Heat treatment of large-scale rolling machine rolls by high-power gas dynamic laser at Cherepovetz Metallurgy Works

AbstractLithium-ion capacitors are envisaged as promising energy-storage devices to simultaneously achieve a large energy density and high-power output at quick charge and discharge rates. However, the mismatched kinetics between capacitive cathodes and faradaic anodes still hinder their practical application for high-power purposes. To tackle this problem, the electron and ion transport of both electrodes should be substantially improved by targeted structural design and controllable chemical doping. Herein, nitrogen-enriched graphene frameworks are prepared via a large-scale and ultrafast magnesiothermic combustion synthesis using CO2 and melamine as precursors, which exhibit a crosslinked porous structure, abundant functional groups and high electrical conductivity (10524 S m−1). The material essentially delivers upgraded kinetics due to enhanced ion diffusion and electron transport. Excellent capacities of 1361 mA h g−1 and 827 mA h g−1 can be achieved at current densities of 0.1 A g−1 and 3 A g−1, respectively, demonstrating its outstanding lithium storage performance at both low and high rates. Moreover, the lithium-ion capacitor based on these nitrogen-enriched graphene frameworks displays a high energy density of 151 Wh kg−1, and still retains 86 Wh kg−1 even at an ultrahigh power output of 49 kW kg−1. This study reveals an effective pathway to achieve synergistic kinetics in carbon electrode materials for achieving high-power lithium-ion capacitors.

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Suppression of amplitude modulation induced by polarization mode dispersion using a multi-degree-of-freedom fiber filter

High Power Laser Science and Engineering ◽

10.1017/hpl.2018.48 ◽

2018 ◽

Vol 6 ◽

Author(s):

Rao Li ◽

Youen Jiang ◽

Zhi Qiao ◽

Canhong Huang ◽

Wei Fan ◽

...

Keyword(s):

High Power ◽

Amplitude Modulation ◽

Transmission Spectrum ◽

High Speed ◽

Large Scale ◽

Modulation Depth ◽

Free Spectral Range ◽

Polarization Mode Dispersion ◽

Polarization Mode ◽

Mode Dispersion

Polarization mode dispersion (PMD) in fibers for high-power lasers can induce significant frequency modulation to amplitude modulation (FM-to-AM) conversion. However, existing techniques are not sufficiently flexible to achieve efficient compensation for such FM-to-AM conversion. By analyzing the nonuniform transmission spectrum caused by PMD, we found that the large-scale envelope of the transmission spectrum has more serious impacts on the amount of AM. In order to suppress the PMD-induced FM-to-AM conversion, we propose a novel tunable spectral filter with multiple degrees of freedom based on a half-wave plate, a nematic liquid crystal, and an axis-rotated polarization-maintaining fiber. Peak wavelength, free spectral range (FSR), and modulation depth of the filter are decoupled and can be controlled independently, which is verified through both simulations and experiments. The filter is utilized to compensate for the PMD-induced FM-to-AM conversion in the front end of a high-power laser facility. The results indicate that, for a pulse with phase-modulation frequency of 22.82 GHz, the FM-to-AM conversion could be reduced from 18% to 3.2% within a short time and maintained below 6.5% for 3 h. The proposed filter is also promising for other applications that require flexible spectral control such as high-speed channel selection in optical communication networks.

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Peculiarities of Excitation of Large-Scale Plasma Density Irregularities During Modification of the Ionospheric F 2 Region by High-Power HF Radio Waves

Radiophysics and Quantum Electronics ◽

10.1007/s11141-016-9644-3 ◽

2016 ◽

Vol 58 (10) ◽

pp. 717-728 ◽

Cited By ~ 4

Author(s):

V. L. Frolov ◽

E. A. Schorokhova ◽

V. E. Kunitsyn ◽

E. S. Andreeva ◽

A. M. Padokhin

Keyword(s):

Plasma Density ◽

High Power ◽

Large Scale ◽

Radio Waves

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Exhaustive Modal Analysis of Large-Scale Interconnected Power Systems With High Power Electronics Penetration

