- Type of paper
: Paper in journal
Title: Investigations of gibbsite and boehmite dehydroxylation
process by means of dynamic thermogravimetry
- Authors:
- Perić, Jelena (36162)
- Krstulović, Ruža (36162)
- Ferić, Tereza (11612)
- Vučak, Marijan (181073)
Journal: Travaux ICSOBA
Number: 23
ISSN: 0350-7548
Volume: 20
Year: 1991
Pages: from 35 to 41
Number of references: 5
Language: engleski
Summary: The process of dehydroxylation of gibbsite and boehmite has
been examined by means of nonisothermal TG analysis. Examinations have
shown that overall dehydroxylation reaction rate is determined by random
formation of new phase centers, and mechanism can be best described by the
function f(a)=(1-a)Čn. Influence of temperature is greater than that of
process duration, which is characteric for reactions taking place in the
kinetic stage, and which is confirmed by the values for the Ea. The average
value for the Ea for the the gibbsite dehydroxylation amounts to 122,4
kJ/mol; for boemite dehydroxylation it amounts 216,7 kJ/mol.
Keywords: Gibbsite, Boehmite, Dehydroxylation, Dinamic Thermogravimetry, Process Mechanism, Process Kinetics.
- Type of paper
: Paper in journal
Title: A conceptual design for the treatment of waste water from
a printing house zincography
- Authors:
- Perić, Jelena (36162)
- Vučak, Marijan (181073)
Journal: Kemija u industriji
Number: 7
ISSN: 0022-9830
Volume: 41
Year: 1992
Pages: from 269 to 273
Number of references: 8
Language: hrvatski
Summary: Waste water from the etching process was analyzed
qualitatively and quantitatively, and the conceptual design for its
processing was evaluated on the basis of laboratory tests. For a number of
advantages, milk of lime was chosen as neutralization -sedimentation agent.
Optimum pH-region was determined to be around 9. Based on the data obtained
by laboratory measurementsand the material balance of the etching process,
a batch processing plant is proposed, consisting of an oil separator and a
neutralizer-settler.
Keywords: Waste Water, Zincography, Treatment, Neutralization, Precipitation, Zinc.
- Type of paper
: Paper in journal
Title: Microcalorimetry in the cement hydration process
- Authors:
- Krstulović, Ruža (36162)
- Ferić, Tereza (11612)
- Krolo, Petar (23832)
Journal: Periodica Polytechnica
Number: 3
ISSN: 0324-583
Volume: 33
Year: 1989
Pages: from 315 to 321
Number of references: 9
Language: engleski
Summary: The paper presents a differential laboratory made
microcalorimetric system disigned to enable scientific research into cement
hydration .The reproducibility and the statistical processing of the data
on the hydration heat were calculated by a computer which provided a basis
for calculation of same hydration kinetics parameters.
Keywords: cement, microcalorimeter, calibration, heat of hydration, statistical processing
- Type of paper
: Paper in proceedings
Title: Preparation of calcium carbonate by carbonation of milk of
lime
- Authors:
- Perić, Jelena (36162)
- Krstulović, Ruža (36162)
- Vučak, Marijan (181073)
- Ferić, Tereza (11612)
- Editors
- Žižić, Petar
Proceedings title: Zbornik radova
Language: hrvatski
Place: Zagreb
Year: 1992
Pages: from 169 to 178
Meeting: XV Savjetovanje o tehničkim dostignućima i ekološkim rješenjima u proizvodnji cementa i azbest-vlakno cementa
Held: from 11/05/92 to 11/07/92
Summary: A process of obtaining the precipitated CaCO3 was carried
out by carbonation of suspension of technical lime with a gas mixture CO2 +
air. Process took place at the constant gas flow, and stirring rate at
different temperatures. Process was traced by measuring the pH of a
suspension. Qualitative and quantitative phase analysis of obtained CaCO3
samples were carried out bymeans of Meigen asay, IR-spectroscopy, and X-ray
diffraction.
Keywords: Calcium Carbonate, Carbonation, Milk of Lime, Phase Analysis.
- Type of paper
: Paper in proceedings
Title: Precipitation of calcium carbonate from a suspension of
lime by a electrical conductivity monitoring
- Authors:
- Perić, Jelena (36162)
- Vučak, Marijan (181073)
- Krstulović, Ruža (36162)
- Editors
- Rojkowski, Zbigniew
Proceedings title: Proceedings in 2 volumes
Language: engleski
Place: Warsaw, Poland
Year: 1993
Pages: from 91 to 96
Meeting: 12th Symposium on Industrial Crystallization
Held: from 09/21/93 to 09/23/93
Summary: This report descibes a process of obtaining PCC by means of
carbonation of suspension of lime; purity and concentration of raw material
was varied, as well as operation temperature at constant mixing rate.
Process was monitored through changes in el. conductivity of the
suspension. k-t curves have been qualitatively kinetcally interpreted, i.e.
they were used to determine the effect of temperature, and gas composition
and flow, on carbonation duration. Qualitative phase analysis was
determined by means of Meigen assay and X-ray diffraction.
Keywords: Calcium Carbonate, Carbonation, Suspension, Precipitation, Electrical Conductivity.
- Type of paper
: Paper in proceedings
Title: Deterination of kinetic parameters in cement hydration
- Authors:
- Krstulović, Ruža (36162)
- Krolo, Petar (23832)
- Editors
- Mullick, A. K.
