bluuebunny/crossref_metadata_2025 huggingface dataset:
Smart pansharpening approach using kernel‐based image filtering
Authors: Smadi Ahmad AL , Yang Shuyuan , Mehmood Atif , Abugabah Ahed , Wang Min , Bashir Muzaffar
Published: May 2021

Remote sensing image fusion plays important roles in numerous applications, including monitoring, metrology, and agriculture. Image fusion gathers essential information from several image sources and consolidates them into a single image called a fused image. The fused image involves relevant data, and it is more informative than any other images extracted from one source. This study proposed a pansharpening technique based on image filtering utilising a bilateral filter to generate high‐frequency details from panchromatic image. The various types of side window guided filters are employed to enhance the multispectral band from panchromatic image and then used these filters to adjust spatial data misfortune that happens when images are combined. Experimental results demonstrated that the proposed method provides consistent results concise with reported by the previous research in terms of subjective and objective assessments on remote sensing data.
X-ray-induced chemistry of water and related molecules in low-mass protostellar envelopes
Authors: Notsu Shota , van Dishoeck Ewine F. , Walsh Catherine , Bosman Arthur D. , Nomura Hideko
Published: May 2021

Context. Water is a key molecule in star- and planet-forming regions. Recent water line observations toward several low-mass protostars suggest low water gas fractional abundances (<10−6 with respect to total hydrogen density) in the inner warm envelopes (r < 102 au). Water destruction by X-rays is thought to influence the water abundances in these regions, but the detailed chemistry, including the nature of alternative oxygen carriers, is not yet understood.

Aims. Our aim is to understand the impact of X-rays on the composition of low-mass protostellar envelopes, focusing specifically on water and related oxygen-bearing species.

Methods. We computed the chemical composition of two proto-typical low-mass protostellar envelopes using a 1D gas-grain chemical reaction network. We varied the X-ray luminosities of the central protostars, and thus the X-ray ionization rates in the protostellar envelopes.

Results. The protostellar X-ray luminosity has a strong effect on the water gas abundances, both within and outside the H2O snowline (Tgas ~ 102 K, r ~ 102 au). Outside, the water gas abundance increases with LX, from ~10−10 for low LX to ~10−8–10−7 at LX > 1030 erg s−1. Inside, water maintains a high abundance of ~10−4 for LX ≲ 1029–1030 erg s−1, with water and CO being the dominant oxygen carriers. For LX ≳ 1030–1031 erg s−1, the water gas abundances significantly decrease just inside the water snowline (down to ~10−8–10−7) and in the innermost regions with Tgas ≳ 250 K (~10−6). For these cases, the fractional abundances of O2 and O gas reach ~10−4 within the water snowline, and they become the dominant oxygen carriers. In addition, the fractional abundances of HCO+ and CH3OH, which have been used as tracers of the water snowline, significantly increase and decrease, respectively, within the water snowline as the X-ray fluxes become larger. The fractional abundances of some other dominant molecules, such as CO2, OH, CH4, HCN, and NH3, are also affected by strong X-ray fields, especially within their own snowlines. These X-ray effects are larger in lower-density envelope models.

Conclusions. X-ray-induced chemistry strongly affects the abundances of water and related molecules including O, O2, HCO+, and CH3OH, and can explain the observed low water gas abundances in the inner protostellar envelopes. In the presence of strong X-ray fields, gas-phase water molecules within the water snowline are mainly destroyed with ion-molecule reactions and X-ray-induced photodissociation. Future observations of water and related molecules (using, e.g., ALMA and ngVLA) will access the regions around protostars where such X-ray-induced chemistry is effective.
Histoire et organisation du programme français de dépistage néonatal systématique (1967-2020)
Authors: Farriaux Jean-Pierre
Published: May 2021

Au cours du dernier quart du xxe siècle s’est construit en France un ambitieux programme de santé publique. Il s’agissait du dépistage de maladies de l’enfant inapparentes à la naissance, mais dont le diagnostic et le traitement précoces allaient transformer l’état de santé des enfants porteurs de ces maladies. Ce programme très bien structuré est toujours en œuvre et a donné les fruits que nous espérions. Ce texte raconte l’histoire de cette action de santé et résume l’organisation et les objectifs du programme.
Dépistage de l’hypothyroïdie congénitale
Authors: Léger Juliane
Published: May 2021

L’hypothyroïdie congénitale est une maladie due à une sécrétion insuffisante d’hormones thyroïdiennes. Les causes sont multiples, mais les plus fréquentes sont dues à une anomalie de développement de la glande thyroïde ou à un trouble de l’hormonosynthèse thyroïdienne. Cette insuffisance thyroïdienne avait jadis des conséquences très graves sur le développement de l’enfant, dues essentiellement à un traitement bien trop tardif du déficit hormonal. Le dépistage néonatal systématique, mis en place depuis plus de 40 ans en France, permet actuellement une prise en charge dès le début de la deuxième semaine après la naissance. Il a transformé le pronostic de l’affection tant sur le plan de la croissance que sur celui du développement intellectuel et de l’insertion socio-professionnelle, qui sont normaux. Une augmentation de l’incidence de la maladie a été rapportée ces dernières années. Elle concerne essentiellement les formes avec glande thyroïde en place. Il est nécessaire de réévaluer la fonction thyroïdienne de ces patients car ces hypothyroïdies peuvent être transitoires.
Effect of charge modulation on the electroconvective flow of a low conducting liquid
Authors: Nekrasov Oleg O. , Smorodin Boris L.
Published: May 2021

