Al-Azhar University, Faculty of Science (Boys)
Al-Azhar Bulletin of Science
1110-2535
2636-3305
27
Issue 2-B
2016
12
01
STRUCTURAL STUDY OF SOME LITHIUM BOROPHOSPHATE GLASSES USING DENSITY, HARDNESS AND INFRARED SPECTROSCOPY
1
9
EN
A.
M.
Nassar
Phys. Dept. Faculty of Science (Girls branch) Al Azhar university, Nasr city,
Cairo, Egypt.
E.
Nabhan
Phys. Dept. Faculty of Science (Girls branch) Al Azhar university, Nasr city,
Cairo, Egypt.
Al-Sh.
Ramadan
Phys. Dept. Faculty of Science (Girls branch) Al Azhar university, Nasr city,
Cairo, Egypt.
10.21608/absb.2016.43970
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 melt<br />quenching technique. Density, molar volume, hardness and Ft-IR spectroscopy have been employed to study the<br />role of B 2 O 3 on the structure of the glass network. The results of density and hardness showed that both<br />increased 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 ))].<br />After Y 0.4 both of them decreased. Infrared spectra reveal that with the replacement P-O-B bonds are present<br />at very low B 2 O 3 content and their relative amount increased within the whole range of B 2 O 3 . BO 4 tetrahedral<br />groups are predominant (~ 100%) up to 15 mole% B 2 O 3 . Then, the proportion of BO 3 units starts to appear.
https://absb.journals.ekb.eg/article_43970.html
https://absb.journals.ekb.eg/article_43970_4a085068e7bc6b9cd9f16c2c70f06e24.pdf
Al-Azhar University, Faculty of Science (Boys)
Al-Azhar Bulletin of Science
1110-2535
2636-3305
27
Issue 2-B
2016
12
01
SIMULATION OF DIFFERENT CUMULUS SCHEMES OF WRF MODEL FOR TWO EXTREME EVENTS OVER EGYPT
1
11
EN
10.21608/absb.2016.60526
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.
https://absb.journals.ekb.eg/article_60526.html
https://absb.journals.ekb.eg/article_60526_f34f33caf1595f570934e324931361a0.pdf