scholarly journals THERMAL ANALYSIS OF STILBITE, WITH SPECIAL REFERENCE TO AN EXOTHERMIC REACTION AROUND 500°C

1973 ◽  
Vol 68 (11) ◽  
pp. 341-345
Author(s):  
RYOHEI OTSUKA ◽  
SADAO TSUTSUMI ◽  
TAKABUMI SAKAMOTO ◽  
KUMIKO KANDA
Keyword(s):  
Thermal Analysis ◽  
Special Reference ◽  
Exothermic Reaction

Thermal Analysis of the Exothermic Reaction between Galvanic Porous Silicon and Sodium Perchlorate

2010 ◽  
Vol 2 (11) ◽  
pp. 2998-3003 ◽  
Author(s):  
Collin R. Becker ◽  
Luke J. Currano ◽  
Wayne A. Churaman ◽  
Conrad R. Stoldt
Keyword(s):  
Thermal Analysis ◽  
Porous Silicon ◽  
Exothermic Reaction ◽  
Sodium Perchlorate

Identification of Elastomers in Tire Sections by Total Thermal Analysis. III. White Sidewall Compounds of Neoprene Rubber Blends

1975 ◽  
Vol 48 (4) ◽  
pp. 640-652 ◽  
Author(s):  
A. K. Sircar ◽  
T. G. Lamond
Keyword(s):  
Thermal Analysis ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Exothermic Reaction ◽  
Crosslinking Reaction ◽  
Rubber Blends ◽  
Tg And Dtg ◽  
Dsc Curves ◽  
Residual Weight

Abstract DSC curves of sulfur-cured CR differ from peroxide-cured vulcanizates in the shape of the exotherm and the peak temperatures. The exothermic reaction, attributed to dehydrochlorination and subsequent crosslinking, is accelerated by sulfur. TG and DTG curves support this contention. In blends with NR, BR, or SBR, the second polymer intervenes in the crosslinking reaction, resulting in a lower residual weight for the CR network. White sidewall compounds of NR/CR or NR/CR/CSM can be identified by their DSC peaks in nitrogen, glass transition temperature, and DTG peaks. DSC and thermogravimetric curves supplement each other in the identification of these elastomers.

A DTA Study on HVOF Thermally Sprayed WC–M Coatings

2007 ◽  
Vol 566 ◽  
pp. 155-160
Author(s):  
M. Heydarzadeh Sohi ◽  
Shahin Khameneh Asl ◽  
Kazuyuki Hokamoto ◽  
M. Rezvani
Keyword(s):  
Heat Treatment ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
High Temperature ◽  
Amorphous Phase ◽  
Exothermic Reaction ◽  
Intermetallic Phase ◽  
Chemical Compositions ◽  
Crystalline Phases ◽  
Sprayed Coatings

Five types of tungsten carbide based powders with different chemical compositions (WC-12Co, WC-17Co, WC-10Ni, WC-10Co-4Cr and WC- 20Cr-7Ni) were deposited onto ST37 mild steel substrate using high velocity oxy fuel (HVOF) spray technique. The feedstock powders and sprayed coatings were studied by using X-ray diffraction (XRD), and differential thermal analyzing (DTA). The results were shown during HVOF thermal spraying, WC-M powders become partially melted before being sprayed on the surface of the substrate with supersonic speed. In these types of coatings, the crystallographic structures are normally non equilibrium, because the cooling rates of the deposited splats are very high due to the cold substrate acting as a thermal sink. These partially melted powders are then rapidly solidified to an amorphous phase. XRD analysis showed that the amorphous phase was existed in all of the as sprayed coatings. The amorphous phase in WC-12Co, WC-17Co and WC-10Ni coatings was transformed to crystalline phases by heat treatment at high temperature. Heat treatment of these coatings at high temperature also resulted in partially dissolution of WC particles and formation of new crystalline phases. In cobalt base coatings, the new phases were eta carbide phases like Co6W6C and Co3W3C but in WC-10Ni coating a NiW intermetallic phase was formed. Heat treatment of WC-10Co-4Cr and WC-20Cr-7Ni coatings did not change the amorphous phases in these coatings. Differential thermal analysis of cobalt containing coatings revealed an exothermic reaction at approximately 880°C. This exothermic reaction may be related to the transformation of the amorphous phase to eta phases. On the contrary, DTA analysis of feedstock powders of these coatings showed an endothermic reaction at approximately 1000°C. DTA analyses of nickel containing cermets also showed similar results. Differential thermal analysis of chromium containing cermets did not show any noticeable exothermic or endothermic reactions.