Nonlinear evolution of the electroconvective flow patterns is analysed in a horizontal low conductive fluid layer under heating from above and under modulated charge injection. To examine the complex evolution of the system, numerical simulations are carried out using a finite difference method. The influence of amplitude and frequency modulation on the oscillatory electroconvection is studied. Traveling waves with modulated amplitudes and phase velocities and synchronously modulated patterns are found as stable solutions.
An extremal problem with applications to renewable energy production
Authors: Ashley Thomas , Carrizosa Emilio , Fernández-Cara Enrique
Published: May 2021

Dynamic optimisation provides complex challenges for optimal solution, but greatly increases applicability when considering time dependent situations. In this work, a constrained dynamic optimisation problem is analysed and subsequently applied to the resolution of a real-world engineering problem concerning Solar Power Tower plants. We study the existence of solutions and deduce an appropriate optimality characterisation in this applied framework. Two iterative algorithms are presented, convergence properties are discussed and a numerical illustration is given utilising realistic data. Finally, conclusions are drawn on the considered model and some ideas for future work are discussed.
Process-based approach to organizing the accounting of labor costs and motivation in the digital economy
Authors: Blizkyi Roman , Timokhina Olga , Vlasova Tatyana , Gavrish Yekaterina
Published: May 2021

The article discusses the main risks of accounting for settlements with personnel in modern conditions, including those caused by significant changes in legislation, in terms of regulating the procedure for implementing expenses for labor remuneration. The authors systematized the main risks pursuant to a number of basic accounting criteria: purpose, order, content. The proposed approach, in contrast to the existing approaches, allows to quickly segment problematic risk areas of work in accounting. The article presents the characteristics of accounting procedures in the course of reflecting operations related to the accrual, retention and payment of wages, considering the conditions of digital transformation, where, in contrast to the existing approaches, the aspects of the influence of endo- and exogenous factors in the dynamics of the development of digital transformations are systematized. The content of IAS 19 Employee Benefits has been structured by different types of benefits. The criteria for recognizing the fact of remuneration are considered, a critical assessment of the classification and approaches to different types of remuneration in the context of noonomics is given.
Energy-saving behavior of households in a digital and nature-like economy as an object of research
Authors: Burganov Rais , Maimakova Ludmlia , Altynbaiva Emina
Published: May 2021

The study of the behavioral aspects of households in the field of energy conservation is one of the activities of the global energy policy. From this perspective, the topic of the article is relevant. The purpose of the study is to consider the theoretical and methodological basis for studying the transformation of energy-saving behavior of a household in the context of the introduction of digital and nature-like technologies. The authors, based on the use of provisions (neoclassicism, institutionalism and Keynesianism), investigated the essence and manifestations of energy-saving behavior of a household in such conditions. For a deeper study, an analysis of organizational forms, institutional infrastructure, technical and technological relations arising in the process of energy consumption is proposed. Based on this analysis, a number of results have been obtained. The very concept of “energy” is used in a broad sense, as consisting of many of its types and used in consumption by households. The overall result of the study is the provision that the energy-saving behavior of households should be investigated in a comprehensive manner with the integration of various theoretical concepts. In the absence of such an integrated approach, the energy-saving process at the household level will be divided into different actions, including contradictory or even opposite ones, which will affect the effectiveness of the government measures taken.
Research of the mechanisms for coordinating the work of personnel when implementing 3D technologies
Authors: Gritskevich Olga , Pavlenko Valeriia
Published: May 2021

The article is devoted to the consideration of the mechanisms for coordinating the work of personnel for the complex solution of innovative production problems at an instrument-making enterprise. The research considers the formation of coordination mechanisms in an organization, a technique is proposed that can be used to reduce the technical system lifecycle at an enterprise. The practical implementation of the coordination methodology on the example of the implementation of 3D technologies at an instrument-making enterprise contains specific proposals for the implementation of a virtual management structure, as well as a planning and personnel questionnaire system. The study is aimed to develop a methodology for the efficient use of personnel coordination mechanisms. The research object is innovative technologies at the instrument-making enterprise. The research subject is the coordination mechanisms in the context of the innovative technology deployment at the instrument-making enterprise.
Innovation activity impact on adding value to the enterprise: empirical analysis
Authors: Badykova Idelia , Romanova Anna
Published: May 2021

