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Now showing items 21-30 of 32
On the Valence State of Iron in Sr0.52+Ca0.52+Fe0.54+ Me0.54+O32−
(
WILEY-VCH Verlag GmbH & Co.
, 1989 , Article)
Powder samples of Sr0.5Ca0.5Fe0.5Me0.5O3 (Me = Co, Zr or Mn) and Sr0.3La0.7FeO3 are investigated by X-ray diffraction and Mossbauer effect spectroscopy.
Analysis of the completely ordered spectra suggested three kinds ...
Ventifacts distribution in Qatar
(
John Wiley & Sons, Ltd
, 1985 , Article)
This study attempts to investigate the distribution of ventifacts in Qatar. It is believed that ventifacts are confined to the areas within about 5 km of the Miocene or Mio-Pliocene Hofuf formations and the spreads of ...
Distribution and ultrastructure of neurosecretory cells in the cerebral ganglion of the earthworm
(
Wiley Subscription Services, Inc., A Wiley Company
, 1988 , Article)
Neurosecretory (Nsy) cells within the cerebral ganglion of Lumbricus terrestris were classified ultrastructurally. The Nsy cells within the subesophageal ganglion, nerve cord ganglion, and the peripheral nervous system ...
Synthesis and biological activity of some new aminoacylcarbazole derivatives. Part I
(
Wiley-Blackwell
, 1982 , Article)
The syntheses of different 9-(N-phthalyl- or N-tosyl- or free aminoacyl)carbazoles and the corresponding derivatives of 3,6-dinitrocarbazoles and some derivatives of 3,6-diamino-9-(N-phthalylaminoacyl)carbazoles (II-XXXII) ...
Constituents of plants growing in Qatar III - Nutritive constituents of Garawah (Glossonema edule)
(
Junk Publishers
, 1983 , Article)
Both the pericarp and the unripe seeds of the unripe fruits of Glossonema edule were separately analysed. The crude protein content of the unripe seeds is double that of the pericarp. Investigation of the amino acids of ...
Constituents of plants growing in qatar V. Constituents of the volatile oil of cymbopogon parkeri
(
Elsevier
, 1983 , Article)
Analysis of the volatile oil of Cymbopogon parkeri has been carried out by capillary gas chromatography-mass spectrometry. To facilitate identification, prefractionation of the oil by adsorption high-performance liquid ...
Sesquiterpene lactones from Pulicaria sicula
(
Elsevier
, 1988 , Article)
The aerial parts of Pulicaria sicula afforded the known xanthanolides 1-6, the guaianolides 7 and 8 as well as two new ones, the lactone 9 and the corresponding epoxide 10. Furthermore nerylisobutyrate and the thymol ...
Chemical survey of some plants Growing in Qatar
(1989 , Other)
Fifty one plants growing in Qatar, belonging to thirty families, were surveyed for alkaloids, anthraquinones, coumarins, flavonoids, tannins and saponins. The medicinal uses of these plants arereported.
Synthesis and biological activity of some new 3-and 6-substituted coumarin amino acid derivatives. Part I
(
Wiley-Blackwell
, 1981 , Article)
The synthesis of 6-nitrocouarrain-3-CO-amino acids and their corresponding methyl esters (II-XVII) and some dipeptide methyl esters (XVIII-XXVI) are described. 6-(N-Tosyl- or N-phthalylaminoacyl)aminocoumarin-3-carboxylic ...
Absolute evaluation of ferrous and ferric concentration in Ca amphibole
(
WILEY-VCH Verlag
, 1982 , Article)
Studies are made of M?sshauer absorption of 57Fe in a Ca-amphibole schist sample at room and liquid nitrogen temperatures. The absolute concentration and the recoilless fraction for ferrous and ferric cations are determined ...