontext zur
Vermeidung von Zwangsmaßnahmen.

Methode Inhaltsanalytische Auswertung von 98 Behandlungsvereinbarungen
(BV) mittels Frequenzanalyse (Sekundärdatenanalyse).

Ergebnisse Als Intervention bei sich zuspitzenden Krisensituationen wurden
in über der Hälfte der BV der Rückzug in eine reizarme Umgebung (64,3%), ein
Gespräch (62,2%) und ein Spaziergang (57,1%) vereinbart. Ein signifikanter
Unterschied (p=0,020) zeigte sich in Bezug auf die Einnahme von
(Bedarfs)Medikation, die ausschließlich durch männliche Personen festgelegt
wurde.

Schlussfolgerung Die Ergebnisse liefern potentiell hilfreiche Anregungen
für sich zuspitzende Krisensituationen und geschlechterspezifische Erkenntnisse
in Bezug auf die vereinbarten Interventionen.
Synthesis and Derivatization of Diaminobenzene Fluorophores with Amine Protecting Groups
Authors: Kim Dokyoung , Park Myung Hwan , Kim Min , Kim Haein , Kim Dopil , Kim Jun Yeong , Lee Sangho , Yang Won-Geun , Kim Dongwook , Kim Ki Tae
Published: October 2024

Introducing two electron-donating groups and two electron-withdrawing groups together in symmetrical positions on the benzene ring is a fundamental way to synthesize and prepare single-benzene-based fluorophores (SBBFs). Their photophysical properties are adjusted through the electronic and structural properties of the functional groups. Reported herein is the functionalization of diaminobenzene derivatives with various amine protecting groups, including amides, urea, carbamates, and sulfonamides. Both absorption and emission properties of the obtained SBBF molecules were carefully investigated. Sequential and unsymmetric diamine protections were also explored with diaminobenzene derivatives for fine-tuning of the molecular properties.
Challenging the deglobalization narrative: Global flows have remained resilient through successive shocks
Authors: Altman Steven A. , Bastian Caroline R. , Fattedad Davis
Published: October 2024

We challenge the popular narrative that the world has entered a period of deglobalization, arguing that deglobalization is still a risk rather than a current reality. Drawing upon the DHL Global Connectedness Index, we show that international flows have not decreased relative to domestic activity, there is not an ongoing shift from global to regional business, and geopolitically driven shifts in international flows still primarily involve countries at the center of present conflicts. We propose policy and research implications, warning that misperceptions of deglobalization could themselves contribute to costly reductions in international openness.
Exploring the role of diffusive coupling in spatiotemporal chaos
Authors: Raj A. , Paul M. R.
Published: October 2024

We explore the chaotic dynamics of a large one-dimensional lattice of coupled maps with diffusive coupling of varying strength using the covariant Lyapunov vectors (CLVs). Using a lattice of diffusively coupled quadratic maps, we quantify the growth of spatial structures in the chaotic dynamics as the strength of diffusion is increased. When the diffusion strength is increased from zero, we find that the leading Lyapunov exponent decreases rapidly from a positive value to zero to yield a small window of periodic dynamics which is then followed by chaotic dynamics. For values of the diffusion strength beyond the window of periodic dynamics, the leading Lyapunov exponent does not vary significantly with the strength of diffusion with the exception of a small variation for the largest diffusion strengths we explore. The Lyapunov spectrum and fractal dimension are described analytically as a function of the diffusion strength using the eigenvalues of the coupling operator. The spatial features of the CLVs are quantified and compared with the eigenvectors of the coupling operator. The chaotic dynamics are composed entirely of physical modes for all of the conditions we explore. The leading CLV is highly localized and localization decreases with increasing strength of the spatial coupling. The violation of the dominance of Oseledets splitting indicates that the entanglement of pairs of CLVs becomes more significant between neighboring CLVs as the strength of diffusion is increased.
Beam–plasma dynamics in finite-length, collisionless inhomogeneous systems
Authors: Mishra R. , Moulick R. , Adhikari S. , Marholm S. , Eklund A. J. , Miloch W. J.
Published: October 2024