Proceedings title: 9-th International Congress of the Chemistry of Cement
Language: engleski
Place: New Delhi, India
Year: 1992
Pages: from 31 to 38
Meeting: 9-th International Congres of the Chemistry of Cement
Held: from 11/23/92 to 11/28/92
Summary: The differential microcalorimetric technique was used to
study cement hydration in the presence of a superplastificiser as
admixtures. This paper introduces a systematic approch to calculation of
the important kinetic parameter for the accelerated hydration period.
Mathematical anlysis of the hydration kinetics models applied made it
possible to get an insight into mechanism of the cement hydration process.
Keywords: differential microcalorimeter, cement hydration, admixture, kinetic parameres, mechanism
Other: Izdavač: National Council for Cement and Building
Materials(NCB), New Delhi ,India, Vol.IV, Theme III-A
- Type of paper
: Paper in proceedings
Title: Tracing the interaction of KMS admixture with the ions
from hydrated cement
- Authors:
- Žmikić, Anka (55784)
- Krstulović, Ruža (36162)
- Dabić, Pero
- Krolo, Petar (23832)
- Editors
- Žižić, Petar
Proceedings title: XV Savjetovanje o tehničkim dostignućima i ekološkim riješenjima u proizvodnji
Language: hrvatski
Place: Zagreb
Year: 1992
Pages: from 7 to 16
Meeting: XV Savjetovanje o tehničkim dostignućima i ekološkim rješenjima u proizvodnji cementa i vlakno-cementnih proizvoda
Held: from 11/05/92 to 11/07/92
Summary: Interaction of ion species from hydrated cement with
theadixture, superplastifier, melamine sulphonic acid condesate
withformaldehyde, KMS, was traced by means of conductometric methods. The
conductograms of the extract of cement with the admixture indicate that
along with adsorption another reaction takes place - that of association of
individual species (Ca++, Al+++, Fe+++ ) with the admixture, forming
precipitate or acomplex ion.
Keywords: cement, hydration, conductometry, superplasifier
Other: Znanstveno - stručni skup!
- Type of paper
: Paper in proceedings
Title: Properities and preparation of concrete with the optimum
quantity of admixture and strength analysis by non-destructive methods
- Authors:
- Krstulović, Ruža (36162)
- Ferić, Tereza (11612)
- Dabić, Pero
- Žmikić, Anka (55784)
- Krolo, Petar (23832)
- Editors
- Žižić, Petar
Proceedings title: XV savjetovanje o tehničkim dostignućima i ekološkim riješenjima
Language: engleski
Place: Zagreb
Year: 1992
Pages: from 302 to 309
Meeting: XV Savjetovanje o tehničkim dostignućima i ekološkim rješenjima u proizvodnji cementa i vlakno-cementnih proizvoda
Held: from 07/05/92 to 11/07/92
Summary: Physical and mechanical properities of concrete, prepared
out of PC-30T-45 cement with addition of Izola Be admixture were
examined.The behaviour of cement was analyzed when adixture was added, and
the optimum quantity to be used in preparation of concrete was determined.
The strength of concrete prepared with the optimum quantity of admixture
was measured both by means of the standard method - and by non-destructive
methods such as ultrasound and sclerometers. The optimum addition of Izola
Beadmixture ranges aroud 1.7 % mass, in wich case the strength wasthe
highest for all examination times.
Keywords: cement, admixture, concrete, strength, examination methods
- Type of paper
: Paper in proceedings
Title: Influece of Chrysotile asbestos on cement hydration
- Authors:
- Ferić, Tereza (11612)
- Krstulović, Ruža (36162)
- Perić, Jelena (36162)
- Editors
- Žižić, Petar
Proceedings title: XV savjetovanje o tehničkim dostignućima i ekološkim rijećenjima
Language: hrvatski
Place: Zagreb
Year: 1992
Pages: from 25 to 33
Meeting: XV Savjetovanje o tehničkim dostignućima i ekološkim rješenjima u proizvodnji cementa i azbest-vlakno cementa
Held: from 11/05/92 to 11/07/92
Summary: Cement hydration was traced by means of hydration heat
andadsorption activities of asbestos.The asbestos samples used
wereshortfibered,belonging the chrysotile asbestos by theirmineralogical
composition.The heat released and the heatdevelopment rate were higher in
all samples containig asbestosthan with pure cement paste
samples.Examination of adsorption ofcalcium - hidroxide to asbestos fibers
points to the asbestossurface activity,wich inproves cement hydration
capabilities inthe presence of asbestos.
Keywords: chrysotile asbestos,cement hydration,calorimetry,adsorption, surface activity
Other: Znanstveno-stručni skup!
- Type of paper
: Paper in proceedings
Title: Precipitation of calcium carbonate by carbon dioxide
method
- Authors:
- Perić, Jelena (36162)
- Vučak, Marijan (181073)
- Krstulović, Ruža (36162)
- Editors
- Vincenzini, P.
Proceedings title: Ceramics: Charting the Future, Vol. B, Proceedings of the 8th CIMTEC
Language: engleski
Place: Faenza, Italija
Year: 1995
Pages: from 1245 to 1250
Meeting: Eight Cimtec - World Ceramics Congress
Held: from 06/28/94 to 07/04/94
Summary: Milk of lime has been carbonated and CaCO3 precipitated by
means of gas mixture, whose composition approximately corresponds to taht
of gasses produced by lime kilns. Milk of lime was prepared by slaking
quicklime which had been produced by calcination of limestone. The process
development was traced by measuring pH values. The samples of PCC were
examined for CaCO3 content, particle fineness, and phase composition.
