bluuebunny/crossref_metadata_2025_split huggingface dataset:
Smart and sustainable agriculture through weather and climate informatics and multi-scale modelling.
Authors: Prashant Goswami Prashant Goswami , Rao E. V. S. P. 
Published: April 2021

Abstract
Most agricultural processes, from choice of crops to sowing schedule to harvest management, depend on a number of weather variables; shifts in the weather regimes due to climate change determine crop variability at regional levels. Thus, advance and accurate information on weather variables, and their quantitative relations to the crop processes (agro-weather informatics) as well as quantification of role of climate conditions in agricultural processes (agro-climate informatics) can play critical to enabling roles in sustainable and smart (optimal in terms of planning, resource utilization and adaptability) agriculture. In particular, agro-weather-climate informatics have scopes and challenges including but beyond those in agriculture or weather informatics in isolation. This review examines principles and the scope of applications of weather and climate informatics in some of the key areas of agriculture such as crop choice, irrigation, energy management and long-term sustainability. While a serious bottleneck in application of forecast-based agro-advisories is low reliability of the forecasts, methodology combining optimization of forecast model, assimilation of data, multi-scale modelling and design of evaluation strategy for specific farm advisories is possible, so that the forecasts are risk-free and yet useful in spite of their errors. We provide a brief overview of weather and climate forecasting at different scales and the general methodology used; this is followed by an overview of status of these applications at different timescales such as daily, seasonal and beyond for a variety of issues such as precision agriculture and pro-active control of crop diseases. The roles of high-performance computing and multi-platform observations, including remote sensing, are outlined. This is followed by our conclusions and perspectives.
More is less: Partisan ideology, changes of government, and policy integration reforms in the UK
Authors: Maggetti Martino , Trein Philipp 
Published: April 2021

ABSTRACT
Researchers have argued that political parties in government matter for policy integration reforms, but the way they do so remains somewhat undetermined. In this paper, we contribute to this literature by tackling two interrelated open questions: How does the presence of different political parties in government, which rely on policy programs on opposite sides of the ideological spectrum, shape the intensity of policy integration reforms? To what extent do changes in governing political parties affect the political motivation of policy integration reforms and thereby influence the goals and means of these reforms? To explore these questions, we examine a case where institutional capacity is generally favorable to such reforms. Specifically, we compare policy integration reforms in the UK under the New Labor government (1997–2010) with those passed by the Conservative governments (1979–1996), and by the coalition government of Conservatives and Liberal Democrats (2010–2014). We find that political parties’ policy positions, and respectively, their political motivations, decisively shape the intensity of policy integration reforms, as well as their substantial goals and means. Furthermore, our results imply that changes in governing parties increase the overall frequency but can reduce the coherence of reform programs over time. These results point to a paradox for the governance of problems through policy integration, whereby the presence of high institutional capacity as provided by a majoritarian system can have negative long-term consequences for policies aiming to solve complex problems.
Chaotic ultrasound generation using a nonlinear piezoelectric microtransducer
Authors: Defoort Martial , Rufer Libor , Basrour Skandar 
Published: April 2021

