bluuebunny/crossref_metadata_2025 huggingface dataset:
Gas and dust from extremely metal-poor AGB stars
Authors: Ventura P. , Dell’Agli F. , Romano D. , Tosi S. , Limongi M. , Chieffi A. , Castellani M. , Tailo M. , Lugaro M. , Marini E. , Yagüe Lopez A.
Published: August 2021

Context. The study of stars that evolve through the asymptotic giant branch (AGB) proves crucial in several astrophysical contexts because these objects provide important feedback to the host system in terms of the gas that is poured into the interstellar medium after being exposed to contamination from nucleosynthesis processes, and in terms of the dust that forms in their wind. Most of the studies conducted so far have been focused on AGB stars with solar and sub-solar chemical composition, whereas the extremely metal-poor domain has been poorly explored.

Aims. We study the evolution of extremely metal-poor AGB stars with metallicities down to [Fe/H] = −5 to understand the main evolutionary properties and the efficiency of the processes able to alter their surface chemical composition, and to determine the gas and dust yields.

Methods. We calculated two sets of evolutionary sequences of stars in the 1−7.5  M⊙ mass range that evolved from the pre-main sequence to the end of the AGB phase. To explore the extremely metal-poor chemistries, we adopted the metallicities Z = 3 × 10−5 and Z = 3 × 10−7, which correspond to [Fe/H] = −3 and [Fe/H] = −5, respectively. The results from stellar evolution modelling were used to calculate the yields of the individual chemical species. We also modelled dust formation in the wind to determine the dust produced by these objects.

Results. The evolution of AGB stars in the extremely metal-poor domain we explored proves highly sensitive to the initial mass of the star. M ≤ 2  M⊙ stars experience several third-dredge-up events, which favour the gradual surface enrichment of 12C and the formation of significant quantities of carbonaceous dust, ∼0.01  M⊙. The 13C and nitrogen yields are found to be significantly smaller than in previous explorations of low-mass metal-poor AGB stars because the proton ingestion episodes experienced during the initial AGB phases are weaker. M ≥ 5  M⊙ stars experience hot bottom burning, and their surface chemistry reflects the equilibria of a very advanced proton-capture nucleosynthesis; little dust production takes place in their wind. Intermediate-mass stars experience both third dredge-up and hot bottom burning: they prove efficient producers of nitrogen, which is formed by proton captures on 12C nuclei of primary origin dredged up from the internal regions.
Morphology of supernova remnants and their halos
Authors: Brose R. , Pohl M. , Sushch I.
Published: August 2021

Context. Supernova remnants (SNRs) are known to accelerate particles to relativistic energies, on account of their nonthermal emission. The observational progress from radio to gamma-ray observations reveals more and more morphological features that need to be accounted for when modeling the emission from those objects.

Aims. We use our time-dependent acceleration code RATPaC to study the formation of extended gamma-ray halos around supernova remnants and the morphological implications that arise when the high-energetic particles start to escape from the remnant.

Methods. We performed spherically symmetric 1D simulations in which we simultaneously solved the transport equations for cosmic rays, magnetic turbulence, and the hydrodynamical flow of the thermal plasma in a volume large enough to keep all cosmic rays in the simulation. The transport equations for cosmic rays and magnetic turbulence were coupled via the cosmic-ray gradient and the spatial diffusion coefficient of the cosmic rays, while the cosmic-ray feedback onto the shock structure can be ignored. Our simulations span 25 000 yr, thus covering the free-expansion and the Sedov-Taylor phase of the remnant’s evolution.

Results. We find a strong difference in the morphology of the gamma-ray emission from supernova remnants at later stages dependent on the emission process. At early times, both the inverse-Compton and the Pion-decay morphology are shell-like. However, as soon as the maximum-energy of the freshly accelerated particles starts to fall, the inverse-Compton morphology starts to become center-filled, whereas the Pion-decay morphology keeps its shell-like structure. Escaping high-energy electrons start to form an emission halo around the remnant at this time. There are good prospects for detecting this spectrally hard emission with the future Cerenkov Telescope Array, as there are for detecting variations in the gamma-ray spectral index across the interior of the remnant. Further, we find a constantly decreasing nonthermal X-ray flux that makes a detection of X-ray unlikely after the first few thousand years of the remnants’ evolution. The radio flux is increasing throughout the SNR’s lifetime and changes from a shell-like to a more center-filled morphology later on.
Numerical solutions to linear transfer problems of polarized radiation
Authors: Janett Gioele , Benedusi Pietro , Belluzzi Luca , Krause Rolf
Published: August 2021

Context.The numerical modeling of the generation and transfer of polarized radiation is a key task in solar and stellar physics research and has led to a relevant class of discrete problems that can be reframed as linear systems. In order to solve such problems, it is common to rely on efficient stationary iterative methods. However, the convergence properties of these methods are problem-dependent, and a rigorous investigation of their convergence conditions, when applied to transfer problems of polarized radiation, is still lacking.

Aims.After summarizing the most widely employed iterative methods used in the numerical transfer of polarized radiation, this article aims to clarify how the convergence of these methods depends on different design elements, such as the choice of the formal solver, the discretization of the problem, or the use of damping factors. The main goal is to highlight advantages and disadvantages of the different iterative methods in terms of stability and rate of convergence.