Keywords: Calcium Carbonate, Calcite, Aragonite, Milk of Lime, Carbonation, Phase Analysis.
- Type of paper
: Paper in proceedings
Title: A Study of Degradatin of Cement and Asbestos-Cement
Materials
- Authors:
- Krstulović, Ruža (36162)
- Tončić, Damir
- Ferić, Tereza (11612)
- Krolo, Petar (23832)
- Editors
- Fischer, H. B.
Proceedings title: 12 Internationale Baustofftagung (IBAUSIL), 22-24 Sept.,Weimar
Language: engleski
Place: Weimar, Njemačka
Year: 1994
Pages: from 328 to 338
Meeting: 12 Internationale Baustofftagung (IBAUSIL)
Held: from 09/22/94 to 09/24/94
Summary: his paper presents a part of results obtained in a study
undertaken to improve the quality of AC materials and their service life.
Various parameters causing product degradation were examined from the
initial stage of the production process up to the final treatment stage.It
was concludet that along with attention paid to selection of raw materials
and to stability of the production process, special attention should be
turend to conditions and methods of post-production treatment of AC
products.
Keywords: Cement, Asbestoscement Materials, degradation, damages, examinations,post-production treatment
- Type of paper
: Paper in proceedings
Title: Determination of the C-S-H Phase formed by Pozzolana
Reaction of Silica Fume in Hydrated Cement
- Authors:
- Krolo, Petar (23832)
- Krstulović, Ruža (36162)
- Zelić, Jelica (143203)
- Žmikić, Anka (55784)
- Editors
- Jungwirth, Noemi
- Stokić, Vladislav
- Kuzmanić, Ante
- Grisogono, Petar
- Žižić, Petar
Proceedings title: XVI. savjetovanje o tehnološkim dostignućima i ekološkim rješenjima u proizvodnj
Language: hrvatski
Place: Split
Year: 1995
ISBN/ISSN: 953-9638-0-8
Pages: from I-25 to I-33
Meeting: XVI Savjetovanje o tehnološkim dostignućima i ekološkim rješenjima u proizvodnji cementa i vlakno-cementnih proizvoda
Held: from 03/09/95 to 03/11/95
Summary: The effect of the admixture of silica fume on the quantity
of hydrates components of the C-S-H phase formed in the water -cement
reaction system was examined. The Ca(OH)2 content, i.e. the quantity of
water bound to Ca(OH)2 was used to determine the quantity of water bound to
hydrates in the hydraulic ( C-S-H ) phase. The lowest values of the Ca(OH)2
content correspond to the highest content of the C-S-H phase formed during
cement hydration and pozzolana reaction.
Keywords: Silica Fume, PC pastes, CH, CSH phase, Thermogravimetry
- Type of paper
: Paper in proceedings
Title: Study of Interaction of KMS and KNS Admixtures with Ions
from Hydrated Cement
- Authors:
- Žmikić, Anka (55784)
- Krstulović, Ruža (36162)
- Krolo, Petar (23832)
- Editors
- Jungwirth, Noemi
- Stokić, Vladislav
- Kuzmanić, Ante
- Grisogono, Petar
- Žižić, Petar
Proceedings title: XVI. Savjetovanje o tehn. dostignućima i ekološkim rješenjima u priz. cementa i
Language: hrvatski
Place: Split
Year: 1995
Pages: from I-73 to I-80
Meeting: XVI Savjetovanje o tehnološkim dostignućima i ekološkim rješenjima u proizvodnji cementa i vlakno-cementnih proizvoda
Held: from 03/09/95 to 03/11/95
Summary: Conductometrical and UV- spectrophotometrical methods were
used to trace the interaction between the admixtures: KMS and KNS,
respectively, and Ca2+, Al3+, Fe3+, AlO2-, H3O+ and OH- ions. The
conductrograms and apsorption electron spectra provided a basis for a
discussion of the interaction of hydrated or complex ions with the
superplasticizers used.
Keywords: Admixtures, Interaction, electrolytic solutions, Spectrophotometry, Conduction
- Type of paper
: Summary in proceedings
Title: A solution of treatment of waste water from a zincography
of printer's
- Authors:
- Perić, Jelena (36162)
- Vučak, Marijan (181073)
Proceedings title: Abstracts
Language: engleski
Place: Zagreb
Year: 1991
Pages: from 361 to 361
Meeting: Symposium Ecologically Rational Development of Chemical Technologies
Held: from 02/14/91 to 02/15/91
Summary: Waste water from the etching process was analyzed
qualitatively and quantitatively, and the conceptual design for its
processing was evaluated on the basis of laboratory tests.
Keywords: Waste Water, Zincography, Tretment, Neutralization, Precipitation, Zinc.
- Type of paper
: Summary in proceedings
Title: Kinetics of gibbsite dehydroxylation process in
non-isothermal conditions
- Authors:
- Perić, Jelena (36162)
- Krstulović, Ruža (36162)
- Ferić, Tereza (11612)
- Dabić, Pero
Proceedings title: Sinopsisi
Language: hrvatski
Place: Zagreb
Year: 1991
Pages: from 235 to 235
Meeting: XII. Sastanak kemičara Hrvatske
Held: from 02/11/91 to 02/13/91
Summary: The process of dehydroxylation of gibbsite has been
examined by means of nonisothermal TG analysis.
