Thermal analysis of diazo pigments

The differential-thermal and thermogravimetric analysis of eight derivatives of 1,4-bis-(8′-hydroxy-3′,6′-disulpho-1′-naphthyl)-benzenediamide showed that these compounds have a marked exothermic effect, with maxima in the temperature range 290–340°C. The 4-nitroaniline derivative was found to undergo a blast-like decomposition in the temperature interval 285–295°C, reflected by large steps in the TG curves. The thermal analysis of diazo pigments permits determination of their applicability at higher temperatures.     

Thermal analysis of disazo pigments

The differential-thermal and thermogravimetric analysis of eight derivatives of 1,4-bis-(5-hydroxy-7-sulpho-2naphthyl)-benzenediamide showed that these compounds have a marked exothermic effect, with maxima in the temperature range 280–330°C. The derivative of 4-nitroaniline-2-sulphonic acid were found to undergo a blast-like decomposition in the temperature intervals 255–265°C and 285–290°C, which is reflected by large steps in their TG curves.The thermal analysis of disazo pigments permits determination of their applicability at higher temperatures.

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Zusammenfassung Die DT- und TG- Analyse von acht Derivaten von 1,4-bis-(5-Hydroxy-7-sulpho-2naphthyl)-benzoldiamid zeigte, dass diese Verbindungen mit einem Maximum im Temperaturbereich 280–330°C einen eindeutigen exothermen Effekt aufweisen. Derivate mit 4-Nitroanilin-2-sulfonsäure zeigen eine explosionsartige Zersetzung im Temperaturintervall 255–265°C und 285–290°C, was sich in den TG-Kurven in einer großen Stufe wiederspiegelt.Die Thermoanalyse von Bisazopigmenten ermöglicht eine Ermittlung ihrer Anwendbarkeit für höhere Temperaturen.

     

Untersuchungen über die Oxydation von Butylbenzol in flüssiger Phase in Gegenwart von Kobalt- und Mangansalzen der Pyridincarbonsäuren

Zusammenfassung Es wurde der Einfluß der Kobalt- und Mangansalze der -, - und -Pyridincarbonsäuren auf die Luftoxydation von Rutylbenzol in flüssiger Phase untersucht. Dabei wurde festgestellt, daß das Kobaltpicolinat, Manganisonicotinat und Kobaltisonicotinat den Oxydationsverlauf zur Bildung von Carbonylverbindungen und Säuren lenken. Das Manganpicolinat weist ein selektives Oxydationsvermögen auf, vorwiegend zur Bildung von Estern.

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Liquid phase oxidation of butyl-benzene in presence of Co and Mn pyridine carboxylates

The influence of Co- and Mn-salts of -, - and -pyridinecarboxylic acids, resp., on the oxidation of butylbenzene by air has been studied. It has been found that the Co salt of picolinic acid, Mn and Co isonicotinate direct the oxidation process in favour of carbonyl compounds and acids. With the Mn salt of picolinic acid, the oxidation mainly gives esters.

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Mit 5 Abbildungen     

Approximation of Functions by the Szász-Mirakjan-Kantorovich Operator

We characterize the approximation of functions in the L_p-norm by the Szász-Mirakjan-Kantorovich operator. We prove a direct and a strong converse inequality of type B in terms of an appropriate K-functional.     

Retrieving reflection responses by crosscorrelating transmission responses from deterministic transient sources: application to ultrasonic data

By crosscorrelating transmission recordings of acoustic or elastic wave fields at two points, one can retrieve the reflection response between these two points. This technique has previously been applied to measured elastic data using diffuse wave-field recordings. These recordings should be relatively very long. The retrieval can also be achieved by using deterministic transient sources with the advantage of using short recordings, but with the necessity of using many P-wave and S-wave sources. Here, it is shown how reflections were retrieved from the cross correlation of transient ultrasonic transmission data measured on a heterogeneous granite sample.     

Über die Einwirkung von Ammoniak auf arylsubstituierte Indone in Abwesenheit von Metallsalzen

Zusammenfassung Die optimalen Reaktionsbedingungen der Einwrikung von Ammoniak auf substituierte Indone unter Druck in Abwesenheit von Metallsalzen, die zur Bildung dunkelblauer Verbindungen führen, werden festgestellt. Die Reaktion ist auf Diarylindone beschränkt; als Nebenprodukte werden Benzoesäure (in äquivalenter Menge zur dunkelblauen Verbindung) und 1-Benzal-2,3-diphenylinden gebildet. Oxydativer Abbau der dunkelblauen Verbindungen liefert die entsprechende aromatische Säure und das Amid der Aroylbenzoesäure im Molverhältnis 12. Für die dunkelblauen Verbindungen ergibt sich die Struktur der (1-Aryl-3-isoindolyl)-(1-aryl-3-pseudoisoindolenyliden)-arylmethane, die durch Synthese aus 1-Phenyl-isoindol und Benzaldehyd bestätigt wird. Es wird ein Mechanismus für die Bildung der dunkelblauen Verbindungen und der Nebenprodukte vorgeschlagen.

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Dark-blue compounds can be isolated from the reaction of substituted indones with ammonia under pressure and in the absence of metal salts. Optimum conditions, scope and limitations of this reaction were determined. It was established, that the dark-blue products were formed only from diarylindones. An amount of benzoic acid comparable to that of the dark-blue compound, and 1-benzylidene-2,3-diphenylindene were isolated as by-products in the reaction of diphenylindone with ammonia. Oxidative degradation of the dark blue compounds obtained fromdifferent diarylindones yielded the corresponding aromatic acids and aroylbenzoic acid amides, respectively, in a 12 ratio. On the grounds of the evidence obtained, a (1-aryl-3-isoindolyl) (1-aryl-3-pseudoisoindolenylidene)aryl methane structure for the dark blue compounds is proposed. This structure was confirmed by the synthesis of the dark-blue product, obtained from diphenylindone and ammonia, from 1-phenylindone and benzaldehyde. Mechanisms both for the formation of the dark-blue compounds as well as for the by-products are suggested. *** DIRECT SUPPORT *** A3615129 00016

     

Direct estimates of the weighted simultaneous approximation by the Szász–Mirakjan operator

Periodica Mathematica Hungarica - We establish direct estimates of the rate of weighted simultaneous approximation by the Szász–Mirakjan operator for smooth functions in the supremum...     

The first chemical synthesis of boronic acid-modified DNA through a copper-free click reaction

The first chemical incorporation of the boronic acid group into DNA using a copper-free click reagent was reported. Compared with the PCR-based method, this approach allows for site-specific incorporation and synthesis on a larger scale.     

On Simultaneous Approximation by Iterated Boolean Sums of Bernstein Operators

The paper presents upper estimates of the error of weighted and unweighted simultaneous approximation by the Bernstein operators and their iterated Boolean sums. The estimates are stated in terms of the Ditzian–Totik modulus of smoothness or appropriate K-functionals.