Determination of the gain nonlinearity time constant in 1.3 μm semiconductor lasers

1991 ◽  
Vol 58 (3) ◽  
pp. 234-236 ◽  
Author(s):  
J. Eom ◽  
C. B. Su ◽  
W. Rideout ◽  
R. B. Lauer ◽  
J. S. LaCourse
Keyword(s):  
Semiconductor Lasers ◽  
Time Constant

Respiratory mechanics in mechanically ventilated patients with respiratory failure

1985 ◽  
Vol 58 (6) ◽  
pp. 1849-1858 ◽  
Author(s):  
A. Rossi ◽  
S. B. Gottfried ◽  
B. D. Higgs ◽  
L. Zocchi ◽  
A. Grassino ◽  
...  
Keyword(s):  
Time Constant ◽  
Inflation Rate ◽  
Respiratory Mechanics ◽  
Mechanically Ventilated ◽  
Mechanically Ventilated Patients ◽  
Airway Occlusion ◽  
The Relationship ◽  
Resistance Value ◽  
Ventilated Patients

In 11 mechanically ventilated patients, respiratory mechanics were measured 1) during constant flow inflation and 2) following end-inflation airway occlusion, as proposed in model analysis (J. Appl. Physiol. 58: 1840–1848, 1985. During the latter part of inflation, the relationship between driving pressure and lung volume change was linear, allowing determination of static respiratory elastance (Ers) and resistance (RT). The latter represents in each patient the maximum resistance value that can obtain with the prevailing time constant inhomogeneity. Following occlusion, Ers and RT were also obtained along with RT (min) which represents a minimum, i.e., resistance value that would obtain in the absence of time constant inhomogeneity. A discrepancy between inflation and occlusion Ers and RT was found only in the three patients without positive end-expiratory pressure, and could be attributed to recruitment of lung units during inflation. In all instances Ers and RT were higher than normal. RT(min) was lower in all patients than the corresponding values of RT, indicating that resistance was frequency dependent due to time constant inequalities. Changes in inflation rate did not affect Ers, while RT increased with increasing flow.

Thermocouple Time Constant Test System and Uncertainty Analysis Based on Semiconductor Lasers

2016 ◽  
Vol 53 (8) ◽  
pp. 081408
Author(s):  
郝晓剑 Hao Xiaojian ◽  
张根甫 Zhang Genfu ◽  
昝清波 Zan Qingbo
Keyword(s):  
Uncertainty Analysis ◽  
Semiconductor Lasers ◽  
Time Constant ◽  
Test System

Accurate Determination of Capture Time Constant of Interface States in MOS Structures

1986 ◽  
Vol 10-12 ◽  
pp. 499-504
Author(s):  
D. Vuillaume ◽  
J. Barrier ◽  
Didier Stiévenard ◽  
J.C. Bourgoin
Keyword(s):  
Time Constant ◽  
Accurate Determination ◽  
Interface States ◽  
Capture Time ◽  
Mos Structures

Parallel analysis of thermal field in a layered DC cable

2014 ◽  
Vol 24 (3) ◽  
pp. 613-626
Author(s):  
Jerzy Golebiowski ◽  
Robert Piotr Bycul
Keyword(s):  
Steady State ◽  
Field Distribution ◽  
Time Constant ◽  
Thermal Field ◽  
Thermal Time ◽  
Content Type ◽  
The Core ◽  
Thermal Time Constant ◽  
Steady State Current

Purpose – The purpose of this paper is to prepare procedures for determination of characteristics and parameters of DC cables on the basis of transient and steady thermal field distribution in their cross-sections. Design/methodology/approach – Steady-state current rating was computed iteratively, with the use of steady thermal field distribution in the cable. The iterative process was regulated with respect to this field by changes of the mean surface temperature of the sheath of the cable. It was also controlled with respect to the unknown current rating by deviations of the temperature of the core from the maximum sustained temperature of the insulation (material zone) adjacent to the core. Heating curves were determined (in arbitrarily selected points of the cross-section of the cable) by a parallel algorithm described thoroughly in the first part of the paper. The algorithm was used for computing of transient thermal field distribution throughout the whole cross-section. Thermal time constant distributions were determined by the trapezium rule, where the upper integration limit of respective thermal field distributions was being changed. Findings – Using the methods prepared the following characteristics/parameters of the cable were determined: steady-state current rating, spatial-time heating curves, mean thermal time constant distribution. The results were verified and turned to be in conformance with those of the IEC 287 Standard and a commercial software – Nisa v. 16. Speedup and efficiency of the parallel computations were calculated. It was concluded that the parallel computations took less time than the sequential ones. Research limitations/implications – The specialized algorithms and software are dedicated to cylindrical DC cables. Practical implications – The knowledge of the determined characteristics and parameters contributes to optimal exploitation of a DC cable during its use. Originality/value – The algorithms of determination of the steady-state current rating and thermal time constant are original. The software described in the appendix has also been made by the authors.

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