In the context of economy digitalization corporate innovative activity is one of the main competitive advantages, which should have impact on adding value to the enterprise. The aim of this study is to explore if there is relation between innovation activity level of the Russian companies and their value. Analysis of balanced panel data based on the application of random effects and fixed effects models is used to test research hypotheses. The sample contains 19 Russian nonfinancial public companies (2012-2019). The results of the empirical study demonstrate the positive relation between corporate innovation activity level and company value. The influence of expenditures on staff development (one of the corporate social responsibility (CSR) directions) on the latter is addressed as well, however, no statistically significant result is received in the short run, probably confirmation of a positive relationship can be obtained in the long term. Moreover, impact of general CSR indicator on corporate value can be tested to make further conclusions on the validity of the idea of joint influence of innovation activity and CSR on the value of companies.
Digital financial assets and digital currency: legal nature and legal regulation of turnover
Authors: Bashilov Boris , Galkina Marina , Berman Alisa
Published: May 2021

In the past few years digital financial assets and digital currency have been getting more popularity among the tools of digital economy. Due to the demand for turnover of digital financial assets and digital currency, as well as the formation of an increasing number of jural relations, the object of which they are, they require efficient legal regulation, which is not a simple task for the legislator because of their dinamic development. Lack of such regulation causes the formation of non-uniform regulatory enforcements practices and the unpredictability of legal relations that are developed in relation to these instruments. One of the keys to the formation of effective regulation is a definition and precise legislative consolidation of the legal nature of digital financial assets and digital currency. This article analyzes the approaches to determining the legal nature of digital financial assets and digital currency in the current domestic legislation at the stage when such legislation has not been formed yet based on the analysis of regulatory enforcement practices and clarifications of state bodies. The current legislation is also analyzed in terms of the presence of legislative gaps taking into account the relationship between the relevant regulation and the provisions contained in other, non-major legislation. Moreover, the authors also analyzed the approaches to the regulation of the turnover of digital financial assets and digital currency abroad. Such approaches were classified as well, which allowed to identify the main trends of regulation of their turnover and to determine their legal nature.
Legal forms and ways of application of artificial intelligence technology in making corporate decisions by the board of directors: problems and prospects
Authors: Sushkova Olga
Published: May 2021

This study investigates the impact of scientific and technological advances and adaptation of artificial intelligence on corporate governance practices. It applies or can be applied in three dimensions - business, technology, and society. Therefore, to assess the necessity, feasibility, effectiveness, and responsibility of decision-making automation at the Board of Directors (supervisory body of a legal entity) to ensure effective corporate governance, it is necessary to consider all normative regulators in the field of corporate law. Based on an assessment of the potential and limitations of human and machine learning for effective decision-making at the level of the collegial governance body, the Board of Directors, the paper proposes five AI-based governance scenarios, i.e., supportive, augmented, enhanced, autonomous, and autopoietic, that can shape the governance of organizations today, tomorrow, and in the future. It is important to understand the implications of such AI-enabled governance in the areas where the Board is empowered to make certain corporate decisions.
Legal risks of using regulatory technologies in business and professional activities
Authors: Sushkova Olga
Published: May 2021

When using artificial intelligence technology in RegTech or SupTech solutions to prevent, detect and control financial crimes such as money laundering, it is necessary to be aware that due to compliance costs, many online financial firms are prohibited from providing financial advice, especially if they process transactions on behalf of clients or provide p2p investment platforms. RegTech streamlines KYC/CDD processes and therefore has the ability to reduce compliance costs. This, in turn, will allow more firms to enter the market to offer services. The regulatory goal of ensuring market integrity directly conflicts with the rights of individuals and the Data Protection Acts. It is argued that data governance will need to be established to protect individual rights and public safety. Furthermore, the question remains unresolved as to whether fiduciary duties can be assumed by robo-advisors or consultants using algorithms. Fiduciary duties may also be modified and limited by the parties. The fiduciary duty concerns what the fiduciary (investment adviser) cannot do (conflict of interest) but should not do (act in the best interest of the client). Consequently, the use of common law principles to protect consumer investors is currently underdeveloped, particularly if the AI seeks to provide access to finance and fill gaps in guidance.
Advanced information technologies in education
Authors: Idrisova Jaradat , Alikhadzhiev Saydmagomed , Moiseenko Natalia
Published: May 2021

Modern mankind has joined the general historical process called computerization. In contrast to the industrial society, in which the main thing was the production of material goods, in today’s post-industrial society the production of information becomes the main activity (by information we mean knowledge as information about people, objects, facts, events), phenomena and processes, regardless of their form representation that can be recorded on a tangible medium), and this process is called computerization (hence the term - information society). Such a shift in emphasis is caused, on the one hand, by the fact that humanity is aware of the limited natural (natural) resources of its habitat, and on the other hand, by the emergence of global problems (for example, energy, the environment), a solution that is impossible with previous methods. Information is becoming the main resource for the development of the world community and significantly affects the development of other industries and spheres of life: science, technology, social spheres (cultural communication between people, education). The core values of the information society are:- knowledge; -qualification; - independent thinking; -the ability to work with information and make informed decisions based on it; - awareness not only in a narrow professional field, but also in related fields.
Digital educational resources for English language studies: teachers and learners’ attitude
Authors: Zakirova Elena , Kulikova Elena , Medvedeva Ekaterina
Published: May 2021

