scholarly journals Optimization of orbit correction systems using generalized response matrices and its application to the LHC injection transfer lines

2002 ◽  
Author(s):  
Yu-Chiu Chao ◽  
V. Mertens
Keyword(s):  
Transfer Lines ◽  
Orbit Correction

Use of vent stack temperature as a feedforward variable for dissolver total titratable alkali (TTA) control

TAPPI Journal ◽  
2018 ◽  
Vol 17 (05) ◽  
pp. 261-269
Author(s):  
Wei Ren ◽  
Brennan Dubord ◽  
Jason Johnson ◽  
Bruce Allison
Keyword(s):  
Feedback Control ◽  
Current Practice ◽  
Feedforward Control ◽  
Control Variable ◽  
Indirect Measurement ◽  
Tight Control ◽  
Transfer Lines ◽  
Green Liquor ◽  
Process Dynamics ◽  
Downstream Processes

Tight control of raw green liquor total titratable alkali (TTA) may be considered an important first step towards improving the overall economic performance of the causticizing process. Dissolving tank control is made difficult by the fact that the unknown smelt flow is highly variable and subject to runoff. High TTA variability negatively impacts operational costs through increased scaling in the dissolver and transfer lines, increased deadload in the liquor cycle, under- and over-liming, increased energy consumption, and increased maintenance. Current practice is to use feedback control to regulate the TTA to a target value through manipulation of weak wash flow while simultaneously keeping dissolver density within acceptable limits. Unfortunately, the amount of variability reduction that can be achieved by feedback control alone is fundamentally limited by the process dynamics. One way to improve upon the situation would be to measure the smelt flow and use it as a feedforward control variable. Direct measurement of smelt flow is not yet possible. The use of an indirect measurement, the dissolver vent stack temperature, is investigated in this paper as a surrogate feedforward variable for dissolving tank TTA control. Mill trials indicate that significant variability reduction in the raw green liquor TTA is possible and that the control improvements carry through to the downstream processes.

scholarly journals Improving the dynamical reference frame through minor planet orbit correction using crossing point observations

1988 ◽  
Vol 128 ◽  
pp. 55-60
Author(s):  
Arthur L. Whipple ◽  
Raynor L. Duncombe ◽  
Paul D. Hemenway
Keyword(s):  
Computer Program ◽  
Reference Frame ◽  
Reference System ◽  
Hubble Space Telescope ◽  
Simulated Data ◽  
Minor Planet ◽  
Minor Planets ◽  
Space Telescope ◽  
Orbit Correction ◽  
Crossing Point

We have begun a program to establish a dynamical reference frame based on the motions of minor planets. The program will utilize observations from the Hubble Space Telescope, and will ultimately tie the HIPPARCOS reference system to a dynamical base. Thirty-four minor planets, 20 of which are suitable for observation with the Hubble Space Telescope, have been selected. Ground based observations, particularly crossing-point observations with long focus reflectors, have been initiated.A computer program to simultaneously solve for the corrections of the orbits of the 34 minor planets including the crossing-point observations, was successfully run. The observations are treated by the method of W. H. Jeffreys. Using simulated data, solutions with and without crossing point observations demonstrate the value of those observations to produce a homogeneous and coherent set of results.

SBAS-Based Satellite Orbit Correction for the Generation of DInSAR Time-Series: Application to RADARSAT-1 Data

2011 ◽  
Vol 49 (12) ◽  
pp. 5150-5165 ◽  
Author(s):  
A. Pepe ◽  
P. Berardino ◽  
M. Bonano ◽  
L. D. Euillades ◽  
R. Lanari ◽  
...  
Keyword(s):  
Time Series ◽  
Satellite Orbit ◽  
Orbit Correction

scholarly journals Orbit correction implementation at CEBAF

2002 ◽  
Author(s):  
M. Bickley ◽  
B.A. Bowling ◽  
D. Douglas ◽  
A. Hofler ◽  
J. Kewisch ◽  
...  
Keyword(s):  
Orbit Correction

A reactive GRASP and Path Relinking for balancing reconfigurable transfer lines

2012 ◽  
Vol 50 (18) ◽  
pp. 5213-5238 ◽  
Author(s):  
Mohamed Essafi ◽  
Xavier Delorme ◽  
Alexandre Dolgui
Keyword(s):  
Path Relinking ◽  
Transfer Lines
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