KALORIMETRICKÝ SEMINÁŘ 2003 – SBORNÍK PRACÍ – ABSTRAKTA

Proceedings p. 13-16

APPLICATION OF COMBUSTION CALORIMETRY IN BASIC RESEARCH AND DURING STUDIES OF PLANT PHYSIOLOGY PROCESSES

Vratislav Novák

Katedra botaniky a fyziologie rostlin AF ČZU v Praze, Kamýcká 129, Praha 6 – Suchdol, 16521, Czech Republic

Combustion calorimetry method can be applied in applied research, basic research and during studies of some physiology processes. This method is suitable especially for observing of distribution and energy accumulation into vegetative and generative organs or into individual parts of plants. Both in climatized and outside conditions we can study influence of some factors on growth, sun radiation usage or usage of known spectral content radiation.

At young germinated plants we can study energy disribution from seeds into individual plant parts and plant transition from heterotrophic to autotrophic nutrition, photosynthesis output and some other processes. It is very useful to combine calorimetry with other physical, chemical and other methods and by such way gain complex overview of solved physiology problematic.

Proceedings p. 17-20

THE TOTAL ENERGETIC YIELD BY CULTIVARS OF ALTERNATIVE VARIETIES OF WHEAT

František Hnilička¹, Jiří Petr², Markéta Hofmanová¹, Radek Vavera²

¹ Česká zemědělská univerzita, katedra botaniky a fyziologie rostlin, Kamýcká 129, 16521 Praha 6 - Suchdol, Czech Republic, hnilicka@af.czu.cz

² Česká zemědělská univerzita, katedra rostlinné výroby, Kamýcká 129, 16521 Praha 6 - Suchdol, Czech Republic

In the field experiments established in the years 2001 – 2002 I studied the total energetic yield by cultivars of alternative varieties: Anemos, Kalistos, Melon, Naxos, Thasos, Velos, Česká přesívka, Postoloprtská přesívka and Chlumecká 12. The gathered results show, that the statistically significant lowest amount of energy in grain per hectare was found by Postoloprtská přesívka variety (70,13 GJ.ha^-1) and highest amount of energy in grain per hectare was found by Anemos variety (90,35 GJ.ha^-1). The gathered results show, that the statistically significant lowest amount of energy in straw per hectare was found by Chlumecká 12 variety (58,72 GJ.ha^-1) and highest amount of energy in straw per hectare was found by Anemos variety (75,39 GJ.ha^-1).

Proceedings 21-24

THE INFLUENCE OF ABIOTIC STRESSES UPON PHOTOSYNTHETIC ACCUMULATION ENERGY INTO LEAVES OF WINTER WHEAT PLANTS

František Hnilička¹, Jiří Petr², Helena Hniličková³

¹ Česká zemědělská univerzita, katedra botaniky a fyziologie rostlin, Kamýcká 129, 16521 Praha 6 - Suchdol, Czech Republic, hnilicka@af.czu.cz

² Česká zemědělská univerzita, katedra rostlinné výroby, Kamýcká 129, 16521 Praha 6 - Suchdol, Czech Republic

³ Česká zemědělská univerzita, katedra zahradnictví, Kamýcká 129, 16521 Praha 6 - Suchdol, Czech Republic

In the field experiments established in the years 2001 – 2002 we studied the energy content by cultivars of winter wheat: Ebi, Estica and Mironovská. The plants cultivated under controlled glasshouse conditions and under conditions with mutual combination of 2 representative abiotic stresses – low pH and drought. There is possibility to conclude ¨, it is possible to conclude negative impact of abiotic stresses on accumulation of rich in energy content in comparison with control variant. The gathered results show, that the statistically significant lowest amount of energy in leaf was found by Mironovská variety (12.18 kJ.g^-1 – 2001 and 12.59 kJ.g^-1 – 2002) and highest amount of energy in leaf was found by Ebi variety 12.67 kJ.g^-1(2001) and 12.81 kJ.g^-1 ( 2002).

Proceedings 25-28

The influence of water stress on Physiological processes and akumulation of energy in selected varieties of cauliflower

Helena Hniličková^A, Josef Duffek^A, František Hnilička^B

Česká zemědělská univerzita, ^Akatedra zahradnictví, ^Bkatedra botaniky a fyziologie rostlin, Kamýcká 129, 16521, Czech Republic, hnilickova@af.czu.cz

Water stress influences the basic physiological process and the following consequences for the crops. Cauliflower is during the vegetation period the most water-demanding plant from the cabbage family. For the selected varieties of cauliflower the effect of water stress on the rate of photosynthesis, transpiration and stomal conductance were studied. The results for the accumulation energy of Opaal variety is given as well. For the long-term water stressed plants the accumulation energy decreased. The energy accumulation and the rate of photosynthesis after subsequent watering increased up to the level of control plants. The less accumulated energy was found for roots

Proceedings 29-32

THE JUXTAPOSITION OF ENERGY CONTENT IN LEAVES OF CONSERVATIVE

AND UNTRADITIONAL FOLIAR VEGETABLES

Jiří Vondráček¹, František Hnilička¹, Kamila Holubová²

¹ Česká zemědělská univerzita, katedra botaniky a fyziologie rostlin, Kamýcká 129, 16521 Praha 6 - Suchdol, Czech Republic, hnilicka@af.czu.cz

² Česká zemědělská univerzita, Institut tropického a subtropického zemědělství, Kamýcká 129, 16521 Praha 6 - Suchdol, Czech Republic

In the field experiments established in the years 2000 – 2002 we studied energy content by cultivars of spinach: Matador, Triptiek and amaranth species: Amaranthus caudatus (CAC), Amaranthus cruentus (R124) a Amaranthus hypochondriacus. At the species A. cruentus was the average combustion heat value 14,07 kJ.g^-1. By the A. hypochondriacus we have found content of rich in energy matters 14,36 kJ.g^-1. The gathered results show, that the statistically not significant differences from among amaranth species. However lowest amount of energy in leaves was found Matador variety of spinach (12,75 kJ.g^-1) and highest amount of energy in leaves was found by spinach variety Triptiek - 12,66 kJ.g^-1.

