bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluating the effects of the analogical learning approach on eighth graders’ learning outcomes: the role of metacognition
Authors: Wang Chia-Yu
Published: December 2022

Teaching with analogies is an important pedagogy that helps learners construct abstract conceptions through reasoning with something familiar. Heat concepts were chosen for this study because they have an intangible nature and involve complex mechanisms that often challenge school-aged learners. Learning this kind of complex concept with analogies involves complicated mental processes that could demand learners’ metacognitive abilities; yet, to date, the influence of metacognition has been left unexamined. This study therefore investigated how metacognition differentially affected adolescents’ processes and outcomes of analogical learning about abstract heat concepts. Eighty-three eighth graders participated in the study and attended two units of Teaching-With-Analogies on specific heat and heat transfer. This study adopted a mixed-method approach along with within-group comparisons. Among them, eight individuals from each of the high-, moderate- and low-metacognitive groups were interviewed to explore the utilized metacognitive activities and their relation with the ability to reason with analogies. The quantitative findings revealed that analogies benefited the moderate metacognitive learners, and yet did not alter the conceptual understanding of the high and low metacognitive cohorts. A unique explanatory power of metacognition was also observed on the learners’ post conceptual understanding, in addition to on their prior knowledge. Verbal process data illustrated that metacognitive abilities substantially influenced every stage of solving heat problems with analogies. The differential outcomes of the analogical learning approach were explained by in-depth case analyses considering the use of prior knowledge and the absence of metacognition during analogical reasoning. Metacognitive characteristics of the dynamic analogy-inferring process for different metacognitive groups were synthesized. The associated implications for the analogical learning approach and accommodations for adolescents of different levels of metacognition are also discussed.
A study of superstructure Hf6Ta2O17 ceramics for electrochemical energy storage applications
Authors: Xue Yufeng , Cao Yi , Ruan Piao , Lu Munan , Chen Fenhua , Han Weijian , Qiu Wenfeng
Published: December 2022

Introducing oxygen vacancies into the superstructure HTO ceramic to improve its electrochemical energy storage performance.
The progress and efficiency of CsPbI2Br perovskite solar cells
Authors: Liu Xin , Li Jie , Cui Xumei , Wang Xiao , Yang Dingyu
Published: December 2022

This review gives a full-scale and in-depth summary of CsPbI2Br perovskite materials for the photovoltaic applications.
Highly efficient Mn–Mn dimer activated phosphors for high-power near-infrared LED application
Authors: Li Xiaoshuang , Liu Tianpeng , Zhang Kang , Hu Zhiyu , An Hongxiang , Deng Shuwei , Kong Youchao , Wang Bo
Published: December 2022

Broadband NIR phosphors as light sources are receiving increasing attention.
Modelling the evolution of novelty: a review
Authors: Colizzi Enrico Sandro , Hogeweg Paulien , Vroomans Renske M.A.
Published: December 2022

Evolution has been an inventive process since its inception, about 4 billion years ago. It has generated an astounding diversity of novel mechanisms and structures for adaptation to the environment, for competition and cooperation, and for organisation of the internal and external dynamics of the organism. How does this novelty come about? Evolution builds with the tools available, and on top of what it has already built – therefore, much novelty consists in repurposing old functions in a different context. In the process, the tools themselves evolve, allowing yet more novelty to arise.

Despite evolutionary novelty being the most striking observable of evolution, it is not accounted for in classical evolutionary theory. Nevertheless, mathematical and computational models that illustrate mechanisms of evolutionary innovation have been developed. In the present review, we present and compare several examples of computational evo–devo models that capture two aspects of novelty: ‘between-level novelty’ and ‘constructive novelty.’ Novelty can evolve between predefined levels of organisation to dynamically transcode biological information across these levels – as occurs during development. Constructive novelty instead generates a level of biological organisation by exploiting the lower level as an informational scaffold to open a new space of possibilities – an example being the evolution of multicellularity. We propose that the field of computational evo–devo is well-poised to reveal many more exciting mechanisms for the evolution of novelty. A broader theory of evolutionary novelty may well be attainable in the near future.
Building trust via blockchain in UAV‐assisted ultra‐dense 6G cellular networks
Authors: Wang Taotao , Shi Long , Wang Jessie Hui , Wang Zhe , Deng Xiumei , Li Jun , Zhang Shengli
Published: December 2022

The ultra‐dense deployment of unmanned aerial vehicles (UAVs) as mobile small cell base stations (SBS) is expected to support ultra‐high‐speed, ultra‐reliable, and ultra‐low‐latency wireless connections in sixth generation (6G) wireless cellular networks. Inevitably, the explosively increasing number of SBSs each with ever‐shrinking cell size will result in the spectrum scarcity and pose critical challenges to the spectrum management. Towards the centralized spectrum management system, a third‐party authority is employed to coordinate the spectrum sensing, sharing, and allocation among participants. However, a centralized authority is vulnerable to numerous security threats, such as single point of failure, denial of service attacks, and privacy disclosure, and cannot guarantee fair and efficient spectrum management without mutual trusts among participants. To address these problems, a novel framework of blockchain‐aided spectrum management is designed to securely record the spectrum auction data and spectrum allocation data in the decentralized spectrum sharing. Moreover, a trust management scheme is proposed to evaluate the trusts of all UAVs participating in the decentralized spectrum sharing, where the trust increase depends on legal use of spectrum allocation and honest report of spectrum sensing. In particular, it is shown that the proposed trust management can not only incentivize the UAVs to comply with the legal rule of spectrum sharing in blockchain, but also punish the malicious behaviour that either violates the spectrum sharing rule or provides misleading spectrum sensing results.
Stopband enhanced patch‐type filter using common‐mode feeding method based on multilayer liquid crystal polymer lamination technology
Authors: Huang Feng , Aliqab Khaled , Alsharari Meshari , Lu Jiayuan
Published: December 2022

