Browsing College of Arts & Sciences by Publication Date
Now showing items 1-20 of 3562
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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 ... -
Constituents of plant growing in Qatar. II. Investigation of Euphorbia granulata
(1982 , Article)N/A. -
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) ... -
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 ... -
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 ... -
Constituents of plants growing in Qatar VII an examination of certain plants for anti-inflammatory activity
( Taylor & Francis , 1985 , Article)Six desert plants native to the State of Qatar were successively extracted with hexane, chloroform and ethanol. These extracts were examined for their ability to inhibit aggregation of rabbit blood platelets induced by ... -
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 ... -
Mössbauer study of ZnxNi5/3−xFe1Sb1/3O4 spinel ferrite
( Springer Verlag , 1985 , Article)The antimony substituted nickel ferrite ZnxNi5/3–xFe1Sb1/3O4 with different values ofx are prepared, checked by x-ray and studied with57Fe Mössbauer spectroscopy over a wide temperature range. Characteristic spectra of ... -
Constituents of plants growing in Qatar
( Elsevier , 1986 , Article)N/A. -
Iridoids and flavonoids of Teucrium polium herb
( Thieme , 1986 , Article)The iridoid glycoside teucardoside and the flavonoids salvigenin and cirsiliol have been isolated from Teucrium polium var. pilosum and T. polium var. alba. The medicinal significance of these findings is discussed. -
Constituents of plants growing in Qatar IX. The antispasmodic components of cymbopogon parkeri stapf. Parkeri stapf
( Taylor & Francis , 1986 , Article)Investigation of the lipid fraction of Cymbopogon parkeri revealed the presence of several active constituents, one of which possesses an antispasmodic activity and was identified as cryptomeridiol. Study of the other ... -
Far-infrared and Raman spectroscopic studies of polyiodides
( American Chemical Society , 1986 , Article)The far-infrared and Raman spectra of (CH3)4NI5, (TMA.H2O)10HI5 (TMA = trimesic acid), (phen)2HI5 (phen = phenacetin), (CH3)4NBrI4, (C2H5)4NI7, and (CH3)4NI9 have been recorded and analyzed. The first three compounds contain ... -
Resonance Raman studies of the peroxotitanate(IV) complexes K2(Ti(O2)(SO4)2).5H2O and K2(Ti(O2)(C2O4)2).3H2O
( Elsevier , 1986 , Article)The resonance Raman spectra of K2(Ti(O2)(SO4)2)·5H2O and K2(Ti(O2)(C2O4)2)·3H2O are recorded. The results are consistent with the triangular structure of the peroxotitanium unit, Ti(O2), with C2ν symmetry. The ν(OO), ... -
Resonance Raman and far-infrared studies of charge-transfer complexes of iodine
( John Wiley and Sons Inc , 1986 , Article)The reactions of I2 with phenazine (PH), acridine (AC) and hexamethylenetetramine (HMTA) have been investigated by resonance Raman and far-infrared spectroscopy. The results indicate that the species (PH)2I+I3−, (AC)2I+I3− ... -
Vibrational analysis of the trigonal bipyramidal NbCl5 and NbBr5 molecules
( Elsevier , 1986 , Article)Vibrational normal coordinate analysis has been made for NbCl5 and NbBr5 molecules with D3h symmetry and using Wilson's GF matrix method. The observed frequencies are quantitatively assigned on the basis of the calculated ... -
Mössbauer effect study of Li21+Me4+Fe63+O122−spinels
( Baltzer Science Publishers, Baarn/Kluwer Academic Publishers , 1986 , Article)Mossbauer effect spectra are obtained for the cubic ferrites Li2 Me Fe6 O12 (where Me4+ is one of the tetravalent elements Ge, Si and Ti) at 78K up to their magnetic transition temperatures. In a rather large temperature ... -
Polarization Resistance Study on Copper Corrosion in Aqueous Potassium Hydrogen Phthalate Solution
( WILEY-VCH Verlag , 1987 , Article)The effect of temperature on corrosion of copper in 0.1 M aqueous solution of potassium hydrogen phthalate (KHPh) has been investigated using polarization resistance technique. it was found that that the corrosion rate in ... -
Spectroscopic studies of nickel and iron clusters at 12 K
( AIP Publishing , 1987 , Article)The electronic and far‐infrared spectra of nickel and iron clusters trapped in argon matrices at 12 K are reported. The ν3 antisymmetric stretching frequencies for Ni3 and Fe3 were observed for the first time at 198 and ... -
Constituents of plants growing in Qatar part XV. Chemical investigation and pharmacotoxicity of pyrrolizidine alkaloids of moltikiopsis ciliata
( Taylor & Francis , 1988 , Article)Chemical study of the alkaloidal constituents of Moltikiopsis ciliata resulted in the isolation and identification of heliotrine and echinatine, in addition to other minor alkaloids. Pharmacological experiments revealed: ...