scholarly journals Muscle: A Three Phase System

1959 ◽  
Vol 43 (1) ◽  
pp. 55-79 ◽  
Author(s):  
Shirley E. Simon ◽  
B. M. Johnstone ◽  
K. H. Shankly ◽  
F. H. Shaw
Keyword(s):  
Steady State ◽  
Sartorius Muscle ◽  
Phase System ◽  
Extracellular Material ◽  
Foreign Ions ◽  
Three Phase ◽  
Na Efflux ◽  
Muscle Water ◽  
Toad Bufo ◽  
Normal Controls

The partition of Li+, Br-, and I- across the membrane of the sartorius muscle of the toad Bufo marinus has been investigated both at the steady state and with kinetic methods. Li+ was found to have access to an amount of muscle water similar to that of Na+. Br- and I- could be regarded as being interchangeable with cellular Cl-. None of the foreign ions caused significant losses of cellular K+. Li+ efflux from the cell was slower in muscles which were equilibrated for long periods in Li+ than in short equilibrated muscles. Na+ efflux from Li+-treated muscles was similar in rate to normal controls, but the amount of Na+ in the slow fraction was increased by Li+. I- efflux was extremely rapid, and it was not possible to differentiate kinetically between intra- and extracellular material. These results have been found to be consistent with the hypothesis of a three phase system for muscle.

scholarly journals Muscle: A Three Phase System

1959 ◽  
Vol 43 (1) ◽  
pp. 81-96 ◽  
Author(s):  
R. Frater ◽  
Shirley E. Simon ◽  
F. H. Shaw
Keyword(s):  
Ringer Solution ◽  
Cellular Level ◽  
Sartorius Muscle ◽  
Phase System ◽  
Divalent Ions ◽  
Intracellular Content ◽  
Three Phase ◽  
Muscle Water ◽  
Inorganic Sulfate

The partition of sulfate, Ca++, and Mg++ across the membrane of the sartorius muscle has been studied, and the effect of various concentrations of these ions in the Ringer solution on the cellular level of Na+, K+, and Cl- has been determined. The level of the three divalent ions in toad plasma and muscle in vivo has been assayed. Muscle was found to contain an almost undetectable amount of inorganic sulfate. Increases in the external level of these ions brought about increases in intracellular content, calculated from the found extracellular space as determined with radioiodinated serum albumin or inulin. Less of the cell water is available to sulfate than to Cl-, and the Mg++ space is less than the Na+ space. An amount of muscle water similar to that found for Li+ and I- appears to be available to these divalent ions. Sulfate efflux from the cell was extremely rapid, and it was not found possible to differentiate kinetically between intra- and extracellular material. These results are consistent with the theory of a three phase system, assuming the muscle to consist of an extracellular phase and two intracellular phases. Mg++ and Ca++ are adsorbed onto the ordered phase, and increments in cellular content found on raising the external level are assumed to occur in the free intracellular phase.

The Role of Dissolved and Nascent Air in Oil-Hydraulic Systems

2000 ◽  
Author(s):  
Hansjoerg Stern
Keyword(s):  
Steady State ◽  
High Performance ◽  
Transient Behavior ◽  
Operating Conditions ◽  
Phase System ◽  
Hydraulic Systems ◽  
Three Phase ◽  
Significant Damage ◽  
Water Hydraulic

Abstract In modern, high performance hydraulic systems the transient behavior of dissolving, dissolved and nascent air under changing dynamic conditions of pressure and temperature is emerging as an increasingly important factor, capable of creating undesirable operating conditions. The paper discusses the question of how to predict the performance of pump inlets and valve discharges, where we have known for some time that cavitation and cavitation-like conditions exist and can cause significant damage. The steady state conditions at which nascent air evolves from saturated air-in-oil solutions is normally one or two orders of magnitude above the vapor pressure of the system fluid. To what extent, therefore, is “cavitation” in these systems an air-oil problem? Or is it an oil-vapor problem that is analogous to cavitation in water hydraulic pumps and turbines? Or have we created the combination of the two, a three-phase system of liquid, gas and vapor?

scholarly journals Analysis of direct power control AC-DC converter under unbalance voltage supply for steady-state and dynamic response

2020 ◽  
Vol 10 (4) ◽  
pp. 3333
Author(s):  
Nor Azizah Mohd Yusoff ◽  
Azziddin M. Razali ◽  
Kasrul Abdul Karim ◽  
Raja Nor Firdaus Kashfi Raja Othman ◽  
Auzani Jidin ◽  
...  
Keyword(s):  
Steady State ◽  
Power Control ◽  
Pulse Width Modulation ◽  
Dynamic Performance ◽  
Harmonic Distortion ◽  
Voltage Source ◽  
Phase System ◽  
Direct Power ◽  
Direct Power Control ◽  
Three Phase