Proceedings 33-36

THE INFLUENCE OF RECOVERY OF HOP PLANTS ON THE ENERGY ACCUMMULATION IN THE UNIT OF DRY MATTER

Luboš Türkott, Václav Hejnák, Vratislav Novák

Katedra botaniky a fyziologie rostlin AF ČZU v Praze, Kamýcká 129, 16521 Praha 6, Czech Republic, hejnak@af.czu.cz

Using a combustible calorimetry we have determined the net energy content in dry matter of non-recovered and recovered clones of hop-plants which were cultivated in the experimental hop-garden of the Hop Research Institute (Žatec) in 2001 and 2002. In both experimental years recovered plants had higher values of energy content (kg.J^-1) compared to non-recovered plants. This difference was most pronounced during the middle (vegetative) stage of hop-plant development. Net energy content in dry matter was decreasing with the progression of vegetation. During the later stage of plant development there was a significant shift of energy-rich substances from the vegetative organs to the generative ones.

Proceedings 37-40

THE CHANGES OF ENERGY CONTENT DURING ONTOGENY OF SELECTED AMARANTH SPECIES (AMARANTHUS SP.)

Jaroslava Martinková¹, Matyáš Orsák², Kamila Holubová³, František Hnilička¹

¹ Česká zemědělská univerzita, katedra botaniky a fyziologie rostlin, Kamýcká 129, 16521 Praha 6 - Suchdol, Czech Republic, hnilicka@af.czu.cz

² Česká zemědělská univerzita, katedra chemie, Kamýcká 129, 16521 Praha 6 - Suchdol, Czech Republic

³ Česká zemědělská univerzita, Institut tropického a subtropického zemědělství, Kamýcká 129, 16521 Praha 6 - Suchdol, Czech Republic

The energy content of leaves in three selected amaranth species: Amaranthus caudatus, Amaranthus cruentus and Amaranthus aureus were studied under field conditions in the years 2000 and 2002. The amaranthus plants were grown on the fields of CAU in Prague. The gathered results show, that the statistically not significant differences from among amaranth species. However lowest amount of energy in leaves was found Amarantus cruentus – R124 (14,07 kJ.g^-1) and highest amount of energy in leaves was found by Amarantus aureus - 14,28 kJ.g^-1. The statistically significant lowest amount of energy was found by 2001 year - 13,27 kJ.g^-1 and highest amount of energy was found by 2002 year (15,84 kJ.g^-1).

Proceedings 41-44

THE PRODUCTION OF DRY MATTER AND ENERGY CONTENT IN LEAVES OF AMARANTH PLANTS (AMARANTHUS SP.) GROWING AS FOLIAR VEGETABLES

Petr Menšík¹, František Hnilička¹, Kamila Holubová², Matyáš Orsák³

¹ Česká zemědělská univerzita, katedra botaniky a fyziologie rostlin, Kamýcká 129, 16521 Praha 6 - Suchdol, Czech Republic, hnilicka@af.czu.cz

² Česká zemědělská univerzita, Institut tropického a subtropického zemědělství, Kamýcká 129, 16521 Praha 6 - Suchdol, Czech Republic

³ Česká zemědělská univerzita, katedra chemie, Kamýcká 129, 16521 Praha 6 - Suchdol, Czech Republic

The content of energy and dry matter of leaves in three selected amaranth species: Amaranthus caudatus, Amaranthus cruentus and Amaranthus hypochondriacus were studied under field conditions in the years 2000 and 2002. The amaranthus plants were grown on the fields of CAU in Prague. At the species A. caudatus was the average combustion heat value 14,21 kJ.g^-1. By the A. hypochondriacus we have found content of rich in energy matters 14,37 kJ.g^-1. The content of dry matter grew during ontogeny form the period of code 24 to code 90. At the species A. caudatus has been average weight of dry matter 70,68 g per plant. By the A. hypochondriacus we have higher of dry matter - 85,22 g.

Proceedings 45-48

Energy accumulation in the root biomass of European beech ecosystem

Milan Kodrík

Ústav ekológie lesa, Slovenská akadémia vied, Štúrova 2, 96053 Zvolen, Slovac republic,

kodrik@sav.savzv.sk

Energy values of different diameter fractions of European beech below-ground biomass are presented. The highest energy value of sample tree was found in the roots with diameter over 10 cm – from 0.52 GJ to 0.72 GJ. Dominant tree roots are presented by the highest energy values – 2,12 GJ. Energy value of codominant tree presented 67% of energy value of dominant tree (1.42 GJ).