In this study, a new common‐mode feeding approach to the 2‐D square patch resonator is proposed and applied in the design of bandpass filter (BPF) with wideband harmonic suppression. Different from the conventional single‐point feeding structure, the proposed one has two physical feeding points on the patch. It is indicated from the electric field distributions that the presented feeding method can not only support the excitation of the desired fundamental TM01 mode, but also enable the rejection of high‐order modes by selecting proper feeding positions. For demonstration, a second‐order BPF centred at 4.0 GHz with wide stopband suppression has been implemented by using multilayer liquid crystal polymer circuit technology. Moreover, benefitting from mixed‐coupling, a transmission zero is introduced to improve the filtering selectivity. Measured and simulated results are in good agreement with each other, validating the proposed feeding concept.
A dichotomy in group II Herbig disks
Authors: Stapper L. M. , Hogerheijde M. R. , van Dishoeck E. F. , Paneque-Carreño T.
Published: December 2022

Context. Herbig stars can be classified as group I or group II depending on the shape of the far-infrared excess from the spectral energy distribution. This distinction may be evolutionary and related to the vertical structure of the Herbig disks.

Aims. Our aim is to determine the emission height of Herbig disks and compare the resulting vertical extent of both groups.

Methods. We used Atacama Large Millimeter/submillimeter Array (ALMA) Band 6 observations of 12CO J = 2−1 emission lines at sufficient velocity (~0.3 km s−1) and spatial resolution (~30 au) of eight Herbig disks (four group I and four group II sources) to determine the emission heights from channel maps generated via geometrical methods previously developed in other works.

Results. We find that all group I disks are vertically extended with a height to radius ratio of at least 0.25 and that for three of the disks, the gas emission profile can be traced out to 200–500 au. The group II disks are divided between MWC 480 and HD 163296, which have emission height profiles similar to the group I disks, and AK Sco and HD 142666, which are very flat (not exceeding a height of 10 au over the full extent traced) and more compact (<200 au in size). The brightness temperatures show no differences between the disks when the luminosity of the host star is accounted for.

Conclusions. Our findings agree with previous work that suggests group I disks are vertically extended and that group II disks are either large and self-shadowed or compact. Both MWC 480 and HD 163296 could be precursors of group I disks that have not yet formed a cavity that would allow for irradiation of the outer parts of the disk. The very flat disks, AK Sco and HD 142666, could have been caused by significant settling due to the advanced age of the disks (~20 instead of <10 Myr). The large differences in vertical structure are not reflected in the spectral energy distributions of these disks. More and deeper observations at higher spatial and velocity resolution are necessary to further characterize the Herbig subgroups.
A global view on star formation: The GLOSTAR Galactic plane survey
Authors: Dokara R. , Gong Y. , Reich W. , Rugel M. R. , Brunthaler A. , Menten K. M. , Cotton W. D. , Dzib S. A. , Khan S. , Medina S.-N. X. , Nguyen H. , Ortiz-León G. N. , Urquhart J. S. , Wyrowski F. , Yang A. Y. , Anderson L. D. , Beuther H. , Csengeri T. , Müller P. , Ott J. , Pandian J. D. , Roy N.
Published: December 2022

Context. While over 1000 supernova remnants (SNRs) are estimated to exist in the Milky Way, only less than 400 have been found to date. In the context of this apparent deficiency, more than 150 SNR candidates were recently identified in the D-configuration Very Large Array (VLA-D) continuum images of the 4–8 GHz global view on star formation (GLOSTAR) survey, in the Galactic longitude range −2° < l < 60°.

Aims. We attempt to find evidence of nonthermal synchrotron emission from 35 SNR candidates in the region of Galactic longitude range 28° < l < 36°, and also to study the radio continuum emission from the previously confirmed SNRs in this region.

Methods. Using the short-spacing corrected GLOSTAR VLA-D+Effelsberg images, we measure the ~6 GHz total and linearly polarized flux densities of the SNR candidates and the SNRs that were previously confirmed. We also attempt to determine the spectral indices by measuring flux densities from complementary Galactic plane surveys and from the temperature-temperature plots of the GLOSTAR-Effelsberg images.

Results. We provide evidence of nonthermal emission from four candidates that have spectral indices and polarization consistent with a SNR origin, and, considering their morphology, we are confident that three of these (g28.36+0.21, G28.78-0.44, and G29.38+0.10) are indeed SNRs. However, about 25% of the candidates (8 out of 35) have spectral index measurements that indicate thermal emission, and the rest of them are too faint to have a good constraint on the spectral index yet.