Keywords: Gibbsite, Dehydroxylation, Nonisothermal TG, Process Mechanism, Process Kinetics.
- Type of paper
: Summary in proceedings
Title: Examination of phase transformation of aragonite into
calcite by means of DSC analysis
- Authors:
- Perić, Jelena (36162)
- Krstulović, Ruža (36162)
- Ferić, Tereza (11612)
- Vučak, Marijan (181073)
- Dabić, Pero
Proceedings title: Sinopsisi radova
Language: hrvatski
Place: Sarajevo, Jugoslavija
Year: 1991
ISBN/ISSN: 0367-4444
Pages: from 133 to 133
Meeting: Šesti jugoslavenski simpozijum analitičke hemije
Held: from 09/30/91 to 10/02/91
Summary: In examined samples of CaCO3, sinthesized in laboratory and
industrial samples, Phase analysis of CaCO3 samples was carried out by
means of X-ray diffraction. Transformation of the aragonite modification
into the stable calcite structure was traced by means of DSC analysis. A
mathematical analysis ofe xperimental DSC curves defined mechanism and the
kinetics of the process.
Keywords: Aragonite, Calcite, Calcium Carbonate, Phase Transition, DSC Analysis, Process Kinetics, Process Mechanism.
- Type of paper
: Summary in proceedings
Title: Examination of dehydroxylation process of gibbsite into
boehmite by means of DSC anlysis
- Authors:
- Perić, Jelena (36162)
- Krstulović, Ruža (36162)
- Ferić, Tereza (11612)
- Vučak, Marijan (181073)
- Editors
- Bardossy, Gy.
Proceedings title: Abstracts
Language: engleski
Place: Budapest, Hungary
Year: 1992
Pages: from 82 to 82
Meeting: 7th International Congress of ICSOBA
Held: from 06/22/92 to 06/26/92
Summary: Dehydroxylation of gibbsite into boehmite was traced by
means of DSC analysis. A mathematical analysis of experimental DSC curves
defined the mechanism and the kinetics of gibbsite dehydroxylation process.
Keywords: Gibbsite, Boehmite, Dehydroxylation, DSC Analysis, Process Mechanism, Process Kinetics.
- Type of paper
: Summary in proceedings
Title: Precipitation of calcium carbonate by carbonation of milk
of lime
- Authors:
- Perić, Jelena (36162)
- Vučak, Marijan (181073)
- Krstulović, Ruža (36162)
- Ferić, Tereza (11612)
Proceedings title: Sinopsisi
Language: hrvatski
Place: Zagreb
Year: 1993
Pages: from 359 to 359
Meeting: XIII. Skup hrvatskih kemičara
Held: from 02/08/93 to 02/10/93
Summary: This report describes process of obtaining PCC by means of
carbonation of suspension of lime; concentration and gas flow were varied
as well as operation temperature. Process was monitored through changes in
el. conductivity of the suspension. k-t have been qualitatively kinetically
interpreted. The content of CaCO3 and the qualitative phase analysis of
samples synthesized was determined.
Keywords: Calcium Carbonate, Carbonation, Suspension, Precipitation, Electrical Conductivity.
- Type of paper
: Summary in proceedings
Title: Adsorption of calcium hydroxide on polyacrylnitrile,
cellulose and chrysotile fibers
- Authors:
- Ferić, Tereza (11612)
- Krstulović, Ruža (36162)
- Perić, Jelena (36162)
- Vučak, Marijan (181073)
Proceedings title: Sinopsisi
Language: hrvatski
Place: Zagreb
Year: 1993
Pages: from 345 to 345
Meeting: XII. Skup hrvatskih kemičara
Held: from 02/08/93 to 02/10/93
Summary: This paper presents results obtained for surface activity
in two types of polyacrylnitrile fibers and treated celluloze fibers as
compared to chrysotile asbestos, by determination of adsorption of calcium
hydroxide to the fibers. Fibers examined have a surface activity similar to
that of asbestos fibers, and may be expected to have a similar effect on
cement hydration.
Keywords: Adsorption, Calcium Hydroxide, Asbestos, Polyacrylonitrile Fibers, Chrysotile.
- Type of paper
: Summary in proceedings
Title: Examination of interaction of different ions from
synthetic solution with admixtures to cement
- Authors:
- Žmikić, Anka (55784)
- Krstulović, Ruža (36162)
- Dabić, Pero
- Krolo, Petar (23832)
Proceedings title: Šesti jugoslovevenski simpozijum analitičke hemije
Language: hrvatski
Place: Sarajevo, Jugoslavija
Year: 1991
ISBN/ISSN: 0367-4444
Pages: from 132 to 132
Meeting: Šesti jugoslovenski simpozijum analitičke kemije
Held: from 09/30/91 to 10/02/91
Summary: The KMS and KNS admixtures adsorb on the particles of
hydrated cement. Ionic species ineract in the solution with the admixtures.
Conuctometrictal methods examined the interaction of the ionicspecies
CaCl2, AlCl3, FeCl3, Ca(OH)2 and NaAlO2 with the admixtures. Conductograms
obtained explain the interaction of various ionic species with the
admixtures.
