bluuebunny/crossref_metadata_2025_split huggingface dataset:
Theoretical analyses of magnetoelectric effects for magnetostrictive/radial mode piezoelectric transformer composite under dual ac stress and magnetic field modulation
Authors: Xiao Ning , Wang Yao , Chen Lei , Wen Yumei , Wang Guoqiang , Li Ping , Xiao Rui , Ji Xiaojun , Han Tao 
Published: May 2021

Abstract
Magnetoelectric (ME) composite based on the converse magnetoelectric (CME) effect is promising for the high sensitivity dc and low-frequency magnetic field detection application, however, the performance is restricted by the stress modulation ability of piezoelectric phases and the narrow bandwidth. This work presents a nonlinear equivalent circuit model to design a new ME composite consisting of magnetostrictive layers/radial mode piezoelectric transformer/magnetostrictive layers under dual ac magnetic field and stress modulation. The theoretical model is based on the nonlinear constitutive relationships of magnetostrictive material, motion equation with imperfect interface condition, and improved ME equivalent circuit. This model cannot only predict the resonant ME effects of electrically modulated ME composite under the dual ac stress and magnetic field drive, but can also predict the conventional CME and mutual inductance effects separately. Specifically, the theoretical prediction indicates that with negligible extra power consumption, the dual modulated ME composite provides higher dc and low-frequency magnetic field sensitivity with frequency conversion method and significantly wider bandwidth compared to the conventional CME effect. Such theoretical predictions are further verified by the experimental results of Metglas/piezoelectric transformer/Metglas and Terfenol-D/piezoelectric transformer/Terfenol-D laminate. The theoretical study plays a guiding role in designing the new ME magnetometer with low power consumption, high sensitivity, and wide bandwidth.
Manipulation of the asymmetric Einstein–Podolsky–Rosen steering via coherent population transfer
Authors: Li Jingyan , Chen Quan 
Published: May 2021

Abstract
We investigate the Einstein–Podolsky–Rosen (EPR) steering of two cavity modes generated via four-wave mixing processes. For a three-level V-type configuration, a strong coherent field as a dressing field couples the atoms, and a weak coherent field as a control filed resonantly couples one dressed state to the auxiliary state. By using the approach of dressed states and Bogoliubov modes, we find that only one Bogoliubov mode is mediated into the interaction with the dressed atoms, and the other one is decoupled. Due to the presence of the coherent control filed, the channel for dressed state population transfer is established, which plays a key role in the generation of the asymmetric EPR steering of two cavity fields. It is shown that the one-way EPR steering can be manipulated by the Rabi frequencies of the control field and the cooperativity parameters.
HTS generator, cable and rectifier as a system for hybrid propulsion system
Authors: Kovalev K , Ivanov N , Shishov D. , Zanegin S. 
Published: May 2021

Abstract
Designing systems of future aircraft is a very complex task due to demanding requirements. Superconducting electrical machines and cables could be a solution due to their high specific power. Developing a system which includes an HTS generator, a rectifier, and an HTS cable needs application of analytical techniques. Besides, some optimization techniques should be used to choose proper device parameters in order to provide maximum specific power of the entire system. This paper describes the main principals of developing such a system and provides the results of preliminary calculation of the specification of the system with a 500kW output power.
Simulation of flow over high-lifted turbine cascade at low Reynolds numbers
Authors: Duben A P , Kozubskaya T K , Marakueva O V , Voroshnin D V 
Published: May 2021

Abstract
This paper is dedicated to the simulation of flow in the T106C high loaded turbine cascade. A presence of a laminar-turbulent transition at the suction side of the blade caused by the separation of the boundary layer leads to a significant increase in kinetic energy losses. Predictions using both RANS and scale-resolving methods are carried out. The RANS computations are performed by the SST and BSL-EARSM models with Abu-Ghannam and Shaw criterion of laminar-turbulent transition or the