Conclusions. Additional observations at longer wavelengths and higher sensitivities will shed more light on the nature of these candidates. A simple Monte Carlo simulation reiterates the view that future studies must persist with the current strategy of searching for SNRs with small angular size to solve the problem of the Milky Way’s missing SNRs.
Antithrombotisches Management nach akutem oder chronischem Koronarsyndrom
Authors: Moser Martin , Westermann Dirk
Published: December 2022

Nach akutem oder chronischem Koronarsyndrom mit Koronarintervention ist eine antithrombotische Therapie mit dualer Plättchenhemmung erforderlich. Die Intensität und Dauer der Therapie
unterscheiden sich je nach Indikation. Für besondere Situationen mit erhöhtem ischämischem Risiko oder erhöhtem Blutungsrisiko liegen Studiendaten vor, auf deren Basis fundierte
Entscheidungen zur Intensivierung oder auch zur Deeskalation der Standardtherapie getroffen werden können, um das Nutzen-Risiko-Verhältnis zu optimieren.
Nutzen und zukünftige Relevanz der Corona-bedingt befristeten
Änderungen in der Substitution in Deutschland
Authors: Müllerschön Babette , Stöver Heino
Published: December 2022

Ziel der Studie Die COVID-19-Pandmie hat die Substitutionsbehandlung vor
große Herausforderungen gestellt. An der oft als restriktiv angesehenen
Rechtsgrundlage (BtM-VV) wurden befristete Änderungen vorgenommen, um
Behandler:innen mehr Spielraum bei der Gestaltung der Therapien zu
gewährleisten. Weitreichende Flexibilisierungen wurden in den Bereichen
Take-Home-Verschreibungen, konsiliarische Behandlung und Delegation vorgenommen.
Zusätzlich wurden neue Vergütungsmöglichkeiten im
Einheitlichen Bewertungsmaßstab (EBM) geschaffen. Durch
leitfadengestützte Interviews mit substituierenden Ärzt:innen
wurde eine Evaluation der befristeten BtM-VV- und EBM- Änderungen
vorgenommen.

Methodik Im Jahr 2021 wurden 16 qualitative Interviews mit
substituierenden Ärzt:innen aus zehn verschiedenen Bundesländern
in Deutschland geführt. Die Interviewten wurden zu ihren Erfahrungen mit
den Corona-bedingt befristeten BtM-VV- und EBM-Änderungen befragt. Im
Fokus stand dabei, ob die temporären Flexibilitäten dauerhaft in
die post-pandemische Praxis übernommen werden sollten. Der
Interviewleitfaden enthielt zusätzlich Fragen zu strukturellen
Barrieren, Nachwuchsmangel und Stigmatisierung.

Ergebnisse Zur Kontaktreduzierung verlängerte die Mehrheit der
Ärzt:innen Take-Home-Rezepte. In Folge machte nur eine befragte Person
ausschließlich negative Erfahrungen. Insgesamt berichteten die
Ärzt:innen über keine und/oder positive
Veränderungen im Therapieverlauf. Behandler:innen nutzten die meisten
der befristeten Rechts- und Vergütungsänderungen in der
Behandlungsgestaltung. Sie sprachen sich überwiegend für eine
Übernahme der befristeten Regelungen in den post-pandemisch Regelbetrieb
aus. Kontrovers wurden die Änderungen bezüglich der Aufhebung
der Kapazitätsgrenze bei der Konsiliarregelung und der erweiterten
Delegation diskutiert.

Schlussfolgerung Die Ergebnisse sprechen für die Übernahme
der befristeten BtM-VV- und EBM-Änderungen in den post-pandemischen
Regelbetrieb. Die Flexibilisierungen erleichtern die Anpassung der Therapie an
individuelle Umstände der Behandler:innen und Patient:innen. Dies
könnte dazu beitragen, die derzeitigen Versorgungsengpässe zu
entschärfen und mehr Menschen mit Opioid-Abhängigkeit eine
qualitativ hochwertige Substitutionstherapie anbieten zu können. Eine
Untersuchung und Beseitigung struktureller Barrieren darf bei der Ein- bzw.
Fortführung erweiterter Handlungsspielräume nicht vergessen
werden. Da gesetzliche Flexibilisierungen zwangsläufig mehr
Verantwortung auf die einzelnen Ärzt:innen übertragen, sollte
eine verstärkte Unterstützung durch Schulungen und Vernetzung
angeboten werden.
Readability, Content, and Quality of Online Patient Education Materials on Anesthesia and Neurotoxicity in the Pediatric Population
Authors: Freed Karen , Taylor Michael G. , Toledo Paloma , Kruse Jessica H. , Palanisamy Arvind , Lange Elizabeth M.S.
Published: December 2022

Objective Internet-based patient education materials (PEMs) are often above the recommended sixth grade reading level recommended by the U.S. Department of Health and Human Services. In 2016 the U.S. Food and Drug Administration (FDA) released a warning statement against use of general anesthetic drugs in children and pregnant women due to concerns about neurotoxicity. The aim of this study is to evaluate readability, content, and quality of Internet-based PEMs on anesthesia in the pediatric population and neurotoxicity.

Study Design The websites of U.S. medical centers with pediatric anesthesiology fellowship programs were searched for PEMs pertaining to pediatric anesthesia and neurotoxicity. Readability was assessed. PEM content was evaluated using matrices specific to pediatric anesthesia and neurotoxicity. PEM quality was assessed with the Patient Education Material Assessment Tool for Print. A one-sample t-test was used to compare the readability of the PEMs to the recommended sixth grade reading level.

