Abstract. Precise Point Positioning (PPP) technique, using single GPS receiver, has been used from several years especially in the static applications. Recently, there are many applications that rely on kinematic point positioning where the rover locations is determined using single GPS receiver in addition to the precise GPS satellite orbit and clock corrections that is developed and maintained by International Global Navigation Satellite System Service(IGS). In such environment, the GPS survey discrepancies should be addressed taken into consideration varying system dynamics, modeling algorithms, used software, receiver's types and other factors.This paper address the accuracy of GPS vehicle trajectory with high frequency data using kinematic point positioning technique and IGS data products. The study involves analyzing the kinematic GPS dual frequency carrier phase and pseudorange measurements utilizing the Real-Time Kinemtic LIB (RTKLIB) software and available data in a post processing mode. The receiver position utilizing point positioning technique has been verified and compared with the post processing relative kinematic trajectory solution. The PPP accuracy results using a low cost receiver were in the level of 10 cm for the horizontal components and 32 cm for the vertical component. The conclusions and further works are also included in the paper.

Abstract. Utilization of waste materials in agriculture products reduces the technical and environmental problems of plants wastes. Although rice husk ash (RHA) is a valuable admixture for concrete and soils, only about 5% of the total available RHA are used for enhancing concrete properties and improvement of swelling properties of expansive soil. However, the utilization rate of it is steadily increasing every year. Newly developed admixture allow decreasing of swelling properties of expansive soil by incorporating of rice husk ash as waste material and silica fume (SF) which denote RHA-SF. This study presents an experimental study on expansive soil mixed with additives in different ratios. The work involves three types of mixes the first consisted of four different percentages of RHA without SF. The second trial used four different percentages of SF without RHA. The last mixes included sixteen different percentages of mixed RHA and SF. The research concluded that 7.5% of rice husk ash and 20% silica fume are the optimum amount of additives to reduce swelling properties of expansive soil.

Abstract. Usually, construction industry exposed for many of the risks that may affect the quality of execution and duration of the projects. This paper will discuss the key risk factors that affect the construction contractors in the Arab Republic of Egypt and the Republic of Yemen during a field study that included 108 contractors in Egypt, in addition to 124 contractors in Yemen. The contractors, distributed on five categories saluting, were surveyed by the study and their views on the most important risks that they are exposed to were recorded. Then Contractors’ answers were introduced to a statistical analysis program (SPSS) taking into account the statistical measures adopted .The study concluded that the main risk factors faced by construction companies in Egypt and Yemen were somewhat close and may be reported as follows1-Losses due to war, civil disorder, revolutions.....etc.2-Financial risks including: (Losses due to inflation, cost overrun, delay in progress payment by owner, Devaluation and varying rate of exchange, Cost overrun due to planning estimation.)

Progress in graphene carbon nanotubes manufacturing processes and their tremendous applications directed the research groups all over the world towards investigating the performance related to their specializations. The carbon nanotubes networks (CANETs) are a promising target for any related nanonetwork sensors application fields. In this paper, the overall CANETs performance is firstly studied. Higher bandwidth and data rate are achieved under some selected properties of network elements. The carbon nanotubes (CNTs) are essential part of these nano-networks. For that, the isotropy of CNTs into the CANET is studied under various CNT angle, lengths, numbers and CNTs adjacent distance in x and y directions and at various connection probabilities values for random distribution. From the obtained results, higher isotropy is assigned when the CNTs angle equal π/2. Also, certain square peaks are noticed at assigned angle values in the range. These peaks describe the ability to exchange, store, and process data into CNTs intersections, nanonodes, between the terminals. Theoretical description of the dependence of Field Effect Transistor (FET) conductance into CNTs parameters is derived. i.e., to discover the effects of CNTs parameters more in the behavior of CANET performance, FET conductance value as function of angle values, adjacent distance deviations are separately discussed. In the first case, conductance peaks are noticed at periodically values of angle such as . These accurate determinations of angle value can be assigned for information transformation via the CANET. In the second phase, the conductance are studied as a function of CNTs adjacent distances deviations for two values of CNTs numbers while the other parameters are held constant. From the obtained results, increasing the CNTs number will decrease the conductance value and adjacent distance deviations. It is preferable to adopt the CANET parameters to preserve the data rate and encoding process which attributed in CNTs angle phases.