scholarly journals Mathematical models and methods of numerical investigation of processes which accompany aircraft icing

2021 ◽  
Vol 33 (5) ◽  
pp. 237-248
Author(s):  
Ivan Alekseevich Amelyushkin ◽  
Maksim Aleksandrovich Kudrov ◽  
Alexey Olegovich Morozov ◽  
Andrey Sergeevich Shcheglov
Keyword(s):  
Numerical Modeling ◽  
Mathematical Models ◽  
High Performance ◽  
Practical Importance ◽  
Particle Dynamics ◽  
Software Systems ◽  
Aircraft Icing ◽  
Properties Of Coatings ◽  
Practical Applications ◽  
Physical And Mathematical Models

The study of aircraft icing modes, in which it is necessary to take into account the effect of droplet crushing, is of great interest in calculating the icing of aircraft, optimizing the hydrophobic and anti-icing properties of coatings, and is relevant in a number of other practical applications. Of great practical importance is the development of high-performance methods for calculating the interaction of aerosol flows with a solid. This work is devoted to the development of a model of particle dynamics, as well as a model of fragmentation of supercooled droplets of an aerosol flow during its interaction with the surface of a streamlined body. Developed physical and mathematical models can be used in software systems for numerical modeling of aircraft icing.

Physical and mathematical models of ballast bed tamping via rotary device

2016 ◽  
pp. 5-16
Author(s):  
Nikita Polyanichko
Keyword(s):  
Mathematical Model ◽  
Mathematical Models ◽  
Operation Mode ◽  
Practical Importance ◽  
Theoretical Research ◽  
Technological Parameters ◽  
Physical Experiments ◽  
Physical And Mathematical Models ◽  
The Mathematical Model ◽  
Rotary Device

Objective: To develop a mathematical model and program for defining rational technological parameters and operation mode of a rotary device for tamping the ballast bed in the tie space area. Establish the veracity of calculations performed using the mathematical model and program developed via mathematical and physical experiments. Methods: Experimental and theoretical research conducted. Results: Established veracity of the mathematical model and program for calculating the technological parameters and operation mode of the device for tamping the ballastbed in the tie space area. Practical importance: The program developed provides the ability to select rational technological parameters and operation mode for the device. It is recommended that it be used when creating tools for ballast bed solidification in the ballast box area.

scholarly journals DICHOTOMOUS MARKOV NOISE: EXACT RESULTS FOR OUT-OF-EQUILIBRIUM SYSTEMS

2006 ◽  
Vol 20 (20) ◽  
pp. 2825-2888 ◽  
Author(s):  
IOANA BENA
Keyword(s):  
Mathematical Models ◽  
White Noise ◽  
Gaussian White Noise ◽  
Stokes Drift ◽  
Nonequilibrium Systems ◽  
Exact Results ◽  
Asymptotic Regime ◽  
Practical Applications ◽  
Long Time ◽  
Physical And Mathematical Models

Nonequilibrium systems driven by additive or multiplicative dichotomous Markov noise appear in a wide variety of physical and mathematical models. We review here some prototypical examples, with an emphasis on analytically-solvable situations. In particular, it has escaped attention till recently that the standard results for the long-time properties of such systems cannot be applied when unstable fixed points are crossed in the asymptotic regime. We show how calculations have to be modified to deal with these cases and present a few relevant applications — the hypersensitive transport, the rocking ratchet, and the stochastic Stokes' drift. These results reinforce the impression that dichotomous noise can be put on par with Gaussian white noise as far as obtaining analytical results is concerned. They convincingly illustrate the interplay between noise and nonlinearity in generating nontrivial behaviors of nonequilibrium systems and point to various practical applications.

Hybrid Model using Firefly and BBO for Feature Selection in Software Product Line

2020 ◽  
Vol 13 ◽  
Author(s):  
Hitesh Yadav ◽  
Rita Chhikara ◽  
Charan Kumari
Keyword(s):  
Hybrid Model ◽  
High Performance ◽  
Software Product Line ◽  
Product Line ◽  
Feature Model ◽  
Software Systems ◽  
Feature Sets ◽  
Research Article ◽  
Software Product ◽  
Multiple Variants

Background: Software Product Line is the group of multiple software systems which share the similar set of features with multiple variants. Feature model is used to capture and organize features used in different multiple organization. Objective: The objective of this research article is to obtain an optimized subset of features which are capable of providing high performance. Methods: In order to achieve the desired objective, two methods have been proposed. a) An improved objective function which is used to compute the contribution of each feature with weight based methodology. b) A hybrid model is employed to optimize the Software Product Line problem. Results: Feature sets varying in size from 100 to 1000 have been used to compute the performance of the Software Product Line. Conclusion: The results shows that proposed hybrid model outperforms the state of art metaheuristic algorithms.

scholarly journals Flux Method Growth of Large Size Group IV–V 2D GeP Single Crystals and Photoresponse Application

