Gamma radiolysis of Methyl Red solution and reaction induced by γ-irradiated NaCl in Methyl Red

The -radiolysis of Methyl Red solution in HCl medium at pH=2 has been studied along with energy transfer reaction brought about byF and hole centers of -irradiated NaCl. The G-values for degradation of the azo dye indicator by radiolysis and -irradiated salt were determined as 9·10^–1 and 4.8·10^–3, respectively. The kinetic rate constants (k) of degradation are evaluated as 2·10^–5 rad^–1 in the case of direct radiolysis, while for the irradiated salt it is 2·10^–7 rad^–1. The extent of degradation by direct -radiolysis is 100–200 times greater as compared to that by the -irradiated salt. The same mechanism is proposed for radiolysis as well as the reaction induced by -irradiated sodium chloride.     

On the use of a dead-time meter for pile-up corrections

Correction for pile-up losses in the amplifier is possible by the dead-time fraction indicator of the ADC in case of long-lived radionuclides. If the dead-time meter has been calibrated, an accuracy of 1.5% is feasible up to a dead-time fraction of 25%. The precision decreases from 1.5% at 10% dead-time fraction to 3% at a deadtime fraction of 30%.     

Kinetics of ammonia decomposition of polycrystalline rhodium at pressures between 0.013 and 103 kPa

The rates of ammonia decomposition on polycrystalline Rh wires between 600 and 1800 K and at pressures between 13.3 Pa and 103 kPa were measured and fitted with a Langmuir-Hinshelwood unimolecular reaction rate expression. At high temperatures and pressures the reaction seems to be mass transfer controlled.

---

Rh 600–1800 K 13,3 –103 . , -. .

     

Calculation of thermal effects in DTA

By considering that the temperature of the end of the thermal effect and the return of the thermal curve to the baseline do not coincide new calculation methods for the thermal effect become possible. Both the integral value of the thermal effect and its distribution over temperature may be calculated by processing only that part of the DTA curve which corresponds to the temperature interval of the transformation.It is demonstrated on the examples of non-variant transformation and transformation with an even distribution of the thermal effect over the temperature interval of the transformation that, under certain assumptions, the values of the thermal effect calculated by the suggested method and by the area of the peak are identical.

---

Zusammenfassung Bei Berücksichtigung, daß die Temperatur des Endes des thermischen Effekts und die Rückkehr der thermischen Kurve zur Grundlinie nicht zusammenfallen, werden neue Methoden zur Berechnung des thermischen erschlossen. Sowohl der Integralwert des thermischen Effekts, als auch seine Verteilung in dem Temperaturbereich können durch Behandlung ausschließlich desjenigen Teils der DTA-Kurve berechnet werden, welcher dem Temperaturbereich der Umwandlung entspricht.Anhand von Beispielen der nicht-varianten Transformation und der Transformation mit gleichmäßiger Verteilung des thermischen Effekts im Temperaturbereich der Umwandlung wurde gezeigt, daß — unter gewissen Voraussetzungen — die Werte des durch die vorgeschlagene Methode und des aus der Peakfläche berechneten thermischen Effekts identisch sind.

---

Résumé En considérant le fait que la température de la fin de l'effet thermique et le retour à la ligne de base de la courbe ATD ne coïncident pas, on a développé de nouvelles méthodes du calcul de l'effet thermique. La valeur intégrale de l'effet thermique ainsi que sa distribution dans l'intervalle de températures peuvent être calculées en ne considérant que la partie de la courbe ATD qui correspond à l'intervalle de température de la transformation.A l'aide d'exemples de transformations invariantes et de transformations à distribution uniforme de l'effet thermique dans l'intervalle de températures de la transformation, on a montré qu'avec certaines hypothèses, les valeurs de l'effet thermique calculées par la méthode proposée et à partir des surfaces des pics, sont identiques.

---

. , -, . , , .

     

Some remarks about butene-1 transformations on NaHY zeolite

Comments are given on the paper Alternative Interpretation of Infrared Spectra of the Zeolite NaHY+Butene-1 System of Forster and Seelemann /2/. Our previous paper /1/ was partly revised but the usefulness of comprehensive studies by infrared and temperature-programmed desorption methods has been emphasized.

---

: NaHY+-1. [2]. [1] , - .

