scholarly journals IIR Spectra of Low-Metamorphosed Barzas Coal Subjected to Thermal Treatment in Carbon Dioxide Medium

2018 ◽  
Vol 41 ◽  
pp. 01037 ◽  
Author(s):  
Ivan Petrov ◽  
Boris Tryasunov ◽  
Konstantin Ushakov ◽  
Alexander Bogomolov
Keyword(s):  
Carbon Dioxide ◽  
Heat Treatment ◽  
Methylene Chloride ◽  
Total Content ◽  
Thermal Transformations ◽  
Alkyl Groups ◽  
Methylene Chloride Extract ◽  
Close Relationship ◽  
Liquid Products ◽  
Ir Spectroscopic

Using FTIR spectroscopy, elemental analysis and gas chromatography methods, the temperature effects on the thermal transformations of low-metamorphosed Barzas coal (sapromixite) in carbon dioxide media have been studied. According to the IR spectroscopic data, an increase in the relative content of alkyl groups (-CH3 and >CH2) in the solid residue of sapromixite with a rise in the process temperature up to ~ 475°C was observed, followed by a rapid decrease in their concentration at higher heat treatment temperatures. Such behavior may be associated with an initial accumulation of alkyl fragments, formedfrom the coal matter, and their subsequent transition into the gaseous phase. A close relationship (an antibate dependence) has been discovered between H/C atomic ratios in resin-containing solid products of thermally treated Barzas coal and the yields of gases formed during its pyrolysis. Chromatographic analysis of liquid products formed after Barzas coal heat treatment at 475°C showed that the main organic constituents of liquid phase (about 3-5% by weight) were phenol and its methyl-and dimethyl derivatives (their total content in methylene chloride extract was of > 77% by weight).

Gas Cell Infrared and Attenuated Total Reflection Infrared Spectroscopic Studies for Organic–Inorganic Interactions in Adsorption of Fulvic Acid on the Goethite Surface Generating Carbon Dioxide

2021 ◽  
pp. 000370282199121
Author(s):  
Yuki Nakaya ◽  
Satoru Nakashima ◽  
Takahiro Otsuka
Keyword(s):  
Carbon Dioxide ◽  
Activation Energy ◽  
Fulvic Acid ◽  
Spectroscopic Studies ◽  
Reaction Model ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Gas Cell ◽  
Rate Determining Step ◽  
Ir Spectroscopic

The generation of carbon dioxide (CO2) from Nordic fulvic acid (FA) solution in the presence of goethite (α-FeOOH) was observed in FA–goethite interaction experiments at 25–80 ℃. CO2 generation processes observed by gas cell infrared (IR) spectroscopy indicated two steps: the zeroth order slower CO2 generation from FA solution commonly occurring in the heating experiments of the FA in the presence and absence of goethite (activation energy: 16–19 kJ mol–1), and the first order faster CO2 generation from FA solution with goethite (activation energy: 14 kJ mol–1). This CO2 generation from FA is possibly related to redox reactions between FA and goethite. In situ attenuated total reflection infrared (ATR-IR) spectroscopic measurements indicated rapid increases with time in IR bands due to COOH and COO– of FA on the goethite surface. These are considered to be due to adsorption of FA on the goethite surface possibly driven by electrostatic attraction between the positively charged goethite surface and negatively charged deprotonated carboxylates (COO–) in FA. Changes in concentration of the FA adsorbed on the goethite surface were well reproduced by the second order reaction model giving an activation energy around 13 kJ mol–1. This process was faster than the CO2 generation and was not its rate-determining step. The CO2 generation from FA solution with goethite is faster than the experimental thermal decoloration of stable structures of Nordic FA in our previous report possibly due to partial degradations of redox-sensitive labile structures in FA.

Phytochemical investigation of the antisalmonellal effect of Cyperus sphacelatus Rottb. (Cyperaceae)

2021 ◽  
Vol 01 ◽  
Author(s):  
Napoleon A. Mfonku ◽  
Gabriel T. Kamsu ◽  
Norbert Kodjio ◽  
Jie Ren ◽  
James A. Mbah ◽  
...  
Keyword(s):  
Typhoid Fever ◽  
Antimicrobial Agents ◽  
Methylene Chloride ◽  
2D Nmr ◽  
Sub Saharan Africa ◽  
Resistant Isolate ◽  
Bacterial Strains ◽  
Phytochemical Investigation ◽  
Methylene Chloride Extract ◽  
Sub Saharan