Keywords: superplastificiser, KMS, KNS, electrolyte solution, conductometry, ionic reactions
- Type of paper
: Summary in proceedings
Title: Microclorimetry in study of the kinetic heterogenous
cement - water reaction
- Authors:
- Krstulović, Ruža (36162)
- Ferić, Tereza (11612)
- Dabić, Pero
- Krolo, Petar (23832)
Proceedings title: XII sastanak kemičara Hrvatske
Language: hrvatski
Place: Zagreb
Year: 1991
Pages: from 236 to 236
Meeting: XII. Sastanak kemičara Hrvatske
Held: from 02/11/91 to 02/13/91
Summary: Differential microcalorimetry was used to monitor cement
hydration in the presence of superplastificiser. The kinetic parameters
examined were shown to depend on the quantity of admixture added which
therefore affects the reaction rate.
Keywords: differential microcalorimeter, cement, superplastifizer, hydration, kineticparameters
- Type of paper
: Summary in proceedings
Title: Conductometric tracing the interaction ions from hydrated
cement with admixture KNS
- Authors:
- Žmikić, Anka (55784)
- Krstulović, Ruža (36162)
- Dabić, Pero
- Krolo, Petar (23832)
Proceedings title: XIII skup hrvatskih kemičara
Language: hrvatski
Place: Zagreb
Year: 1993
Pages: from 361 to 361
Meeting: XIII. Skup hrvatskih kemičara
Held: from 02/08/93 to 02/10/93
Summary: The effect of the KNS superplasticizer on cement hydration
has been examined. The specific conductivity of the adixture in the cement
extract, w(%) = 0.1 - 0.15 % was measured by conductomertrical methods
before and after adsorption. It wasconcluded that ionic species of hydrated
cement interacted with the adixture.
Keywords: cement, KNS admixture, hydration, conductometry, interaction of ionic species
- Type of paper
: Summary in proceedings
Title: Superplasticiser activity of melamin-formaldehyde
admixture in the cement-water reacting system
- Authors:
- Krstulović, Ruža (36162)
- Dabić, Pero
- Ferić, Tereza (11612)
- Žmikić, Anka (55784)
- Krolo, Petar (23832)
Proceedings title: XIII Skup hrvatskih kemičara
Language: hrvatski
Place: Zagreb
Year: 1993
Pages: from 362 to 362
Meeting: XIII. Skup hrvatskih kemičara
Held: from 02/08/93 to 02/10/93
Summary: Microcalorimetrical methods were used to examine the
efffect of the "Melment" (KMS) superplastciser admixture. The effect of the
KMS on induction duration was determined as well as its optimum quantity
added to cement. The results were in accord with strenghts obtained in
concrete and in comparison to non-destructive methods.
Keywords: cement, "Melment" adixture, hydration,microcalorimetry, optimum admixture quantity, concrete strength
- Type of paper
: Summary in proceedings
Title: High Purity Precipitated Calcium Carbonate
- Authors:
- Perić, Jelena (36162)
- Vučak, Marijan (181073)
- Krstulović, Ruža (36162)
- Dabić, Pero
Proceedings title: Sinopsisi
Language: hrvatski
Place: Zagreb
Year: 1995
Pages: from A62 to A62
Meeting: XIV. Skup hrvatskih kemičara
Held: from 02/06/95 to 02/08/95
Summary: In this paper the influence of temperature on the
carbonation process of calcium nitrate solution in monoethanolamine and
product properties have been examined.
Keywords: Precipitation, High purity Calcium Carbonate, Carbonation, Monoethanolamine.
- Type of paper
: Summary in proceedings
Title: Precipitation of Calcium Carbonate in Calcium Nitrate and
Monoethanolamine Solution
- Authors:
- Vučak, Marijan (181073)
- Perić, Jelena (36162)
- Krstulović, Ruža (36162)
Proceedings title: ICCGXI-Abstracts
Language: engleski
Place: The Hague, The Netherlands
Year: 1995
Pages: from 410 to 410
Meeting: The Eleventh International Conference on Crystal Growth
Held: from 06/18/95 to 06/23/95
Summary: Extra pure precipitated calcium carbonate was obtained in
laboratory by carbonation of calcium nitrate and monoethanolamine solution.
Process parameters and product properties have been discussed.
Keywords: Precipitation, Crystallization, Extra Pure Calcium Carbonate, Carbonation, Morphology.
- Type of paper
: Summary in proceedings
Title: Characterization of Crystal Morphology by Image Analysis:
Application to Calcium Carbonate and Various Oxalates
- Authors:
- Vučak, Marijan (181073)
- Vivier, H.
- Pons, M.N.
Proceedings title: Abstracts
Language: engleski
Place: Nancy, Francuska
Year: 1995
Pages: from 6 to 7
Meeting: 26th Seminar: Nancy-Karlsruhe-Enschede
Held: from 06/23/95 to 06/25/95
Summary: Caracterization of crystal shapes has been carried out
using image analysis of precipitated calcium carbonate and various Me
oxalate crystals.
Keywords: Calcium Carbonate, Me Oxalates, Crystal Shapes, Morphology, Image Analysis.
- Type of paper
: Summary in proceedings
Title: The effect of silica fume on formation of C-S-H phase by
determination of hydrated water in portlad cement pastes
- Authors:
- Krolo, Petar (23832)
- Krstulović, Ruža (36162)
- Zelić, Jelica (143203)
- Žmikić, Anka (55784)
Proceedings title: Sinopsisi
Language: hrvatski
Place: Zagreb
Year: 1995
Pages: from g361 to g361
Meeting: XIV. Skup hrvatskih kemičara
Held: from 02/06/95 to 02/08/95
Summary: The TG analysis has been used to examine the effect of
different amounts of silica fume admixtureon formati on ofrmation of CSH
phases in the cement- water reaction system, through determinatin of the
content of water bound during hydration. the silica fume has been proved to
affect the content on non-bound Ca(OH)2 and thereby the content of CSH
phases formed by the puzzolana reaction.
