Comparative testing of the flammability of upholstery textiles

Flash ignition temperatures of upholstery textiles were measured with a modified derivatograph, and the TG, DTG, DTA and T curves were also recorded. The results obtained with the newly-developed system were compared with those of the ASTM D 1929 test procedure and with the simultaneously recorded thermal analysis curves.

---

Zusammenfassung Der Flammpunkt von Upholstery-Textilien wurde mittels eines modifizierten Derivatographen gemessen. TG-, DTG-, DTA- und T-Kurven wurden registriert. Die mit diesem neuentwickelten System erhaltenen Ergebnisse wurden mit den nach dem ASTM D 1929 Testverfahren erhaltenen und mit den simultan registrierten thermoanalytischen Kurven verglichen.

---

, -, -, - -. , ASTM 1929 .

---

---

Paper presented at the World Conference on Thermal Analysis, Madeira (Portugal), 1986.     

Studies of vapor phase synthesis of pyridine bases on non-steady state catalysts

The reaction of NH₃ with R–CHO (R=CH₃, Ph) has been studied. Experimental data and parameters of the laboratory catalytic reactor are reported.

---

NH₃ c R–CHO(R=CH₃, Ph). .

     

Study of hydrogen adsorption on iridium catalysts

The influence of dispersity on hydrogen adsorption on Ir black and Ir/C catalysts has been studied. It is shown that supported iridium reduces the heat of hydrogen adsorption as compared to Ir black. With decreasing catalyst dispersity, the amount of weakly bound hydrogen increases, while its adsorption heat decreases on all Ir catalysts.

---

Ir- Ir/C-. , Ir-. C , Ir-.

     

Interaction of nitric oxide with NiCr2O4

Interaction of NO with NiCr₂O₄ has been studied at 473–1173 K. It has been established that on nickel-chromium spinels NO decomposition practically does not take place. Nitric oxide can interact only with prereduced samples to reoxidize them.

---

473–1173 NO NiCr₂O₄. , NO . (II) ; .

     

Ab initio investigation of the electron structure in bis-Cu+ acetylene and vinylidene complexes

[Cu(-C₂H₂)₂]⁺, [Cu(-CCH₂)₂]⁺ and [Cu(-C₂H₂) (-CCH₂]⁺ complexes have been studied by the ab initio double-zeta basis set method. It has been established that all calculated compounds are stable to decomposition into two C₂H₂ molecules and Cu⁺ cation and into one C₂H₂ molecules and the respective monocomplex. Calculation results suggest the possibility of intramolecular acetylene-vinylidene rearrangement in the coordination sphere of Cu⁺.

---

ab initio : [Cu(-C₂H₂)₂]⁺, [Cu(-CCH₂)₂]⁺, [Cu(-C₂H₂) (-CCH₂)]⁺. C₂H₂ Cu⁺ C₂H₂ . - Cu⁺.

     

Thermal decomposition kinetics of sodium metaperiodate

Aged and fresh samples of sodium metaperiodate are subjected to thermal decomposition studies in air by TG, DTG and DTA techniques. The kinetic parameters for their decomposition have been evaluated by weighted least squares method using equations of Coats-Redfern, Horowitz-Metzger and Freeman-Carroll. The results indicate that, within the limits of experimental error, ageing did not change the E^* values considerably.

---

, . , -, - -. , , , E^*.

     

Fossil age determination by thermal analysis

Subsequent to a comparative examination of recent bone material the author has recently completed the paleobiogeochemical evaluation of classical Quaternary and Pliocene terrestrial fossils of vertebrata from Hungary. A derivatograph (MOM) has been used to determine two thermoanalytical parameters which are closely associated with the passage of geological time: the total bound organic-matter content of the fossil and the fossilization cofficient.Derivatographic measurement of the organic matter in the bones is supplemented by fine-structure analysis of bone-tissue slides.Sample material of unknown age from several provenances was evaluated with the new dating method. The importance of the procedure is even greater in cases when only indefinite sporadic finds can be obtained from the sediments.

