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The phytochemical screening of Citharexylum spinosum L. aerial parts resulted in the presence of flavonoids, tannins, carbohydrates and/or glycosides, triterpenes and/or sterols and saponins. The percentage of hydrocarbons and sterols in C. spinosum petroleum ether extract were 99.57 and 0.3%, respectively. In petroleum ether extract, saturated fatty acids (78.76%) and unsaturated fatty acids (9.14%) were found. Chromatographic fractionation of 80% aqueous, methanol and chloroform extracts of C. spinosum resulted in isolation of 10 compounds; β-Sitosterol, β-Sitosterol 3-O-β-Dglucopyranoside, Oleanolic acid, Gallic acid, Quercetin, 6-Methoxy acacetin 7-O-β-D-glucopyranoside, Naringenin, Quercetin 3-O-α-L-rhamnopyranoside (Quercetrin), 1, 2, 6-tri-O-galloyl-β-D-glucopyranoside and Rutin. The antipyretic activity of aqueous methanolic residue using Brewer's yeast-induced pyrexia in rats was significant at dose 300 mg/kg. All tested samples had no analgesic activity. The major isolated compounds were quercetin and quercetrin, their biological activities, antimicrobial and cytotoxic activities, were determined parallel to the extracts. It was found that the aqueous methanolic residue, chloroform extract, quercetin and quercetrin exerted significant antimicrobial activity. From 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell proliferation assay on A2780 human ovarian cell line, quercetrin showed moderate cytotoxic activity, whereas quercetin showed significant cytotoxic activity.

Abstract. Ionospheric delay, can be derived from dual frequency GNSS signals, and then converted into the Vertical Total Electron Contents (VTEC) along the signal path. Various models were devised to calculate VTEC. Examples of such models are the polynomial function model and spherical harmonics model. A common hypothesis of these models is that they are constructed based on the assumption that the entire electron content in the ionosphere is concentrated in a single thin shell at a selected height above Earth. The primary goal of the current research to develop an algorithm capable of producing VTEC maps on an hourly basis, using carrier phase observations from dual frequency GPS receiver. The developed algorithm uses a single GPS station (Zero-difference) to map VTEC over a regional area. The carrier phase measurements are much more precise than the code pseudorange measurements, but they contain an ambiguous term. If such ambiguities are fixed, thence the carrier phase measurements become as unambiguous pseudoranges, but accurate at the level of few millimeters. In current research Sequential Least Square Adjustment (SLSA) was considered to fix ambiguity term in carrier phase observations. The proposed algorithm was written using MATLAB and Called (ZDPID). Two GPS stations (ANKR and BSHM) were used from IGS network to evaluate the developed code, VTEC values were estimated over these two stations. Results of the proposed algorithm were compared with the Global Ionosphere Maps (GIMs), which is generally used as a reference. The results show that the mean difference between VTEC from GIM and estimated VTEC at ANKR station is ranging from −2.1 to 3.67 TECU and its RMS is 0.44. The mean difference between VTEC from GIM and estimated VTEC at BSHM station is ranging from −0.29 to 3.65 TECU and its RMS is 0.38. Another three GPS stations in Egypt were used to generate regional ionosphere maps over Nile Delta, Egypt. The mean differences between VTEC from GIM and estimated VTEC at SAID station is ranging from −1.1 to 3.69 TECU and its RMS is 0.37, from −1.29 to 3.27 TECU for HELW station with RMS equal 0.39, and from 0.2 to 4.2 TECU for BORG station with RMS equal 0.46. Therefore, the proposed algorithm can be used to estimate VTEC efficiently.

Over the last years of the era of the modern Egyptian state, we have witnessed a remarkable development in all different sectors. To be able to continue this development, it was necessary to pay attention to the energy sector and its development, by dispensing with the main dependence on fossil fuels and finding new sources of energy that are less harmful to the environment, less costly and more abundant. The interest of the Egyptian state, represented by the Ministry of Electricity and Renewable Energy, appeared in the search for various renewable energy sources such as wind energy, solar energy, and others. Our role as researchers is to assist the state in making decisions about determining the optimal sites for the establishment of renewable energy plants of various kinds, based on the criteria for each of these types of stations. This is indeed what has been worked on in several previous studies and research in recent years. In this research, we have reviewed the most important researches related to choosing the best renewable energy sites (specifically wind energy as a model) in the Arab Republic of Egypt and other countries. The results were reviewed, and comparisons were made between the different study areas and the methodology of each research to clarify the effectiveness of geographic information systems in completing the decisionmaking process to determine the best sites for energy harvesting, and accordingly choosing the best sites for constructing wind power plants. Note that the researches reviewed here is based on Multi-Criteria decision analysis (MCDA) by analytical hierarchy process (AHP) method using Geographic Information System (GIS).

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