Engineering Sector

Novel characteristics for the FexCoy alloys have been obtained when these compounds were synthesized in the form of nanofibers encapsulated in a graphite shell. The prepared nanofibers reveal good semiconducting features as a thin film from the prepared nanofibers supported on a graphite disk and could be utilized as a diode with good rectifying behaviour. Magnetic properties study showed that the introduced nanofibers are magnetically clean as very low remanent magnetizations were detected; moreover the saturation magnetization is a temperature-independent property. Optical properties study indicated that these nanofibers have band gap energies of 4.73 and 5.43 eV. FexCoy bimetallic alloys could be produced in the form of nanofibers encapsulated in a graphite shell by calcination of electrospun nanofiber mats composed of poly(vinyl alcohol), ferrous acetate and cobalt acetate tetrahydrate in an argon atmosphere at 750 °C. The composition of the nanofibers could be adjusted by controlling the concentration of the original electrospun solution; two formulations have been prepared: FeCo and FeCo2.7. Transmission electron microscopy indicated that the thickness of the graphite shell enveloping the obtained nanofibers is 10 nm. A graphite disk possessing on its surface a well attached thin film from the introduced nanofibers could be successfully prepared when a diskette made of poly(acrylonitrile) was used as a collector during the electrospinning process. The introduced methodology is effective, simple and can be exploited to produce different metallic alloys nanofibers.

Climate considerations are essential dimensions in the assessment of quality of outdoor built environments. This paper provides an analysis of bioclimatic classification of Egypt to help the environmental design of wide range of purposes, including: climate responsive design; energy conservation and thermal comfort in the outdoor built environments. The analysis of this classification uses a bioclimatic approach in which the comfort zone and monthly climatic lines were determined and plotted on the psychrometric chart. Since the mean radiant temperature (Tmrt) is the most important input parameter for the energy balance in outdoor environments, the charts apply the ASHRAE 55-2004 standard considering the operative temperature as a function of Tmrt. Analysis for each bioclimatic zone determines the potential of passive design strategies to maintain thermal comfort in outdoor spaces and to contribute to energy efficient built environment. Finally, this study suggests a design guideline matrix for landscape architectural design for the different bioclimatic zones.

The sophisticated Application of Soft computing Techniques and Artificial Intelligent Approaches were introduced recently in Protection of Transmission line in electric power systems. In this article, the application of one of the artificial intelligence techniques; which is Adaptive Neuro-Fuzzy Inference System (ANFIS); for Distance Relay Protection for Transmission line in Electrical Power systems (EPS) will be presented. The applied technique is concentrating on fault detection, classification, as well as fault location. These issues will be addressed in this article. The ANFIS can be viewed as a fuzzy system, a neural network or fuzzy neural network. This paper aims; firstly, to detect the fault occurrence in very short time using ANFIS, and isolate the faulty section of the transmission lines. Secondly to classify the fault type using ANFIS also, then decide which of the three phases are exposed to the fault. Finally, locating the fault will be achieved easily via ANFIS. The input data of the ANFIS are derived from the fundamental values of the voltage and current measurements using digital signal processing via Discrete Fourier Transform. However, the loading conditions over the protected transmission line are assumed to be nearly constant in this research.

The dielectric breakdown of SF6/N2 gas mixture insulating system is believed to be sensitive to local irregularity of the electric field which may result from the presence of defects such as contaminants adhering to the electrode surface and surface roughness. Normally the surface roughness is produced from machine finishing and due to the aging of the system. This paper models the insulation breakdown mechanism of SF6 gas mixture in the presence of surface roughness for non- uniform field gaps. The electric field inside the gap is computed by using the charge simulation method taking into consideration the perturbations of the field in the presence surface roughness. The breakdown voltage is assessed by applying the criterion of slightly and highly divergent field and using the experimental results of figure-of-merit which is a measure of quantifying of the sensitivity of the gas to the effects of the electrode surface roughness.

Sustainable urban development is essential to enhance the quality of life of the citizens and to decrease the impact of cities upon resources outside the urban context. Redeveloping and planning green spaces and urban structure become the fundamentals of the sustainable urban planning of a city. An effective urban planning using recent technology is required to contribute to the physical and social development of the cities through promoting the land value and the local economy. This paper aims to develop a method to maintain ecological balance and organization of the urban green areas, using Geographic Information Systems (GIS) techniques that assist in effective planning of green areas. Land suitability analysis and ecological threshold methods based on GIS techniques are applied on one of the Egyptian new cities in a desert environment (i.e., El-Sadat City). Results revealed that the green ways could be developed to play a more significant role in bringing nature into the city. This paper suggests a method of green network planning that would help in enhancing the connectivity and reduce fragmentation though integrated greenway system. Finally, an ecological base for building an eco-city of El-Sadat City in the future is proposed.

In many practical robotic systems, large disturbances in the load are unavoidable. In this paper, a PID controller for a flexible arm robot is designed to satisfy the objectives :( 1) stability and H? performance specifications (disturbance rejection). Iterative linear matrix inequality technique is utilized to build an algorithm to calculate the parameters of the PID feedback controller. The proposed design is applied to practical industrial robot manipulator with load disturbances at the motor and the tool. The results show that the controller attenuates the effect of the disturbances in the output and provides a precise performance regarding the tool tracking.