Keywords: C-S-H phase, hydrated water, silica fume, pozzolana reaction
- Type of paper
: Summary in proceedings
Title: The determination of calcium hydroxide in cement pastes by
means DTA
- Authors:
- Ferić, Tereza (11612)
- Krstulović, Ruža (36162)
- Perić, Jelena (36162)
- Krolo, Petar (23832)
Proceedings title: Rinopsisi radova
Language: hrvatski
Place: Sarajevo, Jugoslavija
Year: 1991
ISBN/ISSN: ISSN0367-4444
Pages: from 134 to 134
Meeting: Šesti jugoslovenski simpozijum analitičke kemije
Held: from 09/30/91 to 10/02/91
Summary: samples has been prepared by mixing industrial cement and
water at W/C00.476 and addition of 12.5% asbestos, with different hydration
durations. The surface under the DTA curves was determined in order to
calculate the quantity of Ca(OH)2 for the period up to five months. The
results indicate that the DTA method is suitable for determinatin of
Ca(OH)2 in the cement-water- admixtures system.
Keywords: Hydration, thermal-analysis, calcium- hydroxide, cement paste
- Type of paper
: Ph.D.
Title: Phenomena in Cement Hydation in the Presence of Asbestos
Faculty: Tehnološki fakultet Sveučilište u Splitu
Author: FERIĆ TEREZA
Date of defense: 06/13/91
Language: hrvatski
Number of pages: 225
Summary: The influence of asbestos on hydration process was studied
in the system cement-asbestos-water. The samples were prepared in
proportions similar to those in industrial mixtures.The hydration was
determined by mesuments of hydration heat (calorimetry) and development of
Ca(OH)2. It was proved that hydration mechanism in asbestos cement is
similar to that in pure cement regardless of asbestos sort and type and
depends on adsorption capacity of asbestos, which has approx 10 EXP 18
active sites per sqm of surface, which explains the influence of asbestos
on cement hydration intensity. The methodology used can be applied to other
fiber materials and their effect on cement hydration.
Keywords: Cement , Asbestos fibers , Hydration , calorimetry , TG , DTA , adsorption , mechanism
- Type of paper
: M.A.
Title: Process for obtaining precipitated calcium carbonate by
carbonation of milk of lime
Faculty: Fakultet kemijskog inženjerstva i tehnologije Sveučilište u Zagrebu
Author: VUČAK MARIJAN
Date of defense: 12/03/93
Language: hrvatski
Number of pages: 129
Summary: Precipitated CaCO3 was obtained in laboratory by
carbonation of milk of lime with CO2; purity and concentration of Ca(OH)2
were varied, as well as gas composition and flow, and temperature. The
process took place at a constant mixing rate. El. conductivity has been
used as a parameter for tracing the carbonation process. An analysis of the
shape and the flow of k-t curves provided an insight into possibilities of
formation of the precipitate and its phase transformations during
carbonation, and process kinetics. The precipitated CaCO3 was examined for
CaCO3 content, phase composition, apparent density in a condensed state,
and for particle size.
Keywords: Amorphous CaCO3, Aragonite, Calcite, Calcium Carbonate, Carbonation of Milk of Lime, Precipitation, Vaterite.
- Type of paper
: M.A.
Title: A MATHEMATICAL MODEL FOR DETERMINING THE OPTIMUM ASBESTOS
MIXTURES FOR ASBESTOS-CEMENT MATERIALS
Faculty: Tehnološki fakultet Sveučilište u Splitu
Date of defense: 01/18/91
Language: hrvatski
Number of pages: 144
Summary: The aim was to determine the optimum combination of
mixtures to be used in asbestos industry, and satisfy the need for engine
productivity, system economy, and the finished product quality. Each
asbestos type was correlated to the referent one. A redefinid linear
programming model was used to solve this system. It was proved that only
the optimum asbestos content satisfies the aims set. Asbestos fibers
surplus does not improve the quality of asbestos cement products.
Keywords: Asbestos, optimum mixture, calculation, computer programming, correlations
- Type of paper
: M.A.
Title: Kinetic analysis of cement hydration
Faculty: Tehnološki fakultet Sveučilište u Splitu
Author: DABIĆ PERO
Date of defense: 06/19/95
Language: hrvatski
Number of pages: 103
Summary: This thesis the experimental and mathematical approach to
solving the cement hydration kinetics with the main objective of
development and application of such a mathematical model that would best
describe individual stages of the process as a whole. The matherial used
was the industrial Portland cement PC-55, alit, and the PC-30z-45s cement
with addition of slag, to which four different types of commercial
admixtures were added.
the model assumed that all tree stages take place simultaneously; bat
individual hydration stages are governed by the slowest process. when alfa
was inserted in the appropriate kinetic equations for individual process
stages, expression for nucleation and growth (NR) were obtained, as well
phase-boundary (I) and the diffusion process (D).When adixtures were
introduced into cement the changes in kinetic parameters were observed, in
the process intesity relative to the admixture type. The mathematical model
developed can be show the hydration kinetics events quantitatively and in
greater detail, based on the data on heat development. It is necessary to
link task solution in kinetic analysis by all groups with the computer by
means of the program support, which has been done in this work.