     

A simple autonull-type servo-controlled electronic balance for thermogravimetric applications

A simple electronic autonull-type recording balance using a helical quartz spring is described. Deviation from the null position is detected by a pair of photoemissive cells. The error signal generated across the cells as a result of weight change is processed by a servo-system which, in turn, produces an electric current in the balancing coil proportional to the force required to restore the null position. This current, recorded as the potential drop across a standard resistor, is a direct measure of the weight change.The balance has good linear response and can record weight changes up to 150 mg. The performance of the balance was tested in a thermogravimetric set-up, by studying the decomposition in air of the oxalates of copper, nickel and magnesium. The decomposition of nickel oxalate was also studied in flowing hydrogen. The weighing accuracy of the balance, compared against a Mettler model H-15 single-pan balance, was found to be within±1.5%.

---

Zusammenfassung Eine einfache elektronische registrierende Quartz-Spiralfeder Kompensationswaage wird beschrieben. Die Abweichung von der Nullposition wird durch zwei Photoemissionszellen angezeigt. Das infolge der Gewichtsänderung durch die Zellen erzeugte Fehlersignal wird durch ein Servosystem empfangen, das seinerseits in der Ausgleichsspirale einen elektrischen Strom erzeugt, der proportional zur für die Wiederherstellung der Null-position benötigten Kraft ist. Dieser Strom, der als Spannungsgefälle in einem Standardwiderstand registriert wird, ist eine direkte Maßzahl der Gewichtsänderung.Die Waage zeigt ein gutes lineares Verhalten und kann Gewichtsänderungen bis zu 150 mg registrieren. Die Leistung der Waage wurde in einer thermogravimetrischen Vorrichtung durch Untersuchungen der Zersetzung der Oxalate von Kupfer, Nickel und Magnesium in Luft geprüft. Die Zersetzung von Nickeloxalat wurde auch in strömendem Stickstoff untersucht. Die Meßgenauigkeit der Waage, vergleichen mit der Einschalenwaage Mettler H-15 wurde im Bereich von±1.5% gefunden.

---

Résumé On décrit une balance électronique enregistreuse simple du type auto-zéro, à hélice de quartz. La déviation de la position zéro est décelée par une paire de cellules photoémissives. Le signal de déséquilibre décelé par les photocellules et résultant d'un changement de poids, est reçu par un système asservi qui, à son tour, produit un courant électrique dans la bobine de la balance, proportionnel à la force nécessaire pour rétablir la position zéro. Ce courant, enregistré comme chute de potentiel dans une résistance étalon, est une mesure directe du changement de poids.La balance donne une bonne réponse linéaire et peut enregistrer des changements de poids allant jusqu'à 150 mg. Ses caractéristiques ont été examinées dans un montage thermogravimétrique, en étudiant la décomposition dans l'air des oxalates de cuivre, nickel et magnésium. La décomposition de l'oxalate de nickel a aussi été étudiée sous courant d'hydrogène. L'exactitude de la balance, comparée à celle d'un modèle Mettler monoplateau (type H-15), coïncide à±1.5%.

---

, . . , , -, , . , , . 150 . , . . -15 +1.5%.

---

---

The authors wish to express their thanks to Mr. S. P. Sen, Manager. Catalyst Development and Production Department of Fertilizer (Planning and Development) India Limited, for his keen interest and valuable suggestions.     

Contribution a l'etude des associations aminophenazone-uree aminophenazone-thiouree et aminophenazone-noxythioline

The phase diagrams for aminophenazone-urea (a), aminophenazone-thiourea (b) and aminophenazone-noxythioline (c), established by differential scanning calorimetry, transparency method and thermomicroscopy, revealed the presence of definite compounds (1–3). These compounds are formed during eutectic fusion for (a) and (c); the definite compound for (b) displays non-congruent fusion.

---

Zusammenfassung Aus den durch DSC ermittelten Phasendiagrammen für Aminophenazon-Harnstoff (a), Aminophenazon-Thioharnstoff (b) und Aminophenazon-Noxythiolin (c) sowie durch die Transparenzmethode und Thermomikroskopie wurde die Existenz der definierten Verbindungen (1–3) nachgewiesen. Diese Verbindungen werden im Falle von (a) und (c) in eutektischen Schmelzen gebildet. Die definierte Verbindung für (b) schmilzt nicht-kongruent.

---

- (a), - () - (), , , . ((a)) (), () .

     

Studies on the V?Ti?O system obtained by thermal decomposition of vanadyl and titanyl oxalates in argon atmosphere

The V–Ti–O system as a product of thermal decomposition of vanadyl and titanyl oxalates at 873 and 1173 K in argon atmosphere was studied by X-ray diffraction and infrared spectroscopy. The results obtained, the analysis and surface measurement data suggest that a V³⁺–V⁴⁺–Ti⁴⁺–O solid solution is formed. Spectroscopic measurements reveal the presence of a V=O bond in the system obtained at 873 K.

