Thin films of pure ZnO have been prepared on glass substrate using the Sol–Gel spin coating technique. Transmittance and absorbance spectra have been measured by using double beam UV-Visible 1800 spectrophotometer in the wavelength range (300-800)nm. It was found that the absorbance decreases with increasing the wavelength, while the transmittance increases with rising the wavelength. The transmittance exceeds 90% in the visible light region and in the near-infrared. The obtained results have shown that intrinsic ZnO is a semiconductor of wide optical energy band gap estimated to be 3.33eV. Furthermore, some optical properties and optical constants have been calculated from absorption and transmission measurements such as absorption coefficient, Urbach energy, extinction coefficient, refractive index and dielectric constant. arabic 12 English 63
Fawzeia Khamis(8-2020)

ركزت هذه الدراسة على خوارزميات التوقيع الرقمي ذات المفتاح المتماثل (خوارزميات التوقيع الرقمي ذات المفتاح الخاص والعام). وهذا الموضوع هو واسع الانتشار ولكن لم يتم تغطيت كل المفاهيم المتعلقة به.بدايتا قمنا بعرض مفصل لمفهوم امن المعلومات وكل المصطلحات المتعلقة به في الفصل الاول من الدراسة. ثم وضحنا مفهوم التوقيع الرقمي والطرق المستخدمة في التوقيع الرقمي وكذلك عرضنا خوارزميات التوقيع الرقمي وكان هذا في الفصل الثاني. اما في الفصل الثالث فقد قمنا بتوضح خدمات الامان المتعلقة بخوارزميات التوقيع الرقمي.في الفصل الرابع ناقشنا الطريقة المقترحة لمقارنة ودراسة خوارزميات التوقيع الرقمي محل الدراسة وقمنا ايضا بعرض الدراسات السابقة ، كما قمنا بسرد نتائج الدراسة التي توصلنا اليها من خلال مقارنة نتائج الطريقة المقترحة مع نتائج الدراسات السابقة Abstract This thesis focuses on the topic symmetric key digital signature algorithms (Public–Privet Key digital signature algorithms). This subject is very wide, but still it is tried to cover many of the topics related to it. Firstly, a brief introduction about information security is given and its related terms are discussed. Thereafter showed digital signature algorithms and its methods. After that, comes the security services related to digital signature algorithms and it is discussed in Chapter 3. In last chapter, discussed the proposed method of evaluation with previous studies and write the results.
رمزي حميد القانوني (2014)

Abstract The basaltic Intrusions of the Central Jabal Nafūsah Foothills which extend from NW Wādi Zāret to NE Wādi Ghān Dām are part of the latest stage of Gharyān Volcanic Province (GVP). These intrusions are classified on basis of their shape and mechanism of emplacement into four kinds of volcanic bodies. These are; sheets (dykes and a sill), dykes associated with volcaniclasts, volcanic cone and lava mounds. Generally, the dyke emplacements are restricted only to the area between Wādi Zāret to Abū Ghaylān, while the other forms extend from Rās al Mazūl Dome to Wādi Ghān Dam. The more differentiated rocks are restricted to the area between Rās al Mazūl Dome and Wādi Ghān. Farther west towards Wādi Zāret, ultramafic xenoliths and magnesium-number increase, suggesting closer proximity to the source. The rocks are essentially alkaline with within Intraplate signatures. They straddle the composition from picrites, basanites, alkali basalts through hawaiites, mugearite to benmoreites with a compositional gap between the last two types. Generally, the phenocrysts are represented by foresteritic olivine, Cadiopsidic pyroxene, magnesiotaramitic amphibole, plagioclase, K-feldspar and titanomagnetite. The chemical composition of the mafic minerals indicates that they are high pressure phenocryst phases. The most primitive picrites satisfied the criteria of primary mantle melts. The rocks are generally, enriched in LILE suggesting an enriched mantle source. The studied rocks were grouped into five groups based on incompatible trace element ratios; Group-A includes picrite, basanites and hawaiites, and Group-B includes picrite (Z-3), basanites , alkali basalts, and hawaiites, while Group-C is formed of hawaiites, Group-D is composed of mugearite and Group-E is made up of benmoreites. Picrites and basanites of these rock have high Mg-number (>0.64), high Cr and Ni contents and strong light rare earth element enrichment, but systematic depletion in Rb, K and Ba relative to trace elements of similar compatibility in anhydrous mantle. Alkali basalts and more differentiated magmatic rocks have lower Mg-number and lower abundances of Ni and Cr, and have undergone fractionation of mainly olivine, clinopyroxene, Fe–Ti oxide, amphibole and plagioclase. The variation in the concentrations of major, trace, rare earth elements, and incompatible element ratios in the rock samples demonstrate the heterogeneous character of their source region. Such heterogeneity can be interpreted by the involvement of a heterogeneous mantle reservoir to different degrees of partial melting. The REE data require residual spinel stability peridotite field in the source and constrain the melting process of Group-C and Group-D to 2% to 3.5% degrees of melting respectively, Group-A and Group-B both to 5% degree of partial melting while Group-E to 10% degree of partial melting of spinel lherzolite xenoliths of Al Ourban area. Mass balance modelling of the major suggests two possible FC scenarios; Derivation of basanites and hawaiites of group-A from G-3 picritic parental magma. Derivation of Group-D and Group-E was also possible from these basanites. Derivation of basanites of Group-B from Z-3 picrite parental magma and simultaneous derivation of G-4 and QJ-1 alkali basalts from Z-3 picrite parental magma. V Simple mass-balance calculations suggest that the melting assemblages of picrites and basanites consisted of forsteritic olivine, diopsidic clinopyroxene, Ti-magnetite. While the alkali basalts and more differentiated magmatic rocks, mass-balance calculations suggest that the melting assemblages consisted of sodic plagioclase, magnesiotaramitic amphibole, diopsidic pyroxene, Ti-magnetite, K-feldspar with sub amounts of apatite and sphene.
سمية عون (2015)