Results We identified 27 PEMs pertaining to pediatric anesthesia and eight to neurotoxicity. Mean readability of all PEMs was greater than a sixth grade reading (p <0.001). While only 13% of PEMs on anesthesia for pediatric patient mentioned the FDA warning, 100% of the neurotoxicity materials did. PEMs had good understandability (83%) and poor actionability (60%).

Conclusion The readability, content, and quality of PEMs are poor and should be improved to help parents and guardians make informed decisions about their children's health care.

Key Points
Effective spin injection into the organic semiconductor PTCDA evaluated by a normalization method
Authors: Weng Sheng-Yueh , Singh M. Sanjoy , Hong Cheng-Feng , Lin Wen-Teng , Wu Po-Hsun , Huang Ssu-Yen , Lin Jauyn Grace , Chu Yu-Hsun , Chiang Wen-Chung , Lin Minn-Tsong
Published: December 2022

Studies of spin current injection, transport, and interface control have drawn attention recently for efficient organic spintronic devices. In this study, we apply both spin pumping (SP) and the longitudinal spin Seebeck effect (LSSE) to inject spin currents into a π-conjugated organic semiconductor, perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA), and characterize injection and transport by measuring inverse spin Hall voltage VISHE in spin detectors. A normalization factor introduced to SP analysis eliminates a contribution provoked by deviation of spin sources and leads to a more accurate determination of the spin diffusion length in PTCDA. While SP with Permalloy as a spin source is effective in generating detectable VISHE, the LSSE from yttrium iron garnet shows no convincing sign of spin injection. In addition, spin-flip scattering induced by hybrid states undermining electrical spin injection is negligible in SP. These results are attributed to interfaces between spin sources and PTCDA, indicative of the importance of injection methods and material choices.
Multiple tunnel diode peaks in I–V curves of a multijunction laser power converter
Authors: Wang An-Cheng , Yin Jia-Jing , Yu Shu-Zhen , Sun Yu-Run
Published: December 2022

How to characterize tunnel diodes (TDs) in multijunction photovoltaic cells is a challenge. Here, we investigate a locally illuminated six-junction InGaAs laser power converter (LPC) by measuring the wide-voltage-range I–V curves. Multiple TD peaks are observed in the reverse breakdown area of the dark-state I–V curve, while with increased laser power, the peaks break into more subpeaks successively, and the subcell photocurrent steps are found to shrink due to the moving subpeaks at the right side of the steps. A model of a multijunction LPC under localized illumination is proposed, and the shrinkage of a step originates from the larger local overproduced subcell photocurrent than the local peak current of the very TD below this subcell. Therefore, the correspondences between TD peaks in the I–V curves and their physical locations in the structure of the LPC are determined. This work gives in-depth insight into the current limiting mechanism of TDs in multijunction photovoltaic devices under non-uniform illumination and expands the knowledge of multijunction photovoltaic devices.
The clarification of leakage conduction mechanism of HfO2/SiNx stacked a-IGZO TFT and its variation at high temperature
Authors: Wang Ruozheng , Wang Juan , Niu Gang , Wei Qiang , Wu Shengli , Yu Cui , Wang Hong-Xing
Published: December 2022

In this paper, the current conduction mechanisms of an a-IGZO thin-film transistor based on HfO2/SiNx stacks were investigated at room temperature and its variation at 523 K. Ti/HfO2/SiNx/ITO metal–insulator–metal capacitors were fabricated and researched under positive gate bias by performing current–voltage measurements. As a function of electric field, different types of current conduction mechanisms were detected, i.e., ohmic conduction (5–15 MV/m), Frenkel–Poole emission (17.5–50 MV/m), and trap assisted tunneling (52.5–100 MV/m). With the increase in temperature, leakage current increased about two orders of magnitude combined with the variation of leakage mechanisms. The barrier height and dielectric constant were reduced simultaneously, proving the deterioration of dielectric properties at high temperature.
Radiative sky cooling of silicon solar modules: Evaluating the broadband effectiveness of photonic structures
Authors: Dumoulin Jérémy , Drouard Emmanuel , Amara Mohamed
Published: December 2022

Photovoltaic solar cells are designed to efficiently absorb solar photons but convert only a limited proportion of them into electricity. Under real operating conditions, the remaining energy causes solar modules to heat up to 50–60 °C, which is detrimental to their power conversion efficiency and lifetime. In recent years, there has been a growing interest in the so-called radiative sky cooling strategy. This approach consists in optimizing the thermal radiation of cells or modules—with the help of photonic structures—by taking advantage of the atmospheric transparency in the 8–13 range. In this paper, we present an in-depth analysis of radiative sky cooling applied to silicon based photovoltaic modules. A simulation of a preliminary design of a photonic structure for possible radiative sky cooling of a module is also proposed.
Mathematical modeling of the Chilean riots of 2019: An epidemiological non-local approach
Authors: Cartes Carlos
Published: December 2022

