Determination of the lower concentration limit for flame propagation in a unitary fuel gas suspension

1982 ◽  
Vol 18 (4) ◽  
pp. 430-435
Author(s):  
I. Kh. Rakhmatulina
Keyword(s):  
Flame Propagation ◽  
Concentration Limit ◽  
Gas Suspension ◽  
Fuel Gas ◽  
Lower Concentration Limit ◽  
Unitary Fuel

The effect of drop size on flame propagation in liquid aerosols

1954 ◽  
Vol 225 (1162) ◽  
pp. 375-392 ◽  
Keyword(s):  
Flame Propagation ◽  
Drop Size ◽  
Size Range ◽  
Concentration Limit ◽  
Practical Consequence ◽  
Lower Concentration Limit ◽  
Air Suspension ◽  
Combustion Properties ◽  
Nitrogen Dilution

A method has been developed whereby suspensions of controlled uniform drop size can be prepared from pure liquids. Using tetralin as the fuel, it has thus been possible, within limits, to study the effect of the drop size on the combustion properties of a liquid-in-air suspension. Through a study of limits of inflammability, nitrogen dilution limits and burning velocities, it has been shown that the mechanism of flame propagation is completely transformed within the drop-size range 7 to 55 μ . Below 10 μ the suspension behaves like a vapour, but above 40 μ the drops burn individually, in their own air envelope, and one burning drop ignites adjacent ones, thus spreading combustion. At intermediate sizes, behaviour is transitional. A practical consequence of this transformation is that the lower concentration limit of inflammability is reduced and the rate of burning increased for the larger drops.

Determination of Epsilon Aminocaproic Acid Based on Charge Transfer Complexation with p-Nitrophenlol by Spectrophotometry

2020 ◽  
Vol 16 ◽  
Author(s):  
Sheng-Yun Li ◽  
Fang Tian
Keyword(s):  
Charge Transfer ◽  
Aminocaproic Acid ◽  
Concentration Limit ◽  
Official Method ◽  
Good Precision ◽  
Pharmaceutical Dosage Forms ◽  
Relative Standard ◽  
A Charge ◽  
Epsilon Aminocaproic Acid

: A spectrophotometry was investigated for the determination of epsilon aminocaproic acid (EACA) with p-nitrophenol (PNP). The method was based on a charge transfer (CT) complexation of this drug as n-electron donor with π-acceptor PNP. Experiment indicated that the CT complexation was carried out at room temperature for 10 minutes in dimethyl sulfoxide solvent. The spectrum obtained for EACA/PNP system showed the maximum absorption band at wavelength of 425 nm. The stoichiometry of the CT complex was found to be 1:1 ratio by Job’s method between the donor and the acceptor. Different variables affecting the complexation were carefully studied and optimized. At the optimum reaction conditions, Beer’s law was obeyed in a concentration limit of 1～6 µg mL-1. The relative standard deviation was less than 2.9%. The apparent molar absoptivity was determined to be 1.86×104 L mol-1cm-1 at 425 nm. The CT complexation was also confirmed by both FTIR and 1H NMR measurements. The thermodynamic properties and reaction mechanism of the CT complexation have been discussed. The developed method could be applied successfully for the determination of the studied compound in its pharmaceutical dosage forms with a good precision and accuracy compared to official method as revealed by t- and F-tests.

scholarly journals Determination of total sulfur in fuel gas by Dimethylsulfonazo III method

1970 ◽  
Vol 19 (9) ◽  
pp. 1229-1233 ◽  
Author(s):  
Michiyo KASAHARA ◽  
Takeshi ITAHARA
Keyword(s):  
Total Sulfur ◽  
Fuel Gas

scholarly journals Label-Free and Sensitive Determination of Cadmium Ions Using a Ti-Modified Co3O4-Based Electrochemical Aptasensor

Biosensors ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 195
Author(s):  
Yang Liu ◽  
Dongwei Zhang ◽  
Jina Ding ◽  
Kashif Hayat ◽  
Xijia Yang ◽  
...  
Keyword(s):  
Environmental Protection Agency ◽  
Concentration Limit ◽  
Co3o4 Nanoparticles ◽  
Label Free ◽  
Current Signal ◽  
Electrochemical Aptasensor ◽  
Screen Printed Carbon Electrode ◽  
Sensitive Determination