This paper presents an analysis of Direct Power Control (DPC) technique for the Three-Phase Pulse Width Modulation (PWM) AC-DC converter under unbalanced supply condition. Unbalance condition will cause the presence of unbalanced current and voltages thus produce the negative components on the grid voltage as well as severe performance degradation of a grid connected Voltage Source Inverter (VSI). The input structures for conventional DPC has been modified with a three simpler sequence networks instead of coupled by a detailed Three-Phase system method. The imbalance voltage can be resolved by separating from the individual elements of voltage and current into symmetrical components called Sequence Network. Consequently, the input power relatively improved during unbalanced condition almost 70% through the measurement of Total Harmonic Distortion (THD) from the conventional Direct Power Control (DPC) in individual elements which is higher compared to separate components. Hence, several analyses are performed in order to analyze the steady state and dynamic performance of the converter, particularly during the load and DC voltage output reference variations.

scholarly journals Vector Control of Three-Phase Solar Farm Converters Based on Fictive-Axis Emulation

2020 ◽  
Vol 2 (3) ◽  
Author(s):  
Kai Kang ◽  
Qiaoyu Wang ◽  
Jiayi Meng
Keyword(s):  
Steady State ◽  
Controller Design ◽  
Dynamic Performance ◽  
Reference Signal ◽  
Voltage Source ◽  
Phase System ◽  
The Real ◽  
Control Gain ◽  
Three Phase ◽  
Set Up

In this paper, a new method for adjusting the current of three-phase voltage source DC-AC converter in orthogonal (DQ) reference frame is presented. In the DQ reference system, AC variable appears in the constant form of DC, making the controller design the same as the DC-DC converter[1]. It provides infinite control gain at the steady-state operating point, and finally realizes zero steady-state error[2]. In addition, the common method is to set up a set of virtual quantities orthogonal to the actual single-phase system. In general, orthogonal imaginary numbers get the reference signal by delaying the real quantity by a quarter period. However, the introduction of such time delay makes the dynamic response of the system worse. In this paper, orthogonal quantities are generated from a virtual axis system parallel to the real axis, which can effectively improve the dynamic performance of traditional methods without increasing the complexity of controller structure. Through PSCAD simulation, the ideal experimental results are obtained.

Steady-state modelling method for matrix-reactance frequency converter with boost topology

2011 ◽  
Vol 60 (2) ◽  
pp. 137-148
Author(s):  
Igor Korotyeyev ◽  
Beata Zięba
Keyword(s):  
Fourier Series ◽  
Steady State ◽  
Differential Equations ◽  
Numerical Method ◽  
Frequency Converter ◽  
Double Fourier Series ◽  
Galerkin’S Method ◽  
Galerkin's Method ◽  
Modelling Method ◽  
Three Phase

Steady-state modelling method for matrix-reactance frequency converter with boost topologyThis paper presents a method intended for calculation of steady-state processes in AC/AC three-phase converters that are described by nonstationary periodical differential equations. The method is based on the extension of nonstationary differential equations and the use of Galerkin's method. The results of calculations are presented in the form of a double Fourier series. As an example, a three-phase matrix-reactance frequency converter (MRFC) with boost topology is considered and the results of computation are compared with a numerical method.

Power Flow Calculation Realization in Software for Grids with Four-Phase Power Lines

2014 ◽  
Vol 698 ◽  
pp. 694-698 ◽  
Author(s):  
Dmitry I. Bliznyuk ◽  
Pavel Y. Bannykh ◽  
Alexandra I. Khalyasmaa
Keyword(s):  
Steady State ◽  
Power Flow ◽  
Calculation Model ◽  
Power Lines ◽  
Power Flow Calculation ◽  
Steady State Analysis ◽  
Flow Calculation ◽  
Analysis Methods ◽  
Electrical Grids ◽  
Three Phase

The paper is devoted to the problem of power flow calculation and steady state analysis methods adaptation for four-phase electrical grids. These methods are based on developed models of four-phase power lines and phase convering transformers. The basis of research is nodal voltages equations for three-phase, four-phase and mixed (combined by three-and four-phase elements) grids. Algorithm of four-phfase elements parameters automized adaptation for power flow calculation model of "RastrWin" software have been developed.

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