During the second half of October 2019, Chile, especially the capital city, Santiago, suffered from widespread violence and public and private infrastructure destruction. This work aims to expand an epidemiological non-local model that successfully described the French riots of 2005 to incorporate the topology of Santiago’s subway network and explain the reported distribution of rioting activity in the city. Although the model reproduced the disorders’ aggregated temporal evolution, it could not deliver results resembling the observed spatial distribution of activity on Santiago. The main reason for this failure can be attributed to the fact that the model lacks a population displacement mechanism, which seems vital to explain Santiago’s unrest episodes.
Revisit of recombination processes of low-charge-state ion generation during picosecond intense laser–gas interaction
Authors: Deng Yanqing , Zhang Qi , Yue Dongning , Wei Wenqing , Feng Lei , Cui Ye , Ma Yanyun , Lu Feng , Yang Yue , Huang Zheng , Wu Yuchi , Zhou Weimin , Weng Suming , Liu Feng , Chen Min , Yuan Xiaohui , Zhang Jie
Published: December 2022

The origin of He+ ions in picosecond intense laser–gas interaction was experimentally and numerically investigated. A nanosecond laser pulse was used to modulate the plasma condition, which helps to distinguish the origin of the helium ions with different charge states. By comparing the energy spectra of He2+ and He+ ions in the experiments with/without plasma shaping, we found neither ion–atom nor electron–ion recombination is responsible for the He+ generation, which is supported by two-dimensional hydrodynamic simulations and theoretical calculations.
Initiation and propagation of one-dimensional detonations in aluminum-particle/C2H2/air system
Authors: Zhou Qixiang , Huang Jin , Han Wenhu , Wang Cheng
Published: December 2022

This work carries out simulations on the initiation and propagation of aluminum (Al)-particle/C2H2/air detonations in a one-dimensional (1D) planar geometry, based on the Euler–Euler two-phase flow models and the fifth-order weighted essentially non-oscillatory scheme. The effect of Al particles on 1D detonation is studied by changing Al-particle diameter and concentration. It is found that for the two-phase detonation, the initiation is achieved by the sudden transition to a detonation and undergoes an extended overdriven stage, which is caused by the afterburning effect of Al particles in the products. During the steady propagation, the detonations with the proper Al-particle diameter manifest the double-front feature created by afterburning of Al particles in the products. For the big Al particles, the second front is formed more slowly and propagates stably. As Al particles are too big to be ignited downstream, the second front disappears. However, the smaller Al particles make a shorter distance between these two fronts. Nevertheless, as Al particles are sufficiently small, a successful initiation is prone to be more difficult because the evaporation of Al particles absorbs heat.
Sensitivity of wave merging and mixing to initial perturbations in Holmboe instabilities
Authors: Yang Adam J. K. , Tedford E. W. , Olsthoorn J. , Lawrence G. A.
Published: December 2022

Initial perturbations are commonly used in direct numerical simulations (DNS) to trigger the shear instability of stratified fluids. We investigate the effects of initial perturbations on the evolution of Holmboe instabilities with DNS. In particular, we model the interaction between a primary Holmboe wave and a subharmonic component that has a wavelength double that of the primary wave. We show that the phase difference and the amplitude of the primary and subharmonic components of the initial perturbation control the merging of Holmboe instabilities, which, in turn, influence diapycnal mixing in stratified flows. The amplitude difference has a more significant effect on the merging of Holmboe instabilities compared to the initial phase difference. For a given amplitude of the primary perturbation, a larger subharmonic perturbation results in an earlier merging event. In three-dimensional simulations, this preference of the subharmonic initial perturbation increased the amplitude of Holmboe waves by a factor of two. Although the subharmonic mode grows slower, it grows for longer producing more net mixing.
Wideband Brillouin light scattering analysis of spin waves excited by a white-noise RF generator
Authors: Flajšman Lukáš , Wojewoda Ondřej , Qin Huajun , Davídková Kristýna , Urbánek Michal , van Dijken Sebastiaan
Published: December 2022

Spin waves are studied intensively for their intriguing properties and potential use in future technology platforms for the transfer and processing of information and microwave signals. The characterization of devices and materials for magnonic systems is time-consuming, and thus, the development of instruments that can speed up the collection and analysis of spin-wave data is crucial. In this Letter, we report a straightforward approach to enhance the measurement throughput by fully exploiting the wideband detection nature of the Brillouin light scattering technique with a white-noise RF generator.
Assessment of the mixing-limited hypothesis with first-principles simulation results
Authors: Schmidt David P. , Arienti Marco , García-Oliver José M , Pastor José M.
Published: December 2022

Starting with two well-tested, one-dimensional models of non-evaporating, mixing-limited sprays, governing equations for liquid mass and two-phase momentum for each model can be manipulated to reveal the formal similarity between momentum and liquid volume fraction. The consequence of this similarity is that momentum, when properly non-dimensionalized, is equal to the liquid volume fraction at any time and at any axial location within a non-evaporating, mixing-limited spray with a constant rate of injection. An alternative, the more well-known similarity between mass fraction and velocity, is also mathematically evident. We compare predictions of this mathematical analysis to high-fidelity, first-principles simulation results of a non-evaporating spray to assess the validity of the theoretical similarity. The analysis of the simulation not only confirms the mathematical derivations but also points to subtlety in the definition of the spray velocity. In particular, the density-weighted velocity is required to observe similarity. The requirement of density-weighted velocity means that similarity tests require knowledge of both phase velocities. The agreement also works to confirm that the first-principles simulations are indeed mixing-limited, despite the finite nature of domain size and resolution.
Turbulent/non-turbulent interface for laminar boundary flow over a wall-mounted fence
Authors: Li Sicheng , Long Yanguang , Wang Jinjun
Published: December 2022

