- Type of paper
: Paper in book
Title: Fundamentals of Nonlinear Systems
- Authors:
- Kurtanjek, Želimir (24881)
- Editors
- Berovič, Marin
- Koloini, Tine
Publisher: "Boris Kidrič", Institut of Chemistry
ISBN: 66-023-2-579
Year: 1991
Pages: from 285 to 298
Number of references: 5
Language: engleski
Summary: Systems theory approach to biotechnology is reviwed. Given
is aclassification of the input process and information variables andthe
state variables, and basic control structures forbioreactors. Conditions
for multiplicity of steady states ofchemostat are derived. Local dynamic
properties of steady statesare discussed in state space. Derived are
criteria for localasymptotic stability. For the case of 3 dimensional model
of achemost is proven an existance of Hopf's bifurcation of steadystate to
sustained autonomous oscillations.
Keywords: nonlinear systems, control, biotechnology, chemostat, stability of chemostat, Hopf bifurcation, sustained autonomous oscillations
- Type of paper
: Paper in book
Title: Mathematical Modeling and Optimization in Food Engineering
- Authors:
- Kurtanjek, Želimir (24881)
- Editors
- Barbarić, Slobodan
Publisher: Prehrambeno biotehnološki fakultet
Year: 1992
Pages: from 192 to 200
Number of references: 16
Language: engleski
Summary: System theory for control purposes in food indistry is
reviewed.Derived is a nonstationary model for three stage evaporation
unitfor juice concentration and process control is disscused. Also
anonsteady state model of thermal food processing is given.Balances for
heat, microorganism and B6 as a key component forproduct quality are
presented. Industrial process optimization isdiscussed from a view of
linear programming method.
Keywords: food engineering, process modeling, control, multistage evaporation unit, thermal food processing, optimization, linear programming
- Type of paper
: Paper in journal
Title: Optimal Nonsingular Control of Fed-Batch Fermentation
- Authors:
- Kurtanjek, Želimir (24881)
Journal: Biotechnology and Bioengineering
ISSN: 0006-3592
Volume: 37
Year: 1991
Pages: from 814 to 823
Number of references: 23
Language: engleski
Summary: Presented is a new simple method for
multidimensionaloptimization of fed-batch fermentations based on the use of
theorthogonal collocation technique. Considered is the problem
ofdetermination of optimal programs for fermentor temperature,substrate
concentration in feed, feeding profile, and processduration. By
reformulation of the state and control variables isobtained a nonsingular
form of the optimization problem which hasconsiderable advantage over the
singular case. The method isapplied for a homogeneous model of fermentation
with volume,substrate, biomass, and product concentration as the
statevariables. Computer study shows considerable simplicity of themethod,
its high accuracy for low order of approximation, andefficient convergence.
Keywords: nonsingular optimal control, Pontryagin optimal principle, fed-batch fermentation, orthogona collocations
- Type of paper
: Paper in journal
Title: An Investigation of Surface Phenomena Associated With
Oscillatory Oxidation of CO on Pt
- Authors:
- Kurtanjek, Želimir (24881)
- Froment, Gilbert
Journal: Chemical Engineering Science
Number: 12
ISSN: 0009-2509
Volume: 46
Year: 1991
Pages: from 3189 to 3201
Number of references: 31
Language: engleski
Summary: The oscillatory oxidation of CO on Pt under atmospheric
pressureis modeled on uniform and nonuniform surfaces. The multiplicityof
the steady states and the temporal and spatial dynamicbehavior are
analyzed. Synchronization by temperature, gas phaseand CO surface migration
are investigated. The latter is proposedas the basic mechanism, but gas
phase interaction is required tosynchronizate surfaces with dimensions of
the order of 1 mm orensembles of crystallites with nonuniform properties.
For anonuniform surface temperature oscillations of the order ofseveral
degrees are not sufficient for synchronization. Wavepropagation was also
studied and velocities of the order of 0.1m/s seem realistic.
Keywords: oxidation of CO on Pt, mathematical model, oscillations, waves, synchronization
- Type of paper
: Paper in journal
Title: Mathematical Model and Estimation of Kinetic Parameters
for Production of Lactic Acid by Lactobacillus delbruckii
- Authors:
- Šušković, Jagoda
- Beluhan, Sunčica
- Beluhan, Damir
- Kurtanjek, Želimir (24881)
Journal: Chemical and Biochemical Engineering Quarterly
Number: 3
ISSN: 0352-9568
Volume: 6
Year: 1992
Pages: from 127 to 132
Number of references: 15
Language: engleski
Summary: Production of food grade lactic acid by L. delbrueckii in
flaskfermentations and in bioreactor were examined. As a carbon
sourcehigh-fructose syrup, sucroce and high-glucose syrup were usedwith
addition of malt rootlets as the growth factor, and COCO3for neutralization
of lactic acid. During fermentation thesubstrate and product concentrations
and concentration of viablecells were measured. The data were used for the
estimation of thekinetic parameters in the differential equations for the
balancesfor the substrate, the number of cells and the product. Thederived
model with estimated parameters was simulated on acomputer for the
determination of optimal production in batch andfed-batch fermentations.