The current work demonstrates an electrochemical aptasensor for sensitive determination of Cd2+ based on the Ti-modified Co3O4 nanoparticles. In this unlabeled system, Ti-modified Co3O4 nanoparticles act as current signal amplifiers modified on the screen-printed carbon electrode (SPCE) surface, while the derivative aptamer of Cd2+ works as a target recognizer. In addition, the sensing is based on the increase in electrochemical probe thionine current signal due to the binding of aptamer to Cd2+ via specific recognition. In the current study, key parameters, including aptamer concentration, pH, and incubation time were optimized, respectively, to ensure sensing performance. Cyclic voltammetry was used not only to characterize each preparation and optimization step, but also to profile the bindings of aptamer to Cd2+. Under optimal conditions, Cd2+ can be determined in a linear range of 0.20 to 15 ng/mL, with a detection limit of 0.49 ng/mL, significantly below the maximum concentration limit set by the U.S. Environmental Protection Agency. Based on comparative analysis and the results of recovery test with real samples, this simple, label-free but highly selective method has considerable potential and thus can be used as an in-situ environmental monitoring platform for Cd2+ testing.

Characteristic of Low Calorific Fuel Gas Combustion in Porous Burner by Preheating Air

2014 ◽  
Vol 624 ◽  
pp. 361-365 ◽  
Author(s):  
Min Hui Fan ◽  
Guan Qing Wang ◽  
Dan Luo ◽  
Ri Zan Li ◽  
Ning Ding ◽  
...  
Keyword(s):  
Co Oxidation ◽  
Flame Propagation ◽  
Reaction Rate ◽  
Combustion Characteristic ◽  
Gas Combustion ◽  
Fuel Gas ◽  
Flame Propagation Velocity ◽  
Co Oxidation Reaction ◽  
Porous Burner ◽  
Reaction Region

The combustion characteristic of low calorific fuel gas was numerically investigated in porous burner by preheating air. Two-dimensional temperature profile, flame propagation precess, and CO reaction rate were analyzed detailly by preheating air, and compared with that of room air. The results showed that when the air is preheated, the combustion flame location locates to upstream, the maximum combustion temperature is higher than that of room air, and flame propagation velocity decreases.The CO oxidation reaction rate increases gradually with the radius distance increaing, but reaction region decreases. CO oxidation region guradually decreases and locates to the upstream with air preheating temperature increasing. Peaks of CO oxidation rate gradually change from two to one.

scholarly journals Applications of Accurate Isentropic Exponent Determination for Fuel Gas Measurement

1995 ◽  
Author(s):  
David J. Pack ◽  
Terry J. Edwards ◽  
Derek Fawcett
Keyword(s):  
Natural Gas ◽  
Gas Flow ◽  
Precise Measurement ◽  
Gas Flows ◽  
Fuel Gas ◽  
Isentropic Exponent ◽  
Natural Gas Transmission ◽  
Gas Measurement ◽  
Cost Penalty

This paper discusses the determination and application of the isentropic exponent to the various thermodynamic processes found in a high pressure natural gas transmission system. Increasing demands for more precise measurement of natural gas, coupled with the need for greater efficiency and accountability of transportation and processing operations had led to our research and development efforts into the more precise measurement of gas flow, and the determination of gas thermodynamic properties including isentropic exponent. The isentropic exponent has many applications, some of which include: • the determination of the expansion factor ϵ, for calcuation of flow using an orifice or venturi type meter; • the volumetric efficiency in a reciprocating compressor; • the determination of the compression head for a centrigual compressor; • the engine power required for the set given conditions for gas compressor; • the calculation of discharge temperatures for compressors; and • the direct measurement of gas density. As can be appreciated, the application of an incorrect value for the isentropic exponent represents an error in the parameter determined. For large volume gas flows, this can translate into a significant cost penalty.

Sign in / Sign up

Export Citation Format

Share Document