γ
−

Re

θ
t

˜

model with different closing correlation dependencies. The hybrid RANS-LES IDDES method is used for scale-resolving simulations. The validation is done by comparing the numerical results with the experimental data on the isentropic Mach number along the blade surface and the relative total pressure losses at different Reynolds numbers. The RANS and IDDES results are comparatively analyzed. A strong dependence of all the numerical results on the incoming turbulent flow conditions is observed.
Developing a mathematical model and a computer program for a preliminary design of a transonic axial compressor
Authors: Borovkov A.I. , Galerkin Yu. B. , Solovieva O.A. , Drozdov A.A. , Rekstin A.F. , Semenovsky V.B. , Brodnev P.N. 
Published: May 2021

Abstract
This paper presents a mathematical model underlying the program for calculating and designing axial compressors. The process of calculating pressure loss in the elements of the axial compressor’s stage flow path is described. The loss coefficient consists of losses on the limiting surfaces, secondary losses and profile losses. The effect of roughness on the pressure loss is taken into account by introducing the corresponding empirical coefficient. An algorithm for calculating the blades’ and vanes’ angles of the impeller and the guide apparatus is presented by calculating the incidence angle and the lag angle of the flow. The flow lag angle is the sum of the lag angle of the flow on the profile and the lag angle due to viscous flow on the limiting surfaces.
Differential fluid mechanics – basis of the theory of flows with combustion
Authors: Chashechkin Yuli D. 
Published: May 2021

Abstract
The basis of invariant models is a system of fundamental equations with an empirical formula for the Gibbs potential and density. This paper presents an analysis of fast direct atomic-molecular, mechanical with a flow or wavy with a group velocity, and slow diffusion transfer of energy. The classification of components, including ligaments, waves, and vortices is given based on the compatibility condition, which determines the rank and the order of the linearized version of equations. The requirements for numerical and laboratory modeling are formulated. The structure of the flow near the strip and the rotating disk is studied. Comparison of calculations with the data of experiments carried out at the stands of the Unique science facilities “GFK IPMech RAS” is given. Expanding developed approaches to flows with combustion is discussed.
Finishing surface treatment of GTE parts with dry electropolishing
Authors: Krioni N.K. , Mingazhev A.D. , Gafarova V.A. 
Published: May 2021

Abstract
One of the major problems in GTE production is ensuring high performance of compressor blades. Existing methods of surface polishing have a number of disadvantages and, cannot ensure a high-quality surface of gas turbine engine blades. The most advanced method of polishing parts is the technology of dry electropolishing in the medium of granules (DEPG). However, the use of the DEPG method during polishing leads to defects. The study of the defect causes during DEPG allowed the authors of this paper to develop a brand new technology of dry tape electropolishing. This method made it possible to eliminate the disadvantages of DEPG and to ensure the specified geometric parameters of the blade airfoil.
Influence of operating conditions on the protective polyurethane coating for carbon fiber reinforced plastic blades of gas turbine engines
Authors: Orlov M A , Polikarpova I A , Storozhuk I P , Afanasiev D V , Solodilov V I , Kireinov A V , Shapagin A V 
Published: May 2021

Abstract
The article presents research results of protective coating, which is a two-component composition based on polyurethane, developed in Bauman Moscow State Technical University, in operating conditions. The influence of sea water and negative temperature on the properties of carbon fiber reinforced plastic with protective coatings, as well as resistance to erosion wear, was determined. It is shown that the developed coating has high performance properties and resistance to erosion wear compared to existing commercial coatings certified by Boeing, Pratt & Whitney and Airbus.
Dynamic loading of spur gears with linear tooth profile modification: modelling and experimental comparisons
Authors: Kalinin D V 
Published: May 2021

Abstract
A dynamic model of a gear pair has been developed to investigate methods of decreasing dynamic loads and analysing dynamic stresses of gears in aviation engine drives. The effect of tooth profile modification on dynamic stresses in the system, as well as the effect of main gear parameters is analysed. It is shown that high level of dynamic stresses and vibrations in gears may be caused by using standard parameters of tooth profile modification. An experimental study of the dynamics of gears with various profile modification parameters has been carried out. The paper shows the necessity of changing the approach to calculating parameters of tooth profile modification of teeth.
A study on the operation of a gas turbine unit using hydrogen as fuel
Authors: Marin G E , Mendeleev D I , Osipov B M 
Published: May 2021

