Controller tuning is needed to select the optimum response for the controlled process. This work presents a new tuning procedure of PID controllers with safety and response quality measures on a non-linear process model by optimization procedure, with a demonstration of two tanks in series. The model was developed to include safety constraints in the form of path constraints. The model was then solved with a new optimization solver, NLPOPT1, which uses a primal-dual interior point method with a novel non-monotone line search procedure with discretized penalty parameters. This procedure generated a grid of optimal PID tuning parameters for various switching of steadystates to be used as apredictor of PID tunings for arbitrary transitions. The interpolation of tuning parameters between the available parameters was found to be capable to produce state profiles with no violation on the safety measures, while maintaining the quality of the solution with the final set points targeted achievable.
Cellulose I can be irreversible transformed into cellulose II via mercerisation or regeneration treatments.
In the past few decades, mercerisation was used mainly to improve fibre properties for textile industries.
A few studies have focused on the effects of mercerisation treatment on the cellulose polymorph itself
and after it was downscaled to nanosize. This study aims to characterise the micro size crystalline
cellulose after complete polymorph conversion via mercerisation technique and investigate its effects
on isolation to nanosize crystalline cellulose. A microcrystalline cellulose (MCC) was purchased and
converted into cellulose II via mercerisation technique. Sulphuric acid hydrolysis was carried-out
to produce nanocrystalline cellulose (NCC). The MCC and NCC of different polymorphs were then
characterised and analysed for its crystallography, morphology, particles size distribution and thermal
stability using wide-angle X-ray diffraction (WXRD), electron microscopes, dynamic light scattering
analyser and thermogravimetric analyser, respectively. Both MCC and NCC fibres showed complete
conversion of cellulose I to cellulose II and decrement of crystallinity index (CI). Electron micrographs
revealed that both cellulose II polymorph fibres (MCC II and NCC II) were morphological affected.
The analysis of size distribution and dimension
measurement confirmed that mercerisation
treatment causing increment in fibre diameter and
shortened length. The thermal stability of both
cellulose II polymorph fibres (MCC II and NCC
II) was also found to be improved.