The introduction of electronic educational content optimizes and facilitates the learning process. This attitudinal study aims to investigate the relation of English teachers and students of the Russian universities (pointed out below) towards digital educational recourses and their usage in the context of foreign language learning. In general, it enables the authors to gather the information about popularity of digital educational recourses for English language learning in order to identify: 1) for what purposes and which digital education recourses are mainly used by English language teachers and whether they manage to achieve the planned result; 2) which resources are of the students’ greatest interest and what is the base of their choice; 3) weather the students are satisfied with the introduction of digital education recourses in the educational process in general and in the ELT in particular. The study is based on the analysis of the results of the questioning. Participants of the study were school and university teachers and students from Universities of Moscow and Moscow region. The findings of the study showed that there is no significant difference between educators and students’ attitudes towards digital education resources. The most participants both teachers and students consider them increasing the effectiveness of learning English. Some of the recourses are popular with both groups of respondents while others have been adopted by one group and easy accessed to the process of language learning.
Computer analysis of biographies to study family influence on the educational way of a person
Authors: Proshkova Zoya
Published: May 2021

The article presents the results of a computer analysis of biographical materials on the educational way of a person. In this sociological study, a collection of autobiographical essays of students of higher educational institutions was carried out. The received texts were processed using the Russian computer program Discant. Structuring, classification and digital codification of the content of biographical texts were used. As a result of the computer analysis, family factors that influence the development and implementation of the educational route of children were identified and described in detail. The sociological study resulted in a rating of effective ways of family support for children’s education. It has been established that the most effective family factors for ensuring the educational way of children are the education of parents, the values of education and culture in the family, the parents’ search for strong educational institutions and their willingness to invest in children’s education. The findings indicate the need for individualization of modern educational routes and social support for families with children of school and preschool age. The methodological perspective of the project is to develop new methods for computer analysis of large amounts of biographical data.
Bruxismus: Muskuloskelettales Assessment und Management
Authors: von Piekartz Harry J. M.
Published: May 2021

Bruxismus ist keine Krankheit, sondern ein Sammelbegriff für Parafunktionen wie Zähnepressen oder Knirschen. Um Begleitsymptome des Bruxismus zu beeinflussen, ist eine Untersuchung des orofazialen und kraniozervikalen Systems sinnvoll. Die gefundenen auffälligen Zeichen leiten die Therapeuten in der muskuloskelettalen Therapie, die aus Hands-on und -off-Techniken besteht.
Prevalence of immunoglobulin E against cross-reactive carbohydrate determinants and the impact of a blocker in canine sera
Authors: Mohammaddavoodi Amirhossein , Christian Maria , Müller Elisabeth , Panakova Lucia , Burgener Iwan , Wagner Regina
Published: May 2021

Gegenstand und Ziel Kreuzreaktive Kohlenhydrat-Seitenketten (cross reactive carbohydrate determinants, CCD) führen bei saisonalen In-vitro-Allergietests zu multipositiven Ergebnissen. Diese Bindung von Immunglobulin E gegen CCD von Pollenallergenen (Anti-CCD-IgE) verursacht falsch-positive/klinisch irrelevante Resultate. Ziel dieser Studie war, die Prävalenz von polysensibilisierten Serumproben zu untersuchen und die Auswirkungen eines CCD-Inhibitors/Blockers auf die Ergebnisse von saisonalen Allergietests bei Hunden zu evaluieren.

Methoden Die Analyse berücksichtigte Seren von 4614 Hunden, die für einen Allergietest zum Nachweis von IgE gegen saisonale Allergene (ELISA basierend auf der Fc-Epsilon-Rezeptor-Technologie) von Juli 2017 bis Juni 2018 eingeschickt worden waren. Die Proben wurden als polysensibilisierte Seren (Gruppe A) und nicht polysensibilisierte Seren (Gruppe B) klassifiziert. Seren der Gruppe A wurden nach Zugabe eines modifizierten Glykoprotein-Pflanzenextrakts (Blocker) erneut getestet. Um die Auswirkung des Blockers auf jedes Allergen zu bestimmen, erfolgte eine Analyse der Ergebnisse von 96 zufällig ausgewählten Proben vor und nach dem Blocken.

Ergebnisse Eine Polysensibilisierung gegen saisonale Allergene zeigte sich bei 818 (17,7 %) Serumproben. Der Blocker eliminierte die Bindung von Anti-CCD-IgE an Allergenextrakte vollständig (49 %) oder erniedrigte die Reaktionsklassen (40 %), was auf das Vorhandensein von klinisch relevantem IgE hinweist. Negative Reaktionen nach Zugabe des Blockers ergaben sich beim 6-Gräser-Mix (29 %), bei Roggen (22 %) und Sauerampfer (20 %) weniger häufig als bei Brennnessel (82 %), Weide (70 %), Birke-Hasel (65 %), Beifuß-Ragweed (63 %) und Spitzwegerich (57 %).