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 235
Author(s):  
Shuqi Zhao ◽  
Tongtong Yu ◽  
Ziming Wang ◽  
Shilei Wang ◽  
Limei Wei ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Single Crystals ◽  
High Performance ◽  
Group Iv ◽  
X Ray Diffraction ◽  
High Quality ◽  
Practical Applications ◽  
Large Size ◽  
Growth Method ◽  
Polarized Raman

Two-dimensional (2D) materials driven by their unique electronic and optoelectronic properties have opened up possibilities for their various applications. The large and high-quality single crystals are essential to fabricate high-performance 2D devices for practical applications. Herein, IV-V 2D GeP single crystals with high-quality and large size of 20 × 15 × 5 mm3 were successfully grown by the Bi flux growth method. The crystalline quality of GeP was confirmed by high-resolution X-ray diffraction (HRXRD), Laue diffraction, electron probe microanalysis (EPMA) and Raman spectroscopy. Additionally, intrinsic anisotropic optical properties were investigated by angle-resolved polarized Raman spectroscopy (ARPRS) and transmission spectra in detail. Furthermore, we fabricated high-performance photodetectors based on GeP, presenting a relatively large photocurrent over 3 mA. More generally, our results will significantly contribute the GeP crystal to the wide optoelectronic applications.

scholarly journals Copper-graphene heterostructure for back-end-of-line compatible high-performance interconnects

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Myungwoo Son ◽  
Jaewon Jang ◽  
Yongsu Lee ◽  
Jungtae Nam ◽  
Jun Yeon Hwang ◽  
...  
Keyword(s):  
High Performance ◽  
Direct Synthesis ◽  
Chemical Vapor ◽  
Multilayer Graphene ◽  
Time To Failure ◽  
Practical Applications ◽  
Cu Interconnects ◽  
Pressure Chemical ◽  
Cu Interconnect ◽  
Pure Cu

AbstractHere, we demonstrate the fabrication of a Cu-graphene heterostructure interconnect by the direct synthesis of graphene on a Cu interconnect with an enhanced performance. Multilayer graphene films were synthesized on Cu interconnect patterns using a liquid benzene or pyridine source at 400 °C by atmospheric pressure chemical vapor deposition (APCVD). The graphene-capped Cu interconnects showed lower resistivity, higher breakdown current density, and improved reliability compared with those of pure Cu interconnects. In addition, an increase in the carrier density of graphene by doping drastically enhanced the reliability of the graphene-capped interconnect with a mean time to failure of >106 s at 100 °C under a continuous DC stress of 3 MA cm−2. Furthermore, the graphene-capped Cu heterostructure exhibited enhanced electrical properties and reliability even if it was a damascene-patterned structure, which indicates compatibility with practical applications such as next-generation interconnect materials in CMOS back-end-of-line (BEOL).

scholarly journals Biosensing with optical fiber gratings

Nanophotonics ◽  
2017 ◽  
Vol 6 (4) ◽  
pp. 663-679 ◽  
Author(s):  
Francesco Chiavaioli ◽  
Francesco Baldini ◽  
Sara Tombelli ◽  
Cosimo Trono ◽  
Ambra Giannetti
Keyword(s):  
Optical Fiber ◽  
Single Molecule ◽  
High Performance ◽  
Performance Metrics ◽  
Surrounding Medium ◽  
Remote Measurement ◽  
Fiber Gratings ◽  
Practical Applications ◽  
Technology Platforms ◽  
Optical Fiber Gratings

AbstractOptical fiber gratings (OFGs), especially long-period gratings (LPGs) and etched or tilted fiber Bragg gratings (FBGs), are playing an increasing role in the chemical and biochemical sensing based on the measurement of a surface refractive index (RI) change through a label-free configuration. In these devices, the electric field evanescent wave at the fiber/surrounding medium interface changes its optical properties (i.e. intensity and wavelength) as a result of the RI variation due to the interaction between a biological recognition layer deposited over the fiber and the analyte under investigation. The use of OFG-based technology platforms takes the advantages of optical fiber peculiarities, which are hardly offered by the other sensing systems, such as compactness, lightness, high compatibility with optoelectronic devices (both sources and detectors), and multiplexing and remote measurement capability as the signal is spectrally modulated. During the last decade, the growing request in practical applications pushed the technology behind the OFG-based sensors over its limits by means of the deposition of thin film overlays, nanocoatings, and nanostructures, in general. Here, we review efforts toward utilizing these nanomaterials as coatings for high-performance and low-detection limit devices. Moreover, we review the recent development in OFG-based biosensing and identify some of the key challenges for practical applications. While high-performance metrics are starting to be achieved experimentally, there are still open questions pertaining to an effective and reliable detection of small molecules, possibly up to single molecule, sensing in vivo and multi-target detection using OFG-based technology platforms.

