scholarly journals Optimization of the electrical technology complex for high-performance induction heating lines

2020 ◽  
Vol 28 (3) ◽  
pp. 110-124
Author(s):  
Aleksandr I. Danilushkin ◽  
Denis A. Zhivotyagin ◽  
Sergey S. Kibkalo ◽  
Dmitry V. Surkov
Keyword(s):  
Power Distribution ◽  
High Performance ◽  
Nonlinear Dependence ◽  
Piecewise Constant Function ◽  
Heating Process ◽  
Operational Parameters ◽  
Optimal Length ◽  
Piecewise Constant ◽  
Technological Limitations ◽  
Ferromagnetic Steel

The paper discusses the design issues of a high-performance induction installation for heating ferromagnetic billets before processing on deforming equipment. Specific features of the technological process of heating ferromagnetic billets to plastic strain temperatures are noted. It is shown that in order to increase the efficiency of the process, the heating of large-sized preforms from ferromagnetic steel is advisable to be carried out in a two-frequency induction heater with two autonomous sections. A study of the heating process in a two-section heater of ferromagnetic billets was carried out taking into account the nonlinear dependence of the physical characteristics of the heated billets metal on the temperature changing during heating. The problem of minimizing the length of a two-section heater is formulated and solved taking into account energy and technological limitations. A condition for determining the optimal length of the first section is to achieve a temperature corresponding to the loss of magnetic properties in the layer equal to the depth of current penetration at the frequency of the second section power supply. The results of numerical calculation of the optimal parameters of a two-section heater are presented. It is shown that the power distribution algorithm along the length of a two-section heater is a piecewise constant function. The results of calculating the temperature distribution in the workpieces during heating are presented. The results of the study can be used to solve the problem of optimizing the structural and operational parameters of a multi-section heater.

scholarly journals Gauge theories on compact toric manifolds

2021 ◽  
Vol 111 (3) ◽  
Author(s):  
Giulio Bonelli ◽  
Francesco Fucito ◽  
Jose Francisco Morales ◽  
Massimiliano Ronzani ◽  
Ekaterina Sysoeva ◽  
...  
Keyword(s):  
Partition Function ◽  
Gauge Theories ◽  
Blow Up ◽  
Gauge Coupling ◽  
Piecewise Constant Function ◽  
Partition Functions ◽  
Piecewise Constant ◽  
Toric Manifolds ◽  
Holomorphic Anomaly ◽  
The One

AbstractWe compute the $$\mathcal{N}=2$$ N = 2 supersymmetric partition function of a gauge theory on a four-dimensional compact toric manifold via equivariant localization. The result is given by a piecewise constant function of the Kähler form with jumps along the walls where the gauge symmetry gets enhanced. The partition function on such manifolds is written as a sum over the residues of a product of partition functions on $$\mathbb {C}^2$$ C 2 . The evaluation of these residues is greatly simplified by using an “abstruse duality” that relates the residues at the poles of the one-loop and instanton parts of the $$\mathbb {C}^2$$ C 2 partition function. As particular cases, our formulae compute the SU(2) and SU(3) equivariant Donaldson invariants of $$\mathbb {P}^2$$ P 2 and $$\mathbb {F}_n$$ F n and in the non-equivariant limit reproduce the results obtained via wall-crossing and blow up methods in the SU(2) case. Finally, we show that the U(1) self-dual connections induce an anomalous dependence on the gauge coupling, which turns out to satisfy a $$\mathcal {N}=2$$ N = 2 analog of the $$\mathcal {N}=4$$ N = 4 holomorphic anomaly equations.

scholarly journals Fabrication and Optimization of a Lipase Immobilized Enzymatic Membrane Bioreactor based on Polysulfone Gradient-Pore Hollow Fiber Membrane

Catalysts ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 495 ◽  
Author(s):  
Peng-Cheng Chen ◽  
Zhen Ma ◽  
Xue-Yan Zhu ◽  
Da-Jing Chen ◽  
Xiao-Jun Huang
Keyword(s):  
Hollow Fiber ◽  
High Performance ◽  
Hollow Fiber Membrane ◽  
Candida Rugosa ◽  
Operational Parameters ◽  
Membrane Pore ◽  
Microfiltration Membranes ◽  
Glycerol Triacetate ◽  
Operation Pressure ◽  
Enzymatic Membrane

Enzymatic membrane bioreactors (EMBRs) possess the characteristic of combining catalysis with separation, and therefore have promising application potentials. In order to achieve a high-performance EMBR, membrane property, as well as operating parameters, should give special cause for concerns. In this work, an EMBR based on hollow fiber polysulfone microfiltration membranes with radial gradient pore structure was fabricated and enzyme immobilization was achieved through pressure-driven filtration. Lipase from Candida rugosa was used for immobilization and EMBR performance was studied with the enzymatic hydrolysis of glycerol triacetate as a model reaction. The influences of membrane pore diameter, substrate feed direction as well as operational parameters of operation pressure, substrate concentration, and temperature on the EMBR activity were investigated with the production of hydrolysates kinetically fitted. The complete EMBR system showed the highest activity of 1.07 × 104 U⋅g−1. The results in this work indicate future efforts for improvement in EMBR.