Schlussfolgerung und klinische Relevanz Der Blocker sollte bei polysensibilisierten Seren eingesetzt werden, um die Qualität saisonaler In-vitro-Allergietests zu verbessern und die Verwendung klinisch irrelevanter Allergene in der allergenspezifischen Immuntherapie (ASIT) zu vermeiden.
Red Flags für den thorakolumbalem Bereich
Authors: Vielitz Arne
Published: May 2021

Maselli F, Palladino M, Barbari V et al. The Diagnostic Value of Red Flags in Thoracolumbar Pain: a Systematic Review. Disabil Rehabil 2020; 19: 1–17. doi:10.1080/09638288.2020.1804626
Ligand-Free Palladium-Catalyzed Carbonylative Suzuki Couplings of Vinyl Iodides with Arylboronic Acids under Substoichiometric Base Conditions
Authors: Yang Zhiyuan , Gong Pei-Xue , Han Wei , Chen Junjie , Zhang Jie , Gong Xu
Published: May 2021

A ligand-free palladium-catalyzed carbonylation of vinyl iodides with arylboronic acids, permitting the synthesis of chalcones and α-branched enones, has been established. This reaction proceeds smoothly at ambient pressure and temperature, and works well even with a substoichiometric amount of base. Importantly, this mild, efficient, and operationally simple protocol is suitable for the late-stage functionalization of an epiandrosterone-derived complex molecule.
Intramolecular Addition of a Dimethylamino C(sp3)–H Bond across C–C Triple Bonds Using IrCl(DTBM-SEGPHOS)(ethylene) Catalyst: Synthesis of Indoles from 2-Alkynyl-N-methylanilines
Authors: Ohmura Toshimichi , Suginome Michinori , Yagi Kaito , Torigoe Takeru
Published: May 2021

Intramolecular addition of a C(sp3)–H bond of the dimethylamino group across the C–C triple bond in 2-alkynyl-N,N-dimethylanilines is effectively catalyzed by a new iridium complex, IrCl(DTBM-SEGPHOS)(C2H4), in mesitylene at 150 °C. The intramolecular C(sp3)–H addition is followed by double-bond isomerization to afford 3-substituted indoles in good to high yields.
Evaluation of the potential for wake steering for U.S. land-based wind power plants
Authors: Bensason D. , Simley E. , Roberts O. , Fleming P. , Debnath M. , King J. , Bay C. , Mudafort R.
Published: May 2021

The wind power plant-wide control strategy known as wake steering involves the misalignment of upstream turbines with the wind direction to deflect wakes away from downstream turbines, increasing net wind plant power production. In this paper, we evaluate the potential of wake steering for U.S. land-based wind power plants. First, we outline a method for simulating and optimizing wake steering control for existing wind plants by combining the flow redirection and induction in steady state wake steering engineering model with the U.S. Wind Turbine Database and Wind Integration National Dataset Toolkit wind resource dataset. Next, to better understand the potential benefits of wake steering beyond those for existing wind plants, we evaluate the relative impacts of turbine specific power, turbine spacing, and mean wind speed on energy gain and levelized cost of energy (LCOE) using a model land-based wind power plant. For a subset of 60 existing wind plants, assuming a constant turbulence intensity of 8%, wake steering was found to yield an average annual energy production (AEP) gain of 0.80%, equivalent to recovering 13.85% of baseline wake losses. Further, we present a linear approximation between baseline wake losses and AEP gains that can be used to estimate wake steering gains for other wind power plants. Highlighting additional benefits of wake steering, for the model wind power plant we found that energy gains from wake steering enabled an approximate 30% reduction in turbine spacing while keeping LCOE constant.
Modeling financial distress propagation on customer–supplier networks
Authors: Nin Jordi , Salbanya Bernat , Fleurquin Pablo , Tomás Elena , Arenas Alex , Ramasco José J.
Published: May 2021

Financial networks have been the object of intense quantitative analysis during the last few decades. Their structure and the dynamical processes on top of them are of utmost importance to understand the emergent collective behavior behind economic and financial crises. In this paper, we propose a stylized model to understand the “domino effect” of distress in client–supplier networks. We provide a theoretical analysis of the model, and we apply it to several synthetic networks and a real customer–supplier network, supplied by one of the largest banks in Europe. Besides, the proposed model allows us to investigate possible scenarios for the functioning of the financial distress propagation and to assess the economic health of the full network. The main novelty of this model is the combination of two stochastic terms: an additive noise, accounting by the capability of trading and paying obligations, and a multiplicative noise representing the variations of the market. Both parameters are crucial to determining the maximum default probability and the diffusion process characteristics.
Effect of drag force and translation of bubbles on nonlinear pressure waves with a short wavelength in bubbly flows
Authors: Kanagawa Tetsuya , Ayukai Takahiro , Maeda Taiki , Yatabe Takahiro
Published: May 2021