IEEE Transactions on Power Systems ◽

10.1109/tpwrs.2020.2969641 ◽

2020 ◽

Vol 35 (4) ◽

pp. 2759-2768

Author(s):

Mohamed Kouki ◽

Bogdan Marinescu ◽

Florent Xavier

Keyword(s):

Power Systems ◽

Modal Analysis ◽

Power Electronics ◽

High Power ◽

Large Scale ◽

Interconnected Power Systems

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Simulation study of the large-scale modification of the mid-latitude F-layer by HF radio waves with different powers

Annales Geophysicae ◽

10.5194/angeo-30-1213-2012 ◽

2012 ◽

Vol 30 (8) ◽

pp. 1213-1222 ◽

Cited By ~ 2

Author(s):

G. I. Mingaleva ◽

V. S. Mingalev ◽

O. V. Mingalev

Keyword(s):

Mathematical Model ◽

Simulation Study ◽

High Power ◽

Large Scale ◽

Radio Waves ◽

Effective Frequency ◽

Heating Facility ◽

Absorbed Power

Abstract. A mathematical model of the ionosphere, developed earlier, is applied to investigate the large-scale mid-latitude F-layer modification by HF radio waves with different powers. Simulations are performed for the point with geographic coordinates of the "Sura" heating facility (Nizhny Novgorod, Russia) for autumn conditions. The calculations are made for distinct cases, in which the effective absorbed power has different values belonging to the 5–100 MW range, both for nocturnal and daytime conditions. The frequency of powerful HF waves is chosen to be close to the most effective frequency for the large-scale F2-layer modification. The results of modeling indicate that the effective absorbed power can influence considerably the F-layer response to high-power radio waves in the mid-latitude ionosphere.

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Induction Heat Treatment for an Automotive Crankshaft: Large Scale Modelling with Moving Inductors

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.554-557.1539 ◽

2013 ◽

Vol 554-557 ◽

pp. 1539-1544

Author(s):

Steffen Klonk ◽

Francois Bay

Keyword(s):

Heat Treatment ◽

Numerical Model ◽

Large Scale ◽

Moving Boundaries ◽

Discrete Level ◽

Mesh Quality ◽

Induction Heat ◽

Induction Heat Treatment ◽

Subsequent Time ◽

Scale Modelling

A numerical model for a multiphysics problem is presented. It includes the movement of subdomains, which are embedded in a global air domain. The description of the movement is based on a discrete level set representation of the moving boundaries. It is based on the original geometry of the moving tools, such that the mesh quality is not reduced in subsequent time steps.

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Combined treatment of green pitch pine wood by heat and superheated steam and the effects on physical properties of the products

Holzforschung ◽

10.1515/hf-2013-0054 ◽

2014 ◽

Vol 68 (3) ◽

pp. 327-335 ◽

Cited By ~ 8

Author(s):

Yonggun Park ◽

Chang-Deuk Eom ◽

Yeonjung Han ◽

Jun-Ho Park ◽

Yoon-Seong Chang ◽

...

Keyword(s):

Heat Treatment ◽

Physical Properties ◽

Large Scale ◽

Superheated Steam ◽

Bending Strength ◽

Combined Treatment ◽

Decay Resistance ◽

Green Wood ◽

Heat Treated ◽

Pitch Pine

Abstract Pitch pine (P. rigida) wood was treated with superheated steam (SHS) and the subsequent effects due to drying and heat treatment (HT) were observed. The following treatment parameters were tested: 180°C air HT, 220°C air HT, 0.1 MPa–180°C SHS HT, 0.1 MPa–220°C SHS HT, 0.5 MPa–180°C SHS HT, and 0.5 MPa–220°C SHS HT. No drying checks were observed in the specimens (500×150×50 mm3) treated at 0.5 MPa–220°C SHS and with these treatment parameters, equilibrium moisture content (EMC) was the lowest. Low EMC has an effect on physical properties such as shrinkage, compressive strength parallel to the grain, bending strength, hardness, and decay resistance. Based on the results, it is expected that the green wood in a large scale is possible to be simultaneously dried and heat-treated without occurrence of checks by the SHS HT process.

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