Studies of the Hard Rubber Reaction. I. Heat of Reaction

1963 ◽  
Vol 36 (4) ◽  
pp. 1059-1070 ◽  
Author(s):  
M. L. Bhaumik ◽  
D. Banerjee ◽  
Anil K. Sircar
Keyword(s):  
Thermal Analysis ◽  
Hydrogen Sulfide ◽  
Differential Thermal Analysis ◽  
Exothermic Reaction ◽  
Heat Evolution ◽  
Linear Increase ◽  
Heat Of Reaction ◽  
Dehydrogenation Reaction ◽  
Rate Of Reaction

Abstract A method for the determination of the heat of the hard-rubber reaction by the application of differential thermal analysis is reported. The heat of reaction was determined with stocks containing different rubber/sulfur ratios and also with a 68/32 stock, preheated to contain different amounts of combined sulfur. Heat evolution is observed first with samples containing about 7 per cent sulfur and therefrom the amount of heat evolved shows a nearly linear increase up to 30 per cent sulfur. With increasing combined sulfur in the 68/32 stock, the quantity of exothermic heat gradually diminishes; so also does the temperature of initiation, i.e., the temperature at which heat evolution appears to begin. Initiation of the exothermic reaction appears to be a function of composition and temperature of the mass. An increase in the rate of reaction was observed when the composition reached 0.5 g-atom of sulfur per isoprene unit. An endothermic dehydrogenation reaction is observed at the end of the hard-rubber reaction. This, however, does not affect the determination of exothermic heat, because there is similar dehydrogenation taking place in the reference material (ebonite) which almost balances this heat loss. The final product has a lower sulfur content due to loss of sulfur as hydrogen sulfide.

scholarly journals Thermal analysis of physical and chemical changes occuring during regeneration of activated carbon

2017 ◽  
Vol 21 (2) ◽  
pp. 1067-1081 ◽  
Author(s):  
Dejan Radic ◽  
Miroslav Stanojevic ◽  
Marko Obradovic ◽  
Aleksandar Jovovic
Keyword(s):  
Thermal Analysis ◽  
Activated Carbon ◽  
High Temperature ◽  
Thermogravimetric Analysis ◽  
Exothermic Reaction ◽  
Drinking Water Treatment ◽  
Mass Change ◽  
Intense Mass ◽  
Loss Of Mass ◽  
Physical And Chemical

High-temperature thermal process is a commercial way of regeneration of spent granular activated carbon. The paper presents results of thermal analysis conducted in order to examine high-temperature regeneration of spent activated carbon, produced from coconut shells, previously used in drinking water treatment. Results of performed thermogravimetric analysis, derivative thermogravimetric analysis, and differential thermal analysis, enabled a number of hypotheses to be made about different phases of activated carbon regeneration, values of characteristic parameters during particular process phases, as well as catalytic impact of inorganic materials on development of regeneration process. Samples of activated carbon were heated up to 1000?C in thermogravimetric analyser while maintaining adequate oxidizing or reducing conditions. Based on diagrams of thermal analysis for samples of spent activated carbon, temperature intervals of the first intense mass change phase (180-215?C), maximum of exothermic processes (400-450?C), beginning of the second intense mass change phase (635-700?C), and maximum endothermic processes (800-815?C) were deter-mined. Analysing and comparing the diagrams of thermal analysis for new, previously regenerated and spent activated carbon, hypothesis about physical and chemical transformations of organic and inorganic adsorbate in spent activated carbon are given. Transformation of an organic adsorbate in the pores of activated carbon, results in loss of mass and an exothermic reaction with oxygen in the vapour phase. The reactions of inorganic adsorbate also result the loss of mass of activated carbon during its heating and endothermic reactions of their degradation at high temperatures.

scholarly journals Dehydroxylation of Minerals of Gadisunkapur Area with Special Reference to FTIR and Thermal Study

2020 ◽  
Vol 11 (1) ◽  
pp. 72-76
Author(s):  
Marularadhya C. Hiremath ◽  
A. Sreenivasa
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
High Temperature ◽  
Thermogravimetric Analysis ◽  
Special Reference ◽  
Thermal Studies ◽  
Thermal Study ◽  
Granitic Rocks ◽  
Schist Belt ◽  
Chlorite Schist

This paper attempts to explain the presence of OH group for micas along with some sulfate, chlorite, quartz and feldspar minerals. These minerals are found to be associated with barite vein, metasediments (quartz-chlorite schist), metarhyolite and varieties of granitic rocks of Gadisunkapur area of Hungund-Kushtagi Schist belt. The samples were collected in and around Gadisunkapur village of Bagalkote district, Karnataka and further processed to determine OH group anion in different minerals present based on FTIR and Thermal studies such as Thermogravimetric analysis (TGA) and Differential Thermal analysis (DTA). The high temperature dehydroxylation is investigated using this analysis. Furthermore, present study indicates the presence of different extra species (CO2, CO32- and OH-). The results show the incorporation of CO2 into the structures due to heating or enhanced by the dehydroxylation process.

Derivatographic Thermal Analysis of Renal Tract Calculi

1969 ◽  
Vol 15 (4) ◽  
pp. 307-311 ◽  
Author(s):  
B Strates ◽  
C Georgacopoulou
Keyword(s):  
Thermal Analysis ◽  
Special Reference ◽  
Main Constituent

Abstract Attention is drawn to the possibility of using the technic of thermal derivatography for structure and main constituent analysis of biologic concretions, with special reference to renal tract calculi.

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