This study investigates the streaming instability triggered by ion motion in a plasma system that is finite in length, collisionless, and inhomogeneous. Employing numerical simulations using particle-in-cell techniques and kinetic equations, the study examines how inhomogeneity emerges from integrating a cold ion beam with a background plasma within a confined system. The findings suggest that steady ion flow can modify ion sound waves through acoustic reflections from system boundaries, leading to instability. Such phenomena are known to be a hydrodynamic effect. However, there are also signatures of the beam-driven ion sound instability where kinetic resonances play a pivotal role. The main objective is to understand the impact of a finite-length system on beam–plasma instability and to identify the wave modes supported in such configurations.
Nonlinear light-output calibration of the oxygenated xylene scintillators used in OMEGA neutron time-of-flight spectrometers
Authors: Martinez J. S. , Knauer J. P. , Forrest C. J. , Glebov V. Yu. , Stoeckl C. , Rosenberg M. J. , Regan S. P.
Published: October 2024

Neutron time-of-flight (nTOF) spectrometers are essential instruments for measuring and evaluating the performance of inertial confinement fusion implosions. The neutron spectrometers utilized for the OMEGA laser include two liquid-based scintillators, each consisting of a large volume filled with xylene that is coupled to four photomultiplier tubes. Analysis of the signal from these detectors requires detailed knowledge of the scintillator’s light output, which is needed to fit the nTOF spectrum, from which the neutron energy spectrum is informed. The light output is nonlinearly proportional to the neutron energy, which, in turn, affects the interpretation of the neutron energy spectrum from a TOF signal. A recent campaign on OMEGA was performed to calibrate the xylene detectors and infer the shape of the light-output curve. The campaign utilized materials with increasing Z placed in the OMEGA target chamber to initiate scattering events with the 14 MeV fusion neutrons. This process leads to the production of backscatter neutrons of varying energies that appear as peaks in the nTOF data. Simulations using a neutron transport code were combined with the measured deuterium–tritium neutron yields to calculate the expected backscattered neutron yields from the well-known scattering cross sections of each material. The neutron-energy dependent light output of the scintillator inferred from the experiment is compared to the light-output curve simulated with a neutron transport code for the following neutron energies: 1.5, 2.5, 6, and 14 MeV.
Multiband topological acoustic waveguide with multistage toroidal resonant cavities
Authors: Zhang Zhi , Liang Xiao , Chu Jiaming , Luo Jiangxia , Meng Daxiang , Zhou Zhuo
Published: October 2024

In recent years, there has been significant development in acoustic waveguides through the introduction of topological phase correlation concepts in acoustics. Many studies have shown the properties of acoustic unidirectional transmission. This paper presents a new ring-shaped acoustic topological insulator that is multi-band, unlike previous structures. The structure improves internal space utilization with the same dimensions, reducing acoustic wave conduction frequency in air environments. Additionally, the introduction of a multistage ring-shaped resonant cavity enables the conduction of acoustic waves in multiple frequency bands. This paper employs the rotational scattering mechanism to invert the topological phase of the lattice. This allows for the construction of two crystals with opposite phases, which can be used to create a topological channel for the transmission of acoustic waves. At the topological interface, the acoustic transmission losses within the four bands are small. Furthermore, this paper verifies by simulation that the defects have little effect on acoustic transmission. The paper's research offers potential for multiband acoustic control.
Resonant effects of long-period ship-induced waves near shallow coasts
Authors: Dempwolff León-Carlos , Windt Christian , Melling Gregor , Holzwarth Ingrid , Bihs Hans , Goseberg Nils
Published: October 2024

This work analyzes the propagation properties of long-period ship-induced waves of vessels in confined waterways that are surrounded by wide and shallow water bodies using numerical simulations. Previous measurements indicated that, in the presence of shallow water surroundings, the drawdown being part of the long-period wave system can travel in the form of depression waves over several ship lengths distance [Parnell et al., “Ship-induced solitary Riemann waves of depression in Venice Lagoon,” Phys. Lett. A 379, 555–559 (2015); Scarpa et al., “The effects of ship wakes in the Venice Lagoon and implications for the sustainability of shipping in coastal waters,” Sci. Rep. 9, 19014 (2019)]. The exact conditions leading to these unexpectedly large propagation distances could to date not be clarified [Parnell et al., “Depression Waves Generated by Large Ships in the Venice Lagoon,” J. Coastal Res. 75, 907–911 (2016)]. In this work, evidence from numerical simulations is presented, indicating that the far-field propagation properties are governed by the wave speed of the shallow water surroundings. In case the ship speed is larger than the surrounding wave speed (supercritical conditions), a free wave is continuously generated traveling over the shallow water with only minimal height decay. In the simulations, depression waves can travel over a distance of three ship-lengths with a height reduction below 10% in the supercritical regime, as compared to 80% height reduction in the sub-critical regime. In a one-dimensional environment, this agreement of free and forced wave speed is known as Proudman resonance.
A local measure of the helicity in turbulent flows
Authors: Ferraro D. , Servidio S. , Lauria A. , Gaudio R.
Published: October 2024

