scholarly journals Люминесцентные свойства разнолигандных beta-дикетонатов неодима, полученных в среде сверхкритического диоксида углерода в полимерных матрицах различной природы

2020 ◽  
Vol 129 (7) ◽  
pp. 869
Author(s):  
В.С. Каплин ◽  
А.С. Копылов ◽  
Т.С. Зархина ◽  
П.С. Тимашев ◽  
А.Б. Соловьева
Keyword(s):  
Carbon Dioxide ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Polymer Matrix ◽  
Supercritical Co2 ◽  
Binary Systems ◽  
Ternary Systems ◽  
Mixed Ligand ◽  
Luminescence Spectra

Multi-ligand phosphor complexes of neodymium acetylacetonate with phenanthroline are synthesized in polymer matrices (oligourethane methacrylate, fluoroplast, polycarbonate) in supercritical carbon dioxide medium. At the same time the role of one of the ligands in such complexes is played by fragments of the polymer matrix. The luminescence spectra of the obtained ternary systems are described. It was shown that the position of the luminescence maxima is bathochromically shifted relative to the binary systems Nd(Acac)3/polymer obtained in a similar way and the magnitude of the shift depends on the nature of the polymer matrix. It was shown that upon the introduction of these components into polymers from a solution, similar phosphor mixed-ligand neodymium complexes do not form. The formation of new structures Nd(Acac)3/Phen/polymer upon impregnation of oligourethane methacrylate with neodymium β-diketonate and phenanthroline in a supercritical CO2 medium was confirmed by the method of differential thermal analysis. The same method confirmed that with the introduction of these components from the solution of the above systems do not form.

Kinetics of temperature-programmed reactivation of a hydrodesulphurization catalyst

1983 ◽  
Vol 48 (12) ◽  
pp. 3340-3355 ◽  
Author(s):  
Pavel Fott ◽  
Pavel Šebesta
Keyword(s):  
Carbon Dioxide ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Thin Layer ◽  
Kinetic Parameters ◽  
Diffusion Region ◽  
Reaction Heat ◽  
Gaseous Products ◽  
Temperature Programmed ◽  
Kinetics Of

The kinetic parameters of reactivation of a carbonized hydrodesulphurization (HDS) catalyst by air were evaluated from combined thermogravimetric (TG) and differential thermal analysis (DTA) data. In addition, the gaseous products leaving a temperature-programmed reactor with a thin layer of catalyst were analyzed chromatographically. Two exothermic processes were found to take part in the reactivation, and their kinetics were described by 1st order equations. In the first process (180-400 °C), sulphur in Co and Mo sulphides is oxidized to sulphur dioxide; in the second process (300-540 °C), in which the essential portion of heat is produced, the deposited carbon is oxidized to give predominantly carbon dioxide. If the reaction heat is not removed efficiently enough, ignition of the catalyst takes place, which is associated with a transition to the diffusion region. The application of the obtained kinetic parameters to modelling a temperature-programmed reactivation is illustrated on the case of a single particle.

Phase Diagrams of Mesogenic Binary Systems of Cobalt(II) and Univalent Metal Octanoates

2011 ◽  
Vol 66 (10-11) ◽  
pp. 661-667 ◽  
Author(s):  
Inna I. Tokmenko ◽  
Tatyana A. Mirnaya ◽  
Galina G. Yaremchuk
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Liquid Crystals ◽  
Phase Diagrams ◽  
Liquid Crystalline ◽  
Binary Systems ◽  
Polarization Microscopy ◽  
Sodium Potassium

The phase diagrams of binary systems of cobalt(II) octanoate and lithium, sodium, potassium, and thallium(I) octanoates have been studied by differential thermal analysis and polythermal polarization microscopy. In all systems, continuous or limited liquid crystalline solutions of smectic modification are formed. The temperature and composition ranges of the formation of liquid crystals and glasses have been determined.

Dielectric-differential thermal analysis IV the role of water

1987 ◽  
Vol 32 (4) ◽  
pp. 1271-1276 ◽  
Author(s):  
M. Carreras ◽  
R. Roque-Malherbe ◽  
C. de las Pozas
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis

Liquid Crystals in Binary Systems of Lead Decanoate with Zinc or Cadmium Decanoate

2000 ◽  
Vol 55 (11-12) ◽  
pp. 899-901
Author(s):  
Mirnaya T. A. ◽  
L. S. Sudovtsova ◽  
G. G. Yaremchuk
Keyword(s):  
Phase Transition ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Room Temperature ◽  
Binary Systems ◽  
Crystal Formation ◽  
Liquid Region ◽  
Polarization Microscopy ◽  
Isotropic Liquid ◽  
Phase Transition Temperatures

Abstract The phase transition temperatures were determined by differential thermal analysis and hot stage polarization microscopy between room temperature and the isotropic liquid region for the binary systems of lead (II) decanoate with zinc (II) or cadmium (II) decanoate. The boundaries of the liquid crystal formation in these systems were found.

scholarly journals Contamination Studies on Mollusk Shell Samples

Radiocarbon ◽  
1985 ◽  
Vol 27 (1) ◽  
pp. 33-42 ◽  
Author(s):  
Tomasz Goslar ◽  
Mieczysław F Pazdur
Keyword(s):  
Carbon Dioxide ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Solid State ◽  
Carbon Exchange ◽  
Laboratory Contamination ◽  
Mollusk Shell

A series of shell samples has been studied to determine the magnitude and mechanisms of carbon exchange between shells and their environment. Laboratory contamination experiments included the storing of shell samples in acid and calcareous environments of different 14C concentrations as well as studies of carbon exchange in the course of thermal recrystallization in solid state in an atomosphere of carbon dioxide. The applicability of differential thermal analysis to studies of the structure and texture of shells is discussed.

scholarly journals DTA/TG analysis of mechanochemicaly activated sodium carbonate

2021 ◽  
pp. 47-55
Author(s):  
Nataša Đorđević ◽  
Slavica Mihajlović ◽  
Gvozden Jovanović ◽  
Branislav Marković
Keyword(s):  
Carbon Dioxide ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Relaxation Time ◽  
Environmental Protection ◽  
Sodium Carbonate ◽  
Room Temperature ◽  
Tg Analysis ◽  
Relaxation Period ◽  
Sorption Characteristics

Sodium carbonate is a material that is very good sorbent of carbon dioxide from the atmosphere, and it is a reason of it is increasing importance in environmental protection. In order to improve it is sorption characteristics, activation of Na2CO3 was performed by mechanochemical procedure and monitoring of changes during the relaxation time. This research is based on differential thermal analysis with thermogravimetry, in order to determine the changes that occurred on the activated samples during the relaxation period under controlled conditions. Sodium carbonate was activated for 2 and 7 minutes in a vibro mill, and then the activated samples were deposited in at room temperature and atmosphere of carbon dioxide at a humidity of 95% for 96h.

Point Defects, Dislocations in GaAs and Material Homogeneity

1987 ◽  
Vol 104 ◽  
Author(s):  
J. C. Bourgoin ◽  
H. J. von Bardeleben ◽  
H. Lin ◽  
D. Stievenard
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Positron Annihilation ◽  
Point Defects ◽  
Bulk Gaas ◽  
Material Homogeneity

ABSTRACTCombined positron annihilation and differential thermal analysis have shown that, in bulk GaAs materials, dislocations are decorated with vacancy related defects which recombine with As interstitials originating from As clusters. The role of these dislocations, the role of As source of these clusters are described and the consequences on the material homogeneity discussed.

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