Methods.We first introduce an algebraic formulation of the radiative transfer problem. This formulation allows us to explicitly assemble the iteration matrices arising from different stationary iterative methods, compute their spectral radii and derive their convergence rates, and test the impact of different discretization settings, problem parameters, and damping factors.

Results.Numerical analysis shows that the choice of the formal solver significantly affects, and can even prevent, the convergence of an iterative method. Moreover, the use of a suitable damping factor can both enforce stability and increase the convergence rate.

Conclusions.The general methodology used in this article, based on a fully algebraic formulation of linear transfer problems of polarized radiation, provides useful estimates of the convergence rates of various iterative schemes. Additionally, it can lead to novel solution approaches as well as analyses for a wider range of settings, including the unpolarized case.
Does a long-lived remnant neutron star exist after short gamma-ray burst GRB 160821B?
Authors: Wu Guang-Lei , Yu Yun-Wei , Zhu Jin-Ping
Published: August 2021

Mergers of double neutron stars (DNSs) could lead to the formation of a long-lived massive remnant NS, which has been previously suggested to explain the AT 2017gfo kilonova emission in the famous GW170817 event. For an NS-affected kilonova, it is expected that a nonthermal emission component can be contributed by a pulsar wind nebula (PWN), which results from the interaction of the wind from the remnant NS with the preceding merger ejecta. Therefore, the discovery of such a nonthermal PWN emission would provide evidence for the existence of the remnant NS. Similar to GRB 170817A, GRB 160821B is also one of the nearest short gamma-ray bursts (SGRBs). A candidate kilonova is widely believed to appear in the ultraviolet–optical–infrared afterglows of GRB 160821B. Here, by modeling the afterglow light curves and spectra of GRB 160821B, we find that invoking nonthermal PWN emission can indeed be highly consistent with the observational data. This may indicate that the formation of a stable massive NS is not uncommon in DNS merger events, and therefore that the equation of state of the post-merger NSs should be stiff enough.
Hubble tension and absolute constraints on the local Hubble parameter
Authors: Gurzadyan V. G. , Stepanian A.
Published: August 2021

It is shown, from the two independent approaches of McCrea-Milne and of Zeldovich, that one can fully recover the set equations corresponding to the relativistic equations of the expanding universe of Friedmann-Lemaitre-Robertson-Walker geometry. Although similar, the Newtonian and relativistic set of equations have a principal difference in the content and hence define two flows, local and global ones, thus naturally exposing the Hubble tension at the presence of the cosmological constant Λ. From this, we obtain absolute constraints on the lower and upper values for the local Hubble parameter, √(Λc2/3) ≃ 56.2 and √(Λc2) ≃ 97.3 (km s−1 Mpc−1), respectively. The link to the so-called maximum force–tension issue in cosmological models is revealed.
The Limagne Basin: a journey through modern and fossil microbial deposits
Authors: Vennin Emmanuelle , Bouton Anthony , Roche Adeline , Gérard Emmanuelle , Bundeleva Irina , Boussagol Pierre , Wattinne Aurélia , Kolodka Christophe , Gaucher Eric , Virgone Aurélien , Visscher Pieter T.
Published: August 2021

The Limagne Basin (Massif Central, France) originated during a major, European-scale, extensive event (European Cenozoic Rift System), which led to the formation of several rift systems in the foreland of the Alps between the Upper Eocene and Pliocene. A fluvio-lacustrine system emplaced in the basin and resulted in a mixed carbonate-siliciclastic sedimentation in which microbial and metazoan buildups occupy an important place. However, microbial deposits are not exclusive to the Cenozoic history of the Limagne Basin; nowadays, in the basin, they still form in association with thermal spring systems. A fieldtrip was carried out in the Limagne Basin as part of the Microbialites: formation, evolution and diagenesis (M-Fed) meeting (October 2019). The objective of this excursion was to assess the diversity of modern and fossil (Chattian to Aquitanian) microbial sediments and structures in three prime locations (the Jussat and Chadrat outcrops and the Grand Gandaillat quarry). A detailed description of the morphologies and fabrics of the buildups and their associated biotic components can be used to discuss the spatio-temporal distribution pattern. Different basin margin models are proposed based on the changes in the distribution, morphology and size of the microbial and metazoan-rich deposits through time. The Jussat outcrop offers novel perspectives to unravel the evolution of the lacustrine/palustrine cycles over time and to establish a long-term paleoenvironmental history of the western margin of the basin during the Aquitanian. These cycles are composed of (i) lacustrine sedimentation comprising microbial and metazoan buildups and organic matter-rich marls reflecting a period of high accommodation, and (ii) palustrine deposits made of mudstones and clayey paleosoils, indicative of a period of low accommodation. It is suggested that climatic, tectonic, volcanic and local parameters (physiography, substrate) control the deposition of the buildups in each of the different cycles. In addition, the modern microbial mats of the Sainte-Marguerite and La Poix outcrops offer an opportunity to constrain the controlling processes at the origin of the mineralization involved in the formation of the microbialites and their preservation in the fossil record.
Differenzialdiagnostik Schulterschmerz
Authors: Corts Magga
Published: August 2021

