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السجلات المعروضة 101 -- 108 من 108
Geology of wadi atalla - el missikat area, eastern desert, egypt.
(
Qatar University
, 1989 , Article)
Wadi Atalla-El Missikat area covers about 2,000 Km2 in the central Eastern Desert of Egypt, between latitudes 26° 10' and 26° 40' N, and longitudes 33° 15' and 33° 40' E. The area is mainly formed of basement complex except ...
The electrical and optical properties of poly (4-ethylidene-l, 3-cyclopentylene vinylene)
(
Qatar University
, 1989 , Article)
The intrinsic viscosity, electrical conductivity and IR absorbance were measured for the sample of poly (4—ethylidene—1, 3—cyclopentylene vinylene). The sample is strongly oxidized in air. Under vacuum the activation energy ...
Study of A Time Dependent Double -Diffusive Salinity Problem
(
Qatar University
, 1989 , Article)
The time-dependent, double diffusive stability problem for a horizontal layer of salty water bounded by two rigid isothermal surfaces is analyzed using a linear perturbation technique. Initially, the layer is subjected to ...
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 ...
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, ...
Polarization resistance study of inhibition of corrosion of lead by sodium benzoate in 0.1 M sodium hydroxide solution
(
Council of Scientific and Industrial Research
, 1989 , Article)
The effect of sodium benzoate (SB) as an inhibitor of corrosion of lead in 0.1 M NaOH solution has been investigated by using the polarization resistance technique. The concentrations of SB employed are in the range 1-5 × ...