Quantum Chemical Application in Inhibitor Suppressed the Spontaneous Combustion of Coal

2012 ◽  
Vol 524-527 ◽  
pp. 658-661
Author(s):  
Feng Wei Dai
Keyword(s):  
Quantum Chemical ◽  
Spontaneous Combustion ◽  
The Other ◽  
Coal Spontaneous Combustion ◽  
Chemical Application ◽  
Form Complex ◽  
Spontaneous Combustion Of Coal ◽  
The Stability ◽  
The One ◽  
Complex Increase

Coal spontaneous combustion needs to have enough oxygen and heat, on the one hand, water salts inhibitor can isolate from coal exposure to air; on the other hand, water salts inhibitor interact with active groups in coal to form complex, increase the stability of coal and boost the heat of spontaneous combustion of coal. This paper has made use of quantum chemical calculation’s software Gaussian 03 to calculate the complex what coal’s active groups and Ca2+ inhibitor interacted to form, and research the mechanism for inhibitor suppressed the spontaneous combustion of coal.

MODELING THE ROLE OF DISSOLVED OXYGEN-DEPENDENT BACTERIA ON BIODEGRADATION OF ORGANIC POLLUTANTS

2014 ◽  
Vol 07 (01) ◽  
pp. 1450008 ◽  
Author(s):  
J. B. SHUKLA ◽  
ASHISH GOYAL ◽  
P. K. TIWARI ◽  
A. K. MISRA
Keyword(s):  
Dissolved Oxygen ◽  
Water Body ◽  
Logistic Model ◽  
Simulation Analysis ◽  
Organic Pollutant ◽  
The Other ◽  
Nonlinear Mathematical Model ◽  
The Stability ◽  
The One

In this paper, a nonlinear mathematical model is proposed and analyzed to study the role of dissolved oxygen (DO)-dependent bacteria on biodegradation of one or two organic pollutant(s) in a water body. In the case of two organic pollutant(s), it is assumed that the one is fast degrading and the other is slow degrading and both are discharged into the water body from outside with constant rates. The density of bacteria is assumed to follow logistic model and its growth increases due to biodegradation of one or two organic pollutant(s) as well as with the increase in the concentration of DO. The model is analyzed using the stability theory of differential equations and by simulation. The model analysis shows that the concentration(s) of one or both organic pollutant(s) decrease(s) as the density of bacteria increases. It is noted that for very large density of bacteria, the organic pollutant(s) may be removed almost completely from the water body. It is found that simulation analysis confirms the analytical results. The results obtained in this paper are in line with the experimental observations published in literature.

scholarly journals Influence of Air Supply on Coal Spontaneous Combustion During Support Withdrawal in Fully Mechanized Coal Mining and its Prevention

2021 ◽  
Author(s):  
Xiaowen Zhang ◽  
Xihua Zhou ◽  
Gang Bai ◽  
Cheng Wang
Keyword(s):  
Spontaneous Combustion ◽  
Characteristic Temperature ◽  
Effect Of Temperature ◽  
Withdrawal Period ◽  
Coal Spontaneous Combustion ◽  
Hydrocarbon Gases ◽  
Working Face ◽  
Air Supply ◽  
Spontaneous Combustion Of Coal ◽  
Temperature Programmed

Abstract It is important to study the oxidation characteristics of coal samples under different air supply rates to prevent spontaneous combustion of coal, particularly when the air supply rate at the working face needs to be changed during support withdrawal. In this work a self-designed temperature-programmed experimental device was used to study the change laws of various index gases released during the spontaneous combustion of coal under various air supply conditions. The study focused on the analysis of the low-temperature (30–200 ℃) oxidation stage, the increase in air supply, and the concentration change process of four hydrocarbon gases (C2H6, C3H8, C2H4, and C2H2) generated by the coal sample. The change law of the CO generation rate under the combined effect of temperature and air supply was analyzed, and surface fitting was performed to determine the characteristics of phased changes. Based on the working face parameters of the Yangchangwan Coal Mine, this study predicted the CO concentration at the upper corner of the working face at the characteristic temperature of coal spontaneous combustion during the withdrawal period. The paper summarizes comprehensive safety measures that can help prevent spontaneous combustion during the withdrawal period.