Einen ersten Hinweis zur Ursache von Schulterschmerzen gibt bereits die Anamnese mit Fragen wie „Wo schmerzt es?“ und „Besteht ein Ruhe-, Bewegungs- oder Ausstrahlungsschmerz?“. Als häufige Ursache für Schmerzen und Bewegungseinschränkung kommt eine Reihe von Erkrankungen infrage, angefangen von der Schultergelenkluxation über Arthrosen bis hin zu Kompressionssyndromen und mehr. Auch Ursachen außerhalb des Bewegungsapparats können sich in Form von Schmerzen in der Schulter oder im Arm ausdrücken. Als Notfall ist das Akute Koronarsyndrom zu differenzieren.
An Efficacy Study between High Viscosity Glass Ionomers and Resin Sealants in Fissure Caries Prevention: A 2-Year Split Mouth Randomized Controlled Trial
Authors: Haricharan Praveen Bhoopathi , Voruganti Sreenivas , Kotha Arpitha , Mahalakshmamma Shivanna Madhuniranjanswamy , Gandhi Bhavana , Suresh Nanditha
Published: August 2021

Objectives This clinical trial compared the efficacy of atraumatic restorative treatment (ART) sealants against resin-based sealants in terms of their retention and fissure caries preventive benefits over a period of 24 months among a section of school children in the Southern Indian state of Telangana.

Materials and Methods A split mouth clinical trial employed 198 children, who received these sealants on their lower permanent first molars. Retention was assessed 6 monthly and caries annually

Statistical Analysis Chi-square tests were utilized to analyze the retention rate and the incidence of dental caries between the two groups. Kaplan–Meier survival analysis plotted the cumulative survival percentage of partially, and fully retained sealants and the survival of dentin carious free pits and fissures among both the groups. A linear binary logistical regression analysis calculated the odds ratio.

Results A statistical significant difference was observed in the retention rate between these sealants at every follow-up stage. The cumulative survival percentage of ART and resin sealants was calculated to be 30.9 and 37.5% by the end of 2 years. The Kaplan–Meier analysis showed no significant difference with regard to the survival of dentin carious free pits and fissures. The odds ratio for this trial was 0.747 (95% confidence interval: 0.493–1.13)

Conclusion Resin sealants fared better than ART sealants in the field of retention. However, no significant differences were observed with regard to fissure caries prevention by the end of the study period.
The Role of Attitude Modification Interventions in the Reduction of Orofacial Pain in Patients Undergoing Orthodontic Treatment: A Scoping Review
Authors: Mando Mahmoud , Talaat Sameh
Published: August 2021

By summarizing evidence from existing literature, the aim of this study is to investigate the effect of attitude modification interventions in the reduction of orthodontic pain in patients undergoing orthodontic treatment. A comprehensive search strategy was implemented using both manual and electronic search methods to identify both indexed and nonindexed articles in databases as well as to reduce the possibility of excluding relevant studies by chance. The online database search strategy incorporated the following databases: PubMed, Google Scholar, and EBSCO from 1940 to May 2020. The results of this review suggest that attitude modification interventions including cognitive behavioral therapy, structured phone calls, and text messages are effective methods in the reduction of pain intensity in patients undergoing orthodontic treatment. In conclusion, attitude modification methods are promising and safe nonpharmacological interventions that can be used to control pain in patients undergoing orthodontic treatment without having any side effects or complications.
Evaluation of Bacterial Reduction after Root Canal Shaping Using ProTaper Gold and WaveOne Gold Rotary Systems
Authors: Otero Denise , Selvaraju Suresh B. , Kathpalia Ankita , Elmallah Waleed , Elbatouty Kareem , Nagy Mohamed Mokhtar
Published: August 2021

Objective The present study evaluated bacterial reduction promoted by the WaveOne system (Dentsply Maillefer, Ballaigues, Switzerland) and ProTaper Gold system (PTG; Dentsply Maillefer) in human extracted central incisors.

Materials and Methods Sixty-two maxillary central incisors that were infected with Enterococcus faecalis (ATCC 51299) were sterilized with ethylene oxide for 21 days, and then root canal initial bacterial sample was collected with paper points and plated on M-Enterococcus agar. The specimens were randomly divided into two groups according to instrumentation: WaveOne Gold group (n = 30) and PTG group (n = 30). Each group was further subdivided into subgroup A (n = 15) where no activation of the irrigant was performed, and subgroup B (n = 15) where passive ultrasonic activation (PUI) was applied. The other two specimens without contamination were control asepsis. After instrumentation, samples were collected with the use of paper points. The bacterial reduction was calculated using colony-forming unit and quantitative real-time polymerase chain reaction. Data were collected and statistically analyzed.

Results All techniques significantly reduced the number of bacteria in the root canal (p < 0.05), in which PTG showed superior bacterial reduction than WaveOne Gold (p > 0.05). The aseptic control group did not show any bacterial growth. PUI showed a significant bacterial reduction with the WaveOne Gold group.