Proceedings 49-52

Influence of canopy density degree on energy value of aboveground biomass of Veronica officinalis L. population

Margita Kováčová, Branislav Schieber, Ján Kukla

Ústav ekológie lesa SAV, Štúrova 2, 96053 Zvolen, Slovak republic, kovacova@sav.savzv.sk

We have studied energy content and production of aboveground biomass of Veronica officinalis L species in the conditions of different canopy density of beech forest. The average energy content of study species in  1994 varied spatially according to tree canopy: 18.639-19.453 kJ.g^-1 (fertile shoots), 18.271-18.822 kJ.g^-1 (sterile shoots) of dry matter. Statistical analysis of energy values confirm significant differences between monitoring plots only in the case of fertile shoots (P < 0,05).

Proceedings 53-56

PHENOLOGY AND ENERGY CONTENT OF BIOMASS OF FRAGARIA VESCA (L.) SPECIES IN THE BEECH ECOSYSTEM

Branislav Schieber, Margita Kováčová, Ján Kukla

Ústav ekológie lesa SAV, Štúrova 2, 96053 Zvolen, Slovak republic, kovacova@sav.savzv.sk

Phenological development and energy content of Fragaria vesca (L.) species were studied in the natural and influenced beech forest stand at the Ecological experimental stationary Kremnické vrchy Mts. Different course of phenophases was found out between the years 1994 and 1995. Alike the analysis of energy content of individuals biomass shows on variability of this parameter between the compared years 1994 and 1995, maximum values in 1995 moved from 59 % (sterile population) to 69 % (fertile population) compared with 1994 on monitoring plots.

Proceedings 57-62

Energy balances of selected untraditional energy plants assigned for combustion at various terms of harvest and systems of drying

Zdeněk Strašil

Výzkumný ústav rostlinné výroby Praha-Ruzyně, , Drnovská 507, 16106 Praha 6, Czech Republic, strasil@vurv.cz

The energetic balances of selected one-year plants (hemp, sorghum) and perennial plants (canary reed grass, giant reed) were conducted at different harvesting terms (in time of the most intensive phytomas growth, in autumn, in early spring) and after-drying system (after-drying on field, by cold air, tempered air, low-temperature drier, hot-air drier). The most pretentious for energetic inputs is hemp (18.29 GJ/ha/year) and sorghum (17.21 GJ/ha/year), the lowest level of additional energy demands cannary reed grass
(7.87 GJ/ha/year). Within all investigated period we have found-out the highest energy loss (phytomass) for giant reed 37.8 % (166.5 GJ/ha/year) and sorghum 37.3 % (100.2 GJ/ha/year), the lowest for canary reed grass 23.7 % (33.0 GJ/ha/year). The highest energy production from acreage provides giant reed (in average 440.2 GJ/ha/year in time period of most intensive phytomass growth), the lowest canary reed grass (140.5 GJ/ha/year). For after-drying on field total inputs presents in average 3 % for giant reed up to 8.1 % for hemp from total energy production according to crops and harvesting difficulty. Similar values shown cold air after-drying. The tempered air after-drying shown the total energetic inputs according to crops in average from 8.5 to 13.9 % of total production. The low-temperature drier after-drying increases share of total energetic inputs in range from 17 to 23 % and the hot-air driver from 58.5 to 66.8 % of totally acquired production.

Proceedings 63-66

MATERIAL ELECTRIC PROPERTIES UTILIZATION AT THEIR OHMIC HEATING

Zuzana Hlaváčová

Katedra fyziky, Slovenská poľnohospodárska univerzita v Nitre, Tr. A. Hlinku 2, Nitra, Slovak republic, Zuzana.Hlavacova@uniag.sk

Electrical properties of biological materials are utilized at moisture content measurements, at the germination of grains and seeds determination, at the grain, seed and plant frost resistivity detection, at the surface level of liquids or grainy materials determination, at the food quality and composition sensing, at the presence disease-producing microorganisms, at the fruit ripeness, at the thermal treatment of food and at many other cases. Either of type heating microwave or direct ohmic is exploited recently at the continual processes of the liquid or heterogeneous food thermal treatment. It is necessary to know the electric properties of food at the direct ohmic heating. The relationships between the conductivity and the temperature and the moisture content for poppy seed are described in this paper.

Proceedings 67-70

Specific Heat Temperature DependencE of Biological Material

Vlasta Vozárová

Slovenská poľnohospodárska univerzita, Katedra fyziky, Tr. A. Hlinku 2, 94976 Nitra, Slovak republic, Vozarova@afnet.uniag.sk

This work deals with measurement of specific heat of biological material by differential scanning calorimetry. Description of measurement equipment and temperature dependence of specific heat at the constant pressure of corn grains are presented.