The turbulent/non-turbulent interface plays an important role in the exchange of mass, momentum, and energy between turbulent and nonturbulent flows. However, the role played by the interface in the separation and reattachment flow remains poorly understood. This study, thus, investigates the geometrical and dynamic properties of the interface in the separation and reattachment flow induced by a wall-mounted fence by using particle image velocimetry in a water tunnel. The flow undergoes laminar separation, reattachment, and the recovery of the boundary layer. Finally, the fully developed turbulent boundary layer is established. The geometrical and dynamic properties of the interface vary consistently with the vortex structure. The geometrical properties change most quickly above the reattachment point, where the dynamic properties are maximal. Before the reattachment point, the shear motion of the fluid contributes significantly to the interface properties. As a result, the interface thickness does not scale with the size of the nearby vortex until reattachment. Additionally, quasiperiodic shedding vortices significantly affect the interface properties. Remarkable bulges and troughs of the interface form corresponding to the spatial arrangement of the shedding vortices. In addition, the conditional averaged dynamic quantities peak along the interface coordinate as the turbulence intensity is enhanced by the shedding vortex. This study provides a new perspective of the turbulent/non-turbulent interface, improves our understanding of turbulent diffusion in the separation and reattachment flow, and clarifies how the separated flow and shedding vortices affect the interface properties.
Boundary layer transition induced by low-speed synthetic jets
Authors: Palumbo Andrea , Semeraro Onofrio , Robinet Jean-Christophe , de Luca Luigi
Published: December 2022

The effect of low-speed, circular synthetic jets (SJ) on the turbulent transition of a laminar boundary layer is studied through direct numerical simulations. The SJ capability in fixating the streamwise location of transition onset is analyzed in terms of its operation parameters (reduced frequency F+ and momentum coefficient Cμ). The effect of free-stream turbulence (FST) on the near-wall vortical structures generated by the synthetic jet is analyzed as well, to mimic the actual operation of the control system. Velocity spectra, phase portraits, and dynamic mode decomposition allow us to investigate flow unsteadiness and transition to a chaotic state. In most of the investigated cases, SJs successfully promote transition, as the result of varicose-symmetric hairpin-like vortices generated at the jet exits. In particular, it is found that increasing the momentum coefficient always reduces the size of the laminar region; a non-monotonic behavior of the laminar fetch is noted as the reduced frequency is increased, suggesting the existence of an optimal frequency value. Combination of FST and SJ actuation results in spanwise-asymmetric vortical structures, with little difference in the location of the transition onset as compared to the previous case. The present analysis can be used to gather information on the practical implementation of low-speed SJ actuators as active turbulators.
Improving CO2 capture in porous 3D-graphene by cationic nitrogen doping
Authors: Luan Daniel , Zhou Victor , Zhou Nianjun , Luan Binquan
Published: December 2022

The highly porous three-dimensional (3D) graphene is a promising solid sorbent for carbon capture and storage. However, generally, the selectivity of a carbon-based sorbent for CO2 in a gas mixture (such as the post-combustion flue gas in a power plant) is only moderate (∼10–20), which limits its applications. Here, using the Grand Canonical Monte Carlo (GCMC) simulation, we investigate a new type of nitrogen doping (N-doping) in graphene that contains cationic nitrogen sites for CO2 adsorption. We found that due to the favorable electrostatic interaction both CO2 adsorption and selectivity are improved substantially for the porous 3D graphene with the cationic N-doping and are at least an order of magnitude higher than those for the ones without N-doping or with neutral N-doping (such as graphitic, pyridinic, and pyrrolic ones). Our results highlight the possibility for this modified porous 3D graphene to possess both high selectivity and large adsorption for carbon capture, enhancing its commercial viability.
Hydrodynamics characteristics of non-uniform inflow in reactor coolant pump based on time-resolved tomographic particle image velocimetry
Authors: Song Yuchen , Xu Rui , Song Yu , Long Yun , Yin Junlian , Wang Dezhong
Published: December 2022

Non-uniform inflow at the inlet of a reactor coolant pump generates performance variations, such as in the head, efficiency, cavitation, and vibrations. The three-dimensional velocity and pressure for non-uniform inflow are reconstructed via time-resolved tomographic particle image velocimetry to evaluate its effect on the reactor coolant pump. Five volume velocity fields were reconstructed through the multiplicative algebraic reconstruction technique, which constitutes the entire non-uniform flow field. The statistics of the velocity fields were used to study the non-uniform inflow characteristics. The non-uniform inflow contains two large-scale vortices in the form of counter-rotating vortex pairs. The influence of non-uniform inflow on the performance of the pump may be caused by the non-uniform pressure field. For power fluctuations during reactor operations, this non-uniform pressure distribution may generate a low-pressure region on the impeller, which induces cavitation. The non-uniform inflow shown by inhomogeneous vectors was evaluated statistically through the turbulent kinetic energy, which represents the velocity variance in each direction. For a constant head, the non-uniformity of the flow field increased with the flow rate, and the scale of small-scale turbulent vortices decreased. With proper orthogonal decomposition analysis, 90% of the energy region and flow structures were dominated by the previous 412 modes. Furthermore, the temporal modes 1, 2, 3, 100, 200, and 400 show that the frequency of large-scale eddy turnover was about 6.6–13.2 Hz. However, the large-scale eddy could be characterized within the first mode of the spatial distribution.
Cavitation nuclei and surface nanobubbles: The model of non-adsorbed interfacial liquid zones
Authors: Mørch Knud Aage , Ren Zibo , Zuo Zhigang , Liu Shuhong
Published: December 2022