To clarify the effect of the drag force acting on bubbles and translation of bubbles on pressure waves, the weakly nonlinear (i.e., finite but small-amplitude) propagation of plane pressure waves with a thermal conduction in compressible water flows containing many spherical bubbles is theoretically investigated for moderately high-frequency and short-wavelength case. This work is an extension of our previous report [Yatabe et al., Phys. Fluids, 33, 033315 (2021)], wherein we elucidated the same for low-frequency and long-wavelength case. Based on our assumptions, the main results of this study are as follows: (i) using the method of multiple scales, the nonlinear Schrödinger type equation was derived; (ii) as in the previous long wave case, the translation of bubbles increased the nonlinear effect of waves, and the drag force acting on the bubbles resulted in the dissipation effect of waves; (iii) the increase in the nonlinear effect of the waves owing to the translation in the present short wavelength case is larger than that in the previous long wavelength case; (iv) the dissipation effect caused by the drag force was smaller than that caused by the liquid viscosity, acoustic radiation (i.e., liquid compressibility), and thermal conduction; (v) we then succeeded the comparison of the four dissipation factors (i.e., liquid viscous damping, thermal conduction, acoustic radiation, and drag force) on pressure waves.
A model for excess Johnson noise in superconducting transition-edge sensors
Authors: Wessels Abigail , Morgan Kelsey , Gard Johnathon D. , Hilton Gene C. , Mates John A. B. , Reintsema Carl D. , Schmidt Daniel R. , Swetz Daniel S. , Ullom Joel N. , Vale Leila R. , Bennett Douglas A.
Published: May 2021

Transition-edge sensors (TESs) are two-dimensional superconducting films utilized as highly sensitive detectors of energy or power. These detectors are voltage biased in the superconducting-normal transition where the film resistance is both finite and a strong function of temperature. Unfortunately, the amount of electrical noise observed in TESs exceeds the predictions of existing noise theories. We describe a possible mechanism for the unexplained excess noise, which we term “mixed-down noise.” The source is Johnson noise, which is mixed down to low frequencies by Josephson oscillations in devices with a nonlinear current–voltage relationship. We derive an expression for the power spectral density of this noise and show that its predictions agree with measured data.
A hybrid recursive regularized lattice Boltzmann model with overset grids for rotating geometries
Authors: Yoo H. , Bahlali M. L. , Favier J. , Sagaut P.
Published: May 2021

Simulating rotating geometries in fluid flows for industrial applications remains a challenging task for general fluid solvers and in particular for the lattice Boltzmann method (LBM) due to inherent stability and accuracy problems. This work proposes an original method based on the widely used overset grids (or Chimera grids) while being integrated with a recent and optimized LBM collision operator, the hybrid recursive regularized model (HRR). The overset grids are used to actualize the rotating geometries where both the rotating and fixed meshes exist simultaneously. In the rotating mesh, the fictitious forces generated from its non-inertial rotating reference frame are taken into account by using a second order discrete forcing term. The fixed and rotating grids communicate with each other through the interpolation of the macroscopic variables. Meanwhile, the HRR collision model is selected to enhance the stability and accuracy properties of the LBM simulations by filtering out redundant higher order non-equilibrium tensors. The robustness of the overset HRR algorithm is assessed on different configurations, undergoing mid-to-high Reynolds number flows, and the method successfully demonstrates its robustness while exhibiting the second order accuracy.
The impact of the seabed morphology on turbulence generation in a strong tidal stream
Authors: Mercier Philippe , Guillou Sylvain
Published: May 2021

Highly energetic turbulent flow structures are observed in strong tidal flows. If they are suspected to result from interactions between the flow and the seabed morphology, the physical processes involved in their generation, as well as their impact on the structure of the flow, are not yet fully understood. Here, the lattice-Boltzmann method is used to simulate a strong tidal flow in large-eddy simulation. The effect of the seabed morphology on the hydrodynamic characteristics of the flow is studied. A high spatial variability of the turbulent kinetic energy (TKE) production is observed. The flow average velocity is significantly reduced in areas of high TKE production. These areas are not necessarily associated with the largest seabed landforms. However, some seabed landforms of specific shapes are identified as turbulence generators. The areas of high turbulence are associated with trails of vortices successively released from the seabed and following similar trajectories. The generation of a large coherent flow structure is observed at the intersection of two vortex trails, suggesting that such a structure, that could be identified as the large boils commonly observed at the surface of strong tidal power flows, could result from the aggregation of smaller vortices.
Symbolic dynamics of music from Europe and Japan
Authors: Basios Vasileios , Oikonomou Thomas , De Gernier Robin
Published: May 2021

After a brief introduction to the theory underlying block-entropy and its relation to the dynamics of complex systems as well as certain information theory aspects, we study musical texts coming from two distinct musical traditions, Japanese and Western European, encoded via symbolic dynamics. We quantify their information content, also known as the degree of “non-randomness” which essentially defines the complexity of the text. We analyze the departure of “total randomness” to the constraints underlying the dynamics of the symbol generating process. Following Shannon on his attribution of these constraints as the key factors of the emergence of complexity, we observe that it can be accurately assessed by the texts’ block-entropy vs block-length scaling laws.
Effects of divertor electrical drifts on particle distribution and detachment near the divertor target plate in DIII-D
Authors: Wang H. Q. , Watkins J. G. , Guo H. Y. , Groth M. , Jarvinen A. E. , Leonard A. W. , Ren J. , Thomas D. M. , Boedo J.
Published: May 2021