Conclusion It can be concluded that the single-file system, WaveOne Gold with the aid of passive ultrasonic irrigation, significantly reduce the bacterial number in the root canal similar to the multifile system, PTG.
Linking a Consortium-Wide Data Quality Assessment Tool with the MIRACUM Metadata Repository
Authors: Kapsner Lorenz A. , Mang Jonathan M. , Mate Sebastian , Seuchter Susanne A. , Vengadeswaran Abishaa , Bathelt Franziska , Deppenwiese Noemi , Kadioglu Dennis , Kraska Detlef , Prokosch Hans-Ulrich
Published: August 2021

Background Many research initiatives aim at using data from electronic health records (EHRs) in observational studies. Participating sites of the German Medical Informatics Initiative (MII) established data integration centers to integrate EHR data within research data repositories to support local and federated analyses. To address concerns regarding possible data quality (DQ) issues of hospital routine data compared with data specifically collected for scientific purposes, we have previously presented a data quality assessment (DQA) tool providing a standardized approach to assess DQ of the research data repositories at the MIRACUM consortium's partner sites.

Objectives Major limitations of the former approach included manual interpretation of the results and hard coding of analyses, making their expansion to new data elements and databases time-consuming and error prone. We here present an enhanced version of the DQA tool by linking it to common data element definitions stored in a metadata repository (MDR), adopting the harmonized DQA framework from Kahn et al and its application within the MIRACUM consortium.

Methods Data quality checks were consequently aligned to a harmonized DQA terminology. Database-specific information were systematically identified and represented in an MDR. Furthermore, a structured representation of logical relations between data elements was developed to model plausibility-statements in the MDR.

Results The MIRACUM DQA tool was linked to data element definitions stored in a consortium-wide MDR. Additional databases used within MIRACUM were linked to the DQ checks by extending the respective data elements in the MDR with the required information. The evaluation of DQ checks was automated. An adaptable software implementation is provided with the R package DQAstats.

Conclusion The enhancements of the DQA tool facilitate the future integration of new data elements and make the tool scalable to other databases and data models. It has been provided to all ten MIRACUM partners and was successfully deployed and integrated into their respective data integration center infrastructure.
Interaction Time with Electronic Health Records: A Systematic Review
Authors: Pinevich Yuliya , Clark Kathryn J. , Harrison Andrew M. , Pickering Brian W. , Herasevich Vitaly
Published: August 2021

Background The amount of time that health care clinicians (physicians and nurses) spend interacting with the electronic health record is not well understood.

Objective This study aimed to evaluate the time that health care providers spend interacting with electronic health records (EHR).

Methods Data are retrieved from Ovid MEDLINE(R) and Epub Ahead of Print, In-Process and Other Non-Indexed Citations and Daily, (Ovid) Embase, CINAHL, and SCOPUS.

Study Eligibility Criteria Peer-reviewed studies that describe the use of EHR and include measurement of time either in hours, minutes, or in the percentage of a clinician's workday. Papers were written in English and published between 1990 and 2021.

Participants All physicians and nurses involved in inpatient and outpatient settings.

Study Appraisal and Synthesis Methods A narrative synthesis of the results, providing summaries of interaction time with EHR. The studies were rated according to Quality Assessment Tool for Studies with Diverse Designs.

Results Out of 5,133 de-duplicated references identified through database searching, 18 met inclusion criteria. Most were time-motion studies (50%) that followed by logged-based analysis (44%). Most were conducted in the United States (94%) and examined a clinician workflow in the inpatient settings (83%). The average time was nearly 37% of time of their workday by physicians in both inpatient and outpatient settings and 22% of the workday by nurses in inpatient settings. The studies showed methodological heterogeneity.

Conclusion This systematic review evaluates the time that health care providers spend interacting with EHR. Interaction time with EHR varies depending on clinicians' roles and clinical settings, computer systems, and users' experience. The average time spent by physicians on EHR exceeded one-third of their workday. The finding is a possible indicator that the EHR has room for usability, functionality improvement, and workflow optimization.
Three Technologies That Will Guide Revascularization of Chronic Coronary Syndrome Patients into the 21st Century: A Review
Authors: Winkler Michael A. , Patel Ripa , Fu Weibo , Arora Vishal , Weintraub Neal L.
Published: August 2021

Although medical therapy is the preferred first-line treatment for patients with chronic coronary syndrome (CCS), revascularization remains an important consideration. We present a review that identifies the three diagnostic technologies most important to guiding the decision to revascularize patients with CCS: (1) cardiac computed tomography, (2) intracoronary imaging, and (3) lesion-specific physiological guidance.
Fluctuations of the plasma potential in atmospheric pressure micro-plasma jets
Authors: Behmani Deepika , Barman Kalyani , Bhattacharjee Sudeep
Published: August 2021