---

Zusammenfassung Nach einer vergleichenden Untersuchung an neuzeitlichem Knochenmaterial hat der Autor kürzlich die paleobiogeochemische Auswertung der klassischen Quaternären und Pliocenen terrestren Fossilien von Vertebraten aus Ungarn ergänzt.Ein Derivatograph (MOM) wurde zur Bestimmung zweier thermoanalytischer Parameter eingesetzt, die eng mit dem Fortschreiten der geologischen Zeit verbunden waren: dem Gesamtgehalt an gebundenem organischem Material und dem Fossilisationskoeffizienten.Die derivatographische Messung der organischen Substanz in den Knochen wurde durch die Feinstrukturanalyse von Knochengewebeschnitten ergänzt.Probenmaterial unbekannten Alters verschiedener Herkunft wurde mit der neuen Methode ausgewertet. Die Bedeutung des Verfahrens ist in den Fällen noch grösser, wenn aus den Sedimenten nur unbestimmte sporadische Funde erhalten werden können.

---

, . (MOM) , : . - . . , .

---

---

The author wishes to thank the staff of the Department of Experimental Physics of L. Kossuth University for the neutron activation measurements and the Computer Center of the University for the calculation work.     

Thermal conductivities of polytetrafluoroethylene and polychlorotrifluoroethylene between 4.2 and 20 K

The thermal conductivities of bulk technical samples of polytetrafluoroethylene and polychlorotrifluoroethylene were measured in the temperature range 4.2–20 K by application of the steady-state method. An interpretation of the thermal conductivity data in terms of the available theoretical and empirical models is presented.

---

Zusammenfassung Die thermischen Leitfähigkeiten technischer Einzelproben von Polytetrafluoräthylen und Polychlortrifluoräthylen wurden im Temperaturbereich von 4.2 bis 20 K durch Einsatz der Festkörper-Methode gemessen. Eine Deutung der thermischen Leitfähigkeitsangaben wird anhand der zur Verfügung stehenden theoretischen und empirischen Modelle gegeben.

---

4.2–20 . .

---

---

This work was done in the International Laboratory of High Magnetic Fields and Low Temperatures, Wrocaw, Poland.     

Theory of differential thermal analysis taking into account heat exchange between the specimen and reference cells

A basic formula of differential thermal analysis is evolved for the case when the heat transfer coefficient between the specimen cell and the reference cell is not zero. The more general formula obtained differs from the classical formula by including the parameters of the reference cell and the heat transfer coefficient between the cells. It indicates that utilization of the classical formula is not correct if heat exchange occurs between the cells. To utilize the generalized formula, additional measurements of the temperature changes of the reference material are required. However, if the time constants of the two cells are identical, the formula can be changed to assume the form of the classical formula for DTA if a correction factor is introduced which takes into account the effect of heat exchange between the cells.

---

Zusammenfassung Für den Fall, dass der Übertragungskoeffizient zwischen der Proben- und der Referenzzelle nicht Zero ist, wurde eine Grundformel der Differentialthermoanalyse entwickelt. Die entstandene Formel, die vielmehr allgemein ist, weicht von der klassischen dadurch ab, dass sie auch die Parameter der Referenzzelle, und den Wärmeübertragungskoeffizient zwischen den Zellen enthält. Sie deutet darauf hin, dass die Anwendung der klassischen Formel in dem Fall nicht einwandfrei ist, wenn ein Wärmeaustausch zwischen den Zellen zustande kommt. Zur Anwendung der verallgemeinerten Formel sind weitere Messungen des Temperaturaustausches vom Referenzmaterial erforderlich. Sind aber die Zeitkonstanten der zwei Zellen identisch, kann die Formel so geändert werden, dass sie die Gestalt der klassischen DTA-Formel annimt, wenn ein, mit der Wirkung des Wärmeaustausches zwischen den Zellen rechnender Korrektionsfaktor eingeführt wird.

---

, . , , . . , , , , .