Helical structures are a hallmark of hydrodynamic turbulence, and they play a key role in determining the transport and diffusion properties of the flow. Helicity, defined by the linking of velocity and vorticity, is, thus, of primary significance, particularly in systems such as propelled jet wakes. In this paper, we present a novel approach for determining helicity in turbulence, based on one-dimensional filtering methods. First, we test our new technique using analytical solutions and numerical simulations and find that the model can identify high-helicity patterns qualitatively well. Then, we employ the technique in experiments with propelled, helical turbulent flows. The model reliance on single-point velocity measurement may be especially advantageous for measurements with limited acquisition dimensionality.
Robust resistance switching performance in a Ca3Ti2O7/La0.67Sr0.33MnO3 heterostructure induced by the interface
Authors: Cao Jin Peng , Tu Wen Hao , Li Xiang Fei , Deng Wei Ye , Lv Zong Lin , Wang Hong Wei , Wu Jun Kun , Liu Tian Xiang , Yang Li Hong , Yan Xiao Qin , Chen Xin , Li Qiang , Lin Kun , Miao Jun
Published: October 2024

Ruddlesden–Popper phase oxides, such as Ca3Ti2O7, have been established as hybrid improper ferroelectrics. However, investigations into Ca3Ti2O7 have primarily concentrated on their structural and ferroelectric properties. In this study, we prepared epitaxial Ca3Ti2O7 thin films via magnetron sputtering. Conducting atomic force microscopy was employed to characterize local current variations under an applied bias voltage. Electron paramagnetic resonance measurements of the Ca3Ti2O7/La0.67Sr0.33MnO3 film were conducted to assess its defect characteristics. Interestingly, the Ca3Ti2O7/La0.67Sr0.33MnO3 stacks exhibited remarkable macroscopic resistance switching, with a resistance on/off ratio reaching 100, alongside robust retention (∼2500 s) and endurance (∼2000 cycles) features. Additionally, density functional theory calculations suggest that the resistance switching is attributable to the interface barrier of the Ca3Ti2O7/La0.67Sr0.33MnO3 interface and the efficacy of space charge limitation. This work proposes an avenue for the utilization of Ruddlesden–Popper phase Ca3Ti2O7 in various applications.
Computational comparison of passive control for cavitation suppression on cambered hydrofoils in sheet, cloud, and supercavitation regimes
Authors: Kumar Prabhakar , Sharma Nidhi , Pattanayek Sudip K. , Garg Ashish
Published: October 2024