Proceedings 71-74

Glass transition in vegetative dormant buds of apple cv. ‘Spartan‘ from natural conditions

Alois Bilavčík^A, Jiří Zámečník^A, Jaroslav Šesták^B

^A Výzkumný ústav rostlinné výroby, Drnovská 507, 16106 Praha 6-Ruzyně, Czech Republic, bilavcik@vurv.cz

^B Fyzikální ústav AV ČR, Cukrovarnická 10, 16200 Praha 6, Czech Republic

The results of DSC measurements in vegetative dormant buds of apple-trees are presented. The glass transitions have been observed for dormant buds of apple-tree ‘Spartan’, which were previously equilibrated to the temperature

Proceedings 75-78

CALORIMETRIC STUDY OF GLASS TRANSITION AND PHASE CHANGES IN PLANT SEEDS

Jiří Zámečník^A, Iva Faberová^A, Miloš Faltus^A, Antonín Sikora^B

^A Výzkumný ústav rostlinné výroby, Drnovská 507, 16106 Praha 6 – Ruzyně, Czech Republic, zamecnik@vurv.cz

^B Ústav makromolekulární chemie AV ČR, Heyrovského nám. 2, 16202 Praha 6, Czech Republic

This work was focused on the observation of thermal property of chosen varieties of vegetable and flower seeds. The thermal characteristics of seeds dried with different speed to the different level of water content were studied with the help of differential scanning calorimetry with constant and modulated cooling/warming rate. Glass transition was found only in seeds of some varieties. The seeds of different varieties distinguished in size, number and temperature of the endothermal peaks. The differences gave evidence not only about the phase changes of water in seeds, but also about the thermal changes of other molecules or macromolecules presented in seeds at studied temperature range and water content.

Proceedings 79-82

THE NEW INSIGHT INTO THE GLASS TRANSITION

Jana Holubová^A, Zdeněk Černošek^A, Eva Černošková^B

^AVýzkumné centrum Univerzity Pardubice a Ústavu anorganické chemie AV ČR nám. Legii 565, Pardubice, 53210, Czech Republic, jana.holubova@upce.cz

^BSpolečná laboratoř chemie pevných látek ÚMCH AV ČR a Univerzity Pardubice, Studentská 84, 53210 Pardubice, Czech Republic

The glass transition has been studied by the StepScan DSC method. This one allows separating of two kinds of processes taking part in this effect: in-phase or thermodynamic process and out-of phase or kinetic process. The thermodynamic part of the glass transition has been the subject of this study. It was found that this part could be regarded as glasssupercooled melt conversion, a, dependent on an equilibrium transformation temperature. This process can be described well by equation derived: a = 1-exp(-(T/T_g)ⁿ). The parameter n, sense of which is the steepness of the glass transition curve C_p vs. T, depends on the glass transition temperature and changes in wide range of values irrespective of the chemical nature of non-crystalline material.

Proceedings 83-86

TIME -TEMPERATURE SUPERPOSITION, TEST OF ITS APPLICABILITY FOR INORGANIC OXIDE GLASS

Eva Černošková^A, Zdeněk Černošek^B, Jana Holubová^B

^ASpolečná laboratoř chemie pevných látek Makromolekulárního Ústavu AV ČR a Univerzity Pardubice, Studentská 84, 53210 Pardubice, Czech Republic, eva.cernoskova@upce.cz

^BVýzkumné centrum Univerzity Pardubice a Ústavu anorganické chemie AV ČR, nám. Legií 565, 53210 Pardubice, Czech Republic

Dynamic termomechanical analysis (DTMA) in multi-sine mode was used for the study of viscoelastic properties of glassy NBS 711. It was found that Williams-Landel-Ferry (WLF) equation as consequence of time-temperature superposition (TTS) is applicable on the glass transition region of glassy NBS 711.

Proceedings 87-90

Mária Chromčíková^A, Eva Černošková^B, Miroslava Krajčíková^A, Jana Holubová^C

MODEL OF DYNAMIC THERMO-MECHANICAL ANALYSIS OF GLASS

^ASpoločné laboratórium skla Ústavu anorganickej chémie SAV a Trenčianskej univerzity Alexandra Dubčeka, Študentská 2, Trenčín, 91150, Slovak republic, chromcikova@tnuni.sk

^BSpolečná laboratoř chemie pevných látek ÚMCH AV ČR a Univerzity Pardubice, Studentská 84, 53210 Pardubice, Czech Republic

^CVýzkumné centrum Univerzity Pardubice a Ústavu anorganické chemie AV ČR,
nám. Legií 565, 53210 Pardubice, Czech Republic

The frequency, temperature range and cooling/heating rate of a dynamic thermo-mechanical experiment were analyzed with respect to the sample thermal and physical homogeneity. The role of structure evolution, and thus viscosity change, during a measurement sinusoidal cycle was found to be a limiting factor for the simple harmonic analysis of experimental data. The viscosity value itself is, together with the experimental time scale, conclusive for the decision between the Kelvin-Voight, Maxwell and Burgers model, respectively. The proposed method was illustrated on the analysis of DTMA data obtained for NBS711 standard glass.

Proceedings 91-94

THERMAL AND PHYSICAL PROPERTIES OF K₂O-PbO-B₂O₃-P₂O₅ GLASSES

Petr Mošner^A, Ladislav Koudelka^A, Jiří Petřík^A_, Bořivoj Hlaváček^B

^AKatedra obecné a anorganické chemie, ^BÚstav polymerních materiálů, Univerzita Pardubice, Fakulta chemicko-technologická, 53210 Pardubice, Czech Republic, petr.mosner@upce.cz

Glasses of the system K₂O-PbO-B₂O₃-P₂O₅ were prepared and studied in two compositional series xK₂O-(50-x)PbO-10B₂O₃-40P₂O₅ and xK₂O-(50-x)PbO-20B₂O₃-30P₂O₅. Thermal behaviour of the glasses was studied by DTA and TMA technique and their basic physical parameters (density, molar volume) and solubility in water were determined. With the replacement of PbO by K₂O the solubility steeply increases at the glasses containing more than 20mol% K₂O. TMA and DTA curves revealed that the glass transition temperature, dilatation softening temperature and crystallization temperature decrease with increasing K₂O content, while the thermal expansion coefficient increases. The correlation of changes of glass structure and properties was discussed.