scholarly journals Symbolic Algorithm of the Functional-Discrete Method for a Sturm–Liouville Problem with a Polynomial Potential

2018 ◽  
Vol 18 (4) ◽  
pp. 703-715 ◽  
Author(s):  
Volodymyr Makarov ◽  
Nataliia Romaniuk
Keyword(s):  
Finite Interval ◽  
General Scheme ◽  
Liouville Problem ◽  
Piecewise Constant Function ◽  
Polynomial Potential ◽  
Discrete Method ◽  
Piecewise Constant ◽  
Sturm Liouville ◽  
Symbolic Algorithm ◽  
Theoretical Results

AbstractA new symbolic algorithmic implementation of the general scheme of the exponentially convergent functional-discrete method is developed and justified for the Sturm–Liouville problem on a finite interval for the Schrödinger equation with a polynomial potential and the boundary conditions of Dirichlet type. The algorithm of the general scheme of our method is developed when the potential function is approximated by the piecewise-constant function. Our algorithm is symbolic and operates with the decomposition coefficients of the eigenfunction corrections in some basis. The number of summands in these decompositions depends on the degree of the potential polynomial and on the correction number. Our method uses the algebraic operations only and does not need solutions of any boundary value problems and computations of any integrals unlike the previous version. A numerical example illustrates the theoretical results.

A comparative study of the methods for calculation of surface elastic deformation

2003 ◽  
Vol 217 (2) ◽  
pp. 145-154 ◽  
Author(s):  
W-Z Wang ◽  
H Wang ◽  
Y-C Liu ◽  
Y-Z Hu ◽  
D Zhu
Keyword(s):  
Surface Deformation ◽  
Contact Problems ◽  
Piecewise Constant Function ◽  
Bilinear Interpolation ◽  
Numerical Accuracy ◽  
Piecewise Constant ◽  
Computation Efficiency ◽  
Influence Coefficients ◽  
Grid Points

A fundamental issue of lubrication analysis is the calculation of surface deformation, which includes two major steps: determination of influence coefficients and multiplication and summation. There are various interpolation schemes, such as the bilinear interpolation, the piecewise constant function or Green's function, available for determining the influence coefficients, while the summation operation may be performed by using one of the following methods: direct summation (DS), multilevel multi-integration (MLMI) or the discrete convolution and fast Fourier transform (DC-FFT) method. To limit the periodical errors, the proper way to implement the DC-FFT method is described in detail. The computation efficiency and numerical accuracy are compared by applying the different methods to typical contact problems. The results show that the three methods can achieve comparable numerical accuracy, but the DC-FFT method shows much higher computation efficiency than the others, especially when a great number of grid points are involved. It is concluded that the DC-FFT method has great potential in applications to the numerical analysis of, for example, surface deformations and temperature rises.

scholarly journals Current-phase relation in layered superconducting structures of SIS’IS type

2021 ◽  
Vol 24 (2) ◽  
pp. 23701
Author(s):  
A. M. Shutovskyi ◽  
V. E. Sakhnyuk
Keyword(s):  
Phase Difference ◽  
Current Density ◽  
Phase Relation ◽  
Dielectric Layer ◽  
Intermediate Layer ◽  
Order Parameter ◽  
Constant Function ◽  
Piecewise Constant Function ◽  
Current Phase ◽  
Piecewise Constant

The dependence of the current density on the phase difference is investigated considering the layered superconducting structures of a SIS’IS type. To simplify the calculations, the quasiclassical equations for the Green’s functions in a t-representation are derived. An order parameter is considered as a piecewise constant function. To consider the general case, no restrictions on the dielectric layer transparency and the thickness of the intermediate layer are imposed. It was found that a new analytical expression for the current-phase relation can be used with the aim to obtain a number of previously known results arising in particular cases.

Resource Allocation for a Cooperative Broadband MIMO-OFDM System

2010 ◽  
pp. 382-398
Author(s):  
Ibrahim Y. Abualhaol ◽  
Mustafa M. Matalgah
Keyword(s):  
Resource Allocation ◽  
Power Distribution ◽  
Power Efficiency ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Performance ◽  
Ofdm System ◽  
Frequency Space ◽  
Input Multiple Output ◽  
Power Loading ◽  
Mimo Ofdm