Fluctuations in plasma floating potential in an atmospheric pressure micro-plasma jet are investigated experimentally. The transport of charged particles toward the ambient air is often seen to be affected by plasma fluctuations. The dependence of fluctuations on operating parameters such as applied voltage, gas flow rate, and gas mixture ratio (He:Ar) is investigated so as to be able to control the fluctuations in the intended application. A single pin probe measures the fluctuations in the jet in a region where the plasma emerges out of the capillary. The fluctuations are characterized by fast Fourier transform and time-frequency analysis (TFA). It is found that with an increase in applied voltage at a fixed flow rate (1 l/min), the fluctuations increase and reach a peak value at ∼11 kV and thereafter decrease at higher voltages due to a high value of discharge current (∼4.77 mA) at 11 kV arising from the intense ionization taking place in the jet. When the gas flow rate is increased at a fixed voltage (14 kV), the fluctuations get enhanced for flow rates beyond 2 l/min due to transition to turbulent flow occurring at a buoyancy induced Reynolds number of ∼474. In the case of gas mixing, an increase in the concentration of Ar and a reduction in He at a fixed applied power (80.6 W) and flow rate (1 l/min) give rise to a higher level of fluctuations, which is considered to be due to lower thermal conductivity and ionization potential of Ar, leading to gas heating, and ponderomotive force, giving rise to filamentation. The TFA shows the time evolution of fluctuation frequencies, which can be tuned by varying the experimental parameters. Understanding the influence of experimental parameters is crucial in controlling the fluctuations in the micro-plasma jet.
Using amplitude modulation of the microwave field to improve the sensitivity of Rydberg-atom based microwave electrometry
Authors: Liu Xiubin , Jia Fengdong , Zhang Huaiyu , Mei Jiong , Yu Yonghong , Liang Weichen , Zhang Jian , Xie Feng , Zhong Zhiping
Published: August 2021

The microwave (MW) field can be measured by the Autler–Townes (AT) splitting of the electromagnetically induced transparency (EIT) spectrum in the Rydberg atomic system; however, the EIT-AT splitting method fails in weak MW fields. We used the amplitude modulation of the MW field to resolve the EIT-AT splitting in weak MW fields. The EIT-AT splitting interval can be directly obtained, and the minimum detectable MW strength is improved by six times compared with the traditional EIT-AT splitting method. The proposed method is more intuitive and convenient for measuring the strength of weak MW fields in practical applications.
Low-temperature direct bonding of SiC and Ga2O3 substrates under atmospheric conditions
Authors: Matsumae Takashi , Kurashima Yuichi , Takagi Hideki , Umezawa Hitoshi , Higurashi Eiji
Published: August 2021

In this study, SiC and Ga2O3 substrates were bonded under atmospheric conditions using an extremely thin amorphous layer (∼7 Å). Conventional wafer-bonding techniques employ an oxidizing treatment for surface functionalization, resulting in the formation of an oxide layer at the bonding interface. This study demonstrates the bonding of a hydrofluoric-acid-treated SiC surface with a plasma-activated Ga2O3 substrate, where the –OH groups on the SiC and Ga2O3 surfaces form direct bonding via a dehydration reaction at 250 °C. The interfacial analysis indicates that bonding using the reduction treatment instead of oxidization reduces the thickness of the intermediate layer at the SiC/Ga2O3 interface, which is a thermal and electrical barrier. In addition, it is remarkable that the SiC and Ga2O3 substrates are directly bonded by generally used surface cleaning processes, contacting the surfaces under atmospheric conditions, and annealing at 250 °C. We believe that the bonding process using the reduction process can contribute to future heterogeneous devices based on integrated dissimilar substrates.
SMGAN: A self-modulated generative adversarial network for single image dehazing
Authors: Wang Nian , Cui Zhigao , Su Yanzhao , He Chuan , Lan Yunwei , Li Aihua
Published: August 2021

Single image dehazing has become a key prerequisite for most high-level computer vision tasks since haze severely degrades the input images. Traditional prior-based methods dehaze images by some assumptions concluded from haze-free images, which recover high-quality results but always cause some halos or color distortion. Recently, many methods have been using convolutional neural networks to learn the haze-relevant features and then retrieve the original images. These learning-based methods achieve better performance in synthetic scenes but can hardly restore a clear image with discriminative texture when applied to real-world images, mainly because these networks are trained on synthetic datasets. To solve these problems, a self-modulated generative adversarial network for single image dehazing named SMGAN is proposed. The SMGAN inputs prior-dehazed images into a parameter-shared encoder to produce some latent information of these dehazed images. During the hazy image decoding process, the latent information is sent to self-modulated batch normalization layers, which makes the network fit in real haze removal. Moreover, consider that there are some over-enhanced regions in the guidance images, and a refine module is proposed to alleviate the negative information. The proposed SMGAN combines the advantages of prior-based methods and learning-based methods, which provides superior performance compared with the state-of-the-art methods on both synthetic and real-word datasets.
Stability assessment of the phase-field lattice Boltzmann model and its application to Taylor bubbles in annular piping geometries
Authors: Mitchell T. , Holzer M. , Schwarzmeier C. , Bauer M. , Rüde U. , Leonardi C.
Published: August 2021