Keywords: Lactobacillus delbrueckii, lactic acid, mathematical model, kinetic parameters, optimization
- Type of paper
: Paper in journal
Title: Modeling and Control by Artificial Neural Networks
- Authors:
- Kurtanjek, Želimir (24881)
Journal: Automatika
Number: 3
ISSN: 0005-1144
Volume: 33
Year: 1992
Pages: from 147 to 150
Number of references: 11
Language: engleski
Summary: In this work is presented versitality of Artificial
NeuralNetworks (ANN) for their use in modelling, parameter and
stateestimation, control of nonlinear systems, and for development ofexpert
systems. Treated is a mathematical model of general MIMOsystem with
arbitrary number of internal hidden layers. Derivedare general expressions
for the backward delta algorithm, andapplied is the general algorithm by
Polak-Ribiere with Powellmodification as the most efficient learning
procedure. Use of ANNalgorithms in biotechnology is emphasized with
examples ofidentification of biological activity in fermentors
forproduction of penicilin.
Keywords: artificial neural networks, expert systems, modelling, control, biotechnology
- Type of paper
: Paper in journal
Title: Mathematical Modeling and Control in Biotechnology
- Authors:
- Kurtanjek, Želimir (24881)
Journal: Kemija u industriji
Number: 6
ISSN: 0022-9830
Volume: 42
Year: 1993
Pages: from 195 to 203
Number of references: 22
Language: hrvatski
Summary: This work is a review of the current research in the
applicationof mathematical modeling and control theory in biotechnology.
Therole of measurement systems, mathematical and computer models,and
control systems is discussed from the systems point of view.The view of WP
on Measurement and Control of EFB is given. Theimportance of dynamic
measurement systems (FIA) and expertsystems for data analysis is
emphasized. Structured modelling ofbiomass from systems point of view is
presented. Adaptive controlof bioreactors is summarized on the basis of
major controlstructures. Special attention is paid to the posibillities
ofusing artificial neural networks ANN for estimation andbioreactor
control.
Keywords: measurements, modeling, control, biotechnology
- Type of paper
: Paper in journal
Title: The Application of Linear Programming to the Low Fat and
Low Cholesterol Loaf-type Meat Products
- Authors:
- Kunsheng, Zhang
- Hanser, Damir
- Kurtanjek, Želimir (24881)
- Roseg, Đuro
Journal: Journal of Tianjin University of Commerce
Number: 3
ISSN: 1001-0262
Volume: 13
Year: 1993
Pages: from 11 to 18
Number of references: 10
Language: kineski
Summary: In this work is optimized a recepie for low fat meat
loafproducts by use of the linear programming optimization. Theproblem is
divided in two steps. Firstly is optimized the fatcomponent of the product,
in which 46 % of pork back fat isreplaced by vegetable oils from soya and
palm. In the second stepis optimized nonfat component of the product. The
total amount offat in the product is less than 12 %. Derived formula has
theminimal cost of row materials and satisfies technological andproduction
constraints.
Keywords: linear programming, optimization, meat technology, cholesterol, soya oil, palm oil
- Type of paper
: Paper in proceedings
Title: Modeling and Control of Baker's Yeast Fermentation by Use
of Artificial Neural Networks
- Authors:
- Kurtanjek, Želimir (24881)
- Editors
- Kecman, Vojislav
Proceedings title: KOREMA 38
Language: engleski
Place: Zagreb
Year: 1993
ISBN/ISSN: 86-81571-11-7
Pages: from 450 to 454
Meeting: 38 Međunarodni godišnji skup KoREMA
Held: from 04/26/93 to 04/29/93
Summary: In the work is investigated use of artificial neural
networks ANNfor modelling and control of the fed-batch fermentation
ofbaker's yeast fermentation. Feremntation is defined as anonlinear system
of 9-th order. Derived as the ANN modul for theyeast respiratory quotient
RQ. The modul is structured as MISOmodel with a single internal layer. The
results are discussedfrom point of on-line adaptive control of industrial
fermentor.
