College of Arts & Sciences: Recent submissions
Now showing items 441-460 of 3507
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Atomic-scale and optical investigation of nanostructured Er disilicates in silica
( Elsevier , 2022 , Article)The optical and structural properties of Er-doped Silicon oxide based thin films elaborated by RF magnetron sputtering were investigated as a function of annealing treatment. Atom Probe Tomography and Transmission electron ... -
Estimating protection afforded by prior infection in preventing reinfection: Applying the test-negative study design.
( Oxford University Press , 2023 , Article)The COVID-19 pandemic has highlighted the need to use infection testing databases to rapidly estimate effectiveness of prior infection in preventing reinfection ($P{E}_S$) by novel SARS-CoV-2 variants. Mathematical modeling ... -
Model for oscillations in the guidance of ions through insulating nanocapillaries
( IOP Publishing , 2011 , Conference Paper)The pre-equilibrium period of the ion guiding through insulating nanocapillaries is characterized by the production of temporary charge patches inside the capillaries. The dynamics of the charge patch creation is revealed ... -
Ion impact induced ionization/fragmentation dynamics of rare gas Dimers
( IOP Publishing , 2013 , Conference Paper)We have measured the ionization and fragmentation of Helium, Neon and Argon Dimers induced by ion impact and observed two different pathways, the sequential ionization on each atom and the interatomic Cou-lombic decay. © ... -
Constituents of plants growing in Qatar
( Elsevier , 1986 , Article)N/A. -
Constituents of plants growing in Qatar XVII anti-inflammatory and cytotoxic activities of extracts of thirty indigenous species
( Taylor & Francis , 1990 , Article)Thirty plants, indigenous to Qatar, were extracted separately with hexane, chloroform and ethanol. The dried extracts were examined for potential anti-inflammatory activities both in vitro by their ability to inhibit ... -
Constituents of plant growing in Qatar. II. Investigation of Euphorbia granulata
(1982 , Article)N/A. -
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 ... -
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 ... -
Amphetamine Selective Electrodes Based on Dibenzo-18-crown-6 and Dibenzo-24-crown-8 Liquid Membranes
( American Chemical Society , 1989 , Article)Two novel membrane electrodes highly sensitive and selective for amphetaminium cation are developed and electrochemically evaluated according to IUPAC recommendations. These electrodes Incorporate amphetamine-dibenzo-18-crown-6 ... -
Selective determination of thiamine (vitamin B1) in pharmaceutical preparations by direct potentiometric argentometric titration with use of the silver-silver sulphide ion-selective electrode
( Elsevier , 1989 , Article)A simple and selective argentometric titration method is described for determination of thiamine (vitamin B1), based on direct potentiometric titration in alkaline media (⩾0.5M) in which a chemical transformation takes ... -
Liquid membrane electrodes for the selective determination of nicotine in cigarette smoke
( The Royal Society of Chemistry , 1989 , Article)Five liquid membrane electrode systems responsive to the nicotinium cation are described. These electrodes are based on the use of the ion-association complexes of the nicotinium cation with tetraphenylborate, 5-nitrobarbiturate, ... -
Solid-state planar microsensors for selective potentiometric determination of ethylmorphine
( Marcel Dekker Inc. , 1999 , Article)The potentiometric performance characteristics of microelectronically fabricated solid-state planar ethylmorphine sensors based on silicon/silicon nitride substrate and a mixture of ethylmorphine-tetraphenylborate and ... -
Spectrophotometric Determination of Hydrogen Peroxide by a Hydroquinone-Aniline System Catalyzed by Molybdate
( Korean Chemical Society , 2004 , Article)In this system hydroquinone is oxidized to pbenzoquinone by H2O2. 2 aniline are added, in successive stages, to pbenzoquinone, to yield the disubstituted quinone as the final product. 20 The UV-VIS spectrum of the product ... -
Thiamine-reineckate liquid membrane electrode for the selective determination of thiamine (vitamin B1) in pharmaceutical preparations
( The Royal Society of Chemistry , 1989 , Article)The construction and electrochemical response characteristics of a liquid membrane electrode for thiamine (vitamin B1) based on the formation of an ion pair between the thiamine cation and the reineckate anion in nitrobenzene ... -
Poly(vinyl chloride) matrix membrane electrodes for manual and flow injection determination of metal azides
( The Royal Society of Chemistry , 1992 , Article)Novel poly(vinyl chloride) matrix membrane electrodes for the azide ion are developed, electrochemically evaluated and used for manual and flow injection determinations of soluble and insoluble metal azides. These electrodes ...