This study parametrically assessed the stability of the phase-field lattice Boltzmann model (PFLBM) before applying it to analyze the effect of annular piping geometry on the flow of Taylor bubbles. The impacts of both eccentricity and pipe diameter ratio were examined, providing an insight into the behavior of these bubbles as well as the applicability and shortcomings in current prediction methodologies. A recently developed PFLBM was implemented into the open-source simulation framework, waLBerla, for this analysis. The stability properties of the code were investigated in detail by assessing various lattice discretizations and relaxation kernels applied to the Rayleigh–Taylor benchmark problem and a Rayleigh–Taylor instability in a tubular geometry, with gravitational Reynolds numbers of up to 30 000 and 10 000, respectively. This paper makes three contributions relating to the stability and usage of the PFLBM as well as the flow of Taylor bubbles in annular pipes. First, the work numerically explored the stability properties of the velocity-based, PFLBM and concluded the impact of various collision models and lattice discretizations on simulation results. Second, it provided a flexible open-source code that the interested researcher can use interactively for practical flow problems as well as the analysis of numerical properties of various lattice Boltzmann algorithms. Finally, it quantified the effect of pipe eccentricity and diameter ratio on the propagation of a Taylor bubble inside a water-filled annular pipe, concluding that a previously defined closure model captured the diameter ratio for the cases examined. To extend this work, future studies aim to analytically investigate the stability properties parametrically observed in this study and apply the findings to simulate the interaction of multiple Taylor bubbles.
Clause-final negative particles in varieties of Swedish
Authors: Rosenkvist Henrik
Published: August 2021

While the Swedish negator inte may be doubled in a final clause-external position, in both
standard Swedish and dialects, many dialects also allow a final, clause-internal particle (e, i or
ai) in negated clauses. FNPs occur in a coherent area around the Baltic Sea, and in contrast with doubling
negation, they are possible both after both inte and aldrig ‘never’. FNPs are also used in
questions and exclamations, contexts that disallow doubling negation. These particles may have developed from the former Swedish
negator ej or from the common inte. An argument for the former alternative is that other
dialectal phenomena that spread from central Sweden during the late Middle Ages have approximately the same geographic
distribution. In the final section of the paper, some typological consequences and implications are discussed. Furthermore, it is
argued that syntactic studies of non-standard varieties may reveal new insights of typological relevance.
Alveolar macrophages rely on GM-CSF from alveolar epithelial type 2 cells before and after birth
Authors: Gschwend Julia , Sherman Samantha P.M. , Ridder Frederike , Feng Xiaogang , Liang Hong-Erh , Locksley Richard M. , Becher Burkhard , Schneider Christoph
Published: August 2021

Programs defining tissue-resident macrophage identity depend on local environmental cues. For alveolar macrophages (AMs), these signals are provided by immune and nonimmune cells and include GM-CSF (CSF2). However, evidence to functionally link components of this intercellular cross talk remains scarce. We thus developed new transgenic mice to profile pulmonary GM-CSF expression, which we detected in both immune cells, including group 2 innate lymphoid cells and γδ T cells, as well as AT2s. AMs were unaffected by constitutive deletion of hematopoietic Csf2 and basophil depletion. Instead, AT2 lineage-specific constitutive and inducible Csf2 deletion revealed the nonredundant function of AT2-derived GM-CSF in instructing AM fate, establishing the postnatal AM compartment, and maintaining AMs in adult lungs. This AT2-AM relationship begins during embryogenesis, where nascent AT2s timely induce GM-CSF expression to support the proliferation and differentiation of fetal monocytes contemporaneously seeding the tissue, and persists into adulthood, when epithelial GM-CSF remains restricted to AT2s.
Wideband low reflection backward scattering with an inter-band transparent window by phase tailoring of a frequency-selective metasurface
Authors: Sima Boyu , Chen Ke , Zhang Na , Zhao Junming , Jiang Tian , Feng Yijun
Published: August 2021

Thin-thickness metasurfaces used for reducing radar cross section (RCS) have attracted much attention due to their promising prospects in many applications, like stealth techniques, antenna radomes, etc. One of the major challenges for antenna radome applications is to achieve inter-band high transmission in addition to broadband RCS reduction by a single device. Here, we propose a frequency-selective metasurface to realize low backward scattering in a wide microwave frequency band while maintaining an inter-band transparent window. To achieve this goal, two basic meta-atoms comprising three cascaded patterned sheets are designed to ensure out-of-phase reflection properties in two sidebands with in-phase high transmission in the center band. Then, we arrange meta-atoms into a checkerboard-like distribution to form the phase cancellation of far-field backward scattering. Simulated results show that the RCS can be reduced by more than 10 dB in a continuous band of 7.5–15.7 GHz while the insertion loss in the transmission window is less than 1.0 dB from 11.8 to 12.1 GHz. Experimental verifications from a fabricated prototype were carried out which agree well with the simulations. This work may provide an effective way to design microwave radomes or find applications in other electromagnetic compatibility devices.
Induced radiofrequency fields in patients undergoing MR examinations: insights for risk assessment
Authors: Yao Aiping , Murbach Manuel , Goren Tolga , Zastrow Earl , Kainz Wolfgang , Kuster Niels
Published: August 2021

Purpose. To characterize and quantify the induced radiofrequency (RF) electric (E)-fields and B
1+rms fields in patients undergoing magnetic resonance (MR) examinations; to provide guidance on aspects of RF heating risks for patients with and without implants; and to discuss some strengths and limitations of safety assessments in current ISO, IEC, and ASTM standards to determine the RF heating risks for patients with and without implants.

