College of Arts & Sciences: Recent submissions
Now showing items 561-580 of 3630
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Ion impact induced ionization/fragmentation dynamics of rare gas Dimers
( IOP Publishing , 2013 , Conference)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. © ... -
Model for oscillations in the guidance of ions through insulating nanocapillaries
( IOP Publishing , 2011 , Conference)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 ... -
Comprehensive investigation of Er2O3 thin films grown with different ALD approaches
( Elsevier , 2022 , Article)The effect of Er precursor nature (Er(CpMe)3 or Er(tmhd)3) and annealing treatment at 500–1100 °C on the structural and optical properties of Er2O3 films grown on Si substrates by thermal or O2-plasma-assisted atomic layer ... -
Dynamics of charge evolution in glass capillaries for 230-keV Xe23 + ions
( American Physical Society , 2012 , Article)We have measured the transmission of 230-keV (10-keV/q) Xe23+ ions through insulating tapered glass capillaries of microscopic dimensions. The dynamics of charging and discharging processes have been investigated, evidencing ... -
Combined theoretical and experimental study of the transmission of tilted ion beams through macroscopic conical glass capillaries
( IOP Publishing , 2015 , Conference)The transmission as a function of the tilt angle of a 3 keV Ar+ ion beam through a conical macroscopic glass capillary is studied theoretically and experimentally. It was found that the charge patches which are responsible ... -
Frequency conversion layers for Si solar cell efficiency improvement
( Springer Nature , 2017 , Book chapter)SiNx and SiNx: Tb3+ thin layers deposited by reactive magnetron co-sputtering have been studied with the aim of optimizing the light management in Si solar cells. Those Si-based layers are developed to be compatible with ... -
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 ... -
Constituents of plants growing in Qatar - Part XIX. Flavonoids of Glossonema edule N. E. Br.
( Springer Nature , 1990 , Article)The study of the flavonoids of the unripe fruits of Glossonema edule, resulted in the isolation and identification of apigenin 6,8-di-C-glucoside (violanthin) and luteolin 7-O-glucoside. © 1990 Kluwer Academic Publishers. -
Constituents of plants growing in Qatar XX. Phytochemical investigation of anastatica hierochuntica: NOTE
( Taylor & Francis , 1993 , Article)A study of the lipid fraction of Anastatica hierochuntica (Cruciferae) resulted in the isolation of hydrocarbon (mainly C25H52, C29H60 AND C31H64) AND sterol fractions (P-sitosterol, campesterol, stigmasterol AND cholesterol). ... -
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: ... -
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 ... -
Constituents of plants growing in Qatar
( Elsevier , 1986 , Article)N/A. -
Novel potentiometric copper (II) selective membrane sensors based on cyclic tetrapeptide derivatives as neutral ionophores
( Elsevier , 2005 , Article)Two novel membrane sensors sensitive and reasonably selective for Cu2+ ions are described. These are based on the use of newly synthesized cyclic tetrapeptide derivatives as neutral ionophores and sodium tetraphenylborate ... -
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 ... -
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 ... -
Poisonous plants contaminating edible ones and toxic substances in plant foods IV. Phytochemistry and toxicity of lolium temulentum
( Taylor & Francis , 2008 , Article)Different procedures were carried out for the preparation and separation of the total alkaloids of Lolium temulentum. Loline has been identified as the major pyrrolizidine alkaloid of the seeds. The toxicity of the alcoholic ... -
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 ...