An Air Texturing Process for Hybridization of Different Reinforcement Filament Yarns by Commingling Process

2006 ◽  
Vol 532-533 ◽  
pp. 333-336 ◽  
Author(s):  
Bok Choon Kang ◽  
Chathura Nalendra Herath ◽  
Jong Kwang Park ◽  
Yong Hwang Roh
Keyword(s):  
High Performance ◽  
Process Development ◽  
Glass Fibers ◽  
Air Pressure ◽  
Practical Applications ◽  
Advantages And Disadvantages ◽  
Significant Parameter ◽  
Air Jet ◽  
Yarn Count ◽  
Air Nozzle

Carbon, aramid and glass fibers are inherently superior to conventional textile fibers in terms of mechanical properties and other characteristics. However, each material has its inherent advantages and disadvantages and it is usually recommended to hybridize them to fully benefit of their high performance in practical applications to many products. This paper is concerned with an air texturing process for hybridization of different reinforcement filament yarns. A normal air texturing machine was selected for process development and modified to suit testing purposes. The modified process for hybridization was introduced mainly in terms of air-jet nozzles employed in experiments. With the proposed air texturing process machine, three types of air-nozzle were applied to the experimental work. Three different filament materials were employed in experiments and they are carbon (CF), aramid (AF), and glass (GF). As matrix materials, polyether-ether (PEEK), polyester (PES), and polypropylene (PP) were selected and experimented. Hybrid yarns produced form the proposed process was evaluated optically in terms of bulkiness, arranging, breaking, and mixing, respectively. The experimental results were also summarized in terms of relationships between applied air pressure and yarn count, and variation in count. As a whole, it was concluded from the experiments that the proposed texturing process could be successfully applied to the practical hybridization of different reinforcement filament yarns. It was also revealed from the experiments that the air pressure in the proposed process is not a significant parameter on the pressing in terms of yarn count.

Building sponge-like robust architectures of CNT–graphene–Si composites with enhanced rate and cycling performance for lithium-ion batteries

2015 ◽  
Vol 3 (7) ◽  
pp. 3962-3967 ◽  
Author(s):  
Xiaolei Wang ◽  
Ge Li ◽  
Fathy M. Hassan ◽  
Matthew Li ◽  
Kun Feng ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Anode Materials ◽  
High Performance ◽  
Rate Capability ◽  
Lithium Ion ◽  
Cycling Performance ◽  
Cycling Stability ◽  
Great Promise ◽  
Practical Applications ◽  
Excellent Cycling Stability

High-performance robust CNT–graphene–Si composites are designed as anode materials with enhanced rate capability and excellent cycling stability for lithium-ion batteries. Such an improvement is mainly attributed to the robust sponge-like architecture, which holds great promise in future practical applications.

Selective Use of High Performance Cementitious Composites in Concrete Structures

2008 ◽  
Vol 400-402 ◽  
pp. 27-36
Author(s):  
Christopher K.Y. Leung
Keyword(s):  
High Performance ◽  
Concrete Structures ◽  
Cementitious Composites ◽  
Conventional Concrete ◽  
Practical Applications ◽  
Concrete Members ◽  
High Performance Fiber ◽  
Cast Concrete ◽  
Good Potential ◽  
Concrete Science

Recent advancements in concrete science and technology have made possible the development of high performance fiber reinforced cementitious composites (HPFRCC) with excellent mechanical properties and long-term durability. However, the costs of these materials are many times that of conventional concrete and the construction of complete structures with them is hard to justify. The strategic application of high performance materials, in selected parts of concrete structures, can bring along higher performance/cost and wider acceptance of the material in practice. This paper will investigate several examples of selective HPFRCC application, including the fabrication of permanent formwork for durability enhancement, the replacement of steel reinforcements at the anchorage zone of post-tensioned members to relieve the steel congestion problem as well as the development of simple and narrow joints for pre-cast concrete members. Based on the experimental results obtained so far, the selected use of HPFRCC in concrete structures appears to have good potential for practical applications.

A waste biomass derived hard carbon as a high-performance anode material for sodium-ion batteries

2016 ◽  
Vol 4 (34) ◽  
pp. 13046-13052 ◽  
Author(s):  
Pin Liu ◽  
Yunming Li ◽  
Yong-Sheng Hu ◽  
Hong Li ◽  
Liquan Chen ◽  
...  
Keyword(s):  
Anode Material ◽  
High Performance ◽  
Coulombic Efficiency ◽  
Low Cost ◽  
Sodium Ion ◽  
Cycle Performance ◽  
Sodium Ion Batteries ◽  
Waste Biomass ◽  
Hard Carbon ◽  
Practical Applications

This study reports a hard carbon material derived from a waste biomass of corn cob and the influence of carbonized temperature on electrochemical performance. This study provides a promising anode material with low cost, high initial coulombic efficiency and excellent cycle performance, making sodium-ion batteries closer to practical applications.

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