Keywords: artificial neural network, baker's yeast fermentation, respiratory quotient, regulation
- Type of paper
: Paper in proceedings
Title: State Estimation of Penicillin Production by Ann Model
- Authors:
- Kurtanjek, Želimir (24881)
- Editors
- Glavič, Petar
Proceedings title: Vodenje kemijskih procesov
Language: engleski
Place: Maribor, Slovenija
Year: 1991
Pages: from 83 to 88
Meeting: Posvetovanje Vodjenje kemijskih procesov
Held: from 10/08/91 to 10/09/91
Summary: A computer model of industrial production of penicillin is
usedfor process simulation. Data base with simulated input / outputpatterns
is used for training artificial neural networks. Studiedare variations of
network structures and methods of optimizationduring the learning
procedure.
Keywords: penicillin, modeling, artificial neural network, network structure, optimization
- Type of paper
: Summary in proceedings
Title: The Dynamic Characteristics of the CO Oxidation
- Authors:
- Kurtanjek, Želimir (24881)
- Editors
- Vasić-Rački, ĐurĐa
Proceedings title: Sinopsisi XII Sastanak kemičara Hrvatske
Language: hrvatski
Place: Zagreb
Year: 1991
Pages: from 231 to 232
Meeting: XII Sastanak kemičara Hrvatske
Held: from 02/14/91 to 02/15/91
Summary: Analyzed are temporal and spatial structures on surface
ofplatinum during oxidation of CO. Model is based on surfacestudies
conducted at pressure < 1ubar. Assumed isLangmuir-Hinshelwood mechanism of
surface reactions. Computersimulations reveal significance of distribution
of oxygensticking coefficient on Pt and its effects on surface
structuresand synchronization of surface phenomena.
Keywords: oxidation of CO, Pt, surface structures, synchronization
- Type of paper
: Summary in proceedings
Title: Determination of Thermophysical Parameters of Surimi by
Differential Thermal Analysis ( DTA )
- Authors:
- Kovačević, Dragan
- Kurtanjek, Želimir (24881)
- Editors
- Tripalo, Branko
- Trinajstić, Nenad
Proceedings title: Sinopsisi XIII Skupa hrvatskih kemičara
Language: hrvatski
Place: Zagreb
Year: 1993
Pages: from 337 to 338
Meeting: XIII Skup hrvatskih kemičara
Held: from 02/08/93 to 02/10/93
Summary: Applied is thermal differential analysis (DTA) for
determinationof thermophysical parameters and enthalpy of frozen
surimi.Samples of surimi were prepeared from Sardina pilcardus bymodified
industrial procedure with 0,4,6,8,10,12 % of sorbnitolas a cryoprotector.
Determined are the following variables:thermal diffusivity, specific heat
capacity and enthalpy in therange of temperature - 20 to 0 C.
Keywords: DTA, surimi, thermophysical parameters, enthalpy
- Type of paper
: Summary in proceedings
Title: Modelling and Control of Baker's Yeast Fermentation by
Artificial Neural Networks
- Authors:
- Repić, Miroslav
- Kurtanjek, Želimir (24881)
Proceedings title: Abstracts of Sixth European Congress on Biotechnology
Language: engleski
Place: Firenze, Italija
Year: 1993
Pages: from 387 to 388
Meeting: Sixth European Congress on Biotechnology
Held: from 06/13/93 to 06/17/93
Summary: Analyzed is multilayerd structure of static neurons for
modelingBaker's yeast fermentation. Applied is backward error
propagationwith Ribiera-Polack algorithm for minimization of variance
duringANN training. Proposed is modular MISO structure. Developed
aremodules for pH, pEtOH and biomass x. Application of ANN modulesfor
control of industrial deep jet fermentor is discussed.
Keywords: artificial neural networks, baker's yeast, process regulation
- Type of paper
: Summary in proceedings
Title: Enthaply Determination of Frozen Food by Use of
Differential Thermal Analysis
- Authors:
- Kovačević, Dragan
- Kurtanjek, Želimir (24881)
- Editors
- Butula, Ivan
Proceedings title: Sinopsisir radova Ružičkini dani i Sastanak kemičara Slavonije i Baranje
Language: hrvatski
Place: Belišće, Hrvatska
Year: 1993
Pages: from 63 to 64
Meeting: Ružičkini dani, Sastanak kemičara i tehnologa Slavonije i Baranje
Held: from 09/23/93 to 09/24/93
Summary: Enthalpy of frozen food is determined by use of the
differentialthermal analysis. For the quantitative analysis is
appliedcollocation technique for approximation of the partialdifferential
equation for nonsteady heat transfer. Determined areenthalpies and initial
freezing points of samples with variouslevels of additives in temperature
range from - 25 C to 0 C. Theobtain results are in a very good agreament
with regression datapublished in literature.
