On-Line Observation of the Composition in Non-Isothermal Batch Reactors with Non-Linear Reactions

1989 ◽  
Author(s):  
H.A. Preisig
Keyword(s):  
Batch Reactors ◽  
Non Linear ◽  
On Line ◽  
Line Observation

Non-Linear Control of a Neutralisation Process

1971 ◽  
Vol 4 (9) ◽  
pp. T151-T157 ◽  
Author(s):  
P D Roberts
Keyword(s):  
Simulation Study ◽  
Digital Simulation ◽  
Linear Control ◽  
Attractive Alternative ◽  
Error Signal ◽  
Linear Controller ◽  
Linear Characteristic ◽  
Non Linear ◽  
On Line ◽  
Extra Parameter

The paper describes a digital simulation study of the application of a non-linear controller to the regulation of a single stage neutralisation process. In the controller, the proportional gain increases with amplitude of controller error signal. The performance of the non-linear controller is compared with that of a conventional linear controller and with the performance obtained by employing a linear controller with a linearisation network designed to compensate for the non-linear characteristic of the neutralisation curve. Although the performance of the non-linear controller is inferior to that obtained by employing a perfect linearisation network, its performance is still considerably superior to that obtained by using a conventional linear controller when operating at a symmetrical point on the neutralisation curve. In contrast to the linearisation network technique, the non-linear controller contains only one extra parameter and can be readily tuned on-line without prior knowledge of the neutralisation curve. Hence, it can be considered as an attractive alternative for the control of neutralisation processes.

Rapid quantification of polyhydroxyalkanoates (PHA) concentration in activated sludge with the fluorescent dye Nile blue A

2011 ◽  
Vol 64 (3) ◽  
pp. 747-753 ◽  
Author(s):  
M. Oshiki ◽  
H. Satoh ◽  
T. Mino
Keyword(s):  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Nile Blue ◽  
Maximum Level ◽  
Fluorescence Measurement ◽  
Batch Reactors ◽  
Floc Size ◽  
Nile Blue A ◽  
On Line ◽  
Rapid Quantification

The present study was conducted (1) to develop a rapid quantification method of polyhydroxyalkanoates (PHA) concentration in activated sludge by Nile blue A staining and fluorescence measurement and (2) to perform on-line monitoring of PHA concentrations in activated sludge. Activated sludge samples collected from laboratory scale sequencing batch reactors and full-scale wastewater treatment plants were stained with Nile blue A and their fluorescence intensities were determined. There was a high correlation (R2 > 0.97) between the fluorescence intensities of Nile blue A and PHA concentrations in activated sludge determined by gas chromatography. The Nile blue A staining and fluorescence measurement method allows us to determine PHA concentrations in activated sludge within only five minutes and up to 96 samples can be measured at once by using microplate reader. On-line monitoring of PHA concentrations in activated sludge was achieved by using a fluorometer equipped with a flow cell and the time point at which PHA concentration in activated sludge reached the maximum level could be identified. In addition, we examined the influence of pH, floc size and co-existing chemicals in activated sludge suspension on the fluorescence intensities of Nile blue A.

Sequencing Batch Reactors - An Overview

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2523-2526 ◽  
Author(s):  
K. L. Norcross
Keyword(s):  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Process Selection ◽  
Wastewater Treatment Process ◽  
Industrial Sites ◽  
Pharmaceutical Manufacturers ◽  
Start Up ◽  
On Line ◽  
Oxygen Requirements ◽  
And Control

Sequencing Batch Reactors (SBR's) offer many advantages and few disadvantages to the wastewater treatment process selection. Due to the relatively recent surge of interest in SBR's, few plants have been on-line long enough for Engineers to have developed a thorough understanding of all design aspects and considerations. The author has been involved directly in the design, equipment supply, start-up and operation of almost 60 SBR's of all sizes. About two thirds of the installations are municipal and one-third of these installations are industrial sites involving wastes from food processors, dairies, distilleries, petro-chemical manufacturers, landfill leachate, tanneries, Government munition plants and pharmaceutical manufacturers. The control of filamentous bulking has also been excellent with SBR's. This paper will consider the mechanical, process and control aspects for design of an SBR. The mechanical aspects will include HRT and basin sizing, selection of aeration equipment and effluent decanters. The process parameters discussed will include loading rates and F:M considerations, MLSS concentration, oxygen requirements and D.O. uptake rate, flow proportional aeration, the benefits of an anoxic fill cycle, and finally, nutrient removal. Control considerations are briefly discussed.

scholarly journals A Comprehensive Survey on On-line Handwriting Recognition Technology and its Real Application to the Nepalese Natural Handwriting

1970 ◽  
Vol 5 (1) ◽  
pp. 31-55 ◽  
Author(s):  
Santosh KC ◽  
Cholwich Nattee
Keyword(s):  
Dynamic Time Warping ◽  
Feature Vector ◽  
Handwriting Recognition ◽  
Recognition System ◽  
Time Warping ◽  
Real Application ◽  
Non Linear ◽  
Comprehensive Survey ◽  
On Line ◽  
Dynamic Time

Handwriting Recognition Technology has been improving much under the purview of pattern recognition and image processing since a few decades. This paper focuses on the comprehensive survey on on-line handwriting recognition system along with the real application by taking Nepali natural handwriting (a real example of one of the cursive handwritings). The survey mainly includes pre-processing, feature vector and similarity measures in between the non-linear 2D sequences of coordinates, and their effective applications. A very highlighting topic "Dynamic Time Warping Algorithm'' (DTW) is introduced, which has been popular in determining the distance between two non-linear sequences ranging from handwriting to speech recognition. Besides these contemporary research issues/areas, stroke number and order free Nepalese natural handwritten recognition system is presented in the second step. Writing one's own style brings unevenness in writing units, which is the most difficult part to classify. Writing units reveal number, shape, size, order of stroke, and speed in writing. Variation in the number of strokes, their order, shapes and sizes, tilting angles and similarities among characters from one another are the important factors, which are to be considered in classification for Nepali. This paper utilizes structural properties of those alphanumeric characters, which have variable writing units. It uses a string of pen tip's positions and tangent angles of every consecutive point as a feature vector sequence of a stroke. We constructed a prototype recognizer that uses the DTW algorithm to align handwritten strokes with stored strokes' templates and determine their similarity. Separate system is trained for original and preprocessed writing samples and achieved recognition rates of 85.87% and 88.59% respectively. This introduces novel real time handwriting recognition on Nepalese alphanumeric characters, which are independent of number of strokes, as well as their order. Key Words: Handwriting Recognition System; Pre-processing; Feature Vector; Dynamic Time Warping; Agglomerating Hierarchical Clustering; Nepali. DOI: 10.3126/kuset.v5i1.2845 Kathmandu University Journal of Science, Engineering and Technology Vol.5, No.1, January 2009, pp 31-55

Sign in / Sign up

Export Citation Format

Share Document