Proceedings 95-102

Calorimetric study of structural relaxation of Ge₁₀Se₉₀ glass

Pavla Pustková^A, Jiří Málek^B

^AKatedra anorganické technologie, Univerzita Pardubice, Nám. Čs. Legií 565, 53210 Pardubice, Czech Republic, pustkova@mail.upce.cz

^BKatedra fyzikální chemie, Univerzita Pardubice, Nám. Čs. Legií 565, 53210 Pardubice, Czech Republic

Differential scanning calorimetry was used to study enthalpy relaxation of Ge₁₀Se₉₀ glass. Glass transition temperature T_g = 94 ± 1 °C and heat capacity ΔC_p = 0,15 ± 0,01 J/g·K were determined. There is a peak shift of the dependence of calorimetric measurement on temperature with annealing time. This peak shift vanished for annealing time higher than 6,7 hours (ΔT = 5,5 °C) and time higher than 15 hours (ΔT = 11,1 °C).

Proceedings 99-102

THERMAL PROPERTIES OF Na-Gd phosphate scintillating glasses

Miroslava Rodová ^A , Jiří Brožek ^B , Antonín Cihlář ^A , Karel Nitsch ^A

^A Fyzikální ústav AV ČR, Cukrovarnická 10, 16352 Praha 6, Czech Republic, rodova@fzu.cz

^B Vysoká škola chemicko-technologická, Ústav polymerů, Technická 5, 16628 Praha 6, Czech Republic

Na-Gd phosphate glasses were prepared by quenching molten NaPO₃, GdPO₄ and P₂O₅ mixture. The stable glass of this system exists if the NaPO₃ concentration in the melt is greater than 45 mol. %. Thermal properties such as glass transition, crystallisation and melting temperatures of glasses consisted of NaPO₃ (45 - 99 mol. %), GdPO₄ (50 – 0 mol. %) and CePO₄ / TbPO (1 až 10 mol. %) were determined by means of DSC and DTA.

Proceedings 103-106

THE KINETIC STUDY OF CRYSTALLIZATION OF Ge-In-S

Daniel Švadlák^A, Zuzana Košáková^B, Jiří Málek^A

^A Katedra fyzikální chemie, Fakulta chemicko-technologická, Univerzita Pardubice, Nám. Čs. Legií 565, 53210 Pardubice, Czech Republic, svadlak@centrum.cz

^B Katedra anorganické technologie, Fakulta chemicko-technologická, Univerzita Pardubice, Nám. Čs. Legií 565, 53210 Pardubice, Czech Republic

Crystallization kinetics of Ge-In-S was studied for 70GeS₂×30In₂S₃ composition by differential scanning calorimetry at nonizothermal conditions of heating rate 5 - 30 K/min. Samples were prepared in both powder form and two-sided glazed wafers. There was only studied the first crystallic effect corresponding to crystallization on In₂S₃. Kinetics of crystallization was described as autocatalytic model SB(M,N) with parametrs M = 0.8 ± 0.2 a N = 2.2 ± 0.3 for both types of sample.

Proceedings 107-110

HEAT CAPACITY AND ENTHALPY OF Bi₂SrO₄ AND Bi₂Sr₂O₅

Milan Hampl^A, Jindřich Leitner^A, David Sedmidubský^B, Květoslav Růžička^C

^A Ústav inženýrství pevných látek, VŠCHT Praha, Technická 6, 16628 Praha 6, Czech Republic, Jindrich.Leitner@vscht.cz

^B Ústav anorganické chemie, VŠCHT Praha, Technická 6, 16628 Praha 6, Czech Republic

^C Ústav fyzikální chemie, VŠCHT Praha, Technická 6, 16628 Praha 6, Czech Republic

Heat capacity of Bi₂SrO₄ (DSC method, 300-570 K) and enthalpy of Bi₂Sr₂O₅ (DROP method, 623-1023 K) were measured. Both phases were prepared by high temperature solid state reaction from binary oxides and analyzed by X-ray diffraction and differential thermal analysis.

Proceedings 111-114

ENTHALPY AND HEAT CAPACITY OF NITRIDES OF A^III ELEMENTS

Jindřich Leitner^A, Petr Maršík^A, Aleš Strejc^B, David Sedmidubský^B Květoslav Růžička^C

^A Ústav inženýrství pevných látek, VŠCHT Praha, Technická 6, 16628 Praha 6, Czech Republic, Jindrich.Leitner@vscht.cz

^B Ústav anorganické chemie, VŠCHT Praha, Technická 6, 16628 Praha 6, Czech Republic

^C Ústav fyzikální chemie, VŠCHT Praha, Technická 6, 16628 Praha 6, Czech Republic

Heat capacity (DSC method) and enthalpy (DROP method) of GaN and InN were measured. Standard thermodynamic functions of GaN (298.15 – 1300 K) and InN (298.15 – 900 K) were evaluated on the basis of obtained results and literature data on standard heats of formation and standard molar entropies of these compounds. Decomposition temperature Of InN were calculated as a function of DH^o_sl(298 K) and the value of –77 kJ mol^–1 seems to us as the most reliable.