Abstract
We report on a piezoelectric micromachined ultrasonic transducer (PMUT) driven in a nonlinear regime, generating chaotic amplitude modulated ultrasonic waves. At large enough drives, the PMUT enters in the Duffing regime which opens a hysteresis with two available states. By modulating the frequency of the driving signal, the system may switch between both states, and selecting the appropriate modulation frequency enables to enter in the chaotic regime. The chaos is then imprinted as a modulation of the PMUT’s amplitude. We characterize this regime in the three accessible domains: electrical, mechanical and acoustic, and demonstrate they are fully correlated. We then focus on the generated acoustic signals and demonstrate that the chaotic modulation propagates according to the PMUT’s linear regime. Remarkably, the detected acoustic waves are strongly correlated to the on-chip piezoelectric measurements, regardless of the acoustic beam profile. The frequency spectrum of the chaotic modulation spreads around the ultrasonic carrier, mimicking a noise modulated carrier signal. We exploit this property for jamming applications where the chaotic PMUT is used to mask surrounding acoustic waves. Unlike most jamming applications, our approach does not require driving signals with a broad frequency spectrum, the noisy pattern arising directly from the structure’s dynamics. Using two PMUTs, one in the linear and the other in the nonlinear regime, we realize a proof-of-concept where the ultrasound generated by the first PMUT is drowned out by the chaotic PMUT signal. We demonstrate that the carrier frequency of the jamming PMUT does not need to match perfectly the one of the linear PMUT. This chaos generation is generic and could be adapted to any PMUT, and thanks to the rich frequency spectrum of the chaotic modulation, the frequency of the signal to jam does not need to be precisely known.
Influence of gas flow turbulence scale on heat exchange intensity in a long smooth pipe
Authors: Nevolin A M , Osipov L E , Plotnikov L V 
Published: April 2021

Abstract
It is known that the initial level of gas flow turbulence has a noticeable effect on the development and structure of the boundary layer and on the intensity of heat transfer, respectively. Many scientists have evaluated the influence of the flow turbulence number on the level of heat transfer for various applications, among them Dyban E.P., Kestin J., Simonich JC, Isomoto K., Dreitser G.A., Terekhov V.I., MacMullin R. and etc. In all cases, the turbulence of the flow led to the intensification of heat transfer. However, insufficient attention is paid to studies of the effect of turbulence on the heat transfer of flows in pipes. The studies were carried out on the basis of numerical modeling of gas dynamics and heat transfer of stationary flows based on the CFD method. The results of numerical modeling to assess the influence of the turbulence scale of gas flows on heat transfer in a long smooth pipe are presented in the article. It has been established that a growth in the heat transfer coefficient by about 3% occurs with an increase in the turbulence scale from 10 to 30% with a Reynolds number equal to 250,000.
The effect of surface structures on evaporation and free convection in evaporating sessile drops
Authors: Morozov V S 
Published: April 2021

Abstract
The effect of various surface structures of the AlMg6 aluminum-magnesium alloy on the evaporation rate and convection in a sessile droplet was experimentally studied. Structures on the surface were created using laser exposure. The evaporation of water droplets on heated structured surfaces was compared with a smooth wall. The wall temperature Tw = 68 °C. The data obtained for the evaporation rate without taking into account the diameter of the droplet base for a structured hydrophilic surface is 11-13% higher than for a smooth surface. The difference between structured hydrophilic and hydrophobic surfaces was 4-6%. The strongest effect of convection enhancement was observed for a structured hydrophobic surface.
Measurements of the gas composition in the flame during evaporating diesel fuel combustion with steam injection
Authors: Kopyev E P , Mukhina M A , Sadkin I S 
Published: April 2021

Abstract
This paper presents a study of the effect of superheated water steam on the combustion of liquid hydrocarbons such as diesel fuel. An experimental study of the content of intermediate components of the combustion process along the axis of flame symmetry inside the burner and in the external torch was carried out using a vaporizing burner with a forced superheated water steam supply to the area of incomplete oxidation of liquid hydrocarbon fuel. The values of oxygen, carbon monoxide, hydrogen, hydrocarbons, and carbon dioxide content were also obtained. It is shown that the content of flame intermediate components of the burner depends on operating parameters such as the steam flow rate or heated air flow rate and the type of the supplied substance.
Optical diagnostics of the temperature field of a hydrogen-air flame
Authors: Zolotukhina O S , Arbuzov V A , Arbuzov E V , Dubnishchev Yu N , Lukashov V V 
Published: April 2021

Abstract
A method for multi-wave optical diagnostics of phase structure and temperature fields in an axisymmetric hydrogen-air flame is discussed. An algorithm for numerical simulation of Hilbert images of phase fields reconstructed from radial temperature profiles and molar concentrations of combustion products using the Abel transform is developed and experimentally justified.
Dynamics of a soluble surfactant and evolution of daughterly concentration tongue in a Hele-Shaw cell
Authors: Demin V A , Petukhov M I 
Published: April 2021

