Browsing Faculty Contributions by Publication Date
Now showing items 61-80 of 17088
-
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 ... -
Liquid and poly (vinyl chloride) matrix membrane electrodes for the selective determination of cocaine in illicit powders
( Elsevier , 1992 , Article)The construction of liquid membrane and PVC matrix-type cocainium ion selective electrodes and their use for direct potentiometry and potentiometric titration of cocaine are described. The ion-pair complexes of cocaine ... -
The use of Robot Redundancy in Contour Path Operations for Selected Manufacturing Applications
( IEEE , 1992 , Conference Paper)Redundant robots have many applications and use in path synthesis for crowded workspace and in minimum time control path tracking problems. In selected manufacturing applications - such as spray painting, continuous welding, ... -
On Transformations and Perturbations of Orthogonal r-Frames
( WILEY-VCH Verlag GmbH & Co. , 1993 , Article)A decomposition of Cn into a finite direct sum of orthogonal subspaces can be conveniently represented by its orthogonal projector frame, which is the collection of the corresponding orthogonal projectors. Two such ... -
Ultrasonic and thermal properties of γ-irradiated low-density polyethylene
( John Wiley & Sons, Inc. , 1993 , Article)The ultrasonic pulse-echo technique and differential thermal analysis were utilized to characterize and to monitor the effect of ?-irradiation on the sonic modulus and the heat effect of low-density polyethylene. The sonic ... -
أسس نظرية المعرفة اليقينية بين الفكر الديني والفلسفي
( دار الحكمة - الدوحة , 1993 , Book)المقدمة هناك معضلة فكرية مهمة تتصل ببنية الحضارة الإسلامية وما تتطلبه هذه الحضارة من أسس ومقومات تقوم عليها، وهي: هل لدى المسلمين مناهج خاصة بهم، اكتشفوها بأنفسهم دون أن تشوبها شائبة مقحمة عليها من الخارج؟ بمعنى هل قامت ... -
The amino acid composition of some Common marine algae from Qatar (Arabian Gulf)
( Qatar University , 1993 , Article)The most dominant twenty algal species representing the main three groups of benthic macroalgae, Chlorophyceae, Phaeophyceae and Rhodophyceae were collected from the coastal zones of the Qatar peninsula. The algae were ... -
Triterpenoids from Salvia aegyptiaca
(1993 , Article)Newly isolated secondary metabolites from Salvia aegyptiaca growing in Qatar -
A coupled vector-scalar potential method for permanent magnet modeling in large-scale 3D-FE magnetic field computations
( IEEE , 1993 , Article)This paper introduces a magnetic scalar potential (MSP) formulation to model permanent magnet volumes. This formulation is suited for use in coupled vector-scalar magnetic potential (CMVP-MSP) 3D-FE computations of large-scale ... -
An Adaptive Newton-Raphson Technique for Combined Vector-Scalar Potential Solutions of Large Scale 3D Magnetic Field Problems Involving Anisotropic Materials
( IEEE , 1993 , Article)In general, magnetic field problems in electrical devices and machines are of nonlinear nature due to magnetic saturation in their ferrous cores. In the combined magnetic vector-magnetic scalar potential (MVP-MSP) method ... -
Teaching Electric Machinery and Associated Electromagnetic Fields-A Case for the Benefits of Academic Computing
( IEEE , 1993 , Article)This paper describes three broad categories of benefits resulting from use of and access to personal computers (PCs) and work stations (WSs) in teaching electric machines and drives. This includes all the electromagnetic ... -
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). ... -
Determination of amitriptyline, imipramine and orphenadrine in antidepressant drugs by potentiometry, spectrophotometry and atomic absorption spectrometry
( Springer-Verlag , 1993 , Article)Methods are described for the determination of amitriptyline, imipramine and orphenadrine in some antidepressant drugs. They are based on a prior reaction with ammonium reineckate to form 1∶1 water-insoluble drugreineckate ... -
A Coupled Vector-scalar Potential Method For Permanent Magnet Modeling in Large-scale 3d-Fe Magnetic Field Computations
( IEEE , 1993 , Conference Paper)This paper introduces a magnetic scalar potential (MSP) formulation of permanent magnet (PM) modeling. This formulation is suited for use in coupled (combined) vector-scalar magnetic potential (CMVP-MSP) 3D-FE algorithms ... -
الزيادة الطبيعية ودورها في معالجة الخلل السكاني في دولة قطر
( جامعة الكويت , 1993 , Article)من المعروف أن نسبة عالية من سكان دول الخليج هم من غير المواطنين ، فعلى سبيل المثال ، فهؤلاء يمثلون أكثر من 70% في كل من الكويت والإمارات وقطر . هذا البحث العلمي يحاول الإجابة على السؤال : إلى أي مدى تتمكن الزيادة الطبيعية ... -
Structure-thermal expansivity relation for isotropic polyoxymethylene sheets
( John Wiley & Sons, Ltd. , 1994 , Article)A detailed parametric mapping analysis of the thermal expansion coefficient for isotropic polyoxymethylene is presented. The molecular composite model has been computerized to investigate the variation of the thermal ... -
Glycosides of Heterocycles: A Direct Route to 1-(β-D-Glycopyranosyl)pyridinethione Nucleosides
( WILEY-VCH Verlag , 1994 , Article)A novel synthesis of 1-(β-d-glycopyranosyl)pyridinethione nucleosides 6 utilizing pyridine-2(1H)-thiones 3 and α-halogeno sugars 4 as starting components is reported. -
Kinetics and mechanism of H2O2 decomposition by Cu(II)-, Co(II)-, and Fe(III)-Amine complexes on the surface of Silica-Alumina (25% Al2O3)
( John Wiley & Sons, Inc. , 1994 , Article)The kinetics of the H2O2 decomposition by Cu(II)-, Co(II)-, and Fe(III)-amine complexes supported on the surface of silica-alumina (25% Al2O3) catalyst have been investigated. The decomposition process proceeded with ... -
Constituents of plants growing in qatar xxv flavonoids of Picris Radicata (forssk.) Less.
( Qatar University , 1994 , Article)Four flavonoids were isolated from the plant and were identified as apigenin, chrysin 7-glucoside, leuteoline and luteolin 7-glucoside. -
Mercury pollution in doha (Qatar) coastal environment
( Wiley Periodicals, Inc. , 1994 , Article)Surface water and sediment samples were collected from the Doha coastal area and analyzed for content of physico-chemical forms of mercury. Dissolved reactive Hg (2.9 ng L?1) represented 81.0% of the total dissolved Hg ...