Cavitation is a transient, highly complex phenomenon found in numerous applications and can have a significant impact on the characteristics as well as the performance of the hydrofoils. This study compares the evolution of transient cavitating flow over a NACA4412(base) (NACA stands for National Advisory Committee for Aeronautics) cambered hydrofoil and over the same hydrofoil modified with a pimple and a finite (circular) trailing edge. The assessment covers sheet, cloud, and supercavitation regimes at an 8° angle of attack and the Reynolds number of 1×106, with cavitation numbers ranging from 0.9 to 0.2. The study aims to comprehensively understand the role of the rectangular pimple in controlling cavitation and its impact on hydrodynamic performance across these regimes. Numerical simulations were performed using a realizable model and the Zwart–Gerber–Belamri (ZGB) cavitation model to resolve turbulence and cavitation effects. The accuracy of the present numerical predictions has been verified both quantitatively and qualitatively with available experimental results. The present analysis includes the time evolution of cavities, temporal variation in total cavity volume, time-averaged total cavity volume, distributions of vapor volume fractions along the chord length, and their hydrodynamic performance parameters. Results demonstrate that rectangular pimples have significant impacts in the different cavitation regimes. In the sheet cavitation regime (σ=0.9), the NACA4412(pimpled) hydrofoil exhibits minimal cavity length and transient volume changes as compared to the NACA4412(base) hydrofoil. In the cloud cavitation regimes (σ=0.5), cavity initiation occurs differently, starting from the pimpled location for the NACA4412(pimpled) hydrofoil, unlike the initiation just downstream of the nose in the case of base hydrofoil. In the supercavitation regimes (σ=0.2), the cavity length remains comparable, but the NACA4412(pimpled) hydrofoil exhibits larger cavity volume evolution in both cloud and supercavitation regimes (σ=0.5 and σ=0.2) after initial fluctuations. Furthermore, hydrodynamic performance for the NACA4412(pimpled) hydrofoil shows 41%, 36%, and 17% lower lift coefficients, and 46%, 27%, and 9% lower drag coefficients in sheet, cloud, and supercavitation, respectively.
A novel meshless method for numerical simulation of fractured-vuggy reservoirs
Authors: Wang Qi , Wang Liang , Deng Xingliang , Zhang Jing , Li Guohui , Zhao Hui , Zhou Yuhui , Zhan Wentao
Published: October 2024

This paper proposes a novel meshless numerical simulation method for fractured-vuggy reservoirs. Initially, model discretization involves extracting fracture and vug feature nodes along the contours of the reservoir bodies and in alignment with fracture orientations, tailored to the characteristics of the fractured-vuggy oil deposit. Subsequently, a connection element model is established within the influence domain. Based on the seepage equations of the connection system, a computational method for the parameters of the connection elements (connection transmissibility and connection volume) is defined. In addition, a sequential method is employed to solve for the pressure and saturation, achieving rapid prediction of the reservoir's production dynamics. On this basis, an automatic history matching algorithm is utilized for real-time fitting of oil–water dynamic indicators, inverting the characteristic parameters of the connection element model, and quantitatively characterizing the injection–production connection elements. The research findings indicate that the method is capable of rapidly fitting and predicting the dynamics of oil reservoir production. Furthermore, conceptual model examples have substantiated that it achieves comparable computational efficiency and superior computational accuracy when compared to the traditional finite difference (volume) method under the same nodal conditions. Additionally, the node arrangement for fractures and vugs is comparatively flexible, and it can ensure the integrity of the flow paths with a limited number of nodes to enhance predictive accuracy. Therefore, this method can effectively meet the rapid prediction requirements for fractured-vuggy reservoirs and also provides a novel meshless computational approach for the numerical simulation of such reservoirs.
Design of SRAM cell using an optimized D-latch in quantum-dot cellular automata (QCA) technology
Authors: Rathore Nitesh Kumar , Singh Pooran
Published: October 2024

A newer nanoscale technology called quantum-dot cellular automata (QCA) has been used by researchers to design digital circuits in place of the more traditional complementary metal–oxide semiconductor (CMOS) technology. This recent development in the technology change is due to the problems faced by CMOS technology in terms of power consumption and physical limitations. The advantages of QCA technology over CMOS technology are high density, low power consumption, high-speed operation, and less footprint area. This research provides a novel circuit for D-latch and static random access memory (SRAM) cells based on QCA technology. Initially, a D-latch circuit is proposed with a layout area of 0.01 μm2, a 0.5 clock cycle delay (latency), and a cell count of 18 QCA cells. Furthermore, an SRAM cell is proposed using the same D-latch circuit, which uses cell counts of 26 QCA cells and contributes to a layout area of 0.02 μm2 with a 0.75 clock cycle delay (latency). It is observed that our proposed circuits have a smaller layout area, fewer QCA cell counts, and a lower clock cycle delay (latency) than existing circuits.
Surface roughness analysis of cilia-driven flow for shear-thinning fluid inside a horizontal passage
Authors: Khan Muhammad Waris Saeed , Asghar Zeeshan , Shatanawi Wasfi , Gondal Muhammad Asif
Published: October 2024

