Twilight is that light appear on the horizon before sunrise and after sunset, Astronomically it is known that sunrise and sunset are effected by high above sea level, but the effect of high above sea level on the time of astronomical twilight still not decided and controversy among astronomers, in This research we studies the effect of high above sea level on the time of astronomical twilight, through adding the equation correct high above sea level to equation computation of twilight and then calculate of changing in the time of twilight for different highest (0-10000) meters above sea level , and the ratio of increase for time with high between (15.45-20.5) minutes. It was found that there was an increase in the time of the twilight along

  The content of Furocoumarin derivatives (Psoralens) of Ruta Chalepensis L. (Whole plant) was studied by simple extraction with petroleum ether (b.p. 60-80C^o). The results indicated that the plant contains a total of about (0.015%).

       Investigation of these compounds by thin layer chromatography (TLC) revealed the presence of at least four compounds of which methoxsalen (8-methoxypsoralen) was isolated.     It was identified and authenticated with a standard by spectral method, IR, NMR, Mass spectra and HPLC.This plant could be considered as a good source for supplying this compound, which is widely used in dermatological preparations.

The Bi2Se3 compound was synthesis by fusing initial compounds consisting of
extra pure elements in stoichiometric ratio from elements compound, charged inside
quartz ampoule. The crystal growth of Bi2Se3 carried out using Brighaman technique
process from melting f (Bi+Se ) at temperature of 810 ºC for about 48 hrs. Single crystal
of Bi2Se3 has been grown in direction (211) after slow cooling on account of heat
gradient to zone furnaces at cooling rate (1-3) C/hr. The structure study of the compound
was determined by x-ray diffraction technique, which it has bismuthinite structure and
orthorhombic unit cell with lattice parameters of a=10.2678 Å, b=11.2392 Å and
c=5.1737 Å

Leishmania is the causative agent of leishmaniasis, a widely distributed disease. Amastigote forms of Leishmania are intracellular and reside within the macrophage of the vertebrate host. Previous studies showed that certain Leishmania species may scavenge host factors for survival, specially sphingolipids, the key element of the eukaryotic membranes. In this study we have investigated the survival of new world L. mexicana amastigotes in murine macrophage cell-line in the presence and absence of foetal bovine serum (FBS). Results showed that there was no significance in the infectivity of amastigotes and also the number of parasite per cell; such findings suggest that L. mexicana amastigotes have its own pathway of sphingolipid intake and c

In this work ester derivatives were synthesized by the reaction of imidazole derivatives (C1) with ethylchloroacetate in ethanol and NaOH to give the corresponding (C2) .While compound (C3) acetohydrazide was synthesized by the reaction of ester derivatives (C2) with hydrazine hydrat in ethanol. Compound (C3) from the reaction with different aromatic aldehydes in absolute ethanol gave the Schiff′s bases (C4,C5). The product compounds were characterized by FT-IR, U.V and 1HNMR spectra and the biological activities were studied as antibacterial.

The electronic structure of zinc blend indium gallium phosphide In0.5Ga0.5P nanocrystals which have dimension (2-2.8 nm) is investigated using the density functional theory coupled with large unit cell (LUC) for the different size core (8 ,16,54,64) atoms respectively. The investigated properties include total energy, energy gap, conduction band, valence band, cohesive energy, ionicity and density of state etc. as a function of core size and lattice constant. Results show the shape effect of increasing the core size and lattice constant on these electronic properties

It is no secret that the prophets speech is of great importance, as the second source of Islamic legislation after the Holy Quran, and as such we must reserve and verify the authenticity of the novel and the narrators seizure, and all the conditions laid down by the scholars.

The subject of our research here concerns part of this verification, which is the unknown, the subject of the unknown hadith is considered a matter of great interest by the modernists because it relates to the validity of the novel and the narrators, and the methods of the modernists varied in terms of the reasons for this weakness, the fool never entertained them by the reckless narrative.

I chose the subject of my research the types of Mahjail and

A set of ten drug compounds containing an amino group in the structure were determined theoretically. The parameters were entered into a model to forecast the optimal values of practical (log P) medicinal molecules. The drugs were evaluated theoretically using different types of calculations which are AM1, PM3, and Hartree Fock at the basis set (HF/STO-3G). The Physico-chemical data like (entropy, total energy, Gibbs Free Energy,…etc were computed and played an important role in the predictions of the practical lipophilicity values. Besides, Eigenvalues named HOMO and LUMO were determined. Linearity was shown when correlated between the experimental data with the evaluated physical properties. The statistical analysis was used to analy

In this paper thermo-hydrodynamic characteristics were investigated experimentally for a new type shell-helical coiled tube heat exchanger used as a storage tank of closed loop solar water heater system. Triple concentric helical coils were made of copper tubes of (12.5mm OD and 10mm ID) with coils diameter of (207, 152.2, 97mm) for outer, middle and inner coils respectively. The experiments were carried out during a clear sky days of (March and April 2012). The parameters studied in this work are: history of average temperature of shell side of the storage tank, collector heat gain, heat rejected from coils to shell side of the storage tank, collector efficiency, thermal effectiveness of the heat exchanger (storage tank), and pressure d