A theory of bubble nuclei at water–solid interfaces is presented based on non-adsorbed interfacial liquid zones (NAILZs). It explains the low-contact-angle of surface nanobubbles observed at clean solid surfaces submerged in purified water from the H–O–H angle of the water molecule. H2O molecules that mirror-hydrogen bond to the solid and remaining alien polar molecules create the bubble surface. When plain water is used, non-polar alien molecules prevent the low-angle bubble formation, but not the NAILZ formation. It gives a key to understanding interfacial bubble nuclei generally, surface nanobubbles, as well as cavitation nuclei on natural solid surfaces.
Heterogeneity induced splay state of amplitude envelope in globally coupled oscillators
Authors: Liu Weiqing , Xie Jiangnan , Liu Hanchang , Xiao Jinghua
Published: December 2022

Splay states of the amplitude envelope are stably observed as a heterogenous node is introduced into the globally coupled identical oscillators with repulsive coupling. With the increment of the frequency mismatches between the heterogenous nodes and the rest identical globally coupled oscillators, the formal stable splay state based on the time series becomes unstable, while a splay state based on the new-born amplitude envelopes of time series is stably observed among the rest identical oscillators. The characteristics of the splay state based on the amplitude envelope are numerically and theoretically presented for different parameters of the coupling strength ϵ and the frequency mismatches Δω for small coupling strength and large frequency mismatches. We expect that all these results could reveal the generality of splay states in coupled nonidentical oscillators and help to understand the rich dynamics of amplitude envelopes in multidisciplinary fields.
Location estimation of subsurface fluid-filled fractures: Cepstral predominant peak analysis and numerical study
Authors: Wang Xiaoqiang , Dong Yan , Li Peichao , Jin Jie , Lu Detang
Published: December 2022

In various subsurface resource development or fluid piping transportation problems, subsurface fluid-filled fractures often appear. Fracture location determination has always been critical in the related fields. Acoustic wave reflection at the junction and boundary in the pipeline can carry information about the property of the system. By using the accompanying acoustic wave information combined with the water hammer effect, the location of subsurface fractures can be estimated. A numerical fluid flow model for instantaneous shut-in is presented based on the water hammer effect. Fluid penetration effects, wellbore storage effect, and fluid inertial effect are considered. A method for determining the locations of subsurface fractures using cepstral predominant peak (CPP) is first proposed. By cepstral, we mean the inverse Fourier transform of the logarithm of the estimated signal spectrum. Also, the relationship between instantaneous shut-in pressure and cepstrum response is investigated in detail. To improve the robustness, CPP analysis based on Kaiser windowed cepstrum is used to identify the impulse period of fracture. Compared with the original cepstrum, Kaiser windowed cepstrum has the better performance for CPP analysis. The proposed flow model is impactful as it can provide pressure data with known fracture locations. Meanwhile, the data can be used to optimize and examine the performance of CPP analysis with Kaiser windowed cepstrum. A field experiment is conducted to validate the analysis about the acoustic wave in a pipeline system with fractures. By installing a high-frequency pressure monitoring device at the pump, the actual instantaneous shut-in pressure for an oil well is obtained. The experiment results show that the CPP analysis can obtain the fracture location efficiently and accurately, which can provide insights for engineering practices.
Probing conformational landscapes and mechanisms of allosteric communication in the functional states of the ABL kinase domain using multiscale simulations and network-based mutational profiling of allosteric residue potentials
Authors: Krishnan Keerthi , Tian Hao , Tao Peng , Verkhivker Gennady M.
Published: December 2022

In the current study, multiscale simulation approaches and dynamic network methods are employed to examine the dynamic and energetic details of conformational landscapes and allosteric interactions in the ABL kinase domain that determine the kinase functions. Using a plethora of synergistic computational approaches, we elucidate how conformational transitions between the active and inactive ABL states can employ allosteric regulatory switches to modulate intramolecular communication networks between the ATP site, the substrate binding region, and the allosteric binding pocket. A perturbation-based network approach that implements mutational profiling of allosteric residue propensities and communications in the ABL states is proposed. Consistent with biophysical experiments, the results reveal functionally significant shifts of the allosteric interaction networks in which preferential communication paths between the ATP binding site and substrate regions in the active ABL state become suppressed in the closed inactive ABL form, which in turn features favorable allosteric coupling between the ATP site and the allosteric binding pocket. By integrating the results of atomistic simulations with dimensionality reduction methods and Markov state models, we analyze the mechanistic role of macrostates and characterize kinetic transitions between the ABL conformational states. Using network-based mutational scanning of allosteric residue propensities, this study provides a comprehensive computational analysis of long-range communications in the ABL kinase domain and identifies conserved regulatory hotspots that modulate kinase activity and allosteric crosstalk between the allosteric pocket, ATP binding site, and substrate binding regions.
Effects of full inversion tillage during pasture renewal on soil and plant cadmium concentrations: a case study in New Zealand
Authors: Peng Yajun , Hanly James A. , Jeyakumar Paramsothy , Calvelo-Pereira Roberto
Published: December 2022