Keywords: Portland cement, admixture, hydration process,microcalorimeter, Hydration heat, kinetic anlysis, mathematical modelling, program pacages, Gwbasic, Qbasic, personal computer
- Type of paper
: Mentorship
Title: Process for obtaining precipitated calcium carbonate by
carbonation of milk of lime
Faculty: Fakultet kemijskog inženjerstva i tehnologije Sveučilište u Zagrebu
Mentor: PERIĆ JELENA
Date of defense: 12/03/93
Number of pages: 129
Author: Vučak Magistar znanosti, zn. novak Marijan
Degree level: M.A.
- Type of paper
: Mentorship
Title: Phenomena in Cement Hydation in the Presence of Asbestos
Faculty: Tehnološki fakultet Sveučilište u Splitu
Mentor: KRSTULOVIĆ RUŽA
Date of defense: 06/13/91
Number of pages: 225
Author: Ferić Doktor znanosti, ZA Tereza
Degree level: Ph.D.
- Type of paper
: Mentorship
Title: A MATHEMATICAL MODEL FOR DETERMINING THE OPTIMUM ASBESTOS
MIXTURES FOR ASBESTOS - CEMENT MATERIALS
Faculty: Tehnološki fakultet Sveučilište u Splitu
Mentor: KRSTULOVIĆ RUŽA
Date of defense: 01/18/91
Number of pages: 144
Author: Milošević magistar Velimir
Degree level: M.A.
- Type of paper
: Mentorship
Title: Kinetic analysis of cement hydration
Faculty: Tehnološki fakultet Sveučilište u Splitu
Mentor: KRSTULOVIĆ RUŽA
Date of defense: 06/19/95
Number of pages: 103
Author: Dabić Zn. novak Pero
Degree level: M.A.
- Type of paper
: Survey/Study
Title: Technical and technological Solution for Waste Water
Treatment of the Zinc Plateing Plant of Poliscom Split
- Authors:
- Perić, Jelena (36162)
- Krolo, Petar (23832)
- Zelić, Jelica (143203)
- Vučak, Marijan (181073)
- Dabić, Pero
- Beroš, Ana
Ordering party: Poliscom-Split
Institution depot: Tehnološki fakultet Sveučilišta u Splitu
Year: 1994
Number of pages: 29
Language: hrvatski
Summary: The laboratory analysis of waste water from chemical
treatment of metal objects prior to zinc-plateing in the Poliscom-Split
firm helped determine the optimum conditions for carrying out oxidation,
neutralization and precipitation of Fe(OH)3 and Zn(OH)2. Based on this
examinations a technical and technological solution has been proposed for
waste water treatment before its draining into the sewage system. The
solution will provide for satisfactory degree of operation efficiency, as
well as for lower costs of treatment with the existing equipment by means
of energy-saving and by reducing the operating hours of the equipment.
Keywords: Waste water, Zinc Plateing, Neutralization, Oxidation, Precipitation, Metal Hydroxides.
- Type of paper
: Manuscript
Title: Investigation of dehydroxylation process of gibbsite into
boehmite by DSC analysis
- Authors:
- Perić, Jelena (36162)
- Krstulović, Ruža (36162)
- Vučak, Marijan (181073)
Language: engleski
Summary: Dehydroxylation of gibbsite into boehmite was traced by
means of DSC analysis. Samples were analyzed by DSC under non isothermal
conditions in the temperature range 453-673 K at heating rates from 2,5 to
20,0 K/min. A mathematical analysis of experimental DSC curves defined the
mechanism and the kinetics of gibbsite dehydroxylation process. The values
of Ea for the first stage of gibbsite dehydroxylation in temerature range
453-673 K amounts to 132,92 - 142,26 kJ/mol.
Keywords: Dehydroxylation, Gibbsite, Boehmite, DSC Analysis, Process Kinetics, Activation Energy.
Other: Rad je u tisku (Časopis: Journal of Thermal Analysis).
- Type of paper
: Manuscript
Title: Adsorption of calcium hydroxide on polyacrylonitrile,
cellulose and chrysotile fibers
- Authors:
- Ferić, Tereza (11612)
- Krstulović, Ruža (36162)
- Perić, Jelena (36162)
- Vučak, Marijan (181073)
Language: engleski
Summary: This paper presents results obtained for surface activity
in two types of polyacrylnitrile fibers and treated celluloze fibers as
compared to chrysotile asbestos, by determination of adsorption of calcium
hydroxide to the fibers. Fibers examined have surface activity similar to
that of asbestos fibers, and may be expected to have a similar effect on
cement hydration.
Keywords: Adsorption, Calcium Hydroxide, Asbestos, Polyacrylonitrile Fibers, Chrysotile.
Other: Rad je u tisku (Časopis: Cement-Kalk-Gips).
- Type of paper
: Manuscript
Title: Position of a young research worker at the university
- Authors:
- Vučak, Marijan (181073)
- Dabić, Pero
Language: engleski
Summary: In this report, problematics related to young research
scientist position and their participating in the scientific project have
been discussed.
Keywords: Ceramic Engineering, Ceramic Technology.
Other: Rad prezentiran na "Second European Conferenceof Higher
Educational Institutions in Ceramics (EUROFORUM'94), 24.04.1994- do
26.04.1994., H‹hr-Grenzhausen (Njemačka).