THE INSTABILITY OF OPEN PARETO EFFICIENT ECONOMIES

2020 ◽  
pp. 1-36
Author(s):  
Antoine Le Riche
Keyword(s):  
Free Trade ◽  
The Other ◽  
Investment Good ◽  
Consumption Good ◽  
Elasticity Of Intertemporal Substitution ◽  
Equilibrium Indeterminacy ◽  
The Stability ◽  
The One ◽  
The Impact ◽  
Capital Intensive

This paper analyzes the impact of trade on the stability properties of trading countries and on stationary welfare. We consider a two-country two-good two-factor overlapping generations model where countries differ in terms of their technology. In the autarky equilibrium and the free-trade equilibrium, indeterminacy relies, under dynamic efficiency, on a capital intensive consumption good and intermediate values of the elasticity of intertemporal substitution in consumption. Opening the borders to trade can be a source of a global destabilizing effect. Indeed, considering a free-trade equilibrium in which one country is an exporter of the consumption good and the other country is an exporter of the investment good, indeterminacy can occur with trade even though the two countries are determinate in autarky. Finally, opening to trade increases the stationary welfare of the country that exports the investment good and deteriorates the one of the other country.

scholarly journals THE ACTION OF ALKALIES ON PEPTIDES AND ON KETOPIPERAZINES

1925 ◽  
Vol 8 (2) ◽  
pp. 183-188 ◽  
Author(s):  
P. A. Levene ◽  
M. H. Pfaltz
Keyword(s):  
The Other ◽  
The Stability ◽  
The One

1. The tripeptide glycyl-levo-alanyl-glycine in solution of either one or ten equivalents of alkali does not undergo racemization on standing. 2. The dipeptide levo-alanyl-glycine under the conditions given in (1) does not undergo racemization. 3. In ketopiperazines, levo-alanyl-glycine anhydride and in levo-prolyl-glycine anhydride under the influence of dilute alkalies, racemization takes place. 4. Racemization in the present experiments was never complete. The degree of racemization seems to depend, on the one hand, on the stability of the ketopiperazine ring; on the other, on the concentration of the alkali. 5. The significance of these observations will depend on the outcome of the work on a larger number of polypeptides and ketopiperazines. The work is now in progress in this laboratory.

scholarly journals Overview of Research and use of Indicator Gases of Coal Spontaneous Combustion in China / Přehled Výzkumu a Využití Indikačních Plynů Samovznícení Uhlí V Číně

2014 ◽  
Vol 60 (1) ◽  
pp. 55-65 ◽  
Author(s):  
Xiyang Feng ◽  
Alois Adamus
Keyword(s):  
Spontaneous Combustion ◽  
Experimental Methods ◽  
Paper Briefly ◽  
Coal Spontaneous Combustion ◽  
Laboratory Equipment ◽  
Significant Development ◽  
The Sixties ◽  
Mine Fires ◽  
Spontaneous Combustion Of Coal ◽  
Program Characteristics

Abstract The beginnings of research and use of results in the area of indicator gas application for early detection of spontaneous combustion of coal in China comes from the sixties of the last century. The significant development occurred in the nineties, when the program “Characteristics of the adsorption of coal oxygen and its application in the prevention of mine fires” had been completed. The paper briefly describes an overview of the historical development, achievements, experimental methods, laboratory equipment, legislation, and the outlook for the use of indicator gases of coal spontaneous combustion in China

Electrochemical reduction of 2,2'-dinitrodiphenylmethane and 2,2'-dinitrobenzophenone at mercury electrodes

1983 ◽  
Vol 48 (2) ◽  
pp. 364-378 ◽  
Author(s):  
Rolf Voigtländer ◽  
Jaromír Hlavatý ◽  
Jiří Volke ◽  
Viktor Bakos
Keyword(s):  
Nitro Group ◽  
Supporting Electrolyte ◽  
Standard Addition ◽  
The Other ◽  
Anodic Wave ◽  
Mercury Electrodes ◽  
Electron Reduction ◽  
The Stability ◽  
The One