Context Cadmium (Cd) accumulation is a concern in permanent pasture soils, as it can lead to increased Cd uptake by plants. Aims This study aimed to quantify the effect of full inversion tillage (FIT or ploughing deeper than 30 cm), used during pasture renewal, on the redistribution of Cd within the soil profile and on plant Cd concentration. Methods Two field trials (Trial 1, Alfisol; Trial 2, Andisol) were established in New Zealand using contrasting tillage practices (FIT; SIT, shallow tillage; and NT, no tillage) to sow turnips as summer forage crops, followed by autumn re-sowing of perennial ryegrass/white clover pasture. Key results In the Alfisol, no measurable differences (P > 0.05) in soil and plant Cd were detected among the tillage treatments. In the Andisol, FIT decreased (P < 0.05) total (0.25 mg/kg) and extractable soil Cd (0.013 mg/kg) in the 0–5 cm depth, compared to pre-tillage (0.42 and 0.031 mg/kg, respectively). Moreover, at this soil depth, FIT achieved a 52% lower (P = 0.034) extractable soil Cd concentration than the ST treatment. In addition, the subsequent new pasture had lower (P = 0.007) average Cd concentration following FIT compared to ST (0.03 vs 0.05 mg/kg). Conclusions We demonstrated that the use of FIT during pasture renewal is a potential solution to reduce topsoil Cd concentration. Implications The FIT is more effective in soil where total soil Cd concentration or its degree of vertical stratification with depth is relatively high.
Noninvasive detection of any-stage cancer using free glycosaminoglycans
Authors: Bratulic Sinisa , Limeta Angelo , Dabestani Saeed , Birgisson Helgi , Enblad Gunilla , Stålberg Karin , Hesselager Göran , Häggman Michael , Höglund Martin , Simonson Oscar E. , Stålberg Peter , Lindman Henrik , Bång-Rudenstam Anna , Ekstrand Matias , Kumar Gunjan , Cavarretta Ilaria , Alfano Massimo , Pellegrino Francesco , Mandel-Clausen Thomas , Salanti Ali , Maccari Francesca , Galeotti Fabio , Volpi Nicola , Daugaard Mads , Belting Mattias , Lundstam Sven , Stierner Ulrika , Nyman Jan , Bergman Bengt , Edqvist Per-Henrik , Levin Max , Salonia Andrea , Kjölhede Henrik , Jonasch Eric , Nielsen Jens , Gatto Francesco
Published: December 2022

Cancer mortality is exacerbated by late-stage diagnosis. Liquid biopsies based on genomic biomarkers can noninvasively diagnose cancers. However, validation studies have reported ~10% sensitivity to detect stage I cancer in a screening population and specific types, such as brain or genitourinary tumors, remain undetectable. We investigated urine and plasma free glycosaminoglycan profiles (GAGomes) as tumor metabolism biomarkers for multi-cancer early detection (MCED) of 14 cancer types using 2,064 samples from 1,260 cancer or healthy subjects. We observed widespread cancer-specific changes in biofluidic GAGomes recapitulated in an in vivo cancer progression model. We developed three machine learning models based on urine (

N
urine

= 220 cancer vs. 360 healthy) and plasma (

N
plasma

= 517 vs. 425) GAGomes that can detect any cancer with an area under the receiver operating characteristic curve of 0.83–0.93 with up to 62% sensitivity to stage I disease at 95% specificity. Undetected patients had a 39 to 50% lower risk of death. GAGomes predicted the putative cancer location with 89% accuracy. In a validation study on a screening-like population requiring ≥ 99% specificity, combined GAGomes predicted any cancer type with poor prognosis within 18 months with 43% sensitivity (21% in stage I;
N
= 121 and 49 cases). Overall, GAGomes appeared to be powerful MCED metabolic biomarkers, potentially doubling the number of stage I cancers detectable using genomic biomarkers.
Stormier Southern Hemisphere induced by topography and ocean circulation
Authors: Shaw Tiffany A. , Miyawaki Osamu , Donohoe Aaron
Published: December 2022

A defining feature of Earth’s present-day climate is that the Southern Hemisphere is stormier than the Northern Hemisphere. Consistently, the Southern Hemisphere has a stronger jet stream and more extreme weather events than the Northern Hemisphere. Understanding the relative importance of land–ocean contrast, including topography, radiative processes, and ocean circulation for determining this storminess asymmetry is important and may be helpful for interpreting projections of future storminess. Here, we show that the stormier Southern Hemisphere is induced by nearly equal contributions from topography and the ocean circulation, which moves energy from the Southern to Northern Hemisphere. These findings are based on 1) diagnostic energetic analyses applied to observations and climate model simulations and 2) modifying surface (land and ocean) boundary conditions in climate model simulations. Flattening topography and prescribing hemispherically symmetric surface energy fluxes (the manifestation of ocean energy transport on the atmosphere) in a climate model reduce the storminess asymmetry from 23 to 12% and 11%, respectively. Finally, we use the energetic perspective to interpret storminess trends since the beginning of the satellite era. We show that the Southern Hemisphere has become stormier, consistent with implied ocean energy transport changes in the Southern Ocean. In the Northern Hemisphere, storminess has not changed significantly consistent with oceanic and radiative (increased absorption of sunlight due to the loss of sea ice and snow) changes opposing one another. The trends are qualitatively consistent with climate model projections.