Methods. Induced E-fields and B
1+rms fields during 1.5 T and 3 T MR examinations were numerically estimated for high-resolution patient models of the Virtual Population exposed to ten two-port birdcage RF coils from head to feet imaging landmarks over the full polarization space, as well as in surrogate ASTM phantoms.

Results. Worst-case B
1+rms exposure greater than 3.5 μT (1.5 T) and 2 μT (3 T) must be considered for all MR examinations at the Normal Operating Mode limit. Representative induced E-field and specific absorption rate distributions under different clinical scenarios allow quick estimation of clinical factors of high and reduced exposure. B
1 shimming can cause +6 dB enhancements to E-fields along implant trajectories. The distribution and magnitude of induced E-fields in the ASTM phantom differ from clinical exposures and are not always conservative for typical implant locations.

Conclusions. Field distributions in patient models are condensed, visualized for quick estimation of risks, and compared to those induced in the ASTM phantom. Induced E-fields in patient models can significantly exceed those in the surrogate ASTM phantom in some cases. In the recent 19
ε2 revision of the ASTM F2182 standard, the major shortcomings of previous versions have been addressed by requiring that the relationship between ASTM test conditions and in vivo tangential E-fields be established, e.g. numerically. With this requirement, the principal methods defined in the ASTM standard for passive implants are reconciled with those of the ISO 10974 standard for active implantable medical devices.
Detecting entanglement can be more effective with inequivalent mutually unbiased bases
Authors: Hiesmayr B C , McNulty D , Baek S , Singha Roy S , Bae J , Chruściński D
Published: August 2021

Mutually unbiased bases (MUBs) provide a standard tool in the verification of quantum states, especially when harnessing a complete set for optimal quantum state tomography. In this work, we investigate the detection of entanglement via inequivalent sets of MUBs, with a particular focus on unextendible MUBs. These are bases for which an additional unbiased basis cannot be constructed and, consequently, are unsuitable for quantum state verification. Here, we show that unextendible MUBs, as well as other inequivalent sets in higher dimensions, can be more effective in the verification of entanglement. Furthermore, we provide an efficient and systematic method to search for inequivalent MUBs and show that such sets occur regularly within the Heisenberg–Weyl MUBs, as the dimension increases. Our findings are particularly useful for experimentalists since they demonstrate that a clever selection of MUBs allows for entanglement detection with fewer measurements.
The minimally extended Varying Speed of Light (meVSL)
Authors: Lee Seokcheon
Published: August 2021

Even though there have been various models of the time-varying speed of light (VSL), they remain out of the mainstream because of their possible violation of physics laws built into fundamental physics. In order to be the VSL as a viable theory, it should inherit the success of special relativity including Maxwell equations and thermodynamics at least. For this purpose, we adopt the assumption that the speed of light, c̃, i.e., c̃[a], varies for the scale factor, a. The background FLRW universe can be defined by the constant cosmic time hypersurface using physical quantities such as temperature, density, c̃, etc. It is because they evolve in cosmic time and the homogeneity of the Universe demands that they must equal at the equal cosmic time. The variation of c̃ accompanies the joint variations of all related physical constants in order to satisfy the Lorentz invariance, thermodynamics, Bianchi identity, etc. We dub this VSL model as a “minimally extended VSL (meVSL)”. We derive cosmological observables of meVSL and obtain the constraints on the variation of c̃ by using current cosmological observations. Interestingly, both the cosmological redshift z and all geometrical distances except the luminosity distance of meVSL are the same as those of general relativity. However, the Hubble parameter of meVSL is rescaled as H(z) = (1+z)-b/4 H(GR)(z), where H(GR)(z) denotes the Hubble parameter obtained from general relativity. Thus, it might be used as an alternative solution for the tension of the Hubble parameter measurements. In this manuscript, we provide the main effects of the meVSL model on various cosmological observations including BBN, CMB, SZE, BAO, SNe, GWs, H, SL, and Δα. Compared to previous VSL models, meVSL might provide alternative solutions for various late time problems of the standard ΛCDM model. This is the main motivation for proposing the meVSL model.
Neutron stars in f(R,T) gravity with conserved energy-momentum tensor: Hydrostatic equilibrium and asteroseismology
Authors: Pretel Juan M.Z. , Jorás Sergio E. , Reis Ribamar R.R. , Arbañil José D.V.
Published: August 2021

We investigate the equilibrium and radial stability of spherically symmetric relativistic stars, considering a polytropic equation of state (EoS), within the framework of f(R,T) gravity with a conservative energy-momentum tensor. Both modified stellar structure equations and Chandrasekhar's pulsation equations are derived for the f(R,T)= R+ h(T) gravity model, where the function h(T) assumes a specific form in order to safeguard the conservation equation for the energy-momentum tensor. The neutron star properties, such as radius, mass, binding energy and oscillation spectrum are studied in detail. Our results show that a cusp — which signals the appearance of instability — is formed when the binding energy is plotted as a function of the compact star proper mass. We find that the squared frequency of the fundamental vibration mode passes through zero at the central-density value corresponding to such a cusp where the binding energy is a minimum.
Quantum multicast communication over the butterfly network
Authors: Pan Xing-Bo , Chen Xiu-Bo , Xu Gang , Dou Zhao , Li Zong-Peng , Yang Yi-Xian
Published: August 2021