Proceedings 115-118

DSC STUDY OF BLENDS OF TWO CRYSTALLIZABLE POLYMERS

Jaroslav Kratochvíl, Antonín Sikora

Ústav makromolekulární chemie AV ČR, Heyrovského nám. 2, 16206 Praha 6, Czech Republic, jakr@imc.cas.cz

DSC studies have shown that the blend of polycarbonate/polyoxyethylane (PC/POE) shows partial miscibility in amorphous phase at temperatures close to T_m POE. At temperatures close to T_m PC polymers do not interact. Crystallization of PC is stimulated and that of POE retarded by presence of the other polymer in the blend.

Proceedings 119-122

PHASE EQUILIBRIUM IN AQUEOUS SOLUTIONS OF OCTABLOCK COPOLYMER OF POLY(PROPYLENE OXIDE)/POLY(ETHYLENE OXIDE)

Antonín Sikora, Josef Pleštil, Jaroslav Kratochvíl

Ústav makromolekulární chemie AV ČR, Heyrovského nám. 2, 16206 Praha 6, Czech Republic, sikora@imc.cas.cz

The phase diagram of the associating octablock star copolymer of polyethylene oxide/polypropylene oxide in water was constructed on the basis of visual observations and DSC measurements.

Proceedings 123-126

THERMOANALYTICAL EVALUATION OF THE OXIDATIVE STABILITY OF LIQUID POLYBUTADIENES

J. Kovářová, J. Podešva

Ústav makromolekulární chemie AVČR, Heyrovského nám. 2, 16206 Praha 6, Czech Republic, kovarova@imc.cas.cz

Hydroxy-terminated liquid polybutadienes (LBH) which contain olefinic double bonds in the polymeric molecule were studied by thermal analysis, DSC and TGA methods under air conditions. The parameters of thermooxidative stability are outlined.

Proceedings 127-130

THERMAL CHARACTERISTICS OF UREA-FORMALDEHYDE ADHESIVES

Jarmila Šívarová, Ferdinand Langmaier

Univerzita Tomáše Bati ve Zlíně, Ústav technologie bílkovin a kůže, Fakulta technologická, nám. T. G. Masaryka 275, 76001 Zlín, Czech Republic, sivarova@ft.utb.cz

The thermal behaviour of the urea-formaldehyde adhesives was studied. Dimethylolurea oligomer was used as model compounds. The thermal properties of these adhesives were compared with the behaviour of the model compound with added urea, which is used as stabilizing agent for adhesives.

Proceedings 131-132

A STUDY OF AN INFLUENCE OF ADMIXTURES ON BRUSHITE CRYSTALLIZATION FROM AQUEOUS SOLUTIONS BY MEANS OF CALORIMETRY

David Bíbrlík, Galina Sádovská, Tomáš Váca

Univerzita Pardubice, FCHT, Katedra anorganické technologie, Nám.čs.legií 565, Pardubice, Czech Republic, galina.sadovska@upce.cz

Study of brushite crystallization in aqueous solutions was studied by means of isoperibolic calorimetry. All measurements were carried out at 25º a 37ºC at constant ionic strength. An influence of several admixtures on brushite crystallization was studied as well.

Proceedings 133-136

COMPUTATIONAL SIMULATION OF HYGROTHERMAL PERFORMANCE OF BUILDING ENVELOPES WITH INTERIOR THERMAL INSULATION SYSTEMS

Jiří Maděra, Robert Černý

ČVUT, Stavební fakulta, katedra stavební mechaniky, Thákurova 7, 16629 Praha 6, Czech Republic, cernyr@fsv.cvut.cz

A computational analysis of hygrothermal performance of stone-wall based building envelopes with interior thermal insulation systems is carried out for four different types of thermal insulation materials, and with water vapor retarders placed between the thermal insulation layer and the load bearing structure. Coupled heat and moisture transport in the particular building envelopes is simulated using the computer code DELPHIN 4. Temperature, relative humidity, moisture content and overhygroscopic moisture fields are calculated for the time period of several years.

Proceedings 137-140

MEASUREMENT OF MOISTURE STORAGE PARAMETERS OF BUILDING MATERIALS

Milena Jiřičková, Robert Černý

Katedra stavební mechaniky, fakulta stavební ČVUT, Thákurova 7, 16629 Praha, Czech Republic, cernyr@fsv.cvut.cz

Moisture storage parameters of three different building materials, namely calcium silicate, ceramic brick and autoclaved aerated concrete, are determined in both hygroscopic and overhygroscopic range. Measured sorption isotherms and moisture retention curves are then combined into moisture storage functions using Kelvin equation.

Proceedings 141-144

TESTING OF HYGROTHERMAL PERFORMANCE OF BUILDING STRUCTURES IN DIFFERENCE CLIMATE CONDITIONS

Zbyšek Pavlík , Robert Černý

ČVUT , Stavební Fakulta, Katedra stavební mechaniky, Thákurova 7, 16629 Praha 6, Czech Republic, cernyr@fsv.cvut.cz

In this work, there are summarized recent generally employed experimental methods for investigation of hygrothermal behaviour of building structures. Advantages and disadvantages of their application are given and their applicability for testing different types of porous materials is discussed. Further, a new measuring and simulating semi-scale system for investigation of hygrothermal performance of newly developed building materials or their multi-layered systems in the conditions very close to reality is designed. The system can also be applied for verification of computational models of heat and moisture transport in porous building materials and their multi-layered systems.