Abstract
The origin and evolution of a concentration tongue, which is generated in the volume of a fluid due to the non-uniform desorption of a soluble surfactant, is investigated theoretically by the method of direct numerical simulation. Initially, a film of the soluble surfactant is located on the surface of the fluid that fills up the thin vertical rectangular slot (Hele – Shaw cell), heated non-uniformly from above. The intensity of desorption into the volume is determined by the compression of the film, caused by the Marangoni force, acting along the up boundary in opposite direction to the tangential component of temperature gradient. The dynamics of concentration tongue depends on the intensity of a creeping convective flow, which is produced in the volume jointly by the Archimedean and thermocapillary forces. The spatial motion of the fluid and the process of an admixture exchange between the surface and the volume in the Hele – Shaw cell are carried out in the plane of wide vertical boundaries of the cavity. This permits to simulate numerically and clearly visualize behaviour of the contaminants in multifarious fluid systems.
Maximum heat fluxes and features of heat transfer mechanisms with boiling during jet impingement cooling of electronics
Authors: Pukhovoy M V , Kunts K A , Spesivtsev S E , Kabov O A 
Published: April 2021

Abstract
The needs of microelectronics for heat removal are growing and have already exceeded the value of 1 kW/cm2. To assess the ability of jet impingement cooling to meet the growing requirements, a review of experimental studies was conducted. The review demonstrated both the lack of progress in increasing critical heat flux value over the past 30 years, and the fact that this technique is still considered effective and promising. The review showed that the movement to intensify heat transfer is in the same direction as in other promising cooling technologies. It is noted that the most productive heat transfer occurs in the region of the thinnest liquid film spreading from a free impingement liquid jet. New fundamental studies are discussed that note the significance of heat transfer values in a very thin liquid film, and this is important for the development of cooling technologies. Problems are formulated for the required detailed studies of highly dynamic processes in the boiling region of an ultrafine liquid film at the micro level, aimed at intensifying heat transfer.
Dependence of the temperature fields of a thin vertical wall on the intensity of the oncoming flow of a heated liquid
Authors: Mikhaylov A V , Grishkov V A , Berdnikov V S 
Published: April 2021

Abstract
The processes of the development of free convection of ethanol in the regimes of heating the vertical wall of a rectangular cavity are experimentally investigated. The hydrodynamics in the cavity and the dependence of the temperature field on the opposite thin vertical wall are studied. Non-stationary temperature fields on a thin wall were measured with a thermal imager. The experiments were carried out at different densities of heat fluxes on the heater and at a discrete set of heights of the liquid layers.
Plasma-chemical synthesis of zinc oxide nanotubes
Authors: Timerkaev B A , Felsinger V S , Kaleeva A A , Erlingayte E A , Uktamov J A , Nuriddinov H S 
Published: April 2021

Abstract
This research presents the results of the synthesis of zinc oxide nanotubes in electric arc plasma. The diameters of these nanotubes are about 120-150 nm, and the length is about several micrometers. Individual nanotubes can reach up to 1 mm. As electron microscopic studies have shown, zinc oxide nanotubes are a “matryoshka”: they are strung on a carbon nanotube. Firstly, a broken carbon nanotube with a diameter of about 30 nm is formed, and then a zinc oxide nanotube grows on it. Moreover, there is no contact between these nanotubes.
Synthesis of silicon spherical nanostructures in argon plasma
Authors: Timerkaev B A , Feltsinger V S , Gevorgian R K , Shaikhattorov R P , Kaleeva A A 
Published: April 2021