In this chapter, a cooperative broadband relay-based resource allocation technique is proposed for adaptive bit and power loading multiple-input-multiple-output/orthogonal frequency division multiplexing (MIMO-OFDM) system. In this technique, sub-channels allocation, M-QAM modulation order, and power distribution among different sub-channels in the relay-based MIMO-OFDM system are jointly optimized according to the channel state information (CSI) of the relay and the direct link. The transmitted stream of bits is divided into two parts according to a suggested cooperative protocol that is based on sub-channel-division. In this protocol, the first part is sent directly from the source to the destination, and the second part is relayed to the destination through an indirect link. Such a cooperative relay-based system enables us to exploit the inherent system diversities in frequency, space and time to maximize the system power efficiency. The BER performance using this cooperative sub-channel-division protocol with adaptive sub-channel assignment and adaptive bit/power loading are presented and compared with a noncooperative ones. The use of cooperation in a broadband relay-based MIMO-OFDM system showed high performance improvement in terms of BER.

scholarly journals Continuous CM-regularity of semihomogeneous vector bundles

2020 ◽  
Vol 20 (3) ◽  
pp. 401-412
Author(s):  
Alex Küronya ◽  
Yusuf Mustopa
Keyword(s):  
Vector Bundle ◽  
Abelian Variety ◽  
Upper Bound ◽  
Vector Bundles ◽  
Projective Variety ◽  
Constant Function ◽  
Piecewise Constant Function ◽  
Piecewise Constant ◽  
Generic Vanishing

AbstractWe ask when the CM (Castelnuovo–Mumford) regularity of a vector bundle on a projective variety X is numerical, and address the case when X is an abelian variety. We show that the continuous CM-regularity of a semihomogeneous vector bundle on an abelian variety X is a piecewise-constant function of Chern data, and we also use generic vanishing theory to obtain a sharp upper bound for the continuous CM-regularity of any vector bundle on X. From these results we conclude that the continuous CM-regularity of many semihomogeneous bundles — including many Verlinde bundles when X is a Jacobian — is both numerical and extremal.

scholarly journals Natural Deep Eutectic Solvents for Simultaneous Extraction of Multi-Bioactive Components from Jinqi Jiangtang Preparations

Pharmaceutics ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 18 ◽  
Author(s):  
Lele Yang ◽  
Ling Li ◽  
Hao Hu ◽  
Jianbo Wan ◽  
Peng Li
Keyword(s):  
High Performance ◽  
Choline Chloride ◽  
Deep Eutectic Solvents ◽  
Bioactive Components ◽  
Operational Parameters ◽  
Ultrasound Assisted Extraction ◽  
Assisted Extraction ◽  
Natural Deep Eutectic Solvents ◽  
Quantification Analysis ◽  
Chemical Profiles

Natural deep eutectic solvents (NADESs), composed of natural primary metabolites, are now widely used as green and sustainable extraction solvents of bioactive components. In the present study, various NADESs were prepared to extract multi-components from different preparations of an herbal formula (Chinese name: Jinqi Jiangtang, JQJT) using ultrasound-assisted extraction (UAE). Results showed that most prepared NADESs provided more effective extraction of phenolic acids and alkaloids from JQJT preparations than conventional solvents. Among the tested NADESs, the solvent formed by choline chloride and laevulinic acid was selected to optimize the operational parameters using response surface methodology. The optimized extraction method was successfully applied to extract six major components in four commercial JQJT products, and quantification analysis was performed by the validated high-performance liquid chromatography with ultraviolet detection (HPLC-UV) method. The quantitative results indicated that preparations from different manufacturers showed different chemical profiles. In conclusion, NADESs-based UAE shows considerable potential as an efficient and green method for extraction of multi-bioactive components from commercial herbal preparations.

scholarly journals Study on the mechanism of degradation of tetracycline hydrochloride by microwave-activated sodium persulfate

2020 ◽  
Vol 82 (9) ◽  
pp. 1961-1970
Author(s):  
Yu Gao ◽  
Shibo Cong ◽  
Yulun He ◽  
Donglei Zou ◽  
Yuzhi Liu ◽  
...  
Keyword(s):  
High Performance ◽  
Degradation Pathway ◽  
Tetracycline Hydrochloride ◽  
Radical Scavenger ◽  
Sodium Persulfate ◽  
Liquid Chromatography Mass Spectrometry ◽  
Operational Parameters ◽  
Mechanism Of Degradation ◽  
Initial Ph ◽  
Concentration Changes

Abstract Among the different antibiotics, tetracycline hydrochloride (TCH) is one of the most commonly used. In this study, the activated sodium persulfate (SPS) process induced by microwave (MW) energy was used to treat TCH. The effect of different operational parameters of MW/SPS-treated TCH, such as SPS concentration, TCH concentration, initial pH, and MW power, was investigated. The concentration changes of TCH were determined using a spectrophotometer. The results of radical scavenger experiments indicated that the sulfate radical () was stronger than the hydroxyl radical (·OH). On the basis of high performance liquid chromatography–mass spectrometry (HPLC–MS) analysis, a possible degradation pathway of TCH was proposed. This research indicates that the MW/SPS system is a promising prospect for the treatment of TCH.

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