Keywords: frozen food, enthalpy, differential thermal analysis, cryoprotectors
- Type of paper
: Summary in proceedings
Title: Static Mixing In the Food Industry
- Authors:
- Bauman, Ingrid (130254)
- Editors
- Trinajstić, Nenad
Proceedings title: Sinopsisi XIII Skupa hrvatskih kemičara
Language: hrvatski
Place: Zagreb
Year: 1993
Pages: from 314 to 314
Meeting: XIII Skup hrvatskih kemičara
Held: from 02/10/93 to 02/11/93
Summary: Aim of this work is to study use of static mixers for
mixing ofcomponents of dehydrated soups and spices. The components
varysignificantly in their size, denisity and shape. Tested weremixtures of
components with different sizes and volumes. The bestresults were obtained
where the component of the largest size hadmain contribution, but a reduced
number of internal mixingelements was used. This experiments show that by
adjusting anumber and size of internal mixing element performance of
staticmixers can be adjusted to specific properties of solid particles.
Keywords: static mixer, dehydrated soup
- Type of paper
: Summary in proceedings
Title: Comparison of Degree of Mixing of Real and Model Systems
In a Laboratory V-Mixer
- Authors:
- Bauman, Ingrid (130254)
Proceedings title: Abstarkti III Jugoslavenskog simpoziujma o hemijskom inženjerstvu
Language: hrvatski
Place: Novi Sad, Jugoslavija
Year: 1991
Pages: from 0 to 0
Held: from 01/16/91 to 01/18/91
Summary: This is an experimental studu of mixing of model and real
solidsystems in a laboratory V- mixer unit. As the model material wasused
quartz sand and components of dehydrated soups were used fortesting with
real systems. Process was analyzed by off-linesamoling and statistical
analysis. The data indicate presence ofdemixing in the experiments with the
real components.
Keywords: V-mixer unit, dehydrated soup, dynamics of mixing
- Type of paper
: Summary in proceedings
Title: Static Mixing In the Food Industry
- Authors:
- Bauman, Ingrid (130254)
- Editors
- Miro, D. Pere
Proceedings title: Abstracts 6th Mediterranean Congress on Chemical Engineering
Language: češki
Place: Barcelona, Spain
Year: 1993
Pages: from 123 to 124
Meeting: 6th Meditteranean Congrees on Chemical Engineering
Held: from 10/18/93 to 10/20/93
Summary:
Experiments in a static mixer were conducted with quartz sand anddehydrated
soups and spices. The volumetric ratio of componentswas: 1:1, 1:2, 1:3. All
experiments were analyzedgranulometyricaly, standard deviation nad Lacy's
index ofmixdness were calculated and presented graphically. Goodhomogeneity
was obtained for mixtures that had ratio 1:1, othercombinations showed some
results after a certain amount of timehad passed. In cases where particles
of dried vegetable rootswere mixed the best results were obtained at the
ratio 3:1.
Keywords: static mixer, quartz sand, dehydrated soup, mixing analysis
- Type of paper
: M.A.
Title: Optimization of Baby Milk Formula With Addition of Whey
Proteins
Faculty: Prehrambeno biotehnološki fakultet Sveučilište u Zagrebu
Date of defense: 06/02/91
Language: hrvatski
Number of pages: 78
Summary: The aim of this research is to apply mathematical model of
linearprograming to optimize " liquid baby milk formula " with additionof
whey proteins. Whey was ultrafiltered to 1/15 of its volume onDDS module
20-1,8 LAB, company De Danske Sukkerfabrikker, withmembranes type GR 60 PP
of total area of 0,936 m2. Inlet pressurewas 6,5 bar and outlet pressure
was 2,0 bar. The ultrafilteredwhey contains 7% proteins, 4% lactose, 0,7%
fat and 0,7% ash.Optimization of the recepie with ultrafiltered whey
compared withwhey in powder deminiralized by ion-exchange or
electrodialysesshows decrease in price for 30% and 45% respectively.
Keywords: "baby milk formula", whey, ultrafiltration, linear programming
- Type of paper
: Mentorship
Title: Optimization of Baby Milk Formula With Addition of Whey
Proteins
Faculty: Prehrambeno biotehnološki fakultet Sveučilište u Zagrebu
Mentor: ADLER NEVENKA
Number of pages: 0
Author: Hanser Mr. sc. Damir
Degree level: M.A.
