Miniature Bomb Calorimeter for the Determination of Heats of Combustion of Samples of the Order of 50 mg Mass

1955 ◽  
Vol 26 (3) ◽  
pp. 280-284 ◽  
Author(s):  
William S. McEwan ◽  
Carl M. Anderson
Keyword(s):  
Bomb Calorimeter ◽  
Heats Of Combustion

Heats of Reaction of the System Rubber-Sulfur

1935 ◽  
Vol 8 (3) ◽  
pp. 456-469
Author(s):  
Archibald T. McPherson ◽  
Norman Bekkedahl
Keyword(s):  
Temperature Rise ◽  
Entire Range ◽  
Sulfur Compounds ◽  
The Other ◽  
Vulcanized Rubber ◽  
Heat Effects ◽  
Heats Of Reaction ◽  
Heats Of Combustion ◽  
Relative Measurements

Abstract PREVIOUS investigators have employed two methods for determining the heat effects when rubber is vulcanized. In one method the heats of vulcanization are found by subtracting the heats of combustion of vulcanized rubber—sulfur compounds from the heats of combustion of the corresponding mixtures of rubber and sulfur before vulcanization (1, 10, 11). This method is limited in precision by reason of the fact that the differences thus obtained are at most only a few per cent of the measured heath of combustion. The other method, which has been used previously, involves the determination of the temperature rise which occurs when mixtures of rubber and sulfur are vulcanized. This method has, for the most part, been used for relative measurements, but Blake (2) has recently employed it for quantitative determinations of the heats of reaction of rubber with proportions of sulfur up to about 8 per cent by weight. Recently Daynes (7) has employed a similar method for measurements over a wider range of composition. This investigation was undertaken for the purpose of measuring the heath of reaction of rubber with different percentages of sulfur over the entire range of composition in which combination takes place. The study was exploratory in character, the aim being to make the measurements by direct means with emphasis on simplicity rather than refinement of calorimetric procedure.

scholarly journals THERMODYNAMIC PROPERTIES OF ORGANIC ACIDS AND SOME THEIR DERIVATIVES

2019 ◽  
Vol 62 (11) ◽  
pp. 38-45
Author(s):  
Vitaly V. Ovchinnikov ◽  
Alexey A. Kulakov ◽  
Irina G. Grigor′eva ◽  
Svetlana A. Maltseva
Keyword(s):  
Experimental Data ◽  
Organic Acids ◽  
Gas Phase ◽  
Thermodynamic Functions ◽  
Bond Energies ◽  
Additional Material ◽  
Electron Pairs ◽  
Valence Electrons ◽  
Heats Of Combustion

The heats of vaporization, combustion, formation, entropy and the heat capacities in different phases of different carbonic acids and their derivatives: acetates, esters with fatty radicals, two-, three- and four-basic acids (52 compounds) were analysed in the framework of one-parametric mathematic equations. The experimental data of all chosen one-, two-, three- and four-basic acids were analyzed. It was determined, that all thermodynamic functions of these types of compounds depend on the number of valence electrons N, from which the sum of lone electron pairs g as represented in the equations Δvap,c,fH° = i ±  f (N-g) and S°(Cp) = i ±  f (N-g) is excluded. The coefficients f in the first equations is in the range of 104-113 kJ mol-1 electron-1, that corresponds to the same values f in the equations, which are mentioned in our earlier papers on the determination of the heats of combustion of organic acids. As concerned of coefficient i in the received equations, necessary to note that situation is not synonymous as with the coefficient f. The magnitudes of this coefficient are different in the equations of vaporization, combustion, formation also as in the equations of entropy and the heat of capacity. On the base of literary experimental data we calculated the 29 new equations, which can be used for the calculation of the same thermodynamic functions for other new organic acids and especially bioorganic substances with the useful properties. Necessary to add, that the received equations can serve as additional material for the calculation of the bond energies of fatty acids and their derivatives in gas phase.

Determination of Uncertainty in Gross Calorific Value of Coal Using Bomb Calorimeter

2011 ◽  
Vol 1 (4) ◽  
pp. 45-52 ◽  
Author(s):  
N.K. Mandavgade ◽  
S.B. Jaju ◽  
R.R. Lakhe
Keyword(s):  
Calorific Value ◽  
Volatile Matter ◽  
Individual Factors ◽  
Uncertainty Of Measurement ◽  
Manufacturing Companies ◽  
Maturity Level ◽  
Gross Calorific Value ◽  
Bomb Calorimeter

A bomb calorimeter is an apparatus used for measuring the performance of coal in term of heat of combustion. Recent awareness has been created regarding uncertainty of measurement, due to mainly two reasons. Laboratory accreditation, which has steadily been on the rise, which requires a estimation of uncertainty of measurement particularly in the field of calibration. Second, increased maturity level of the quality system certification as the manufacturing companies looking at the reliability of measurement through correct calibration of inspection, measuring and test equipment. The quality of coal is decided by the various parameters such as ash content, air dried moisture, volatile matter, gross calorific value and sulphur content etc. The grade of coal is decided by the quality of coal which decides the performance of generation of electricity. The uncertainty of measurement in bomb calorimeter gets affected by various parameters. This paper describes the methodology, uncertainty calculations and effects of individual factors on it.

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