---

V–Ti–O, 873 1173 - . , , V⁺³–V⁺⁴–O . V=O , 873 .

     

Effect of H2S-uptake on the conversion of cyclohexene on Ru- and Pd-promoted molybdena-alumina catalysts

The effect of H₂S on the activity and selectivity of catalysts (Ru/Al₂O₃, Pd/Al₂O₃ and Ru and Pd promoted molydena-alumina) was different (on differnt catalysts and different conversions of cyclohexene). Ru-containing catalysts showed higher sulfur sensitivities than the Pd-containing ones. The sequence of catalysts by their H₂S uptake related to mass of catalyst was PdMo/Al₂O₃RuMo/Al₂O₃Mo/Al₂O₃>Pd/Al₂O₃Ru/Al₂O₃.     

Chemical oscillations in the uncatalyzed bromate oxidation of hydroquinone and nitrophenols

Chemical oscillatory behavior in the uncatalyzed bromate oxidation of hydroquinone and nitrophenols is reported. The reaction is strongly inhibited by stirring. Effect of one-electron redox couples (EZ catalysts) on the system is described.

---

. . - ( EZ) .

     

Strategies to vectorize conventional SCF-Cl algorithms

Recent high-performance computers, especially supercomputers, achieve very high-speed operations but bring about serious I/O problems in quantum chemical computations. Strategies to vectorize conventional SCF-CI algorithms are discussed relating to the I/O problems. The conventional SCF-CI algorithm which is proposed here reduces I/O processing by eliminating all sorting routines and redundant integral files and generates directly nonzero and nonredundant PK integrals with a vectorizable canonically-ordered list. The new implementation has been undertaken and successfully realized as a program system named GSCF3. The vector to scalar acceleration rate of GSCF3 on the HITAC S-810 are as follows: 2.5 5 in the AO integral evaluation, 5 12 in the SCF calculation, 15 30 in the four-index integral transformation, 10 20 in the CI matrix diagonalization, and overall 510 through SCF-CI.     

Kinetics of Cr(VI) and V(V) oxidation of trans-stilbene and indene

Title reactions are acid catalyzed and strongly dependent on the permittivity of the medium. With Cr(VI) indene reacts faster than trans-stilbene, but with V(V), trans-stilbene reacts faster than indene. The mechanism is discussed.

---

. Cr(VI) , -, V(V) - , . , .

     

Toluene disproportionation and coke formation over fluorided alumina and hydrogen-mordenite

Toluene transformation was investigated on a fluorided alumina and a protonic mordenite under hydrogen (0.8, 12 bar) and under nitrogen (12 bar). Hydrogen pressure considerably improves the catalytic stability of H-mordenite by inhibiting the formation of coke. Moreover, hydrogen eliminates part of the coke deposited by reaction under nitrogen, and regenerates the activity of the mordenite. On the contrary, hydrogen has no effect in the case of fluorided alumina. The particular behavior of the mordenite is attributed to its very strong acidity.

---

(0,8, 12 ) (12 ). -, . , , , . , - . .

     

Evaluation of quantum yields in the presence of an absorbing additive

A method is proposed for the evaluation of quantum yields of photochemical reactions studied in the presence of absorbing additives using cylindrical sample tubes.

---

.

     

Activation of magnesia by hydrogen spillover

Magnesia aerogel activated by hydrogen spillover at 430 °C or at 200 °C becomes a catalyst for the hydrogenation of ethylene. This catalytic activity, observed already at 50 °C, is further enhanced by a treatment in oxygen at 430 °C.

---

, 430 200°C, . 50°C 430°C.

     

A rapid method for catalyst activity measurements by combination of pulse reactor, mass spectrometer and process computer

The combination of a pulse reactor attached directly (without a separation column) to a mass spectrometer/process computer system is described. To obtain a conversion/temperature diagram for the dehydration and dehydrogenation of 2-butanol less than one hour is required. Therefore, the method can be used for rapid characterization or comparison of the activities of various samples.

---

, ( ) - . / 2- . .

     

Pallatriazo — A sensitive and selective reagent for the spectrometric determination of palladium(II)

Summary Based on an investigation of the functional and active analytical groups, a new trisazo derivative, pallatriazo, is proposed as a reagent for determining Pd(II) spectrometrically. This reagent shows high sensitivity, allowing palladium determination in the concentration range 0.05–4g Pd(II)/ml even if platinum is present up to the ratio Pd(II)Pt(IV)=130.