     

Catalytic activity of honeycomb catalysts, I. The benzene-cyclohexane (de)hydrogenation reaction

Monolithic supported platinum catalysts were investigated with respect to their hydrogenation and dehydrogenation activity towards benzene and cyclohexane, respectively, between 250° and 350°C. Conversion of benzene to cyclohexane is optimal for the volume ratio H₂/Bz=5 at lower temperatures. In the cyclohexane dehydrogenation reaction, high temperatures, associated with lower N₂/Cy ratios, are beneficial. No byproducts were observed in the two reactions.

---

, , 250 °C 350 °C. H₂/=5. N₂/ . .

     

Calculation of the mass transfer coefficient with a chemical reaction in a gas-liquid system

A solution of the problem of mass transfer in a turbulent boundary layer has been obtained with a first-order chemical reaction occurring in the liquid phase. The dependence of the enhancement factor for absorption and of the mass transfer coefficient on the model parameters can be used for building up a hierarchic model of the gas-liquid reactor.

---

. .

     

Synthesis of light alcohols from carbon monoxide and hydrogen over copper-iron catalysts

The activity and selectivity of copper-iron catalysts for the synthesis of light alcohols from carbon monoxide and hydrogen were studied. The suitable ratio of copper to iron and optimal chemical composition of the catalyst were determined.

---

- . .

     

Preparation and characterization of Ru?Pb supported catalysts

Decomposition of Mn₃Mo₂TeO₁₂ during oxidation of toluene to benzaldehyde was observed. Depending on the surface composition of the initial catalyst, the decomposition leads to less active but highly selective MnMoTeO₆ or to MnMoO₄ which is not selective in toluene oxidation.

---

Mn₃Mo₂TeO₁₂ . , MnMoTeO₆, MnMoO₆.

     

Zersetzungsmechanismus von Mg(OH)2 und Mg(OD)2

Zusammenfassung Man untersucht, unter welchen Bedingungen das Proton einer ionischen OH^–-Gruppe die Elektronenwolke des O^2–Ions verlassen kann, um mit einer benachbarten OH^–-Gruppe ein H₂O-Molekül zu bilden. Voraussetzung zum Tunneln ist in der benachbarten OH^–-Gruppe ein freies Akzeptorniveau auf gleicher Höhe. Wenn die beiden betrachteten OH^–-Gruppen kristallographisch äquivalent sind, ist die letztgenannte Bedingung nicht erfüllt, da das Akzeptorniveau höher liegt als das Donatorniveau. Durch Koplung mit den gegenphasigen OH-Knickschwingungen wird eine Verbreiterung der Niveaus und schließlich — ab einer kritischen Amplitude — eine Überlappung herbeigeführt, die das Tunneln ermöglicht. Die Protonenumlagerung beginnt an der Oberfläche, weil an einer freien Oberfläche die Amplituden der wirksamen OH-Knickschwingungen bei gleicher Temperatur größer sind als im Innern des Kristalls.

---

The conditions have been studied under which the proton of an ionic OH^– group can leave the electron cloud of the O^2– ion to form a H₂O molecule with a neighbouring OH^– group. The condition of tunnelling is the presence of a free acceptor level of similar height in the neighbouring OH^– group. If the two OH^– groups are equivalent crystallographically, this condition is not fulfilled since the acceptor level lies higher than the donor level. Coupling with the opposite-phase OH bending vibrations leads to a broadening of the levels and finally to an overlap, which renders the tunnelling possible. The proton transfer starts at the surface as at any given temperature the amplitude of the effective OH bending vibrations is larger at the surface than inside the crystal.

---

Résumé On recherche les conditions dans lesquelles le proton d'un groupe ionique OH^–peut quitter le nuage électronique de l'ion O^2– pour former une molécule d'eau avec un groupe OH^– voisin. La condition de l'effet tunnel est que le groupe OH^– voisin possède un même niveau libre accepteur. Cette condition n'est pas réalisée dans le cas de deux groupes OH^–voisins cristallographiquement équivalents puisque le niveau accepteur est plus haut que le niveau donneur. Le couplage des vibrations de déformation en opposition de phase des OH provoque un élargissement des niveaux et finalement — à partir d'une amplitude critique — un recouvrement qui permet l'effet tunnel. La transposition protonique commence en surface puisque pour une surface libre les amplitudes des vibrations de déformation actives des OH sont plus grandes qu'à l'intérieur du cristal.

