2024-03-29T04:00:15Z
https://absb.journals.ekb.eg/?_action=export&rf=summon&issue=6854
Al-Azhar Bulletin of Science
1110-2535
1110-2535
2016
27
Issue 2-B
STRUCTURAL STUDY OF SOME LITHIUM BOROPHOSPHATE GLASSES USING DENSITY, HARDNESS AND INFRARED SPECTROSCOPY
A.
Nassar
E.
Nabhan
Al-Sh.
Ramadan
Glasses in the system [50Li 2 O-xB 2 O 3 -(50-x)P 2 O 5 ] (10 < x < 27.5), have been prepared by the meltquenching technique. Density, molar volume, hardness and Ft-IR spectroscopy have been employed to study therole of B 2 O 3 on the structure of the glass network. The results of density and hardness showed that bothincreased as P 2 O 5 is replaced by B 2 O 5 [as y was increased from 0.2 up to 0.4 where (y = B 2 O 3 /(B 2 O 3 +P 2 O 5 ))].After Y 0.4 both of them decreased. Infrared spectra reveal that with the replacement P-O-B bonds are presentat very low B 2 O 3 content and their relative amount increased within the whole range of B 2 O 3 . BO 4 tetrahedralgroups are predominant (~ 100%) up to 15 mole% B 2 O 3 . Then, the proportion of BO 3 units starts to appear.
2016
12
01
1
9
https://absb.journals.ekb.eg/article_43970_4a085068e7bc6b9cd9f16c2c70f06e24.pdf
Al-Azhar Bulletin of Science
1110-2535
1110-2535
2016
27
Issue 2-B
SIMULATION OF DIFFERENT CUMULUS SCHEMES OF WRF MODEL FOR TWO EXTREME EVENTS OVER EGYPT
This work aimed to study two heavy rainfall events over Egypt. The two events occur in January, 17 2010 and 2011. Although both events occur in winter season, their impact was very unusual. In this study an attempt was made to perform diagnostic and prognostic analysis of the events. It was found that the 2010 case was due to interaction between tropical and mid-latitude systems, while the 2011 one was entirely due to mid- latitude systems. WRF model was used to investigate the better scheme from Betts Miller (BM) and Kain Fretch (KF) convective in forecasting rainfall. It is found that BM performance better in predicting the characteristics of the two events.
2016
12
01
1
11
https://absb.journals.ekb.eg/article_60526_f34f33caf1595f570934e324931361a0.pdf