A simple, biogenetically modeled synthesis of 4-(methylthio)butyl thiocyanate: the reaction of thiocyanate anion with S-methyl-(1,n)-epithionium ions

1986 ◽  
Vol 64 (5) ◽  
pp. 940-942 ◽  
Author(s):  
M. H. Benn ◽  
Vinod K. Singh
Keyword(s):  
Natural Occurrence ◽  
Thiocyanate Ion ◽  
Thiocyanate Anion

The reaction of S-methylthiolanium fluorosulphate with thiocyanate ion gives predominantly 4-(methylthio)butyl thiocyanate, a result which is in accord with a hypothesis for the biogenesis of this compound, and which has implications for the natural occurrence of analogous thiocyanates.

The growth of mica polytypes as studied by conventional and high-resolution TEM

1983 ◽  
Vol 41 ◽  
pp. 174-177
Author(s):  
A. Baronnet ◽  
M. Amouric
Keyword(s):  
Water Pressure ◽  
Point Of View ◽  
Temperature Fields ◽  
Natural Occurrence ◽  
Growth Mechanisms ◽  
Long Period ◽  
High Resolution Tem ◽  
Layer Stacking ◽  
Experimental Works ◽  
Potential Use

The origin of mica polytypes has long been a challenging problem for crystal- lographers, mineralogists and petrologists. From the petrological point of view, interest in this field arose from the potential use of layer stacking data to furnish further informations about equilibrium and/or kinetic conditions prevailing during the crystallization of the widespread mica-bearing rocks. From the compilation of previous experimental works dealing with the occurrence domains of the various mica "polymorphs" (1Mr, 1M, 2M1, 2M2 and 3T) within water-pressure vs temperature fields, it became clear that most of these modifications should be considered as metastable for a fixed mica species. Furthermore, the natural occurrence of long-period (or complex) polytypes could not be accounted for by phase considerations. This highlighted the need of a more detailed kinetic approach of the problem and, in particular, of the role growth mechanisms of basal faces could play in this crystallographic phenomenon.

Determination of natural radionuclides in waste generated in the potable water treatment plants of the Zona da Mata of the state of Pernambuco- Brazil

2019 ◽  
Vol 7 (2A) ◽  
Author(s):  
Adriana Muniz De Almeida Albuquerque
Keyword(s):  
Water Treatment ◽  
Potable Water ◽  
Natural Radionuclides ◽  
The United States ◽  
Radioactive Material ◽  
Human Consumption ◽  
Radiological Protection ◽  
Natural Occurrence ◽  
Water Treatment Plants ◽  
Potable Water Treatment

The water purification procedure aims to obtain a product appropriate for human consumption, minimizing the presence of contaminants and toxic substances present in the water. Among these contaminants, some radionuclides of natural origin, such as uranium, thorium and their descendants, have been identified. Studies have shown that the stages of purification are quite effective in removing the radionuclides contained in water. The removal is due to co-precipitation of the radionuclides with the suspended materials and the precipitated material is accumulated and characterized as a Technologically Concentrated Natural Occurrence Radioactive Material (TENORM) by the United States Environmental Protection Agency (USEPA). This residue can present significant levels of radioactivity and, when discarded in the environment without any treatment, can generate a problem of environmental impact and a risk to the health of the population. In this way, some gamma emitters of the series of U, Th and the K-40 were determined in the residues generated at the Potable Water Treatment Plants – PWTPs in six municipalities of Pernambuco. The results obtain corroborate the classification of the residues generated in the PWTPs as concentrators of the radioactive components contained in the water supplied to the system and reinforce the need for the release to the environment, which is the usual way of disposal of this waste, to be carried out only after considering the radiological protection standards established.

First record of the natural occurrence of pentaploid loach, Misgurnus anguillicaudatus in Hubei Province, China

2013 ◽  
Vol 62 (1) ◽  
pp. 14-18 ◽  
Author(s):  
Lei Cui ◽  
Khalid Abbas ◽  
Yongyao Yu ◽  
Weimin Wang ◽  
Li Zhou ◽  
...  
Keyword(s):  
First Record ◽  
Hubei Province ◽  
Natural Occurrence ◽  
Misgurnus Anguillicaudatus

Aminocoumarins: A Privileged Precursor for the Synthesis of Fused Heterocycles

2019 ◽  
Vol 23 (9) ◽  
pp. 1045-1075 ◽  
Author(s):  
Saigal ◽  
Sumbulunnisan Shareef ◽  
Habibur Rahman ◽  
Md. Musawwer Khan
Keyword(s):  
Chemical Reactivity ◽  
Structural Systems ◽  
Natural Occurrence ◽  
Amino Group ◽  
Active Compounds ◽  
The Past ◽  
Fused Heterocycles

Aminocoumarins are one of the important core structural systems, present in several biologically and medicinally active compounds. Owing to its natural occurrence, potential pharmacological applications and remarkable versatility as a privileged precursor, several proficient synthetic protocols have been reported in the literature over the past years. The presence of an amino group and enamine carbon enhances its chemical reactivity and thus such functionality is repeatedly used for the construction of various fused and simple heterocycles. This review highlights the preparation of different aminocoumarins and their applications for the construction of a variety of five, six and eight membered fused heterocycles.

scholarly journals Hydrogen Peroxide Oxidation of Coordinated Thiocyanate Ion in cis- and trans-[Coen2NH3NCS]2+: The Preparation and Properties of trans-[Coen2NH3CN]2+

1973 ◽  
Vol 51 (24) ◽  
pp. 4152-4158 ◽  
Author(s):  
Albert Richard Norris ◽  
James William Lennox Wilson
Keyword(s):  
Hydrogen Peroxide ◽  
Spectral Properties ◽  
Peroxide Oxidation ◽  
Reaction Conditions ◽  
Thiocyanate Ion ◽  
Hydrogen Peroxide Oxidation ◽  
Percent Conversion ◽  
Cis And Trans ◽  
In Cis

The hydrogen peroxide oxidation of thiocyanate ion in cis- and trans-[Coen2NH3NCS]2+ leads to the formation of the corresponding cis- and trans-cyanoammine- and diamminebis(ethylenediamine)cobalt-(III) complexes. The spectral properties of the previously unreported trans-[Coe2NH3CN]2+ are reported and compared to the spectral properties of the cis-isomer.Observations are made concerning the reaction conditions which favor a high percent conversion of trans-[Coen2NH3NCS]2+ to trans-[Coen2NH3CN]2+.

scholarly journals The Natural Occurrence of Sedoheptulose Monophosphate in Liver

1959 ◽  
Vol 234 (8) ◽  
pp. 1955-1957
Author(s):  
Vijai N. Nigam ◽  
Hsien-Gieh Sie ◽  
William H. Fishman
Keyword(s):  
Natural Occurrence
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