---

, , -, ²- [₂] -. -. , , , . -, , , . , , .

     

Rate constants for photochemically induced hydrogen abstraction calculated from spin trapping rates

ESR spin trapping method has been applied to calculate the rate constant for -hydrogen abstraction from ethylbenzene by triplet anthraquinone: k₁=1.1×10⁷ M^–1 s^–1 (error of estimation 25%).

---

( ) -CH : k₁=1.1×10⁷ M^–1–1 ( 25%)

     

The oxygenolysis of 9,10-phenanthrenequinone to copper(II) diphenato complexes by CuX (X=Cl, Br) complexes containing pyridine type ligands

The oxygen dependent cleavage of 9, 10-phenanthrenequinone by CuX (X=Cl, Br) with py, dipy, and phen ligands to well define copper(II) diphenato complexes and evidence for the intermediate Cu–O₂ complexes containing Cu^II and Cu^I are reported.

---

9,10- CuX (X=Cl, Br) py, dipy phen (II), , , Cu–O₂, Cu^II Cu^I.

     

Interaction of V2O5 with oxygen in the gas phase

Sorption/evolution of oxygen from V₂O₅ in the temperature range of 480–520°C is due to a shift in the defect equilibrium 1/2 O₂ (gas)+V_oO_o. A first-order kinetic equation can be derived under the assumption that the activation energy depends on the concentration of defects.

---

/ V₂O₅ 480–520°C 1/2 O₂ ()+V_oO_o. , , .

     

Influence of mechanical activation on decomposition of a chalcopyrite-pyrite mixture in an oxidizing atmosphere

The influence of the addition of pyrite and mechanical activation on an oxidative decomposition of chalcopyrite was studied. The course of the thermoanalytical curves and X-ray identification of the products showed that addition of pyrite affects mainly the endothermic processes taking place in region of low temperatures but does not significantly influence the temperature of CuSO₄ formation and its content in the products of decomposition. Changes in fine and superfine structure of chalcopyrite brought about by mechanical activation at grinding cause the complex of exothermic oxidative reactions to proceed at temperatures as much as 180 deg lower than for a non activated sample. The endothermic effect of these oxidation reactions become more marked and the proportion of CuSO₄ in the products of the oxidative decomposition increases significantly.

---

Zusammenfassung Am oxidativen Zerfall von Chalkopyrit wurde der Einfluss der Zugabe von Pyrit sowie der mechanischen Aktivierung untersucht. Der Verlauf der thermoanalytischen Kurven und Röntgendiffraktionsanalyse der Produkte zeigten, dass die Zugabe von Pyrit hauptsächlich die sich bei niedrigeren Temperaturen abspielenden endothermen Prozesse beeinflusst, nicht aber die Bildungstemperatur von CuSO₄ sowie dessen Gehalt in den Zersetzungsprodukten. Durch mechanisches Aktivieren mittels Feinmahlen hervorgerufene Veränderungen in der Fein- und Superfeinstruktur lassen die Gesamtheit der exothermen oxidativen Reaktionen bei Temperaturen ablaufen, die etwa 180 Grad unterhalb derer für unaktivierte Proben liegen. Die endotherme Färbung dieser Oxidation wird eindeutiger und der Anteil von CuSO₄ in den Produkten des oxidativen Zerfalles nimmt eindeutig zu.

---

. , . , , - , 180° , . - .

     

On the interpretation of differences in mechanisms, kinetics and dynamics of oxidation reactions on metal and oxide catalysts

Langmuir-Hinshelwood type mechanisms with competitive adsorption are suggested to be more typical for metal catalysts, since, unlike on oxide systems, oxidizable substance and molecular oxygen can be adsorbed on the same (reduced) active sites. Therefore, multiple steady states and critical phenomena are more characteristic for catalysis on metals.

---

, - , , () . .