---

Pallatriazo — ein empfindliches und selektives Reagens für die spektrometrische Bestimmung von Palladium(II) (Vorläufige Mitteilung)

Zusammenfassung Auf der Grundlage einer Untersuchung der funktionellen und analytischaktiven Gruppen wurde ein neues Trisazo-Derivat, Pallatriazo, als Reagens für die spektrometrische Bestimmung von Pd(II) vorgeschlagen. Es zeigt hohe Empfindlichkeit und gestattet die Pd-Bestimmung im Gebiet 0,05–4g Pd(II)/ml, auch wenn Platin in 30fachem Überschuß anwesend ist.

     

Donorstärken in 1,2-Dichloräthan

Zusammenfassung Kalorimetrische und spektrophotometrische Untersuchungen über die Donorstärke einer Anzahl nicht-wäßriger Lösungsmittel zeigen, daß die relative Reihung der Donorstärken unabhängig von der Natur des Akzeptors ist. Die Donorreihung lautet gegenüber SbCl₅, Jod und Phenol folgendermaßen: Pyridin > Dimethylsulfoxid > Dimethylacetamid Dimethylformamid > > Trimethylphosphat Diphenylphosphoroxychlorid > Diäthyläther > Aceton > Propandiol-1,2-carbonat > Acetonitril > > Selenoxychlorid Phosphoroxychlorid Benzoylchlorid > > Thionylchlorid > Sulfurylchlorid.

---

Calorimetric and spectrophotometric work on the donor strength of various non-aqueous solvents have shown that the relative order of donor strength is independent from the nature of the acceptor. The order of donor strength towards SbCl₅, I₂ and phenole is pyridine > dimethylsulfoxide > dimethylacetamide dimethylformamide > trimethylphosphate diphenylphosphonic chloride > diethyl ether > acetone > propane diol-1,2-carbonate > acetonitrile > selenium oxychloride phosphorus oxychloride benzoyl chloride > thionyl chloride > sulfuryl chloride.

---

---

Mit 1 Abbildung     

Conversion of n-butane on H-mordenite catalysts

Conversion of n-butane on various mordenite catalysts have been studied at temperatures ranging within 150–500°C. The isomerization activity of the catalysts is shown to depend on the temperature, mordenite composition and its molar ratio of SiO₂/Al₂O₃.

---

150–500°C - H-, . , , SiO₂/Al₂O₃.

     

Zu einigen Besonderheiten des thermischen Zerfalls von Ni(II)-Komplexen mit dreizähnigen Schiffschen Basen

Zusammenfassung Es wurde eine Reihe von Komplexen des zweiwertigen Nickels mit den Schiffbasen H₂L,H₂L der Zusammensetzung NiL·ROH(R=Me, Et, Pr, i-Pr)und NiL ·ROH (R=Me, Et, Pr, i-Pr, Bu) hergestellt und deren thermischer Zerfall untersucht. Es wurde festgestellt, dass bei den Addukten NiL·ROH der Zerfall unter Abspaltung des Alkohols (Zwischenprodukt NiL) verläuft, während bei NiL·ROH sofort nach der Abspaltung des Alkohols zur Massenzunahme auf TG-Kurve durch Oxidation des Stoffes kommt. Das Plateau, das dem Zwischenprodukt NiL entspricht, ist hier nur in der Ineratmosphäre erhaltbar. Es wurden auch die Aktivierungsenergien für die Abspaltung des Alkohols berechnet.

---

Ni(II) Schiff base complexes of compositions NiL ROH (R=Me, Et, Pr, i-Pr) and NiL·ROH (R=Me, Et, Pr, i-Pr, Bu) were prepared and investigated by methods of thermal analysis. The thermal decomposition of NiL·ROH led to NiL (plateau in TG curve), whereas NiL·ROH underwent a similar decomposition only in an inert atmosphere (N₂); thermal decomposition in air involved alcohol fragmentation, followed by a mass increase due to oxidation by atmospheric oxygen. The activation energy of alcohol fragmentation was calculated.

---

NiL · ROH (R=-, -, - ) NiL-ROH (R=-, -, -, -, ). , NiL ] NiL — . , . .

---

---

Wir möchten uns sehr herzlich bei Doz. RNDr. E. Jóna, CSc. und RNDr. I. Horváth, CSc. für die Messungen in der Stickstoffatmosphäre in SAV Bratislava bedanken.