The last two compounds in a 5-membered series of aromatic dinitro compounds are reduced in a completely different manner at mercury electrodes. 2,2'-Dinitrodiphenylmethane (I) - in which a conjugation of both symmetrical moieties is ruled out - is electrolytically reduced in an eight-electron step to a bishydroxylamine this being most stable between pH 4.5 and 5.0. In processing the catholyte increase in concentration of this product leads to its intermolecular disproportionation, resulting in the formation of dibenzo[b, e]-1,2-diazepine 5-oxide (IV) and 2,2'-diaminodiphenylmethane (III). 2,2'-Dinitrobenzophenone (II) reduces at more positive potentials. Its preparative electrolysis in acetonitrile (with 0.1M-N(n-C4H9)4PF6 as supporting electrolyte) the application of which was made necessary by the low solubility of II in ethanol, proceeding in an anomalous way. In the most positive cathodic wave a radical anion results, the following cathodic wave corresponds to a 6-electron reduction of the one nitro group to an amino group while the other nitro group splits off as the anion NO-2 (this later giving an anodic wave). Its formation has been proved by standard addition in polarography and by a qualitative analytical test. The product which results through this electrode process and a follow-up chemical reaction is acridone. This in turn, reduces in the third, most negative 4-electron wave to dihydroacridine. The comparison of all substances studied in this series reveals that their reducibility decreases with respect to the link X, viz. in the sequence CO > O > S and CH2 > NH. The electrolytical reduction on mercury cathodes occurs in a similar manner with analogues where X = O, S or CH2. Here, the main intermediate is the bis-hydroxylamine the stability of which predetermines the structure of final products. The other group comprises the substances with X = CO and NH. Here the main intermediate is the 2-nitro-2'-amino-diphenyl-X which is formed in a 6-electron process taking place at one of the nitro groups. The follow-up cyclization reaction leading to seven-membered heterocyclic rings located between two benzene nuclei only occurs with analogues of the type X = CH2, O and S. A partial reduction of dinitro compounds of this series has been observed with the analogue containing the NH link although that with X = CO has generally good preconditions for this mechanism.

The Comprehensive Fire-Fighting Technology Research of the Section Retracement in Fully Mechanized Workface

2013 ◽  
Vol 709 ◽  
pp. 305-308
Author(s):  
Qun Niu ◽  
Lin Chao Dai ◽  
Fu Dao Liu ◽  
Yu Qiang Guo
Keyword(s):  
Spontaneous Combustion ◽  
Slip Casting ◽  
Mining Industry ◽  
Comprehensive Treatment ◽  
Technology Research ◽  
Coal Spontaneous Combustion ◽  
Nitrogen Injection ◽  
Safe Production ◽  
Spontaneous Combustion Of Coal ◽  
Forecast Technique

Spontaneous combustion of coal is one of the most serious coal mine disasters, which threat the workers' life safety. The paper introduce the comprehensive measures, such as monitor, positive draft technology, nitrogen injection, slip casting, fire preventing and extinguishing under seal, and other relevant coal spontaneous combustion forecast technique used in 1901s fully mechanized workface of FuCheng mining industry, when it has not been mined or its work face has not been removed, which realize the comprehensive treatment of coal spontaneous combustion, guarantee the safe production, and serves as a certain guidance and reference to the efficiency mining of spontaneous combustion coal seam.

scholarly journals Researches in physical astronomy

1837 ◽  
Vol 3 ◽  
pp. 128-129
Keyword(s):  
Differential Equations ◽  
The Other ◽  
Disturbing Function ◽  
Direct Integration ◽  
Planetary Theory ◽  
The Moon ◽  
Disturbing Force ◽  
Other Hand ◽  
The Stability ◽  
The One

The present paper contains some further developments of the theory of the moon, which are given at length, in order to save the trouble of the calculator, and to avoid the danger of mistake. The author remarks, that while it seems desirable, on the one hand, to introduce into the science of physical astronomy a greater degree of uniformity, by bringing to perfection a theory of the moon founded on the integration of the equations employed in the planetary theory, it is also no less important, on the other hand, to complete, in the latter, the method hitherto applied solely to the periodic inequalities. Hi­therto those terms in the disturbing function which give rise to the secular inequalities, have been detached, and the stability of the system has been inferred by means of the integration of certain equations, which are linear when the higher powers of the eccentri­cities are neglected and from considerations founded on the varia­tion of the elliptic constants. But the author thinks that the stability of the system may be inferred also from the expressions which result at once from the direct integration of the differential equations. The theory, he states, may be extended, without any analytical difficulty, to any power of the disturbing force, or of the eccentricities, ad­mitting the convergence of the series; nor does it seem to be limited by the circumstance of the planet’s moving in the same direction.

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