Strong impacts of drifts on the divertor plasma in–out asymmetry and detachment are demonstrated in DIII-D with an open divertor configuration. For forward toroidal field, BT, i.e., with the ion B × ∇B drift toward the divertor, the particle flux to the inner divertor, as represented by the Langmuir probe measured ion saturation current (Jsat), exhibits a double peak structure, with electron temperature, lower at the inner target. Reversing the BT direction reverses both the radial and poloidal E × B flows, leading to a broad particle flux profile in the outboard scrape-off layer (SOL) with a similar double-peak structure to that observed at the inner target with forward BT. The correlation of a double peak structure with divertor temperature profiles confirms physical coupling between the drift flow and sheath boundary condition and their strong impact on divertor profiles. In addition, under reversed BT conditions, increasing the density flattens the target temperature profile. However, Jsat remains high away from the strike point, rendering it difficult to achieve an “effective” detached plasma, i.e., with effective reduction in both peak heat flux and peak temperature (in the far SOL). In contrast, divertor detachment with a cold and flat temperature profile can be achieved at both target plates with the forward BT.
Drag reduction in turbulent Taylor–Couette flow by axial oscillation of inner cylinder
Authors: Zhao Ming-Xiang , Yu Ming , Cao Tao
Published: May 2021

Drag reduction in turbulent Taylor–Couette flows by axial oscillation of inner cylinder is investigated by direct numerical simulation. In the present study, the reference friction Reynolds number is Reτ=210 based on the friction velocity at the inner cylinder in the no control cases and the half gap width. We have obtained the effects of the oscillation period and the radius ratio of the inner to outer cylinders on the drag reduction rate. Our analysis shows that as the radius ratio is getting larger, the maximum drag reduction rate is decreased and the optimal oscillating period is increased. Under the condition of the short oscillating period, a larger radius ratio leads to a lower drag reduction rate. However, when the oscillating period becomes long, the larger radius ratio triggers a higher drag reduction rate. With the help of Fukagata–Iwamoto–Kasagi identity, the wall shear stress has been linked to turbulent motions at different scales. It is found that the long-period oscillations primarily reduce the wall friction drag induced by the large-scale Taylor vortices while the short-period oscillations mainly decrease wall shear stress originating from the small-scale velocity streaks. Visualizations of Taylor vortices and velocity streaks, premultiplied spectra, and the weighted Reynolds shear stress indicate that such different effects are related to the Stokes layer. A thick Stokes layer under the condition of large-period oscillations penetrates to the core region of the flow and the Taylor vortices whose center is located near the middle plane between the cylinders is thus attenuated effectively. On the contrary, the influence range of a thin Stokes layer caused by the short-period oscillation concentrates on the near-wall region, hence, the small-scale velocity streaks there are weakened greatly.
Laser-driven flyer plate impact: Computational studies guided by experiments
Authors: Stekovic Svjetlana , Springer H. Keo , Bhowmick Mithun , Dlott Dana D. , Stewart D. Scott
Published: May 2021

We present a computational approach using a multimaterial, arbitrary Lagrangian–Eulerian code termed ALE3D to model the nanosecond/micrometer dynamics of the launch of 0.5–4.5 km/s laser-driven metal flyer plates and the impact with stationary targets of Pyrex and fused silica glasses, and Lexan and Plexiglas polymers, producing pressures in the target in the range of 5–20 GPa. The simulations are compared to experimental results where the flyer velocity profile and the velocity profile imparted to the target material were measured with high-speed velocimetry. The experimental flyer launch by a high-intensity pulsed laser is modeled by depositing heat into a thin vaporizable layer under the flyer plate. This model produces a flyer plate that has not been exposed to the laser pulse, allowing us to compare the properties of the real flyer to a simulated ideal flyer. The simulations of target impact are generally in good agreement with the experiment except at the highest impact velocities where the shock release process in the experiment is slower than that in the simulation. The cause of this disagreement is attributed to an inadequate description of the shock viscosity during the nanosecond unloading process.
Cross-term events of scale-decomposed skewness factor in turbulent boundary layer at moderate Reynolds number
Authors: Tang Zhanqi , Chen Letian , Fan Ziye , Ma Xingyu , Jiang Nan
Published: May 2021

This study reports the observation of cross term events of scale-decomposed skewness factor in turbulent boundary layer at moderate Reynolds number. The large field-of-view particle image velocimetry was utilized to measure the flow fields. By the approach of multi-scale proper orthogonal decomposition (mPOD), the large- and small-scale structures were reconstructed by the mPOD modes relevant to the predefined frequency bands. Then, the cross term of the scale-decomposed skewness was observed, which was proposed in the previous works by Schlatter and Örlü [Phys. Fluids 22, 051704 (2010)] and Mathis et al. [Phys. Fluids, 23, 121702 (2011)]. The cross term events are featured by both the large and small scales, which were consolidated by the linear fitting of correlation coefficients with different slope angles. The characteristic length of the local intense cross term events is around 0.1δ (δ is the boundary layer thickness), which is comparable with that of the swirling structures related to hairpin vortice in the form of hairpin packets. The conditional averaging results presented the arrangement that the local cross term event appears underneath the hairpin vortex in the statistical viewpoint. Based on the hairpin vortex model, it was proposed that the local intense cross term events are associated with the local low-speed fluids induced by the hairpins through the ejection process. Especially, in the wake region, the cross term events are promoted, and also well-correlated with the swirling structures. This kind of configuration was attributed to the combination of the vortex induction and the entrainment process relative to the turbulent/non-turbulent intermittency.
Aluminum scandium nitride-based metal–ferroelectric–metal diode memory devices with high on/off ratios
Authors: Liu Xiwen , Zheng Jeffrey , Wang Dixiong , Musavigharavi Pariasadat , Stach Eric A. , Olsson Roy , Jariwala Deep
Published: May 2021

