On the natural occurrence of (−)-3-carene, a component of termite defense secretions

I. Valterová; J. Vrkoč; M. Lindström; T. Norin

doi:10.1007/bf01138574

ChemInform Abstract: The Natural Occurrence of (-)-3-Carene, a Component of Termite Defense Secretions.

ChemInform ◽

10.1002/chin.199251271 ◽

1992 ◽

Vol 23 (51) ◽

pp. no-no

Author(s):

I. VALTEROVA ◽

J. VRKOC ◽

M. LINDSTROEM ◽

T. NORIN

Keyword(s):

Natural Occurrence ◽

Defense Secretions

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

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100074690 ◽

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.

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

Brazilian Journal of Radiation Sciences ◽

10.15392/bjrs.v7i2a.763 ◽

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.

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

Folia Zoologica ◽

10.25225/fozo.v62.i1.a2.2013 ◽

2013 ◽

Vol 62 (1) ◽

pp. 14-18 ◽

Cited By ~ 6

Author(s):

Lei Cui ◽

Khalid Abbas ◽

Yongyao Yu ◽

Weimin Wang ◽

Li Zhou ◽

...

Keyword(s):

First Record ◽

Hubei Province ◽

Natural Occurrence ◽

Misgurnus Anguillicaudatus

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Aminocoumarins: A Privileged Precursor for the Synthesis of Fused Heterocycles

Current Organic Chemistry ◽

10.2174/1385272823666190514073610 ◽

2019 ◽

Vol 23 (9) ◽

pp. 1045-1075 ◽

Cited By ~ 1

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.

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