Abstract
The paper presents the results of the synthesis of silicon nanospheres (silicon fullerenes) in argon plasma. During the experiment, silicon atoms were evaporated from the surface of a single crystal using a plasma jet. Silicon atoms were entrained by the flow of argon plasma and, as the plasma cooled, formed in the form of spherical structures several atomic layers thick or in the form of silicon nanotubes. The diameters of silicon nanospheres range from 50 nm to 15 microns, and silicon nanotubes - from 40 to 100 nm.
Synthesis of silicon carbide in arc discharge in fuel oil
Authors: Timerkaev B A , Felzinger V S , Akhmetvaleeva A , Zainutdinova D A , Zalyalieva A A , Dautov G Y , Abramova D A 
Published: April 2021

Abstract
In this work, an experimental physical setup is proposed and a method for the synthesis of silicon carbide in an electric arc drowned into the thickness of hydrocarbon raw materials is described. Silicon carbide and carbon nanotubes were found in the deposits at the cathode. The resulting sample was analyzed using an optical microscope. And also confirmed the hardness of silicon carbide.
Formation of a powerful flow of steam-water plasma in a gas discharge with an aqueous solution cathode
Authors: Tazmeev G K , Tazmeev K K 
Published: April 2021

AbstractA powerful flow of steam-water plasma was created using a gas discharge with a aqueous solution cathode. For this purpose, plasma generators with a power in the range of 25-40 kW were developed and created. The problems of choosing the composition of an aqueous solution and its concentration were solved. The energy characteristics of plasma generators were investigated. It is shown that the thermal protection of the walls of discharge chamber can be carried out by supplying gas to the interelectrode gap.
Synthesis of nanodiamonds and carbon nanotubes in siliconargon arc
Authors: Timerkaev B A , Shaikhattarov R R , Gevorgyan R K , Ibragimov I S , Akhmetvaleeva A R 
Published: April 2021

Abstract
This paper presents the results of the synthesis of nanodiamonds and carbon nanotubes in silicon-argon plasma. At a pressure of 500 Torr in the plasma reactor, carbon atoms evaporated from the surface of the graphite anode of the electric arc. The peculiarity of the graphite anode was that small pieces of silicon were embedded on the surface of the anode. As a result of the experiment, nanodiamonds and carbon nanotubes were formed on the surface of the graphite cathode. The linear dimensions of nanodiamonds range from 10 to 50 nm. The diameters of carbon nanotubes range from 4 nm to 20 nm, and their length is from 100 to 2 microns.
Structural Design Optimization of the Top Beam of a Propeller Processing Machine Tool Using FEA Analysis
Authors: Zheng Wei , Huang Xiaoqing , Liu Shihao 
Published: April 2021

Abstract
Aiming to reduce the weight under its rigidity and strength restrictions of a propeller processing machine tool, structural design optimization of the top beam of the machine tool is carried out using FEA analysis approach. Based on static and modal analysis, both the thickness and the width of the rib are optimized and light-weighted, followed FEA analysis results demonstrate that although the maximum stress and deformation of the optimized structure go up slightly, but are still allowable. After optimization, the weight of the top beam is reduced by approximately 8.03% and the dynamic characteristics of the top beam are also enhanced, which is beneficial to the noise reduction of the machine tool.
Stress and Deformation Analysis of Oil-Free Air Scroll Compressor
Authors: Ullah Hanif , Bin Peng , Bocko Jozef , Pengcheng Zhang , Yubo Zhang 
Published: April 2021

Abstract
This paper examined the deformation and the distribution of von-mises stress on the fixed and orbiting scroll. The stress and deformation of the scroll plate has been achieved under thermal load, structural load and thermo-static load. The full process of compression is achieved by the meshing operation of the moving and fixed scroll during the compression process of the scroll compressor. In this process, the teeth of the scrolls are mainly subjected to the combined effect of temperature and gas force resulting in stress and deformation. The performance of the scroll compressor can be affected by the high stress and deformation of the scroll, so it is important to research the scrolls under different field conditions. In this paper we presented the scrolls specification and deformation of oil-free scroll compressor. This study will enable the researcher and designers to improve the workability of the scroll compressor, resulting in a good performance prototype.
Analysis Method for the Mass Center of Low Earth Orbit Remote Sensing in Orbit
Authors: Jinghao Xu , Wenjing Ding , Lei Zhang , Zhilong Zhang 
Published: April 2021

