Two basic approaches to reduce computational requirements for solving
distillation problems have been studied: simplifications of the model based on
physical approximations and order reduction techniques based on numerical
approximations.
Several problems have been studied using full and reduced-order
techniques along with the following distillation models: Constant Molar
Overflow, Constant...
The extraction of pentachlorophenol (PCP) from pressure treated wood
wafers with supercritical carbon dioxide has been studied. Experimental data
were obtained for the effects of pressure (17.5 - 25.0 MPa), temperature (313 - 353
K), flow rate (1 - 3 ml/min at supercritical conditions), and sample size (0.8 x 10...
A review of Single-Input Single-Output Internal Model Control
(IMC) is presented, showing its relationships to the Dahlin
algorithm, PID type controllers for simple models with and without
deadtime and Smith predictor control.
The effect of errors in the time constant and the gain of a
first order model with deadtime...
The temperature-time-location relationships during steam conditioning and pressure
treatment of timber poles have been studied and mathematical models that take into
account both the thermal properties of the poles and the parameters of the treatment
process have been developed. Although much work has been previously done in this
area, the...
Two approaches to reduce computational requirements for solving reactive
distillation problems have been studied: simplification of the model using physical
assumptions and numerical approximation using an orthogonal collocation technique.
The results of a full-order model with time dependent stage molar holdups was
compared to published steady-state experimental data and was...
A computer assisted design model, developed for
undergraduate students to teach the basic principles of
humidification design, is developed and presented.
Beginning with the development of the differential
equations, the conversion to numerical code is presented,
followed by a series of applications to mechanical draft
in cooling towers, natural draft...
This thesis examines the transient performance of packed bed heat
regenerators when very large temperature differences are involved. The
effects of gas temperature on the key gas physical properties of velocity,
density and heat capacity were studied via simulation.
Three models were developed and compared. The first model
(HRKDV) considers...
The principal objective of this study was to investigate process simulation and
optimization of an existing offshore natural gas process which needed profitability
improvements. Optimization was done using two alternative approaches: a global
approach (response surface methodology) or a local approach (successive quadratic
programming). The global approach was characterized by...
A column which contains a series of three fluidized
beds for counter-current contacting of solid particles with
a gas stream has been studied. Successful, independent
control of solids holdup on each stage has been achieved by
manipulating the field of a magnetic distributor-downcomer
on each stage. Two methods to manipulate...
This thesis examines the transient response of a packed bed heat
regenerator when heated from an initial uniform bed temperature. Very large
(1700 K) temperature differences were studied as well as the effect of
simultaneous chemical reaction in the gas phase.
First the effects of temperature on physical and transport...
Two packages of subroutines were developed to perform material
balances on chemical processes using the simultaneous modular
approach and the equation-based approach. The performances of these
packages were compared for five different processes under at least
two conditions: one with no design specifications, and one with two
or more design...
A digital phase locked loop (DPLL) and a statistical time-to-digital converter (STDC) were previously fabricated in a 0.35µm, 3.3V SOI CMOS process. This work summarizes these designs and characterizes the measured performance. Simulations supplement the measurements where applicable.
The DPLL was found to reach a locked state under a limited...
Pediococcus cerevisiae, Lactobacillus casei, Lactobacillus plantarum,
Leuconostoc mesenteroides, Lactococcus diacetylactis Bifidobacterium
bifidum, Leuconostoc oenos, and mixed cultures of Propionibacterium
shermanii and P. cerevisiae were used to ferment cucumber juice brine
(CJB) at 22-26°C for 1.5 months. Sugar utilization ranged from 14.6 to 86.1%.
pH of the fermented CJB ranged from...
The principal aim of this study was the use and evaluation of dynamic
modeling techniques to identify mathematical models for cereal drying rates and
quality changes that best describe thin-layer malt drying data. Seven thin-layer
malt drying experiments were performed at the Great Western Malting pilot
facilities, Vancouver, WA. Malt...
Ferrites have been used for various high frequency applications as bulk
materials. These applications, however, are limited to large dimension devices. In
this thesis, thin film ferrites were deposited from a low temperature solution-based
deposition process that is suitable for micro-scale high frequency applications. The
low temperature nature of this...
This study examines the effects of pressure, temperature, and treatment time on supercritical fluid impregnation of such composites as plywood, particleboard, flakeboard, and medium-density fiberboard. Carbon dioxide with methanol as a cosolvent was used as the supercritical fluid, with tebuconazole as the biocide. Biocide distribution, as measured by extraction and...