The underlying investigation reports the impact of surface roughness on the mechanism of ciliary transport of Carreau–Yasuda (C–Y) liquid through a horizontal passage. The considered equations are further simplified with the help of a low Reynolds number and large wavelength approximation. The resulting boundary value problem is numerically tackled with the MATLAB built-in function bvp5c. The impact of sundry parameters on physical quantities is examined through graphical representation. The results indicate that the influence of roughness cannot be ignored during the cilia-driven channel flow, as a significant impact of roughness is observed on velocity, pressure, pressure rise, and streamlines. For several non-Newtonian pumping analysis with rough surface, this evaluation will serve as a benchmark. The current findings will also be applied to the creation of new medical pumps for transportation phenomena.
Wind tunnel wall interference correction for transonic airfoils with data-reduced ensemble Kalman filter
Authors: Chen Xin , Wang Gang , Ye Zhengyin
Published: October 2024

The uncertain factors in wind tunnel experiments, especially the interference effects, will cause the flow around the test model to differ from that under the free flow condition. The wind tunnel wall interference effects are challenging to be eliminated, especially in transonic flow regions where classical linear correction methods are ineffective. To address this issue, an efficient wind tunnel wall interference correction framework based on data assimilation is proposed for steady and shock buffet flows around the airfoils in the transonic region in this work. The ensemble Kalman filter (EnKF) is used to find the combination of inflow conditions, which minimizes the differences between the pressure coefficients measured in the wind tunnel experiment and those estimated by computational fluid dynamics (CFD). The polynomial chaos expansion method is used to propagate uncertainty in the forecast step of the EnKF in order to improve efficiency. Typical wind tunnel wall interference correction problems are studied, including two steady cases: the transonic flow around the Royal Aircraft Establishment 2822 (RAE2822) and the National Aerospace Laboratory 7301 (NLR7301) airfoils, and one unsteady case: the transonic shock buffet on the National Aeronautics and Space Administration supercritical (phase 2)-0714 (NASA SC(2)-0714) airfoil. It is demonstrated that with the corrected Mach number and angle of attack, the estimated CFD results are in better agreement with the measured experimental data than traditional linear methods and the computational efficiency is improved compared to the original EnKF.
Monte Carlo methods in the manifold of Hartree–Fock–Bogoliubov wave functions
Authors: Vitali Ettore , Rosenberg Peter , Zhang Shiwei
Published: October 2024

We explore the possibility of implementing random walks in the manifold of Hartree–Fock–Bogoliubov wave functions. The goal is to extend state-of-the-art quantum Monte Carlo approaches, in particular the constrained-path auxiliary-field quantum Monte Carlo technique, to systems where finite pairing order parameters or complex pairing mechanisms, e.g., Fulde–Ferrell–Larkin–Ovchinnikov pairing or triplet pairing, may be expected. Leveraging the flexibility to define a vacuum state tailored to the physical problem, we discuss a method to use imaginary-time evolution of Hartree–Fock–Bogoliubov states to compute ground state correlations, extending beyond situations spanned by current formalisms. Illustrative examples are provided.
Effect of induced charge forming active vortex structures in serpentine microchannels on fluid mixing driven by pressure flow
Authors: Yuan Shuai , Liu Xijiang , Liu Xiaodong , Deng Jiu
Published: October 2024

The incorporation of induced charge into the serpentine curved micromixers driven by negative pressure (Np) can serve as an efficacious way for improving micromixing quality. To comprehensively investigate the hydraulic characteristics and mixing capacity of this model, an investigation is conducted using finite element method. The results indicate that when |−30| Pa ≤ Np ≤ |−50| Pa, active vortex pairs formed by electroosmosis flow on the conductive plate surface are fully developed, which strengthens the chaotic convection and leads to a uniform mixing. For |−50| Pa < Np ≤ |−200| Pa conditions, the compression of pressure flow causes the separation and degradation of active vortex pairs. However, increasing the electric field intensity around the conductive plate, such as forming a shrinking microchannel, or increasing the induction area of the plate, such as rotating the conductive plate, can make the active vortex play a beneficial role again, as both the Zeta potential and slip velocity on the plate surface are enhanced. For |−200| Pa < Np ≤ |−500| Pa conditions, the pressure flow gradually dominates the mixing process. But the conductive plate with combined optimal parameters can increase the mixing quality to above 0.8 when Np varies in border range.