APPLICATION OF DIFFERENTIAL THERMAL ANALYSIS TO THE DISSOCIATION OF MnO2 AND Mn2O3

1965 ◽  
Vol 43 (6) ◽  
pp. 1723-1728 ◽  
Author(s):  
T. Matsushima ◽  
W. J. Thoburn

The method of differential thermal analysis was employed to determine the oxygen pressures produced by the reactions[Formula: see text]and[Formula: see text]in the temperature range 250–1000 °C. The heats of reaction calculated from the slope of the van't Hoff curves are: ΔH835°K0 = 25.8 ± 1.5 and ΔH1200°K0 = 25.3 ± 4.2 kcal per mole of oxygen. These are in agreement with previously reported values based on equilibrium measurements, but are lower than those determined by calorimetry.

1981 ◽  
Vol 36 (3) ◽  
pp. 222-225 ◽  
Author(s):  
Peter Brauer

The investigation of the order-disorder transitions of the ammonium-chlorides and -bromides, in which some of the NH4+ are replaced by Cs+, Rb+ or K+, is extended to the corresponding iodides using birefringence and differential thermal analysis. As the temperature range of the martensitic transition (Pm 3 m↔Fm 3 m) is now overlapping the temperature range of the orderdisorder transitions, the former must be included in the measurements. The results allowing an overlook are discussed using the work of Garland, Lushington, and Leung [5]


HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1136F-1136
Author(s):  
M. Ahmedullah ◽  
C. R. Rom

Roots of one year old grape cvs. Concord, White Riesling, Grenache and Semillon were frozen to 0, -5, -10, -15 and -20°C in a programmable freezer. The tops were protected from cold by insulating them. For survival test, 4 plants of each cv. were planted in the greenhouse and their growth observed. Differential thermal analysis (DTA), using a computer attached to a programmable freezer was performed on roots. To aid in the interpretation of DTA, triphenyltetrazolium chloride (TTC) was performed. Hardiness determinations were based on DTA, TTC and the survival tests. DTA patterns representing exothermic response showed an exotherm associated with extracellular free water in tissue which appeared at about the same temperature range for all cvs. This is not associated with hardiness. Additional minor exotherms related to hardiness appeared at lower temperatures than the extracellular water exotherm. Their location differed from one cv. to another. Based on these tests, Concord roots appear to be hardier than other cvs. with important but minor differences in the hardiness of other cvs.


1987 ◽  
Vol 42 (11) ◽  
pp. 1327-1332 ◽  
Author(s):  
K. Hilpert ◽  
D. Kobertz ◽  
V. Venugopal ◽  
M. Miller ◽  
H. Gerads ◽  
...  

The Al-Ni phase diagram has been investigated in the com position range xNi = 0.70 to 0.97. Phase boundaries were determined by using differential thermal analysis and Knudsen effusion mass spectrometry. The measurements were carried out in the temperature range between 1409 and 1730K. An Al-Ni phase diagram is obtained for xNi ≧ 0.70 by combining the data from this work with selected data from the literature. This diagram deviates from that recommended by phase diagram compilations and used generally in the literature to date; it agrees reasonably well with a diagram which has been rejected in the literature.


2000 ◽  
Vol 15 (9) ◽  
pp. 1994-1997 ◽  
Author(s):  
C. H. Shek ◽  
G. M. Lin

The oxygen chemisorption on nanocrystalline SnO2 at temperature range between 100 and 450 °C was studied with differential thermal analysis (DTA) and electrical conductivity measurement. The O2−, O−, and O2m ionosorptions were observed and could be distinguished from each other only on nanocrystalline SnO2 with grain size less than 5 nm. Assuming steady-state adsorption, the heats of adsorption for O2− and O− (or O2−) on nanocrystalline SnO2 are 1.09 and 1.50 eV respectively from the results of DTA.


2019 ◽  
Vol 33 (09) ◽  
pp. 1950104 ◽  
Author(s):  
A. S. Alekperov ◽  
S. H. Jabarov ◽  
M. N. Mirzayev ◽  
E. B. Asgerov ◽  
N. A. Ismayilova ◽  
...  

X-ray analysis of layered [Formula: see text] crystal has been investigated before and after gamma irradiation. Single crystal [Formula: see text] was irradiated with a [Formula: see text] gamma source which had an energy of 1.33 MeV. The dose rate was [Formula: see text] and the absorption dose was from 1 kGy up to 30 kGy. The thermogravimetric analysis, differential scanning calorimetric, differential thermogravimetric and differential thermal analysis were performed on the samples. The thermodynamic analysis was evaluated for the thermally stable temperature range for unirradiated and irradiated [Formula: see text] compound. The results showed the splitting of GeNdS sample in the manner [Formula: see text] at the temperature range of [Formula: see text] which leads to mass reduction by 0.29%.


HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1136f-1136
Author(s):  
M. Ahmedullah ◽  
C. R. Rom

Roots of one year old grape cvs. Concord, White Riesling, Grenache and Semillon were frozen to 0, -5, -10, -15 and -20°C in a programmable freezer. The tops were protected from cold by insulating them. For survival test, 4 plants of each cv. were planted in the greenhouse and their growth observed. Differential thermal analysis (DTA), using a computer attached to a programmable freezer was performed on roots. To aid in the interpretation of DTA, triphenyltetrazolium chloride (TTC) was performed. Hardiness determinations were based on DTA, TTC and the survival tests. DTA patterns representing exothermic response showed an exotherm associated with extracellular free water in tissue which appeared at about the same temperature range for all cvs. This is not associated with hardiness. Additional minor exotherms related to hardiness appeared at lower temperatures than the extracellular water exotherm. Their location differed from one cv. to another. Based on these tests, Concord roots appear to be hardier than other cvs. with important but minor differences in the hardiness of other cvs.


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