We propose a scheme where one can exploit auxiliary resources to achieve quantum multicast communication with network coding over the butterfly network. In this paper, we propose the quantum 2-pair multicast communication scheme, and extend it to k-pair multicast communication over the extended butterfly network. Firstly, an EPR pair is shared between each adjacent node on the butterfly network, and make use of local operation and classical communication to generate entangled relationship between non-adjacent nodes. Secondly, each sender adds auxiliary particles according to the multicast number k, in which the CNOT operations are applied to form the multi-particle entangled state. Finally, combined with network coding and free classical communication, quantum multicast communication based on quantum measurements is completed over the extended butterfly network. Not only the bottleneck problem is solved, but also quantum multicast communication can be completed in our scheme. At the same time, regardless of multicast number k, the maximum capacity of classical channel is 2 bits, and quantum channel is used only once.
Research status and performance optimization of medium-temperature thermoelectric material SnTe
Authors: Peng Pan-Pan , Wang Chao , Li Lan-Wei , Li Shu-Yao , Chen Yan-Qun
Published: August 2021

Thermoelectric materials have the ability to directly convert heat into electricity, which have been extensively studied for decades to solve global energy shortages and environmental problems. As a medium temperature (400–800 K) thermoelectric material, SnTe has attracted extensive attention as a promising substitute for PbTe due to its non-toxic characteristics. In this paper, the research status of SnTe thermoelectric materials is reviewed, and the strategies to improve its performance are summarized and discussed in terms of electrical and thermal transport properties. This comprehensive discussion will provides guidance and inspiration for the research on SnTe.
The Effects of Air Change Rate and Indoor Particle Generation on Indoor Particulate Concentration Based on Numerical Simulation
Authors: Li Hao , Yi Weiqi
Published: August 2021

The influences of air change rates and particle generation on indoor particulate concentrations in a cleanroom were studied by eight numerical simulation cases. Results show that the influence of ACH on indoor particulate concentration is very significant than that of particle generated concentration when ACH great than 4.0 h-1. And ACH = 4.0 h-1 seems a suitable value for central air conditioning (AC) systems in residential buildings and public buildings.
Research on the Quality Evaluation of Teaching Reform Project in Colleges Based on Computer
Authors: Zhang Dan
Published: August 2021

With the rapid development and change of society, the teaching of colleges should continue to follow up the reform. In addition, with the deepening of teaching reform in colleges, there is an urgent need to develop a quality evaluation system suitable for teaching reform projects. This paper first introduces the theoretical basis of the quality evaluation of teaching reform projects in colleges, then analyzes the construction of the quality evaluation index system of teaching reform projects based on computer, and finally introduces the quality evaluation methods of teaching reform projects.
RETRACTED: Innovative Research on the Integration of Boneless Chinese Painting Techniques and Commercial Comics Based on Big Data Analysis
Authors: Chang Song
Published: August 2021

Nationality is the world. A new type of comic theme with Chinese characteristics has become a new art form and popular trend, and is deeply loved by people. This article focuses on the development of Chinese comics and the needs of authors and customer groups, analyzes the development and creation of Chinese comics, and analyzes the advantages of introducing unique Chinese painting methods into comics from three perspectives: composition, coloring and character design, To bring the boneless technology of Chinese painting into comics, and at the same time, Chinese commercial comics use the Internet and other media to find more commercial cooperation to make Chinese comics and commercial comics more harmonious.
Research on the Integration of Art Production and Education and Urban Ecosystem Construction Based on Digital Media Technology
Authors: Wang Xianghui
Published: August 2021

The development speed of digital media technology is increasing year by year. However, the lack of artistic talents in digital media is a serious problem. In many schools, the upper limit of the level of digital art graduates is very low. The integration of production and education of art has become the main research direction of scholars. In order to effectively implement the green city rectification policy, the State advocates the construction of urban ecosystem. However, the traditional theory of ecosystem construction has been ignored. Many scholars put forward the construction of urban ecological circle with the integration of digital art illustration and teaching. This paper analyzes the characteristics of the integration of art production and education in digital media. On this basis, this paper puts forward the construction path of urbanization ecosystem.
Research on the Application Of Blockchain Technology in Financial Statement Auditing
Authors: He Jiaxuan
Published: August 2021

The audit of financial statements is an important content of business management, improve the quality of financial statements audit work can understand the business status of enterprises, combined with the actual financial status of enterprises to develop in line with the enterprise’s own development of enterprise planning. This paper firstly explains the deficiencies of financial statement auditing and the concept and advantages of blockchain technology, and at the same time puts forward countermeasures and suggestions for the development of audit industry under blockchain technology for the reference of readers.
Kinematics Analysis and Research on Volleyball Serving Using Computer Technology
Authors: Xiong Yulong
Published: August 2021

As one of the most important competitive sports, volleyball is gradually developed in many countries and regions due to its strong interest and simple operation. Volleyball serve is a basic technique for beginners in volleyball sports. This paper firstly analyzes volleyball serve technology and volleyball serve kinematics. At the same time, it makes use of computer technology to analyze volleyball serve kinematics for readers’ reference.