Abstract
The last decade has been driven by the impact of environmental challenges on the energy industry. Decarburization policy is the driver of the global energy transition. Hydrogen can be used as an alternative to natural gas, kerosene, and diesel fuel. A large-scale conversion of generating equipment to hydrogen fuel would significantly reduce carbon impact on the world because the product of hydrogen combustion is water. This paper focuses on the combustion of pure hydrogen in a GE 6FA power gas turbine. A mathematical model has been created in the AS GRET software package. During the simulation, the operation of a gas turbine unit in the load range from 40 to 77 MW was considered. As a result, the dependences of fuel consumption, enthalpy, and air consumption depending on the load were obtained. The value of the heat of the exhaust gases was also obtained.
Developing a critical technologies roadmap for next generation hybrid and electric commuter airplanes
Authors: Sukharev A A , Ovdienko M A , Varyukhin A N , Zakharchenko V S , Galperin S B , Fomin A V 
Published: May 2021

Abstract
Using hybrid and electric propulsion systems (HPS and EPS) as part of commuter airplanes provides a wide range of opportunities for creating fundamentally new aircraft configurations. The main idea is that HPS and EPS allow for flexible aircraft energy redistribution. Therefore, the propulsion system’s efficiency increases, which leads to a decrease of its environmental impact and improves its economic performance. The main barrier to implementing new HPS and EPS commuter airplanes concepts is the inadequate level of technological advancements. This paper covers the review of promising concepts of propulsion systems, and provides the list and the required level of technical perfection for technologies necessary for future commuter airplanes.
Innovative Management of Design Concepts Research and International Cooperation on EU Programs for creating Hybrid Electric Aircraft & Airship
Authors: Ravikovich Yu , Ponyaev L , Klusachek M 
Published: May 2021

Abstract
Fast and expanded implementation of the most relevant innovative developments is becoming a fundamental trend in the strategy of breakthrough economic development of advanced countries. However, today finding and implementing any original idea or a new scientific discovery or technological solution requires more and more tool costs. It is necessary to use highly valuable experience of smart specialists and provide considerable financial support for foreign economic cooperation and targeted scientific interaction on an international level. MAI was included in two international consortiums for the new European programs INEA 2020-2023 to create new promising environmental models of Hybrid Electric Propulsion systems for FUTPRINT50 and IMOTHEP regional passenger aircraft projects.
Characterization of magnetic Czochralski silicon devices with aluminium oxide field insulator: effect of oxygen precursor on electrical properties and radiation hardness
Authors: Ott J. , Bharthuar S. , Gädda A. , Arsenovich T. , Bezak M. , Brücken E. , Golovleva M. , Härkönen J. , Kalliokoski M. , Karadzhinova-Ferrer A. , Kirschenmann S. , Litichevskyi V. , Luukka P. , Martikainen L. , Naaranoja T. 
Published: May 2021

Abstract
Aluminium oxide (Al2O3) has been proposed as an alternative to thermal silicon dioxide (SiO2) as field insulator and surface passivation for silicon detectors, where it could substitute p-stop/p-spray insulation implants between pixels due to its negative oxide charge, and enable capacitive coupling of segments by means of its higher dielectric constant.
Al2O3 is commonly grown by atomic layer deposition (ALD), which allows the deposition of thin layers with excellent precision.

In this work, we report the electrical characterization of single pad detectors (diodes) and MOS capacitors fabricated on magnetic Czochralski silicon substrates and using Al2O3 as field insulator. Devices are studied by capacitance-voltage, current-voltage, and transient current technique measurements. We evaluate the influence of the oxygen precursors in the ALD process, as well as the effect of gamma irradiation, on the properties of these devices. We observe that leakage currents in diodes before the onset of breakdown are low for all studied ALD processes. Charge collection as measured by transient current technique (TCT) is also independent of the choice of oxygen precursor. The Al2O3 films deposited with O3 possess a higher negative oxide charge than films deposited by H2O, However, in diodes a higher oxide charge is linked to earlier breakdown, as has been predicted by simulation studies. A combination of H2and O3 precursors results in a good compromise between the beneficial properties provided by the respective individual precursors.
Controllable performance of a dopamine-modified silk fibroin-based bio-adhesive by doping metal ions
Authors: Yin Zichu , Liu Han , Lin Minjie , Xie Wenjiao , Yang Xiaogang , Cai Yurong 
Published: May 2021