Abstract
A real-time method for estimating the mass center of low earth orbit (LEO) remote sensing satellite in orbit is introduced in this paper. LEO remote sensing satellite requires highly on calculating the position of its mass center, due to the need of precise orbit determination and attitude control. This article offers an analysis method for the factors that play a leading role in the change of the centroid of satellite in orbit, which are the consuming of satellite fuel, the circulation of satellite-to-ground data transmission antenna and rotation of solar arrays. The parameters for calculating the centroid of LEO remote sensing satellite are defined, and a formula for computing the position of the satellite mass center in orbit is proposed.
Numerical analysis of the effect of underpass construction on an existing bridge foundation
Authors: Elgamal Ahmed 
Published: April 2021

Abstract
Micropiles are used effectively in many ground improvement applications, such as increasing soil bearing capacity, reducing the settlement of existing foundations, strengthening existing foundations, and reducing lateral soil movement due to arching. In this research, the micropiles, a geotechnical supposed solution, have applied to maximize the benefit for all the mentioned features. The frictional resistance between the surface of micropiles and the surrounding soil is considered. Besides, the effect of the micropiles network is considered as a possible means for improvement. We have examined a case study in which micropiles of400 mm diameter and 13.00 m length were used to improve the bearing capacity of soil underlies the existing bridge foundations, reduce their settlement, and decrease the side-support system’s deformation. The models created for this study were used to simulate the proposed geotechnical solution.
Thickness-dependent gap energies in thin layers of Hf Te5
Authors: Belke C , Locmelis S , Thole L , Schmidt H , Behrens P , Haug R J 
Published: April 2021

Abstract
Hafnium pentatelluride (Hf Te5) is a layered two-dimensional material with various exotic properties. It is thought to be a topological insulator. Whereas bulk Hf Te5 has a small band gap, single layers are predicted to be a quantum spin hall insulator with a large band gap. Here we measured band gap energies for samples with varying thicknesses and found a clear increase of gap energies for the thinner samples. With decreasing thickness an increase of the measured band gap energies from 40 to 304 meV is observed.
Daily Motivational Text Messages to Promote Physical Activity in University Students: Results From a Microrandomized Trial
Authors: Figueroa Caroline A , Deliu Nina , Chakraborty Bibhas , Modiri Arghavan , Xu Jing , Aggarwal Jai , Jay Williams Joseph , Lyles Courtney , Aguilera Adrian 
Published: April 2021

Abstract

Background
Low physical activity is an important risk factor for common physical and mental disorders. Physical activity interventions delivered via smartphones can help users maintain and increase physical activity, but outcomes have been mixed.

Purpose
Here we assessed the effects of sending daily motivational and feedback text messages in a microrandomized clinical trial on changes in physical activity from one day to the next in a student population.

Methods
We included 93 participants who used a physical activity app, “DIAMANTE” for a period of 6 weeks. Every day, their phone pedometer passively tracked participants’ steps. They were microrandomized to receive different types of motivational messages, based on a cognitive-behavioral framework, and feedback on their steps. We used generalized estimation equation models to test the effectiveness of feedback and motivational messages on changes in steps from one day to the next.

Results
Sending any versus no text message initially resulted in an increase in daily steps (729 steps, p = .012), but this effect decreased over time. A multivariate analysis evaluating each text message category separately showed that the initial positive effect was driven by the motivational messages though the effect was small and trend-wise significant (717 steps; p = .083), but not the feedback messages (−276 steps, p = .4).

Conclusion
Sending motivational physical activity text messages based on a cognitive-behavioral framework may have a positive effect on increasing steps, but this decreases with time. Further work is needed to examine using personalization and contextualization to improve the efficacy of text-messaging interventions on physical activity outcomes.

ClinicalTrials.gov Identifier
NCT04440553.