Background: Typhoid fever is a major health burden in Sub-Saharan Africa. Conventional anti-typhoid drugs are becoming more and more unavailable to most patients in Africa due to the increased costs and emerging drug resistance. Therefore, there is a need for discovery of new antimicrobial agents to combat typhoid fever. Objective: This work aimed to investigate the bioactive components in Cyperus sphacelatus Rottb. (Cyperaceae) and test the antisalmonellal activity of the isolated compounds. Methods: Compound purification was done through column chromatography. Structure elucidation was accomplished based on the 1D and 2D NMR, IR and mass spectra. The biological assay was done using five bacterial strains, including Salmonella enterica subsp. enterica sérovars Typhi ATCC 6539 (STS), S. enterica subsp. enterica sérovars Typhi (ST), S. enteritidis (STE), S. enterica subsp. enterica sérovars Typhimurim (STM), and a resistant isolate of S. enterica subsp. enterica sérovars Typhi (ST566). Results: Three natural products were isolated from the methylene chloride extract of the rhizomes of C. sphacelatus, including a new furanoquinone, scabequinon-6(14)-ene (1) and two known compounds, cyperotundone (2) and vanillin (3). Compound 1 showed moderate antisalmonellal activity, with a minimal inhibitory concentration (MIC) of 32 µg/mL against STM and STS. The best inhibitory result was obtained with compound 2 on STM with a MIC of 8 µg/mL. Compound 2 also gave the best minimum bactericidal concentration (MBC) of 32 µg/mL on the STM strain. Conclusion: Discovery of the three antisalmonellal compounds from C. sphacelatus supports the addition of this plant to typhoid fever preparations.

Cardioprotective effects of methanol/methylene chloride extract of Vitex cienkowskii (Verbebaceae) in l-NAME induced hypertension in rats

2013 ◽  
Vol 5 (6) ◽  
pp. 519-526 ◽  
Author(s):  
Flaure M. Donfack Metchi ◽  
Edwige Nguemfo ◽  
Paulin Nana ◽  
Joel R. Temdié ◽  
Esther Ngo Lemba Tom ◽  
...  
Keyword(s):  
Methylene Chloride ◽  
Methylene Chloride Extract ◽  
Induced Hypertension ◽  
Cardioprotective Effects

THE DECOMPOSITION OF ETHYL ALCOHOL OVER SOME POLY-COMPONENT CATALYSTS

1934 ◽  
Vol 10 (6) ◽  
pp. 743-758 ◽  
Author(s):  
E. H. Boomer ◽  
H. E. Morris
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Ethyl Alcohol ◽  
Quantitative Data ◽  
Carbon Oxides ◽  
Liquid Products ◽  
Secondary Reactions ◽  
Water Gas ◽  
Alcohol Alcohol ◽  
Hydrogenation Of Ethylene

Numerous experiments have been carried out on the decomposition of alcohol, alcohol and water, and alcohol and carbon dioxide mixtures over poly-component catalysts at temperatures up to 500 °C. Quantitative data on the gaseous and the liquid products were obtained. The properties of the poly-component catalysts, as evidenced by the simple primary and secondary reactions, have been shown to be qualitatively those of the single components.Methane can be produced in one or more of several secondary reactions, namely, the decomposition of acetaldehyde, the hydrogenation of carbon oxides and the decomposition of ethylene. Ethane can be produced in one or both of two reactions consisting of auto-oxidation and reduction of the alcohol, or the secondary hydrogenation of ethylene, confirming previous work. Carbon dioxide, in most cases, is formed as a result of the water-gas reaction and the decomposition of carbon monoxide. In other cases its origin is obscure. The results of certain experiments in which carbon dioxide and hydrogen were the major constituents of the off-gas cannot be explained in the same way. Reactions involving ketene decomposition and polymerization, and hydration of alcohol, have been suggested as possible explanations.

scholarly journals Chemical Constituents of the Aerial Parts of Euphorbia Nematocypha

2016 ◽  
Vol 11 (2) ◽  
pp. 1934578X1601100 ◽  
Author(s):  
Chen Xu ◽  
Hai-Yang Jia ◽  
Bo Zuo ◽  
Zhi-Xin Liao ◽  
Lan-Ju Ji ◽  
...  
Keyword(s):  
Oleanolic Acid ◽  
Ellagic Acid ◽  
Betulinic Acid ◽  
Methylene Chloride ◽  
Chemical Constituents ◽  
2D Nmr ◽  
Cytotoxic Activities ◽  
Aerial Parts ◽  
Methylene Chloride Extract ◽  
Oleanane Triterpenoid

Chemical constituents of the dried aerial parts of Euphorbia nematocypha were investigated. A new oleanane triterpenoid, trans, trans-2′,4′-hexadienedioicacid-1′-β-amyrin ester (1), together with, β-amyrin (2), β-amyrin acetate (3), betulinic acid (4), ellagic acid (5), oleanolic acid (6), β-sitosterol (7), kaempferol (8), quercetin (9), lupeol (10) and pseudo-taraxasterol (11) were isolated from the methylene chloride extract. Their structures were elucidated on the basis of extensive spectroscopic (1D- & 2D-NMR) and ESI-MS analysis and comparison with data reported in the literature. The new isolated triterpenoid showed moderate cytotoxic activities against HeLa and MCF-7cell lines.

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