Abstract
Bio-adhesives are essential for wound healing because of their convenience and safety. Although widely used as biomaterials, silk fibroin’s (SF’s) further application as bio-adhesive is hindered due to its weak stickiness with tissue and slow gelation speed. Here, a dopamine-modified SF-based bio-adhesive is fabricated by using genipin as the chemical cross-linking agent. Furthermore, metal ions have been used to adjust the adhesion property of the bio-adhesive. The experimental results shows that the dopamine-modified SF-based composite holds a better stickiness except slow gelation speed. The doping of Cu2+ and Fe3+ can accelerate the gelation of the bio-adhesive. Compared with Cu2+, Fe3+ has a stronger effect on the gelation speed of the bio-adhesive, which is positive correlative to the concentration of Fe3+. The adhesive has injectability and degradability. In addition, the SF-based adhesive has good biocompatibility and good improvement for cell migration in vitro. The SF-based bio-adhesive holds potential application in the field of rapid fixation of wounds.
Estimation of winter soil cover by vegetation before spring-sown crops for mainland France using multispectral satellite imagery
Authors: Nowak Benjamin , Marliac Gaëlle , Michaud Audrey 
Published: May 2021

Abstract
Winter soil cover by vegetation is associated with multiple benefits. In this study, winter soil cover rate before spring-sown crops was estimated for mainland France from multispectral imagery. For 67% and 84% of the area under spring-sown crops for years 2018 and 2019, soil cover during the previous winter was estimated through the computation of the Normalized Difference Vegetation Index (NDVI), using Sentinel-2 multispectral images. At country scale, winter soil cover rate before spring-sown crops was estimated between 37% and 48% for 2018 and between 31% and 43% for 2019, depending on the NDVI threshold for a soil to be considered covered by at least 50% of vegetation. Spatial patterns were relatively similar between the two years studied, highlighting strong heterogeneities between French departments. Cropping systems may explain some of these heterogeneities, as it has been shown that there is a large variability in the soil cover rate between spring-sown crops, but also depending on the previous crop. Winter soil cover rate was higher for crops associated with livestock production, such as maize silage (between 59% and 74% of plots covered before this crop). It was also shown that winter soil cover could be ensured by other means than cover crops: temporary grasslands were the previous crop with the highest soil cover, probably due to late ploughing. For these reasons, mixed systems combining livestock and crop productions may be a solution to increase winter soil cover before spring-sown crops.
Mating Communication of the Variegated Leafhopper, Erasmoneura variabilis, With Notes on Vibrational Signaling of Other Grapevine Cicadellids in California
Authors: Krugner Rodrigo , Gordon Shira D 
Published: May 2021

Abstract
Leafhoppers in the tribe Erythroneurini are a concern for grape growers in California due to direct feeding damage by piercing the leaves. Management of leafhopper populations in vineyards may be accomplished by insecticide applications, the release of natural enemies, conservation biological control, exploitation of controlled deficit irrigation, or a combination of the above. Based on research on other leafhopper species, a behavioral mating disruption is a viable option, but nothing is known about the mating communication and circadian signaling of these species in vineyards. The objectives of this study were to identify and describe vibrational signals associated with mate selection behavior of Erasmoneura variabilis and Erythroneura ziczac, and evaluate the occurrence of vibrational signals within sympatric populations of E. variabilis, E. ziczac, and Homalodisca vitripennis on grapevines. Analysis of vibrational communication signals revealed that 1) one female signal and two distinct male signals are used in E. variabilis pair formation, 2) the pair formation process in E. variabilis is divided into three communication phases, 3) E. variabilis pre-copulatory communication is longer in the presence than in the absence of male-male rivalry, 4) two distinct signals are used in E. ziczac pair formation, and 5) E. variabilis, E. ziczac, and H. vitripennis sing at night and during the day. Results include detailed descriptions of leafhopper communication signals that are relevant for future development of vibrational disruption as a novel method to suppress populations under field conditions.
Microbial Etiologies and Clinical Characteristics of Children Seeking Emergency Department Care Due to Vomiting in the Absence of Diarrhea
Authors: Freedman Stephen B , Xie Jianling , Lee Bonita E , Ali Samina , Pang Xiao-Li , Chui Linda , Zhuo Ran , Vanderkooi Otto G , Tellier Raymond , Funk Anna L , Tarr Phillip I 
Published: May 2021

Abstract

Background
As children with isolated vomiting are rarely able to provide a specimen suitable for routine pathogen testing, we have limited knowledge about their infecting pathogens.

