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Now showing items 71-80 of 95
Possible evidence for the existence of a hairy layer at the surface of polymer latex particles
(
John Wiley & Sons, Ltd.
, 1998 , Article)
In this work, an attempt is made to verify the existence of a hairy layer at the surface of polymer latex particles, and determine its thickness under different conditions. Two systems have been studied. In one system, ...
عرض وتحليل بعض الجوانب التاريخيه لجامعة قطر 73/1974- 93/1994 مع اقتراح عناصر خطة عمل للتطوير المستقبلي
(
كلية التربية - جامعة عين شمس
, 1997 , Article)
جامعة قطر التي سنتحدث عن بعض تاريخها في هذه الدراسة قد بلغت اليوم مستويات من النمو في أعداد طلبتها وفي أعداد أعضاء هيئة التدريس، وفي كلياتها، وتخصصاتها وبرامجها الدراسية وأنشطتها العلمية والثقافية والرياضية والمجتمعية تفوق ...
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 ...
Evidence by ac-conductivity for the higher mobility of boron (over aluminium)-associated Brønsted sites in boron-modified HZSM-5
(
Elsevier
, 1996 , Article)
A correlation ac-conductivity analysis is performed at 102–105 Hz, 373–613 K and 0.8 V for characterizing the effect of increasing boron incorporation in HZSM-5 lattice on altered electric features in BZSM-5 samples of ...
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 ...
Effect of gamma radiation on the morphology and Thermophysical properties of the pollen wall of Phoenix dactylifera L.
(
Qatar University
, 1994 , Article)
Pollen grains of Phoenix dactylifera were exposed to different doses of gamma radiation (250,500,1000 rad and 1 M rad). To access the effect of radiation on the external morphology of the pollen grains, they were examined ...
Beach tar contamination on the Qatari coastline of the Gulf
(
Elsevier
, 1999 , Article)
Beach tar concentrations were measured along the Qatari coastlines. Tar concentrations, collected from 11 locations, varied in space and time with values ranging between 2 and 1132 g m−1 (average 290 g m−1) of beach front. ...
Solid-State Ac-Conductivity Analysis For The Long Debated Catalytic Activity Of The Boralite Sieve
(
Qatar University
, 1996 , Article)
The ac-phase dependent impedance, capacitance and dielectric loss of boralite are measured and correlated with those of a similar history HZSM-5 as a function of frequency (0.1-100 kHz) and temperature (373-638 K) at 0.8 ...
Study on ferroelastic characteristics of gamma irradiated lithium potassium sulfate crystal
(
Elsevier
, 1999 , Article)
A detailed study of the optical absorption vs. γ-irradiation dose for lithium potassium sulfate crystal, LiKSO4 cut out perpendicular to x, y and z directions is presented. The optical density was measured within the ...
A 6th-order local approximation by a cubic curve
(
Qatar University
, 1997 , Article)
We derive and present a MAPLE program for the construction of a parametric cubic polynomial curve which has sixth-order contract with a given smooth curve at a given point, thus providing a local sixth-order approximation ...