- Type of paper
: Manuscript
Title: Effect of chrysotile asbestos on cement hydration
- Authors:
- Ferić, Tereza (11612)
- Krstulović, Ruža (36162)
- Perić, Jelena (36162)
- Krolo, Petar (23832)
Language: engleski
Summary: Hydration of cement in the presence of asbestos was traced
by means of hydration heat and adsorption capabilities of asbestos.
Hydration heat was determined calorimetrically by means of spherical
thermos flasks; adsorption capability of asbestos fibers was determined
relative to Ca(OH)2. Hydration heat development was intesified in the
presence of asbestos. The results obtained for adsorption have showed that
asbestos surface is active and the isotherms obtained are multistep ones
and indicate formation of two layers of adsorbate. Adsorption capabilities
of asbestos intensify cement hydration.
Keywords: Cement, Asbestos, Hydration, Adsorption, Chrysotile, Hydration Heat.
Other: Rad u tisku (časopis: "Cement and Concrete Composites").
- Type of paper
: Manuscript
Title: A mathematical model for determination of optimum asbestos
mixers for asbestos-cement material
- Authors:
- Milošević, Velimir
- Tončić, Damir
- Krstulović, Ruža (36162)
Language: engleski
Summary: The optimum mixture of asbestos types for
asbestos-cementproducts was mathematically modelled by redefined
linearprogramming model ritten in Turbo Pascal 5.5 for an IBMcompatibile
PC.Different mixtures were examined and used inindustrial
experiments.Comparison of mathematically extimatedvalues for expected
finished product strength with experimentalresults (7,28 days) showd very
good correspondece and therebyconfirmen the validity of the method.
Keywords: mathematical modelling,asbest mixture,program product,Turbo Pascal 5.5,industrial experiments,comparison of the method with experimental data
Other: Predano za tiasak u časopis: Cement and Concrete Composites
- Type of paper
: Manuscript
Title: Phase Transformation of Calcium Carbonate Polymorphs
- Authors:
- Perić, Jelena (36162)
- Vučak, Marijan (181073)
- Krstulović, Ruža (36162)
- Brečević, Ljerka
- Kralj, Damir
Language: engleski
Summary: The phase composition of mineral aragonite ans sythetic
vaterite samples was determined qualitatively by using IR-spectroscopy and
XRD analysis. The transformation of aragonite and vaterite into the stable
modification calcite, was folowed using DSC analysis. In order to determine
the kinetics and mechanisms of these phase transformations, a number of
experimental DSC curves were elaborated mathematicaly and the stationary
point theory was applied. The activation energy, Ea, and the enthalpy, dH,
were found to be, respectively, 234.5 +- 5.6 kJ/mol and 122 J/g for the
phase transformation aragonite to calcite, and 252.8 +- 48.7 kJ/mol and
-21.2 J/g for the vaterite to calcite transformation.
Keywords: Phase Transformation, Calcium Carbonate, Vaterite, aragonite, Calcite, Kinetics, Stationary Point Theory.
Other: Thermochimica Acta, u tisku.
- Type of paper
: Manuscript
Title: Precipitation of Calcium Carbonate in a Calcium Nitrate
and Monoethanolamine Solution
- Authors:
- Vučak, Marijan (181073)
- Perić, Jelena (36162)
- Krstulović, Ruža (36162)
Language: engleski
Summary: High purity precipitated calcium carbonate has been
produced in laboratory by carbonation of a solution of calcium nitrate and
monoethanolamine. The process was traced by measurements of the change in
Ca concentration and in el. conductivity of the solution. The k-t and cCa-t
curves were analyzed to determine the effect of temperature and
concentration of carbon(IV) oxide on the process of carbonation. The
samples obtained were mainly of aragonite and vaterite crystal
modifications with traces of calcite. The relationship between the
mineralogical composition and particle size (morphology) and operating
conditions was examined as well.
Keywords: Precipitation, Crystallization, High Purity Calcium Carbonate, Carbonation, Morphology.
- Type of paper
: Manuscript
Title: studies of Cement - water- admixtures reaction system
- Authors:
- Krstulović, Ruža (36162)
Language: engleski
Summary: This report describes examinations carried out in our
laboratory so far-which will be continued with the cement - water -
admixture reaction system. The most important issues are discussed as well
confirmations of results achieved over mani years of research into the
effect of admixtures on the cement hydration process. The principles of
research aimed at understandig hydration both qualitatively and
quantitatively are listed.
Keywords: Cement, admixture, hydration process, methodological - method examinations, kinetic analysis, interaction
- Type of paper
: Other
Title: On the mechamism of inhibitive action of Na-diethyldithio
carbamate
- Authors:
- Aljinović, Ljiljana (362)
- Šmith, Mario (149441)
- Žmikić, Anka (55784)
Type of work: Sažetak u zborniku (vezano za projekt 2-15-122)
Language: hrvatski
Summary: The inhibitive properties of Na-diethyldithiocarbamate
(NaDDTC) for Cu Ni10 Fe alloy corrosion in sea water have been investigated
by means of electrochemical methods and surface analytical technique (AES).
The presence of all elements from organic molecule on the alloy surface has
been estabilished after polarization in agresive media. Besides, the
influence of NaDDTC on the shape and position of polarization curves has
been estabilished. The various reaction posibilities of -DDTC anion as well
as its parts of decomposition after polarization have been discussed.
Keywords: Inhibitor, cunifer alloy, thiocarbamate
Other: Rad je vezan uz projekt 2-15-122.