Methods
Between December 2014 and August 2018, children &lt;18 years old with presumed acute gastroenteritis who presented to 2 emergency departments (EDs) in Alberta, Canada, were recruited. Eligible participants had ≥3 episodes of vomiting and/or diarrhea in a 24-hour period, &lt;7 days of symptoms, and provided a rectal swab or stool specimen. We quantified the proportion of children with isolated vomiting in whom an enteropathogen was identified, and analyzed clinical characteristics, types of enteropathogens, resources used, and alternative diagnoses.

Results
Of the 2695 participants, at the ED visit, 295 (10.9%), 1321 (49.0%), and 1079 (40.0%) reported having isolated diarrhea, vomiting and diarrhea, or isolated vomiting, respectively. An enteropathogen was detected most commonly in those with vomiting and diarrhea (1067/1321; 80.8%); detection did not differ between those with isolated diarrhea (170/295; 57.6%) and isolated vomiting (589/1079; 54.6%) (95% confidence interval of the difference: −3.4%, 9.3%). Children with isolated vomiting most often had a virus (557/1077; 51.7%), most commonly norovirus (321/1077; 29.8%); 5.7% (62/1079) had a bacterial pathogen. X-rays, ultrasounds, and urine tests were most commonly performed in children with isolated vomiting. Alternate etiologies were most common in those with isolated vomiting (5.7%; 61/1079).

Conclusions
The rate of enteropathogen identification in children with isolated vomiting using molecular diagnostic tests and rectal swabs is substantial. Molecular diagnostics offer an emerging diagnostic strategy in children with isolated vomiting.
Social Communication across Reproductive Boundaries: Hormones and the Auditory Periphery of Songbirds and Frogs
Authors: Gall Megan D , Baugh Alexander T , Lucas Jeffrey R , Bee Mark A 
Published: May 2021

Synopsis
Most animals experience reproductive transitions in their lives; for example, reaching reproductive maturity or cycling in and out of breeding condition. Some reproductive transitions are abrupt, while others are more gradual. In most cases, changes in communication between the sexes follow the time course of these reproductive transitions and are typically thought to be coordinated by steroid hormones. We know a great deal about hormonal control of communication behaviors in birds and frogs, as well as the central neural control of these behaviors. There has also been significant interest in the effects of steroid hormones on central nervous system structures that control both the production and reception of communication signals associated with reproductive behaviors. However, peripheral sensory structures have typically received less attention, although there has been growing interest in recent years. It is becoming clear that peripheral sensory systems play an important role in reproductive communication, are plastic across reproductive conditions, and, in some cases, this plasticity may be mediated by steroid hormones. In this article, we discuss recent evidence for the role of peripheral auditory structures in reproductive communication in birds and frogs, the plasticity of the peripheral auditory system, and the role of steroid hormones in mediating the effects of the peripheral auditory system on reproductive communication. We focus on both seasonal and acute reproductive transitions, introduce new data on the role of hormones in modulating seasonal patterns, and make recommendations for future work.
Mustafin Models of Projective Varieties and Vector Bundles
Authors: Hahn Marvin Anas 
Published: May 2021

Abstract
Mustafin varieties are well-studied degenerations of projective spaces induced by a choice of integral points in a Bruhat–Tits building. In recent work, Annette Werner and the author initiated the study of degenerations of plane curves obtained by Mustafin varieties by means of arithmetic geometry. Moreover, we applied these techniques to construct models of vector bundles on plane curves with strongly semistable reduction. In this work, we take a Groebner basis approach to the more general problem of studying degenerations of projective varieties. Our methods include determining the behaviour of Groebner bases under substitution over unique factorisation rings. Finally, we outline applications to the $p-$adic Simpson correspondence, when the respective projective variety is a curve.