In this Letter, we report a back-end-of-line (BEOL), complementary metal–oxide–semiconductor (CMOS)-compatible Al0.64Sc0.36N-based ferroelectric diode that shows polarization-dependent hysteresis in its leakage currents. Our device comprises a metal/insulator/ferroelectric/metal structure (Pt/native oxide/Al0.64Sc0.36N/Pt) that is compatible with BEOL temperatures (≤ 350 °C) grown on top of a 4-in. silicon wafer. The device shows self-selective behavior as a diode with > 105 rectification ratio (for 5 V). It can suppress sneak currents without the need for additional access transistors or selectors. Furthermore, given the polarization-dependent leakage, the diode current–voltage sweeps are analogous to that of a memristor with an on/off ratio of ∼ 50 000 between low and high resistance states. Our devices also exhibit stable programed resistance states during DC cycling and a retention time longer than 1000 s at 300 K. These results demonstrate that this system has significant potential as a future high-performance post-CMOS compatible nonvolatile memory technology.
Doping-related broadening of the density of states governs integer-charge transfer in P3HT
Authors: Hase Hannes , Berteau-Rainville Melissa , Charoughchi Somaiyeh , Orgiu Emanuele , Salzmann Ingo
Published: May 2021

Molecular p-doping allows for an increase in the conductivity of organic semiconductors, which is regularly exploited in thermoelectric devices. Upon doping, integer and fractional charge transfer have been identified as the two competing mechanisms to occur, where the former is desired to promote the generation of mobile holes in the semiconductor host. In general, high dopant electron affinity is expected to promote integer-charge transfer, while strong coupling between the frontier molecular orbitals of dopant and host promotes fractional charge transfer instead. Here, we investigate the role that the width of the density of states (DOS) plays in the doping process by doping the conjugated polymer poly(3-hexylthiophene) (P3HT) with tetracyanoquinodimethane (TCNQ) derivatives of different electron affinities at a 2% dopant ratio. Cyclic voltammetry confirms that only the electron affinity of F4TCNQ (tetrafluorotetracyanoquinodimethane) exceeds the ionization energy of P3HT, while TCNQ and FTCNQ (2-fluoro-7,7,8,8-tetracyanoquinodimethane) turn out to have significantly lower but essentially identical electron affinities. From infrared spectroscopy, we learn, however, that ca. 88% of FTCNQ is ionized while all of TCNQ is not. This translates into P3HT conductivities that are increased for F4TCNQ and FTCNQ doping, but surprisingly even reduced for TCNQ doping. To understand the remarkable discrepancy between TCNQ and FTCNQ, we calculated the percentage of ionized dopants and the hole densities in the P3HT matrix resulting from varied widths of the P3HT highest occupied molecular orbital (HOMO)-DOS via a semi-classical computational approach. We find that broadening of the DOS can yield the expected ionization percentages only if the dopants have significantly different tendencies to cause energetic disorder in the host matrix. In particular, while for TCNQ the doping behavior is well reproduced if the recently reported width of the P3HT HOMO-DOS is used, it must be broadened by almost one order of magnitude to comply with the ionization ratio determined for FTCNQ. Possible reasons for this discrepancy lie in the presence of a permanent dipole in FTCNQ, which highlights that electron affinities alone are not sufficient to define the strength of molecular dopants and their capability to perform integer-charge transfer with organic semiconductors.
Quantifying the effect of mastication on flaming and smouldering durations in eucalypt forests and woodlands under laboratory conditions
Authors: Cawson J. G. , Pickering B. , Penman T. D. , Filkov A.
Published: May 2021

Mechanical mastication is growing in popularity as a wildfire mitigation technique. Yet few studies quantify its effects on fire behaviour. Such information is needed by fire managers to evaluate its efficacy. Our aim was to develop an understanding of how mastication alters flaming and smouldering durations and the longevity of any effects. Flaming and smouldering duration are important determinants of soil heating and smoke emissions. We used a paired sampling design, collecting litter bed (hereafter surface fuel) samples from 15 sites with masticated and untreated vegetation in shrub-encroached Eucalyptus woodlands. We measured a range of fuel bed properties and then burnt the samples in the laboratory. Average smouldering durations increased 88% from 25 to 47 min in untreated v. masticated fuel; flaming durations increased 100% from 6 to 12 min. These changes were attributable to higher fine and coarse fuel loads in the masticated fuel bed. However, fine and coarse fuel load declined significantly over 4 years, meaning the effects of mastication on combustion duration are likely to be short-lived. Despite being a laboratory study, the results assist with evaluating mastication as a fuel treatment by demonstrating the potential magnitude of changes to flaming and smouldering duration.