Proceedings 145-148

DESIGN OF CRITICAL EXPERIMENT FOR THE ASSESSMENT OF HYGROTHERMAL PERFORMANCE OF BUILDING ENVELOPE ON CONCRETE BASIS

Zbyšek Pavlík, Robert Černý

ČVUT, Stavební fakulta, Katedra stavební mechaniky, Thákurova 7, 16629 Praha 6, Czech Republic, cernyr@fsv.cvut.cz

In this paper, design of critical experiment for the assessment of hygrothermal performance of building envelope on concrete basis is presented. The designed critical experiment will be applied in the process of development of new complex reliability based model for service life prediction of concrete structures. Presently employed approaches for predicting the service life of concrete are given, and complexity of deterioration mechanisms in concrete is discussed. In the final part, the necessity of such types of experiments for calibration, specification and test of validity of computational models is discussed.

Proceedings 149-152

THERMAL PROPERTIES OF CARBON FIBRE REINFORCED CEMENT COMPOSITES IN HIGH-TEMPERATURE RANGE

Jitka Poděbradská ^A, Jan Toman^b, Robert Černý ^A

^A ČVUT, Stavební fakulta, Katedra stavební mechaniky, Thákurova 7, 16629 Praha 6, cernyr@fsv.cvut.cz

^B ČVUT, Stavební fakulta, Katedra fyziky, Thákurova 7, 16629 Praha 6, Czech Republic

Basic thermal properties of carbon fibre reinforced cement composites in high-temperature range are analyzed in the paper. For two types of composites, the linear thermal expansion coefficient is determined for temperatures up to 1000 °C, and the thermal diffusivity coefficient for temperatures ranging from 150 °C to 1000 °C.

Proceedings 153-156

NONISOTHERMAL DILATOMETRY OF COMPOSITE CONCRETES

Štefan Valovič

KF FPV UKF, Tr.A.Hlinku 1, 94974 Nitra, Slovak Republic, svalovic@ukf.sk

Results of the nonisothermal dilatometric investigations of composite concretes (cement with alkaliresistant fiberglass and carbon fibers, heating rate 5 °C/min) are presented as well as description of the apparatus and calculation of the coefficient of linear thermal expansion of samples. Some conclusions are made from results.

Proceedings 157-160

EFFECTS OF HIGH TEMPERATURES ON BENDING STRENGHT OF COMPOSITE MATERIALS

Roman Vejmelka^A , Eva Mňahončáková^A , Osvald Sutner^B, Jan Toman^A

^AKatedra fyziky Stavební fakulty ČVUT, Thákurova 7, 16629 Praha 6, Czech Republic, toman@fsv.cvut.cz

^BKloknerův ústav, Zikova 3, 16629 Praha 6, Czech Republic

Within the context of our research the influence of elevated temperatures on strength of the cement-based materials (reinforced with carbonic fibres) has been studied.

Proceedings 161-164

MEASUREMENT OF THE SPECIFICHEAT CONDUCTIVITY λ AND SPECIFIC HEAT CAPACITY c OF MECHANICALLY AND THERMAL STRESSED COMPOSITE MATERIALS

Eva Mňahončáková^A , Roman Vejmelka^A, Jiří Kolísko^B, Jan Toman^A

^AKatedra fyziky Stavební fakulty ČVUT, Thákurova 7, 16629 Praha 6, Czech Republic, toman@fsv.cvut.cz

^BKloknerův ústav, Zikova 3, 16629 Praha 6, Czech Republic

Effect of heat and tension stress both on specific heat conductivity λ and specific heat c of composite cement-based materials (reinforced with carbonic fibres) was analyzed.

Proceedings 165-168

COMPARISON OF TIME-DOMAIN REFLECTOMETRY AND CAPACITANCE METHODS FOR DETERMINATION OF MOISTURE PROFILES IN BUILDING MATERIALS

Pavel Tesárek, Milena Jiřičková, Zbyšek Pavlík, Robert Černý

ČVUT, Stavební Fakulta, Katedra stavební mechaniky, Thákurova 7, 16629 Praha 6, Czech Republic, cernyr@fsv.cvut.cz

Comparison of Time-Domain Reflectometry (TDR) and capacitance methods for determination of moisture content in porous building materials is presented in the paper. Basic principles of compared methods are given, including their calibration process. On the basis of measured moisture profiles, the application of the methods in the engineering practice is discussed.

Proceedings 169-172

MECHANICAL, THERMAL AND HYGRIC PROPERTIES OF LIME PLASTERS WITH POZZOLANIC ADMIXTURES

Aleš Kunca¹, Vratislav Tydlitát¹, Robert Černý¹, Pavla Rovnaníková²

¹ ČVUT, Stavební fakulta, Thákurova 7, 16629 Praha 6, Czech Republic

² VUT Brno, Stavební fakulta, Žižkova 17, 66237 Brno, Czech Republic, rovnanikova.p@fce.vutbr.cz

Measurements of mechanical, thermal and hygric parameters of lime plasters with pozzolanic admixtures are carried out in the paper. Lime plasters with metakaolin and milled brick are subject of testing. Measured results are compared with measurements on common lime plasters.

Proceedings 173-176

PLASTERS WITH POZZOLANIC ADMIXTURES FOR RECONSTRUCTION OF HISTORICAL BUILDINGS

Vratislav Tydlitát¹, Aleš Kunca¹, Robert Černý¹, Pavla Rovnaníková²

¹ ČVUT, Stavební fakulta, Thákurova 7, 16629 Praha 6, Czech Republic

² VUT Brno, Stavební fakulta, Žižkova 17, 66237 Brno, Czech Republic, rovnanikova.p@fce.vutbr.cz

Measurement of the specific heat capacity of lime plasters with pozzolanic admixtures in a mixing calorimeter is described in the paper. Specific heat capacity is determined in the temperature interval of 25-80°C. For lime plaster without admixtures the data of specific heat capacity are 17% higher than in Czech technical standard. The measured data are supplied by error analysis. The estimated total error is ± 1,5%, and corresponds to the mean reproducibility of measured values.

Proceedings 177-180

Differential calorimeter DIK 04 – essential instrument for evaluation of buiding binder properties

Pavla Rovnaníková

Ústav chemie FAST VUT v Brně, Žižkova 17, 66237 Brno, Czech Republic, rovnanikova.p@fce.vutbr.cz

The differential DIK 04 (Elsyst, Ltd., Prague) calorimeter for measurements of reaction enthalpy is described. The evaluation of the effect of water/gypsum ratio on measured hydration enthalpy is given.

Proceedings 181-184

TEST HOUSE FOR VALIDATION OF HYGROTHERMAL PERFORMANCE OF INTERIOR THERMAL INSULATION SYSTEM ON MINERAL WOOL BASIS

Jaroslav Pavlík^A, Jan Toman^B, Robert Černý^A

^AČeské vysoké učení technické, fakulta stavební, katedra stavební mechaniky, Thákurova 7, 16629 Praha 6, Czech Republic, cernyr@fsv.cvut.cz

^BČeské vysoké učení technické, fakulta stavební, katedra fyziky, Thákurova 7, 16629 Praha 6, Czech Republic

The application of interior thermal insulation systems on building envelopes is not a natural solution but sometimes there is no other option available. A typical example is a historical building, where the facade has to be kept in its original appearance mostly, and the exterior insulation systems are excluded for that reason. In that case the utilization of such an insulation system would allow to prevent moisture damages and to upgrade the thermal properties of the envelope as the only reasonable option. In this paper, we present the final stage of development of interior insulation system on the mineral wool basis.

Proceedings 185-188

COMPARISON OF PENTACHLOROPHENOL EXPERIMENTAL DECHLORATION WITH THERMODYNAMICAL CALCULATIONS BY MUNICIPAL INCINERATION WASTE FLY ASH.

Leona Vlková^A, Vladimír Pekárek^A, Michal Bureš^B

^A Ústav chemických procesů AV ČR, Rozvojová 135, 16500 Praha 6, Czech Republic, pekarekvl@icpf.cas.cz

^B Ústav fyzikální chemie, VŠCHT, Technická 5, 16628 Praha 6, Czech Republic

The aim of this study is the comparison of dechlorination experiments of chlorinated phenols by the fly ash from municipal waste incinerators with thermodynamical calculations. Discussed are: isomer stability of chlorinated phenols for the given level of chlorination, isomerization, chlorination and synthetic reactions in the course of dechlorination reactions and the proposed principle ruling the dechlorination process.

Proceedings 189-192

DSC AND TG STUDY OF WATER ADSORPTION ON H-MFI ZEOLITES

Petr Sazama^A, Felix Baitalow^B, Ladislav Svoboda^A

^AUniverzita Pardubice, Fakulta chemicko-technologická, Náměstí Čs. Legií 565, 53210 Pardubice, Czech Republic, petr.sazama@jh-inst.cas.cz

^BInst. für Physikalische Chemie, TU Bergakademie Freiberg, Leipziger Str. 29, D-09596

Freiberg/Sachsen, Germany

Simultaneous TG and DSC analyses of water adsorption were carried out over zeolites H-ZSM-5 with different Si/Al ratio at temperatures 100, 150 and 200°C. Heats of adsorption of water and amounts of adsorbed water were obtained in the H-ZSM-5 zeolites by TG and DSC analyses. Heats of adsorption of water and amounts of adsorbed water in zeolites are function of Si/Al ratio, temperature and pressure of water vapour over zeolites.

Proceedings 193-200

EFFECT OF THE ANALYTICAL WATER ON CALORIC VALUE OF BROWN COALS

Václav Dušák

Masarykova 983, 37341 Hluboká nad Vltavou, Czech Republic

Laboratory conditions affect the equilibrium state of analytical specimens and, thereby, also their composition. Changes in the composition of analytical specimens also affect the determined calorimetric values. Measurement results of duplicate analytical samples differ even in the equilibrium state in dependence on the degree of drying of the employed laboratory method. The paper summarises conditions under which it is possible to achieve reproducible measuring results corresponding to reality.

Proceedings 201-203

CONTRIBUTION TO THE COMBUSTION CALORIMETRY OF WET AND DRIED COAL SAMPLES

Boleslav Taraba, Erika Taušová

Ostravská univerzita, katedra chemie PřF, ul. 30.dubna 22, 70103 Ostrava, Czech Republic, taraba@osu.cz

Combustion heats Qsp of wet and dried coal samples have been determined using adiabatic IKA C400 calorimeter. Combustion heats of dried samples were found to be somewhat lower in comparison with those of wet coals. However, the difference is quite small and it usually falls within limits of the experimental error of 120 J/g. As deduced from immersion heats of the coals in water, the probable difference in combustion heats of dried and wet samples can be expected from 45 to 85 J/g.